Fatty acid composition, enzyme inhibitory, and antioxidant activities of the ethanol extracts of selected wild edible plants consumed as vegetables in the Aegean region of Turkey

ABSTRACT

The aim of this study was to evaluate the fatty acid composition, enzyme inhibitory, and antioxidant activities of the ethanol extracts of selected wild edible plants consumed as vegetable in the Aegean region of Turkey. In general, Mentha piperita L., Rumex patientia L., and R. acetosella L. exhibited quite strong antioxidant activities in the majority of test systems, whereas Urtica dioica L. and Eruca sativa Mill. show quite weak antioxidant activities. Enzyme inhibitory activities of the plants were found quite different than those of their antioxidant activities. Cardaria draba (L.) Desv., E. sativa, R. patientia, and E. cicutarium (L.) L’Hér. showed the highest inhibitory activities on acetylcholinesterase, butyrylcholinesterase, α-amylase, and α-glucosidase, respectively. U. dioica also showed a promising inhibitory activity on these enzymes. In parallel to the experiments, total phenolic, flavonoid, flavonol, and saponin contents of the extracts were also determined. According to the results of these assays, M. piperita had the highest amounts of phenolics, flavonols, and saponins (162.36 mg gallic acid equivalents/g extract, 3.52 mg CEs/g extract and 761.54 mg QAEs/g extract, respectively). Opopanax hispidus (Friv.) Griseb. and Lepidium sativum L. were found to be rich in flavonoid compounds (121.18 and 104.21 mg Res/g extract, respectively). In general, a strong correlation was determined between the phytochemical profile and antioxidant activity of the plant species.

KEYWORDS:

• Wild edible plants
• Antioxidant activity
• Enzyme inhibitory activity
• Fatty acid
• Vegetable

Introduction

According to the results of epidemiological studies, increased consumption of plant-based foods, fruits, and vegetables is extremely important in the prevention of chronic diseases including cancer, diabetes, cardiovascular diseases, Alzheimer’s disease, and age-related functional decline.^[1–3] Fruits and vegetables are among the potential sources of phytochemicals, particularly phenolic compounds that serve as natural antioxidants.^[1,4]

In Alzheimer’s disease, which is a common form of dementia, beta-amyloid peptide fibrils accumulate in extra-cellular area in high quantities. As described by Alias Alzheimer in his original report in 1907, extensive neuronal loss occurs in affected individuals.^[5,6] Scientists are still trying to understand the pathogenesis of this disease and find an effective method or treatment.^[7] There are two main hypotheses for the treatment of this disease, which are named as “amyloid cascade” and “cholinergic.” Until today, numerous studies have been carried out on these hypotheses and many reports were published.^[8] The most commonly observed symptoms of age related neurodegenerative disorders are severe neuronal cell damage, a decline in neurotransmitters, increased inflammation, and oxidative stress.^[9] Recovery of cholinergic transmitter levels by using acetyl cholinesterase (AChE) and butyryl cholinesterase (BChE) inhibitors have been suggested for the treatment of Alzheimer’s disease.^[6,10]

According to data published by the International Diabetes Federation (IDF), 6.4% of the world’s adult population (approximately 285 million people) suffer from diabetes. The same authority claimed that this number is expected to grow to 438 million by 2030.^[11,12] α-Glucosidase and α-amylase inhibitory agents such as acarbose can help to slow down the digestion of carbohydrates and thus reduce the blood glucose concentration.^[11,13] Synthetic α-glucosidase and α-amylase inhibitors may cause several side effects such as abdominal distention, flatulence, meteorism, hypoglycemia, and cholestasis.^[14] Therefore, it is essential to find new and alternative natural agents having no or fewer side effects to reduce the blood glucose level effectively.^[11]

The aim of this study was to evaluate the fatty acid composition, enzyme inhibitory and antioxidant activities of the ethanol extracts of Anethum graveolens L., Petroselinum crispum (Mill.) Fuss., Opopanax hispidus (Friv.) Griseb., Cichorium endivia L., Onopordum tauricum Willd., Cardaria draba (L.) Desv., Eruca sativa Mill., Lepidium sativum L., Sinapis arvensis L., Campanula glomerata L., Erodium cicutarium (L.) L’Hér., Mentha piperita L., Malva sylvestris L., Papaver rhoeas L., Rumex acetosella L., R. patientia L., and Urtica dioica L. Antioxidant activities of the samples were evaluated by using phosphomolybdenum, β-carotene bleaching, radical scavenging [on 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2 Azino-bis (3-ethylbenzothiazloine-6-sulfonic acid; ABTS) cation, and nitric oxide (.NO) radicals], reducing power [cupric ion reducing (CUPRAC) and ferric ion reducing antioxidant power (FRAP)], and metal chelating assays. Inhibitory activities of the plant species were tested on AChE, BchE, α-amylase, and α-glucosidase. In parallel to the experiments, total phenolic, flavonoid, flavonol, and saponin contents of the extracts were also determined.

Materials and methods

Plant material

All of the plant samples were purchased from the local markets in Manisa Province, Aegean Region of Turkey. Aerial parts of the samples were first washed under running water to remove the solid particles, then washed with deionized water, cut into small parts, and hot air-dried in an oven at 40°C for 48 h. Local names, traditional uses and herbarium numbers of the plant species were presented in Table 1. Dr. Olcay Ceylan, who is a senior taxonomist from the Department of Biology, Mugla University, Mugla-Turkey, performed the taxonomic identifications of the plant materials.

Table 1. Wild edible plants traditionally consumed in the Aegean region of Turkey.

No.	Family	Species	Local name	Traditional use	Herbarium number
1	Apiaceae	Anethum graveolens	Dere Otu	Vegetable	MUH610
2		Petroselinum crispum	Maydanoz	Vegetable	MUH715
3		Opopanax hispidus	Kaymak Otu	Vegetable, tea	MUH 834
4	Asteraceae	Cichorium endivia	Hindiba	Vegetable	MUH936
5		Onopordum tauricum	Eşek Helvası	Vegetable	MUH825
6	Brassicaceae	Cardaria draba	Toklu Başı	Vegetable	MUH 2289
7		Eruca sativa	Roka	Vegetable	MUH 5787
8		Lepidium sativum	Tere	Vegetable	MUH5538
9		Sinapis arvensis	Tatlı Hardal	Vegetable	MUH 4817
10	Campanulaceae	Campanula glomerata	Çıngırak otu	Vegetable	MUH1610
11	Geraniaceae	Erodium cicutarium	Leylek Gagası	Vegetable	MUH 2025
12	Lamiaceae	Mentha piperita	Nane	Vegetable, tea	MUH2756
13	Malvaceae	Malva sylvestris	Ebe Gümeci	Vegetable, tea	MUH 5107
14	Papaveraceae	Papaver rhoeas	Kapurcak	Vegetable	MUH 1101
15	Polygonaceae	Rumex acetosella	Kuzu Kulağı	Vegetable	MUH 2170
16		Rumex patientia	Labada	Vegetable	MUH1826
17	Urticaceae	Urtica dioica	Isırgan Otu	Vegetable, tea	MUH 1563

Preparation of ethanol extracts

Dried samples (5 g) were macerated with 100 mL of ethanol at room temperature for 24 h. Ethanol was then removed with a rotary evaporator at 40°C. Yields obtained from the ethanol extraction were presented in Table 2. All of the extracts were stored at +4°C until analyzed.

