Antihyperglycemic activity of the bark methanolic extract of Syzygium mundagam in diabetic rats

Peer review under responsibility of Alexandria University Faculty of Medicine.

Available online 3 January 2017

Figures & data

Table 1 Total phenolics, tannins and flavonoids content of S. mundagam leaf and bark.

Samples		Extracts	Total phenolics (g GAE/100 g extract)	Tannins (g GAE/100 g extract)	Flavonoids (g RE/100 g extract)
S. mundagam	Leaf	Petroleum ether	1.88 ± 0.39	0.38 ± 0.50	6.38 ± 1.06^c
		Ethyl acetate	7.94 ± 0.56^c	3.84 ± 1.01^c	6.47 ± 0.76^c
		Methanol	45.16 ± 0.69^b	40.79 ± 1.98^b	11.03 ± 0.29^b
		Hot water	5.34 ± 2.02^c	4.54 ± 2.08^c	1.38 ± 0.07
	Bark	Petroleum ether	1.61 ± 0.17	0.42 ± 0.32	3.01 ± 0.67
		Ethyl acetate	54.26 ± 1.32^a	47.96 ± 1.83^a	12.78 ± 0.07^a
		Methanol	54.44 ± 1.15^a	40.40 ± 1.59^b	12.48 ± 0.65^a
		Hot water	5.98 ± 0.75	4.18 ± 0.26^c	1.62 ± 0.05

Values are mean of triplicate determination (n = 3) ± standard deviation.

a > b > c > d, where significance among the extracts at p < 0.05 in columns.

GAE - Gallic acid equivalents, RE - Rutin equivalents.

Table 2 Activity of S. mundagam leaf and bark in ABTS⁺, FRAP and phosphomolybdenum assays.

Samples		Extracts	ABTS^+ (μM TEAC/g extract)	FRAP (mM Fe(II)E/mg extract)	Phosphomolyb-denum (g AAE/100 g extract)
S. mundagam	Leaf	Petroleum ether	1592.99 ± 58.18	7.60 ± 2.97	1.85 ± 0.02
		Ethyl acetate	5582.22 ± 341.46^d	1022.79 ± 51.83	10.41 ± 0.86
		Methanol	24198.61 ± 803.64^c	3514.72 ± 3.58^b	34.15 ± 1.68^c
		Hot water	3192.73 ± 138.21	2768.28 ± 44.46^c	6.99 ± 0.47
	Bark	Petroleum ether	1619.99 ± 21.43	97.15 ± 10.20	18.03 ± 1.50
		Ethyl acetate	34042.30 ± 1325.01^b	2011.40 ± 96.61^d	77.17 ± 1.82^b
		Methanol	109686.87 ± 5771.51^a	6612.54 ± 32.00^a	268.54 ± 22.06^a
		Hot water	7674.71 ± 333.36^d	112.25 ± 18.42	38.74 ± 1.47^c

Values are mean of triplicate determination (n = 3) ± standard deviation.

a > b > c > d, where significance among the extracts at p < 0.05 in columns.

TEAC - trolox equivalents antioxidant capacity, Fe(II)E - Fe(II) Equivalents.

AAE - ascorbic acid equivalents.

Fig. 1 DPPH radical scavenging activity of S. mundagam leaf and bark. IC₅₀ – Inhibitory concentration 50%.

Fig. 2 Metal chelating activity of S. mundagam leaf and bark. Values are mean of triplicate determination (n = 3) ± standard deviation. a > b, where significance among the extracts at p < 0.05.

Fig. 3 Superoxide radical scavenging activity of S. mundagam leaf and bark. Values are mean of triplicate determination (n = 3) ± standard deviation. a > b, where significance among the extracts at p < 0.05.

Fig. 4 Nitric oxide radical scavenging activity of S. mundagam leaf and bark. Values are mean of triplicate determination (n = 3) ± standard deviation. a > b, where significance among the extracts at p < 0.05.

Fig. 5 Oral glucose tolerance of S. mundagam bark methanol extract. The data represents mean ± SEM (n = 6). Significantly different at ^***p < 0.001, when compared to control. SMBM- S. mundagam bark methanol extract.

Fig. 6 Antihyperglycemic activity of S. mundagam bark methanol extract. The data represents mean ± SEM (n = 6). Significantly different at ^*p < 0.05, ^**p < 0.01, ^***p < 0.001, when compared to control. SMBM- S. mundagam bark methanol extract.