Table 2. Extraction yields and total antioxidant activities (by phosphomolybdenum and β-carotene bleaching methods) of the ethanol extracts of wild edible plants (mean ± SD).*

Samples	Yield (%)	Phosphomolybdenum (mmol TEs/g extract)**	β-carotene bleaching (%)***	Chelating effect (mg EDTAEs/g extract)
A. graveolens	3.73	3.23 ± 0.14^d	79.03 ± 0.05^fg	21.80 ± 0.86^cd
C. glomerata	3.64	2.10 ± 0.06^ab	72.71 ± 0.59^c	33.13 ± 1.34^fg
C. draba	4.60	2.32 ± 0.02^ab	78.87 ± 0.86^f	14.38 ± 1.38^b
C. endivia	3.85	2.30 ± 0.03^ab	72.62 ± 0.75^c	27.66 ± 1.31^e
E. cicutarium	3.05	2.04 ± 0.35^a	73.98 ± 2.03^cd	22.22 ± 1.25^cd
E. sativa	5.84	4.02 ± 0.05^e	68.77 ± 1.62^b	35.16 ± 0.10^gh
L. sativum	1.77	2.81 ± 0.06^cd	75.71 ± 0.66^de	19.74 ± 0.66^c
M. sylvestris	3.65	2.50 ± 0.01^abc	72.71 ± 0.15^c	47.37 ± 0.78^k
M. piperita	4.13	4.37 ± 0.04^e	81.86 ± 1.07^g	10.29 ± 0.46^a
O. tauricum	4.97	2.55 ± 0.12^bc	85.09 ± 1.18^h	22.33 ± 0.30^cd
O. hispidus	3.12	2.91 ± 0.11^cd	78.76 ± 0.75^f	24.09 ± 1.64^d
P. rhoeas	5.51	2.27 ± 0.01^ab	78.21 ± 0.47^ef	27.85 ± 0.99^e
P. crispum	3.47	2.52 ± 0.18^bc	79.82 ± 0.42^fg	36.13 ± 1.11^h
R. acetosella	3.49	2.54 ± 0.10^bc	85.79 ± 0.34^hi	35.71 ± 0.10^gh
R. patientia	3.13	3.05 ± 0.05^d	86.06 ± 0.62^hi	42.41 ± 0.42^i
S. arvensis	4.49	2.48 ± 0.01^abc	72.26 ± 0.35^c	31.73 ± 1.38^f
U. dioica	4.36	2.10 ± 0.08^ab	63.16 ± 1.94^a	33.79 ± 0.62^fgh
BHA	—	—	88.28 ± 0.26^ik	—
BHT	—	—	90.60 ± 0.77^k	—
Trolox	—	—	89.39 ± 0.11^k	—

*Data marked with different superscript letters within the same column indicates significant difference (p < 0.05).

**TEs, trolox equivalents.

***At 2.0 mg/mL concentration.

Antioxidant activity

Total antioxidant activities of the samples were evaluated by using phosphomolybdenum and β-carotene bleaching methods as previously described in the literature.^[15] Radical scavenging activities were measured by using DPPH, ABTS cation, and NO radical scavenging assays.^[15] Reducing powers of the samples were determined by using CUPRAC and FRAP assays.^[15] Metal chelating activities of the samples on ferrous ions were determined by using the method described in the literature.^[16]

Enzyme inhibitory activity

AChE and BChE inhibitory activities of the samples were measured by using Ellman’s method.^[15] α-Amylase and α-glucosidase inhibitory activity assays were carried out by using the same method.

Total bioactive components

Total phenolic, flavonoid, flavanol, and saponin contents were determined by employing the methods given in the literature.^[15]

Fatty acid analysis

Fatty acid analyses of the samples were determined by employing the methods given in the literature.^[16]

Statistical analysis

All of the assays were performed in triplicate. The results were expressed as mean and standard deviation values (mean ± SD). Differences between the means were determined by using the analysis of variance (ANOVA) with Tukey’s honestly significant difference post hoc test with α = 0.05 by using SPSS v.14.0. Correlation analyses were performed by using a two-tailed Pearson’s correlation test.

Results and discussion

In this study, 17 different wild plant species, which are frequently consumed as vegetable and/or tea by the local people living in the Aegean region of Turkey, were tested for their antioxidant and enzyme inhibitory activities as well as their fatty acid compositions (Table 1). As can be seen from the table, the majority of the plant species have widely been consumed as vegetable. As a result of the extraction procedure performed with ethanol, E. sativa and P. rhoeas gave the maximum extract yields (5.84 and 5.51%, respectively). The lowest extract yield was measured with L. sativum (1.77%).

Antioxidant activity

Antioxidant activities of the samples were tested by using phosphomolybdenum, β-carotene bleaching and chelating effect assays (Table 2). Scavenging abilities of the extracts were tested on DPPH, ABTS cation, and NO radicals (Table 3). Finally, reducing power potentials of the extracts were evaluated by employing CUPRAC and FRAP assays (Table 3).

Table 3. Radical scavenging and reducing power potentials of the ethanol extracts of wild edible plants (mean ± SD).*

Samples	DPPH radical (mg TEs/g extract)**	ABTS radical cation (mg TEs/g extract)**	Nitric oxide radical (mg TEs/g extract)**	CUPRAC (mg TEs/g extract)**	FRAP (mg TEs/g extract)**
A. graveolens	23.71 ± 2.33^e	48.34 ± 0.25^e	1.90 ± 0.35^a	87.93 ± 2.42^b	45.88 ± 1.20^bc
C. glomerata	16.57 ± 2.91^d	52.44 ± 1.93^f	4.87 ± 0.17^cd	99.89 ± 3.06^cde	50.45 ± 1.57^cd
C. draba	43.20 ± 1.20^g	95.32 ± 1.48^k	7.29 ± 0.10^h	103.22 ± 2.12^de	60.96 ± 1.22^e
C. endivia	44.05 ± 1.91^g	56.42 ± 1.93^fg	6.02 ± 0.12^efg	112.20 ± 2.77^f	57.95 ± 2.49^de
E. cicutarium	90.60 ± 0.19^kl	129.12 ± 2.38^l	6.71 ± 0.25^gh	130.44 ± 4.26^h	89.57 ± 2.48^g
E. sativa	13.74 ± 1.23^cd	21.62 ± 1.55^a	3.20 ± 0.25^b	69.67 ± 1.88^a	32.15 ± 2.18^a
L. sativum	48.86 ± 1.23^h	85.62 ± 1.59^i	6.27 ± 0.07^fg	121.28 ± 2.06^g	74.34 ± 2.70^f
M. sylvestris	7.37 ± 1.20^ab	33.93 ± 0.94^c	6.07 ± 0.57^efg	94.15 ± 2.85^bc	50.93 ± 1.68^cd
M. piperita	93.03 ± 0.07^l	365.49 ± 0.25°	6.89 ± 0.45^gh	407.11 ± 1.69^l	284.27 ± 12.84^i
O. tauricum	10.87 ± 2.77^bc	57.54 ± 2.38^g	na	107.04 ± 3.13^ef	58.36 ± 2.14^de
O. hispidus	88.27 ± 0.45^k	138.07 ± 1.48^m	7.18 ± 0.18^h	129.96 ± 3.39^h	89.65 ± 2.37^g
P. rhoeas	25.88 ± 1.62^e	61.64 ± 1.67^h	5.72 ± 0.47^def	105.48 ± 3.82^def	58.59 ± 1.67^de
P. crispum	12.88 ± 1.18^cd	44.24 ± 1.82^d	5.32 ± 0.52^de	98.15 ± 2.45^cd	40.05 ± 1.86^ab
R. acetosella	39.07 ± 1.72^f	82.64 ± 1.02^i	6.72 ± 0.03^gh	140.26 ± 4.02^i	72.68 ± 2.17^f
R. patientia	78.34 ± 0.26^i	151.37 ± 1.65^n	4.01 ± 0.14^bc	215.00 ± 6.71^k	128.46 ± 2.67^h
S. arvensis	14.79 ± 1.97^cd	35.29 ± 0.91^c	7.49 ± 0.17^h	91.89 ± 2.88^bc	51.46 ± 2.72^cde
U. dioica	5.12 ± 0.13^a	27.09 ± 1.84^b	na	89.09 ± 1.21^b	53.18 ± 1.09^cde

*Data marked with different superscript letters within the same column indicates significant difference (p < 0.05).

**TEs: Trolox equivalents.

According to the results of phosphomolybdenum assay, antioxidant activities of the samples were found to be in the range of 2.04–4.37 mmol Trolox equivalents (TEs)/g extract (Table 2). M. piperita exhibited the highest activity (4.37 mmol TEs/g extract). It is closely followed by E. sativa (4.02 mmol TEs/g extract). We did not detect any difference between the results obtained from these two species from the statistical point-of-view (p > 0.05). When compared with the others, E. cicutarium showed the weakest activity (2.04 mmol TEs/g extract).

The samples were also tested for their total antioxidant activities by using β-carotene bleaching assay (Table 2). According to the results presented in the table, this assay was resulted in the superiority of Polygonaceae species. R. patientia effectively protected linoleic acid against the oxidative stress of oxygen (86.06%). It was closely followed by another Rumex species, R. acetosella (85.79%). No statistical difference was determined between the antioxidant potentials of R. patientia and R. acetosella (p > 0.05). O. tauricum also showed antioxidant activity as strong as the Rumex species mentioned above (85.09%). However, the activity of O. tauricum was found statistically different from the Rumex species (p < 0.05). In this assay, as seen in phosphomolybdenum assay, U. dioica exhibited the weakest activity (63.16%). Antioxidant potential of E. sativa was also found quite low (68.77%). It extremely important to point out that, E. sativa exhibited remarkable activity in phosphomolybdenum assay. Antioxidant activities of the other species were found to be in the range of 72.26–81.86%. None of the samples showed activity as strong as the positive controls.

Data obtained from the chelating effect assay were presented in Table 2. As can be seen from the table, this assay was resulted in the superiority of M. sylvestris (47.37 mg EDTAEs/g extract). It was closely followed by R. patientia (42.41 mg EDTAEs/g extract). Activities of P. crispum, R. acetosella, E. sativa, U. dioica, C. glomerata, and S. arvensis were found too close to the each other and no statistical difference was found between the activity potentials of these species (p > 0.05; 36.13, 35.71, 35.16, 33.79, 33.13, and 31.73 mg EDTAEs/g extract, respectively). In this assay, in contrast to its performance obtained from the other antioxidant test systems, M. piperita showed the weakest activity (10.29 mg EDTAs/g extract).

Scavenging abilities of the extracts were tested on DPPH, ABTS cation, and NO. In the case of DPPH free radical scavenging assay, M. piperita showed the strongest scavenging activity (93.03 mg TEs/g extract; Table 3). As can be seen from the previous section, M. piperita also showed considerable antioxidant activity both in phosphomolybdenum and β-carotene bleaching assays. DPPH free radical scavenging activity of M. piperita was closely followed by E. cicutarium (90.60 mg TEs/g extract). Results of these two species were found to be different from the statistical point of view (p < 0.05). U. dioica and M. sylvestris showed quite weak DPPH free radical scavenging activity (5.12 and 7.37 mg TEs/g extract, respectively).

In ABTS cation radical scavenging assay, M. piperita showed the highest activity again (365.49 mg TEs/g extract; Table 3). Scavenging ability of M. piperita was followed by R. patientia, O. hispidus, and E. cicutarium (151.37, 138.07, and 129.12 mg TEs/g extract, respectively). Activities of these species were found statistically different from each other (p < 0.05). As seen in DPPH free radical scavenging assay, E. sativa and U. dioica showed quite weak activity on ABTS cation radical.

In the case of NO radical scavenging assay, activities of the samples were found quite low when compared with those obtained from DPPH and ABTS cation scavenging assays (Table 3). In this assay, O. tauricum and U. dioica remained inactive. Additionally, the majority of the species remained below 7.00 mg TEs/g extract. Among the tested materials, NO scavenging potentials of S. arvensis and C. draba (Brassicaceae) were found to be above this level (7.49 and 7.29 mg TEs/g extract, respectively).

Reducing powers of the samples were evaluated by using two independent test systems named as CUPRAC and FRAP (Table 3). In CUPRAC system, reducing powers of the samples were ranged between 69.97–407.11 mg TEs/g extract. More than half of the samples showed higher activity than 100.00 mg TEs/g extract. Among these species, as seen in other test systems, M. piperita showed the highest activity (401.11 mg TEs/g extract). According to the results presented in the Table 3, E. sativa showed the weakest activity (69.97 mg TEs/g extract).

In the FRAP system, the extracts showed a similar activity profile as seen in CUPRAC assay (Table 3). Reducing power of M. piperita was measured as 284.27 mg TEs/g extract, which is the highest value obtained in this assay. Except R. patientia (128.46 mg TEs/g extract), all of the samples showed activity less than 100.00 mg TEs/g extract. According to the results presented in the Table 3, reducing power of E. sativa was measured as 32.15 mg TEs/g extract.

As far as our literature survey could ascertain, antioxidant activities of A. graveolens, P. crispum, C. endivia, E. sativa, L. sativum, S. arvensis, M. piperita, M. sylvestris, P. rhoeas, R. patientia, R. acetosella, and U. dioica have previously been reported elsewhere. It is quite interesting to point out that, among these plants, the majority of the reports have mainly focused on M. piperita,^[17–21] A. graveolens,^[22–25] and P. crispum.^[26–28]

In the majority of the reports, M. piperita was shown to have strong antioxidant activity. Singh et al.^[17] have reported that essential oil and extracts of M. piperita exhibited significant antioxidant activity and the oil showed about half potency when compared to the standard BHT. Yadegarinia et al.^[29] have compared the antioxidant activity of M. piperita with Myrtus communis L. The oils obtained from these species were screened for their possible antioxidant activities by using DPPH free radical scavenging and β-carotene/linoleic acid test systems. According to the results of this study, M. piperita oil exerted greater antioxidant activity than that of M. communis.

Tanruean et al.^[23] have reported the antioxidant activity of A. graveolens. According to the results of this study, methanol fraction displayed the highest level of DPPH radical scavenging (IC₅₀ 22.3 μg/mL) while the deodorized hot water fraction exhibited the highest lipid peroxidation inhibition (IC₅₀ 4.7 μg/mL). Antioxidant activity of A. graveolens has also been investigated by Orhan et al.^[24] In this study, ethanol extract of A. graveolens was reported to show remarkable .NO scavenging effect. Albayrak et al.^[30] and Edziri et al.^[31] have also reported the free radical scavenging potential of A. graveolens.

Jia et al.^[28] have reported the effect of P. crispum on the oxidative stabilities of food samples under the accelerated oxidative stress. According to the results of this study, oxidative stabilities of foods increased significantly with addition of P. crispum. The authors claimed that P. crispum could be used as an antioxidant substance for the stabilization of foods over a long storage period. Haidari et al.^[32] have also studied the effect of P. crispum on serum uric acid levels, biomarkers of oxidative stress and liver xanthine oxidoreductase activity in oxonate induced hyperuricemic rats. According to this study, P. crispum treatment led to a significant increase in total antioxidant capacity and decrease in malondialdehyde concentration in hyperuricemic rats.

In general, our results were found to be consistent with those reported before. On the other hand, as far as our literature survey could ascertain, antioxidant activities of O. hispidus, O. tauricum, C. draba, C. glomerata and E. cicutarium have not previously been reported elsewhere. From this point-of-view, this study could be assumed as the first report on the antioxidant activities of these plant species.

Enzyme inhibitory activity

Plant species were also evaluated for their inhibitory activities on AChE, BChE, α-amylase, and α-glucosidase (Table 4). In the case of AChE inhibitory activity assay, C. draba showed the highest activity (5.71 mg GALAEs/g extract). It was closely followed by U. dioica and A. graveolens (5.59 and 5.54 mg GALAEs/g extract, respectively). It is extremely important to point out that, U. dioica exhibited a quite different activity profile than that of its antioxidant activity. Results obtained from C. draba, U. dioica, and A. graveolens were found similar from the statistical point-of-view (p > 0.05). In addition to these findings, C. endivia, E. sativa, L. sativum, M. sylvestris, O. tauricum, P. rhoeas, and S. arvensis showed higher activity than 5.00 mg GALAEs/g extract. In this assay, O. hispidus exhibited the weakest activity (1.16 mg GALAEs/g extract).

Table 4. Enzyme inhibitory activities of the ethanol extracts of wild edible plants (mean ± SD).*

Samples	Acetyl cholinesterase (mg GALAEs/g extract)**	Butyryl cholinesterase (mg GALAEs/g extract)**	α-Amylase (mmol ACEs/g extract)***	α-Glucosidase (mmol ACEs/g extract)***
A. graveolens	5.54 ± 0.03^f	17.87 ± 0.99^cde	0.58 ± 0.01^bc	0.33 ± 0.24^a
C. glomerata	4.93 ± 0.05^cdef	12.10 ± 1.83^b	0.54 ± 0.01^b	1.83 ± 0.32^abc
C. draba	5.71 ± 0.03^f	24.38 ± 0.38^g	0.59 ± 0.02^bc	2.38 ± 0.06^abc
C. endivia	5.36 ± 0.09^def	18.67 ± 1.26^de	0.58 ± 0.01^bc	1.13 ± 0.37^ab
E. cicutarium	3.95 ± 1.65^bc	20.08 ± 1.84^def	0.58 ± 0.01^bc	5.52 ± 0.02^d
E. sativa	5.52 ± 0.04^ef	25.61 ± 0.38^g	0.44 ± 0.03^a	1.67 ± 0.20^abc
L. sativum	5.30 ± 0.06^def	24.05 ± 0.19^g	0.71 ± 0.01^def	1.95 ± 0.18^abc
M. sylvestris	5.27 ± 0.07^def	24.15 ± 0.13^g	0.66 ± 0.04^cde	2.62 ± 0.10^abc
M. piperita	3.82 ± 0.11^b	10.44 ± 1.71^b	0.59 ± 0.01^bc	5.20 ± 0.29^d
O. tauricum	5.43 ± 0.03^def	19.54 ± 1.75^de	0.54 ± 0.04^b	1.85 ± 0.23^abc
O. hispidus	1.16 ± 0.49^a	3.98 ± 0.17^a	0.62 ± 0.03^bcd	2.70 ± 0.20^abc
P. rhoeas	5.13 ± 0.11^def	24.13 ± 0.84^g	0.71 ± 0.03^def	0.87 ± 0.30^abc
P. crispum	4.39 ± 0.09^bcd	17.17 ± 1.39^cd	0.66 ± 0.05^cde	2.48 ± 0.05^abc
R. acetosella	4.84 ± 0.12^bcdef	15.27 ± 1.93^c	0.77 ± 0.06^f	3.40 ± 0.04^bcd
R. patientia	4.42 ± 0.30^bcde	19.84 ± 1.36^de	0.96 ± 0.02^g	3.60 ± 0.37^cd
S. arvensis	5.26 ± 0.11^def	20.72 ± 0.25^ef	0.71 ± 0.03^def	2.50 ± 0.14^abc
U. dioica	5.59 ± 0.03^f	23.10 ± 0.29^fg	0.76 ± 0.03^f	5.32 ± 0.01^d

*Data marked with different superscript letters within the same column indicates significant difference (p < 0.05).

**GALAEs: galantamine equivalents.

***KAEs: kojic acid equivalents.

****ACEs: acarbose equivalents.

BChE inhibitory assay was resulted in the superiority of E. sativa (25.61 GALAEs/g extract; Table 4). It was closely followed by C. draba, M. sylvestris, P. rhoeas, and L. sativum (24.38, 24.15, 24.13, and 24.05 mg GALAEs/g extract, respectively). Enzyme inhibitory activities of these species were found similar from the statistical point of view (p > 0.05). As happened in the AChE inhibitory activity assay, O. hispidus showed the weakest activity again (3.98 mg GALAEs/g extract).

In α-amylase inhibitory assay, in contrast to the first two test systems, R. patientia exhibited the maximum activity (0.96 mmol ACEs/g extract; Table 4). R. acetosella, U. dioica, S. arvensis, P. rhoeas, and L. sativum showed inhibitory activities in the range of 70.0–80.0 mmol ACEs/g extract. In general, results of these species were found statistically similar (p > 0.05). In contrary to the result obtained from the BChE inhibitory assay, E. sativa showed the weakest activity (0.44 mmol ACEs/g extract). Inhibitory activities of the other plant species presented in the Table 4 were found to be above 0.50 mmol ACEs/g extract.

In α-glucosidase inhibitory assay, E. cicutarium and U. dioica showed considerable activities (5.52 and 5.32 mmol ACEs/g extract, respectively; Table 4). As can be seen from the table, these results were found similar from the statistical point of view (p > 0.05). It is extremely important to point out that, except Rumex species, inhibitory activities of the plants were found too close to each other (in the range of 0.87–2.70 mmol ACEs/g extract) and no statistical difference was determined between them (p > 0.05). In this assay, inhibitory activity of A. graveolens was measured as 0.33 mmol ACEs/g extract, which is the lowest value determined in this assay.

As far as our literature survey could ascertain, inhibitory activities of A. graveolens on AChE, BChE and tyrosinase,^[24,33] P. crispum on AChE,^[34] M. piperita on AChE,^[35] R. acetosella on α-amylase,^[36] and U. dioica on α-amylase and α-glucosidase^[37,38] have previously been reported. As can be seen from the literature search, the majority of these reports have focused on U. dioica. According to the results of these studies, in general, U. dioica exhibited a promising enzyme inhibitory activity.

Nickavar et al.^[37] have reported the α­amylase inhibitory activity of U. dioica. According to the results of this study, U. dioica leaf (IC₅₀ = 1.89 mg/mL) revealed appreciable inhibitory activity in a concentration dependent manner. Additionally, Onal et al.^[38] have reported this plant to have remarkable α­glucosidase inhibitory activity. According to our literature survey, U. dioica have also exhibited various degrees of inhibitory activities on 5 α-reductase,^[39,40] protease,^[41] and aromatase.^[42] α­Amylase and α­glucosidase inhibitory activities of U. dioica presented here were found to be highly consistent with those reported before. On the other hand, inhibitory activities of O. hispidus, C. endivia, O. tauricum, C. draba, E. sativa, L. sativum, S. arvensis, C. glomerata, E. cicutarium, M. sylvestris, P. rhoeas, and R. patientia have not previously been reported elsewhere. Therefore, data presented for these species could be assumed as the first report on these enzymes.

Total bioactive components

In addition to antioxidant and enzyme inhibitory activities, the samples were also evaluated for their total phenolic, flavonoid, flavonol, and saponin contents (Table 5). According to data presented in the table, M. piperita contained the highest phenolic content (162.36 mg GAEs/g extract). A strong correlation was determined between the phenolic content and antioxidant activity of this plant. M. piperita was followed by R. patientia (61.12 mg GAEs/g extract). For the rest of the plant species, quantities of total phenolics were determined to be in the range of 15.56–37.86 mg GAEs/g extract.

Table 5. Total bioactive components and metal chelating activities of the ethanol extracts of wild edible plants (mean ± SD).*

Samples	Total phenolic (mg GAEs/g extract)**	Total flavonoid (mg REs/g extract)***	Total flavanol (mg CEs/g extract)****	Total saponin (mg QAEs/g extract)*****	Chelating effect (mg EDTAEs/g extract)******
A. graveolens	18.90 ± 2.03^abc	52.00 ± 1.66^c	1.56 ± 0.11^de	193.04 ± 4.67^b	21.80 ± 0.86^cd
C. glomerata	21.48 ± 0.90^cd	64.44 ± 2.14^de	1.80 ± 0.18^e	201.37 ± 3.57^b	33.13 ± 1.34^fg
C. draba	26.50 ± 1.29^ef	77.04 ± 3.20^gh	1.75 ± 0.06^e	233.33 ± 9.99^cd	14.38 ± 1.38^b
C. endivia	31.46 ± 2.18^gh	42.57 ± 0.33^b	1.42 ± 0.05^cd	280.59 ± 2.08^fg	27.66 ± 1.31^e
E. cicutarium	32.14 ± 1.18^gh	52.09 ± 0.45^c	1.25 ± 0.03^bc	134.25 ± 15.45^a	22.22 ± 1.25^cd
E. sativa	15.56 ± 1.77^a	22.96 ± 0.41^a	0.96 ± 0.01^a	138.19 ± 3.57^a	35.16 ± 0.10^gh
L. sativum	31.40 ± 1.59^gh	104.21 ± 1.94^i	1.43 ± 0.05^cd	277.11 ± 9.83^f	19.74 ± 0.66^c
M. sylvestris	23.54 ± 0.81^de	60.94 ± 2.41^d	2.17 ± 0.13^f	305.31 ± 6.87^g	47.37 ± 0.78^k
M. piperita	162.36 ± 4.17^l	79.64 ± 3.10^h	3.52 ± 0.11^h	761.54 ± 9.89^l	10.29 ± 0.46^a
O. tauricum	23.12 ± 1.16^cde	68.71 ± 4.28^def	2.84 ± 0.03^g	267.58 ± 6.19^ef	22.33 ± 0.30^cd
O. hispidus	37.86 ± 1.48^i	121.18 ± 2.18^k	1.08 ± 0.05^ab	459.34 ± 10.48^k	24.09 ± 1.64^d
P. rhoeas	28.50 ± 0.86^fg	65.55 ± 1.58^de	2.70 ± 0.10^g	246.52 ± 13.43^de	27.85 ± 0.99^e
P. crispum	22.80 ± 1.23^cde	74.75 ± 7.08^fgh	1.74 ± 0.03^e	217.77 ± 12.35^bc	36.13 ± 1.11^h
R. acetosella	34.14 ± 1.05^hi	70.48 ± 1.79^efg	3.34 ± 0.05^h	338.10 ± 8.25^h	35.71 ± 0.10^gh
R. patientia	61.12 ± 1.72^k	69.37 ± 1.08^efg	4.09 ± 0.12^i	396.70 ± 5.41^i	42.41 ± 0.42^i
S. arvensis	20.96 ± 1.22^bcd	82.44 ± 1.78^h	1.78 ± 0.14^e	243.41 ± 1.10^cde	31.73 ± 1.38^f
U. dioica	16.64 ± 1.30^ab	40.62 ± 0.19^b	1.46 ± 0.11^cd	262.64 ± 11.27^ef	33.79 ± 0.62^fgh

*Data marked with different superscript letters within the same column indicates significant difference (p < 0.05).

**GAEs: gallic acid equivalents.

***Res: rutin equivalents.

****CEs: catechin equivalents.

*****QAEs: quillaja equivalents.

******EDTAEs: ethylenediaminetetraacetic acid (disodium salt) equivalents.

Total flavonoid content assay was resulted in the superiority of O. hispidus (121.18 mg REs/g extract) and L. sativum (104.21 mg REs/g extract), respectively (Table 5). As can be seen from the table, E. sativa had the lowest flavonoid content (22.96 mg REs/g extract). No correlation was found between the amounts of phytochemicals and biological activity potentials of O. hispidus and L. sativum.

In the case of total flavonol content assay, R. patientia was determined as the richest sample (4.09 mg CEs/g extract). It was closely followed by M. piperita and R. acetosella (3.52 and 3.34 mg CEs/g extract). According to the results of this assay, E. sativa had the lowest total flavonol content (0.96 mg CEs/g extract). As can be seen from the other parameters of the phytochemistry section of this article, E. sativa was also found poor both in phenolics and flavonoids. In general, a significant correlation was determined between the total flavonol contents and antioxidant activities of the plant species. Finally, M. piperita determined as the richest plant species in terms of its saponin content (761.54 mg QAEs/g extract). It was followed by O. hispidus, R. patientia, and R. acetosella (459.34, 396.70 and 338.10 mg QAEs/g extract, respectively).

Fatty acid composition

Fatty acid compositions of the plant species were also determined in parallel to their phenolic, flavonoid, flavonol and saponin contents (Table 6). Among the saturated fatty acids, palmitic acid (C 16:0) was the most abundant one in all species tested. According to the results presented in the table, C. endivia had the highest palmitic acid content (50.23%).

Table 6. Fatty acid composition (%) of wild edible plants (mean ± SD).*

Fatty acids	A. graveolens	C. glomerata	C. draba	C. endivia	E. cicutarium	E. sativa	L. sativum	M. sylvestris	M. piperita
C 12:0	1.51 ± 0.09^bcdef	0.54 ± 0.01^abc	5.56 ± 0.87^g	1.19 ± 0.04^abcdef	1.53 ± 0.03^bcdef	0.87 ± 0.05^abcde	1.72 ± 0.01^def	0.53 ± 0.60^bc	2.26 ± 0.01^f
C 14:0	2.06 ± 0.01^f	2.35 ± 0.04^h	1.45 ± 0.01^e	3.59 ± 0.03^k	1.41 ± 0.06^e	3.18 ± 0.03^I	2.17 ± 0.03^g	1.02 ± 0.01^c	1.98 ± 0.04^f
C 15:0	0.48 ± 0.23^a	0.44 ± 0.01^a	0.30 ± 0.01^a	0.85 ± 0.02 a	0.47 ± 0.01^a	0.39 ± 0.01^a	0.39 ± 0.06^a	0.12 ± 0.01^a	0.19 ± 0.02^a
C 16:0	39.15 ± 0.35^i	30.61 ± 0.19^g	19.68 ± 0.81^c	50.23 ± 0.11^l	20.90 ± 0.02^d	38.04 ± 0.65^i	27.61 ± 0.18^f	23.50 ± 0.05^e	34.17 ± 0.33^h
C 17:0	0.41 ± 0.06^bcd	0.34 ± 0.01^bc	0.20 ± 0.09^ab	0.91 ± 0.04^f	0.32 ± 0.02^abc	0.56 ± 0.02^cde	0.25 ± 0.04^ab	0.22 ± 0.15^ab	0.28 ± 0.01^ab
C 18:0	2.20 ± 0.05^bcd	6.98 ± 0.24^hi	1.70 ± 0.01^abc	8.12 ± 0.01^k	2.28 ± 0.01^bcd	6.34 ± 0.13^h	3.52 ± 0.59^ef	2.56 ± 0.64^cde	3.87 ± 0.08^fg
ΣSFA	45.80 ± 0.12^k	41.25 ± 0.49^h	28.87 ± 0.17^e	64.88 ± 0.16^n	26.89 ± 0.03^d	49.37 ± 0.62^l	35.65 ± 0.48^f	27.93 ± 0.12^de	42.74 ± 0.30^i
C 14:1 ω5	0.28 ± 0.23^abcd	0.04 ± 0.01^a	0.19 ± 0.03^abc	0.59 ± 0.04^def	1.37 ± 0.02^g	1.32 ± 0.02^g	0.54 ± 0.11^de	0.52 ± 0.13^cde	12.46 ± 0.16^h
C 15:1 ω5	3.07 ± 0.04^d	0.39 ± 0.08^ab	5.66 ± 0.78^e	3.00 ± 0.04^d	0.65 ± 0.01^ab	0.29 ± 0.02^a	3.28 ± 0.47^d	3.60 ± 0.21^d	16.73 ± 0.03^g
C 16:1 ω7	1.83 ± 0.01^de	0.75 ± 0.02^abc	1.26 ± 0.01^cd	0.41 ± 0.01^ab	1.15 ± 0.01^cd	0.91 ± 0.66^abc	0.58 ± 0.01^abc	1.08 ± 0.03^bc	20.80 ± 0.37^f
C 17:1 ω7	0.06 ± 0.04^ab	0.08 ± 0.01^bca	0.06 ± 0.01^ab	0.47 ± 0.04^g	0.09 ± 0.01^abc	0.16 ± 0.04^cd	0.27 ± 0.01^ef	0.02 ± 0.01^ab	0.55 ± 0.06^g
C 18:1 ω9	6.96 ± 0.06^f	7.60 ± 0.22^g	10.14 ± 0.13^k	2.49 ± 0.01^c	6.65 ± 0.01^f	8.78 ± 0.03^h	9.60 ± 0.11^I	1.31 ± 0.04^b	0.37 ± 0.03^a
ΣMUFA	12.20 ± 0.18^e	8.85 ± 0.30^c	17.31 ± 0.95^h	6.94 ± 0.06^b	9.89 ± 0.03^cd	11.44 ± 0.66^e	14.25 ± 0.47^g	6.52 ± 0.06^b	50.91 ± 0.53^k
C 18:2 ω6	21.52 ± 0.16^k	18.22 ± 0.08^h	15.95 ± 0.16^g	12.17 ± 0.05^d	25.94 ± 0.03^l	13.97 ± 0.13^f	18.83 ± 0.16^i	9.54 ± 0.01^c	1.25 ± 0.07^a
C 18:3 ω6	3.61 ± 0.21^f	2.99 ± 0.33^ef	0.96 ± 0.13^abc	4.47 ± 0.02^g	1.68 ± 0.06^d	3.13 ± 0.29^ef	0.76 ± 0.06^ab	1.74 ± 0.04^d	4.87 ± 0.10^g
C 18:3 ω3	16.90 ± 0.11^e	28.71 ± 0.06^h	36.92 ± 1.06^k	11.55 ± 0.06^d	35.61 ± 0.04^k	22.10 ± 0.20^g	30.51 ± 0.86^i	54.29 ± 0.01^n	0.28 ± 0.01^a
ΣPUFA	42.02 ± 0.06^f	49.91 ± 0.18^h	53.83 ± 0.78^i	28.18 ± 0.08^c	63.23 ± 0.01^l	39.19 ± 0.04^e	50.10 ± 0.95^h	65.56 ± 0.06^m	6.40 ± 0.18^a
ΣUFA	54.22 ± 0.12^e	58.76 ± 0.49^g	71.14 ± 0.18^k	35.12 ± 0.14^b	73.12 ± 0.04^l	50.63 ± 0.62^d	64.35 ± 0.49^i	72.08 ± 0.12^kl	57.53 ± 0.67^fg
ΣEFA	38.41 ± 0.27^g	46.92 ± 0.14^h	52.87 ± 0.91^k	23.72 ± 0.11^d	61.55 ± 0.06^m	36.07 ± 0.33^f	49.34 ± 1.02^i	63.83 ± 0.02^n	1.53 ± 0.08^a
Σω3	16.90 ± 0.11^e	28.71 ± 0.06^h	36.92 ± 1.06^k	11.55 ± 0.06^d	35.61 ± 0.04^k	22.10 ± 0.20^g	30.51 ± 0.86^i	54.29 ± 0.01^n	0.28 ± 0.01^a
Σω6	25.13 ± 0.05^g	21.21 ± 0.25^f	16.91 ± 0.28^c	16.63 ± 0.03^c	27.62 ± 0.03^h	17.09 ± 0.16^c	19.59 ± 0.09^e	11.28 ± 0.05^b	6.12 ± 0.17^a
ω3/ω6	0.68 ± 0.007^c	1.36 ± 0.021^f	2.18 ± 0.099^h	0.70 ± 0.007^c	1.29 ± 0.001^f	1.30 ± 0.021^f	1.56 ± 0.035^g	4.82 ± 0.021^k	0.05 ± 0.007^a
ω6/ω3	1.49 ± 0.014^g	0.74 ± 0.014^d	0.46 ± 0.021^b	1.44 ± 0.001^g	0.78 ± 0.007^d	0.77 ± 0.014^d	0.64 ± 0.014^c	0.21±0.001^a	22.26 ± 0.049^l

*Data marked with different superscript letters within the same row indicates significant difference (p < 0.05).

**SFA: Saturated fatty acids; MUFA: monounsaturated fatty acids; PUFA: polyunsaturated fatty acids; UFA: unsaturated fatty acids; EFA: essential fatty acids.

TABLE 6(continued)*

Fatty acids	O. tauricum	O. hispidus	P. rhoeas	P. crispum	R. acetosella	R. patientia	S. arvensis	U. dioica
C 12:0	1.54 ± 0.02 ^bcdef	1.46 ± 0.42 ^bcdef	0.70 ± 0.08 ^abcd	1.47 ± 0.04 ^bcdef	1.96 ± 0.11 ^ef	1.66 ± 0.10 ^cdef	1.81 ± 0.06 ^def	0.16 ± 0.01 ^a
C 14:0	7.94 ± 0.02 ^n	0.71 ± 0.01 ^b	1.18 ± 0.01 ^d	6.41 ± 0.02 ^m	2.21 ± 0.02 ^g	1.40 ± 0.01 ^e	4.67 ± 0.04 ^l	0.42 ± 0.01 ^a
C 15:0	0.44 ± 0.01 ^a	0.92 ± 0.97 ^a	0.72 ± 0.01 ^a	0.53 ± 0.01 ^a	0.40 ± 0.06 ^a	0.37 ± 0.01 ^a	0.31 ± 0.01 ^a	0.03 ± 0.01 ^a
C 16:0	46.42 ± 0.01 ^k	16.64 ± 0.17 ^b	22.45 ± 0.08 ^e	27.06 ± 0.02 ^f	33.37 ± 0.04 ^h	18.74 ± 0.09 ^c	53.39 ± 0.18 ^m	10.43 ± 0.04 ^a
C 17:0	0.56 ± 0.02 ^cde	0.28 ± 0.11 ^ab	0.37 ± 0.01 ^bc	0.42 ± 0.03 ^bcd	0.62 ± 0.03d ^e	0.25 ± 0.08 ^ab	0.73 ± 0.03 ^ef	0.10 ± 0.04 ^a
C 18:0	6.36 ± 0.02 ^h	1.17 ± 0.05 ^a	1.56 ± 0.06 ^ab	2.02 ± 0.04 ^abc	4.59 ± 0.01 ^g	2.23 ± 0.01 ^bcd	7.72 ± 0.43 ^ik	3.08 ± 0.03 ^def
ΣSFA**	63.24 ± 0.01 ^m	21.17 ± 0.43 ^b	26.96 ± 0.11 ^d	37.89 ± 0.03 ^g	43.15 ± 0.06 ^i	24.64 ± 0.28 ^c	68.61 ± 0.21 °	14.20 ± 0.04 ^a
C 14:1 ω5	0.88 ± 0.04 ^f	0.34 ± 0.04 ^abcd	0.80 ± 0.08 ^ef	0.43 ± 0.03 ^bcd	0.04 ± 0.01 ^a	0.02 ± 0.01 ^a	0.40 ± 0.01 ^bcd	0.17 ± 0.01 ^ab
C 15:1 ω5	3.36 ± 0.04 ^d	3.70 ± 0.23 ^d	3.06 ± 0.13 ^d	1.32 ± 0.01 ^bc	6.70 ± 0.22 ^f	1.79 ± 0.01 ^c	0.25 ± 0.04 ^a	0.03 ± 0.01 ^a
C 16:1 ω7	0.72 ± 0.03 ^abc	0.71 ± 0.06 ^abc	0.74 ± 0.04 ^abc	0.53 ± 0.01 ^abc	0.74 ± 0.03 ^abc	2.10 ± 0.01 ^e	0.75 ± 0.02 ^abc	0.26 ± 0.03 ^a
C 17:1 ω7	0.18 ± 0.03 ^de	0.06 ± 0.01 ^ab	0.04 ± 0.01 ^ab	0.11 ± 0.02 ^bcd	0.06 ± 0.01 ^ab	0.02 ± 0.01 ^ab	0.31 ± 0.01 ^f	0.01 ± 0.01 ^a
C 18:1 ω 9	6.15 ± 0.21 ^e	2.29 ± 0.11 ^c	8.06 ± 0.11 ^g	11.36 ± 0.03 ^l	12.83 ± 0.04 ^m	1.10 ± 0.21 ^b	5.19 ± 0.01 ^d	14.26 ± 0.18 ^n
ΣMUFA**	11.28 ± 0.21 ^de	7.09 ± 0.03 ^b	12.69 ± 0.12 ^ef	13.74 ± 0.01 ^fg	20.36 ± 0.27 ^i	5.03 ± 0.22 ^a	6.89 ± 0.08 ^b	14.72 ± 0.22 ^g
C 18:2 ω6	6.61 ± 0.21 ^b	30.74 ± 0.27 ^n	30.22 ± 0.06 ^n	27.76 ± 0.02 ^m	12.70 ± 0.01 ^e	18.69 ± 0.04 ^hi	7.11 ± 0.18 ^b	64.19 ± 0.19 °
C 18:3 ω 6	11.30 ± 0.04 ^h	0.62 ± 0.15 ^a	1.39 ± 0.08 ^bcd	1.97 ± 0.04 ^d	4.43 ± 0.24 ^g	1.42 ± 0.05 ^cd	4.73 ± 0.25 ^g	2.64 ± 0.01 ^e
C 18:3 ω 3	7.57 ± 0.03 ^c	40.39 ± 0.35 ^l	28.75 ± 0.01 ^h	18.65 ± 0.01 ^f	19.36 ± 0.04 ^f	50.24 ± 0.06 ^m	12.68 ± 0.21 ^d	4.27 ± 0.01 ^b
ΣPUFA**	25.48 ± 0.23 ^b	71.75 ± 0.47 °	60.35 ± 0.01 ^k	48.37 ± 0.01 ^g	36.49 ± 0.18 ^d	70.34 ± 0.05 ^n	24.52 ± 0.15 ^b	71.10 ± 0.19 ^no
ΣUFA**	36.76 ± 0.01 ^c	78.84 ± 0.45 ^n	73.04 ± 0.11 ^l	62.11 ± 0.02 ^h	56.85 ± 0.08 ^f	75.36 ± 0.27 ^m	31.40 ± 0.23 ^a	85.81 ± 0.03 °
ΣEFA**	14.18 ± 0.18 ^b	71.13 ± 0.62 ^p	58.97 ± 0.06 ^l	46.40 ± 0.03 ^h	32.06 ± 0.06 ^e	68.92 ± 0.10 °	19.79 ± 0.40 ^c	68.46 ± 0.21 °
Σω3	7.57 ± 0.03 ^c	40.39 ± 0.35 ^l	28.75 ± 0.01 ^h	18.65 ± 0.01 ^f	19.36 ± 0.04 ^f	50.24 ± 0.06 ^m	12.68 ± 0.21 ^d	4.27 ± 0.01 ^b
Σω6	17.91 ± 0.25 ^d	31.36 ± 0.12 ^k	31.61 ± 0.02 ^k	29.73 ± 0.02 ^i	17.13 ± 0.23 ^c	20.10 ± 0.01 ^e	11.84 ± 0.06 ^b	66.83 ± 0.18 ^l
ω3/ω6	0.43 ± 0.007 ^b	1.29 ± 0.007 ^f	0.91 ± 0.001 ^d	0.63 ± 0.001 ^c	1.13 ± 0.014 ^e	2.50 ± 0.001 ^i	1.07 ± 0.028 ^e	0.06 ± 0.001 ^a
ω6/ω3	2.37 ± 0.042 ^i	0.78 ± 0.007 ^d	1.10 ± 0.001 ^f	1.60 ± 0.007 ^h	0.89 ± 0.007 ^e	0.40 ± 0.001 ^b	0.94 ± 0.021 ^e	15.65 ± 0.014 ^k

*Data marked with different superscript letters within the same row indicates significant difference (p < 0.05).

**SFA: Saturated fatty acids; MUFA: monounsaturated fatty acids; PUFA: polyunsaturated fatty acids; UFA: unsaturated fatty acids; EFA: essential fatty acids.

Table 7. Correlation coefficients between the assays.^a

Assays	Total bioactive component				Enzyme inhibitory activity				Antioxidant activity
	TPC	TFC	TFLC	TSC	AGIA	AAIA	BChE	AChE	MCA	FRAP	CUPRAC	NOSA	ABTS	DPPH	TAP
TACB	0.38	0.45	0.71**	0.41	–0.08	0.28	–0.35	–0.27	–0.19	0.38	0.44	0.15	0.44	0.39	0.22
TAP	0.63**	0.01	0.22	0.55*	0.03	–0.21	–0.20	–0.18	–0.24	0.59*	0.59*	–0.02	0.56*	0.30
DPPH	0.64**	0.42	0.22	0.57*	0.47	0.16	–0.49*	–0.69**	–0.45	0.71**	0.67**	0.48	0.80**
ABTS	0.96**	0.36	0.49*	0.86**	0.53*	0.07	–0.50*	–0.50*	–0.53*	0.98**	0.96**	0.35
NO	0.28	0.50*	–0.01	0.26	0.09	0.06	–0.24	–0.39	–0.15	0.27	0.25
CUPRAC	0.99**	0.25	0.62**	0.89**	0.53*	0.17	–0.44	–0.36	–0.38	0.99**
FRAP	0.99**	0.28	0.55*	0.89**	0.55*	0.13	–0.44	–0.40	–0.44
MCA	–0.42	–0.31	0.11	–0.30	–0.05	0.41	0.23	0.14
AChE	–0.35	–0.60*	0.02	–0.50*	–0.32	–0.05	0.80**
BChE	–0.43	–0.51*	–0.11	–0.57*	–0.16	0.09
AAI	0.09	0.26	0.56*	0.22	0.29
AGI	0.47	0.02	0.22	0.40
TSC	0.90**	0.46	0.56*
TFOLC	0.56*	0.12
TFC	0.24

^aData represents Pearson Correlation Coefficient R. (AAIA: α-amylase inhibitory activity; ABTS: ABTS radical scavenging activity; AChEIA: acetyl cholinesterase inhibitory activity; AGIA: α-glycosidase inhibitory activity; BChEIA: butyryl cholinesterase inhibitory activity; CUPRAC: CUPRAC reducing power potential; DPPH: DPPH radical scavenging activity; FRAP: FRAP reducing power potential; MCA: metal chelating activity; NOSA: nitric oxide radical scavenging activity; TACB: total antioxidant activity by β-carotene bleaching method; TAP: total antioxidant activity by phosphomolybdenum method; TPC: total phenolic content; TFC: total flavonoid content; TFLC: total flavonol content; TSC: total saponin content).

*Indicates p < 0.05.

**Indicates p < 0.01.

A. graveolens, C. glomerata, C. draba, C. endivia, E. cicutarium, E. sativa, and L. sativum contained considerable amount of oleic acid (C 18:1 ω9). M. sylvestris was found rich in pentadecanoic acid (C 15:1 ω5; 3.60%). On the other hand, M. piperita had a different mono-unsaturated fatty acid composition. It was found to be rich in palmitoleic (C 16:1 ω7; 20.80%), pentadecanoic (C 15:1 ω5; 16.73%), and miristoleic acids (C 14:1 ω5; 12.46%). M. piperita was also determined as the richest sample in terms of mono-unsaturated fatty acids.

Except M. piperita, all of the plant species exhibited a similar polyunsaturated fatty acid composition profile. M. piperita contained considerable amount of γ-linolenic acid (C 18:3 ω6; 4.87%). Linoleic (C 18:2 ω6) and α-linolenic acids (C 18:3 ω3) were determined as the major fatty acids in the rest of the plant species. Among these species, M. sylvestris had the highest total polyunsaturated fatty acid content (65.56%). It was closely followed by E. cicutarium (63.23%). This plant also contained considerable amount of unsaturated fatty acid (73.12%). Total unsaturated fatty acid contents of M. sylvestris and C. draba were found to be too close to that of E. cicutarium (72.08 and 71.14%, respectively). According to our literature survey could ascertain, fatty acid compositions of A. graveolens, C. glomerata, and R. patientia have not previously been reported. Therefore, data presented here could be assumed as the first report on the fatty acid compositions of these species.

Conclusions

As can be seen from the data presented above, M. piperita, R. patientia, and R. acetosella exhibited quite strong antioxidant activities in almost all test systems. In general, a strong correlation was determined between the phytochemical profile and antioxidant activity of the plant species. In order to clarify the relationship between the phytochemistry and biological activity of the plant species, we calculated the correlation coefficients for all the parameters studied (Table 6^{Table 7}). According to data presented in the table, total phenolic content of the samples were found to be highly in correlation with their ABTS free radical scavenging (0.96) and reducing power (0.99) activities. According to the results of the enzyme inhibitory assay, C. draba, E. sativa, R. patientia, and E. cicutarium showed the highest activities on AChE, BChE, α-amylase, and α-glucosidase, respectively. However, no correlation was determined between the phenolic composition and enzyme inhibitory activities of the extracts. According to data presented in Table 6, correlation coefficients between the α-amylase and α-glucosidase inhibitory activities and total phenolic contents of the plants were found to be below 0.90. Additionally, a negative correlation was observed between the cholinesterase inhibitory activity and total phenolics of the samples.

Acknowledgments

The authors would like to thank to Dr. Olcay Ceylan for his kind contribution of identifying and collecting the plant material. The authors declare that there are no conflicts of interest.

Funding

The authors would like to thank to the Scientific Research Council of Celal Bayar University, Manisa-Turkey for the financial support (Project Number: 2013-050).

Additional information

Funding

The authors would like to thank to the Scientific Research Council of Celal Bayar University, Manisa-Turkey for the financial support (Project Number: 2013-050).