Free radical scavenging activity, phenolic contents and phytochemical evaluation of different extracts of stem bark of Butea monosperma (Lam.) Kuntze

Figures & data

Table 1. Phytochemical analysis and extractive value of different solvent extracts of B. monosperma bark in increasing and decreasing order of solvent polarity.

S. No	Phytochemicals	Increasing polarity							Extracts^a Decreasing polarity
		1	2	3	4	5	6	7	1	2	3	4	5	6	7
1	Alkaloids	−	−	−	+	+	+	−	−	−	−	−	+	+	+
2	Carbohydrates	−	−	−	−	−	−	−	−	−	−	−	+	+	+
3	Sterols	−	−	−	−	+	−	−	−	+	−	+	+	+	+
4	Saponins	−	−	−	−	−	−	−	−	−	−	−	+	+	+
5	Tannins	−	−	−	−	+	+	−	−	−	−	−	+	+	+
6	Flavonoids	−	+	−	−	−	−	−	−	+	−	−	−	+	−
7	Amino acids	−	−	−	−	+	−	−	−	−	−	−	+	+	+
8	Proteins	−	−	−	−	+	−	−	−	−	−	−	+	+	+
9	Resins	+	−	−	−	−	+	−	+	+	−	−	−	+	+
Extractive value (%)		0.36	0.41	0.18	0.73	1.14	2.09	ND	0.11	0.22	0.26	0.10	0.51	1.98	4.03
Notes: ^aExtracts: 1, hexane; 2, chloroform; 3, ethyl acetate fraction; 4, water fraction; 5, acetone; 6, methanol; 7, water; ND, not determined.
“+” Indicates presence of the phytochemical, “−” indicates absence of the phytochemical.

Table 2. Total phenolic content (as mg gallic acid equivalents (GAE) per g of extract) in different extracts of B. monosperma.

Plant extracts	Total phenolic content (mg GAE/g of extract)
	Increasing polarity	Decreasing polarity
Acetone	141^ax	128^ay
Methanol	117^bx	121^ax
Ethyl acetate	45^cx	47^cx
Water	45^cx	93^by
Notes: ^a–^cwithin a column different letters are significantly different (p<0.05).
^x−y within a row different letters are significantly different (p<0.05).

Table 3. Percentage inhibition of DPPH radical in the presence of different concentrations of increasing and decreasing polarity extracts of B. monosperma.

	DPPH scavenging activity (%)
	Increasing polarity						Decreasing polarity
Plant extracts						IC50						IC50
(μg ml^−1)	20	40	60	80	100	(μg ml^−1)	20	40	60	80	100	(μg ml^−1)
Acetone	38.26^a	45.83^a	55.12^a	74.75^a	78.10^a	44.77	42.94^a	50.84^a	58.96^a	76.06^a	83.02^a	34.96
Methanol	37.28^a	46.97^a	56.02^a	67.65^a	73.75^a	45.69	27.07^b	34.96^b	55.23^a	79.57^a	83.41^a	51.77
Ethyl acetate	24.59^b	39.24^b	44.19^b	51.50^b	58.85^b	74.77	23.66^b	35.75^b	46.65^b	55.77^b	59.26^b	71.37
Water	19.44^c	24.42^c	26.71^c	35.59^c	36.68^c	139.8	23.69^b	42.46^b	56.56^a	60.16^b	65.44^b	ND
Ascorbic acid	22.14^b	43.19^a	63.97^a	72.19^a	80.75^a	62.87	22.14^b	43.19^b	63.97^a	72.19^a	80.75^a	62.87
Notes: ^a–^cwithin a column different letters are significantly different (p<0.05); ND: not determined.

Table 4. Relative reducing power of different concentrations of increasing and decreasing polarity extracts of B. monosperma.

Plant extracts (μg ml^−1)	Relative reducing power
	Increasing polarity					Decreasing polarity
	20	40	60	80	100	20	40	60	80	100
Acetone	0.926^a	1.250^a	1.382^a	1.558^a	1.779^a	0.455^b	0.705^b	0.970^b	1.294^b	1.852^a
Methanol	0.529^b	0.838^b	1.073^b	1.117^b	1.235^b	0.367^b	0.661^b	0.985^b	1.264^b	1.588^b
Ethyl acetate	0.366^c	0.605^c	0.843^c	0.923^c	1.098^b	0.220^c	0.426^c	0.676^c	0.955^c	1.147^c
Water	0.205^d	0.500^c	0.764^c	0.897^c	0.985^c	0.235^c	0.500^c	0.661^c	0.750^d	0.838^d
Butylated hydroxytoluene (BHT)	0.779^a	1.235^a	1.382^a	1.735^a	1.823^a	0.779^a	1.235^a	1.382^a	1.735^a	1.823^a
Notes: within a column different letters are significantly different (p<0.05).

Figure 1. Scavenging of hydroxyl radicals by various extracts of B. monosperma in (a) site specific and (b) non-site specific deoxyribose degradation assay.

Figure 2. (a) Ferrous ion chelating power and (b) scavenging of the superoxide radical (NBT) by increasing and decreasing solvent polarity extracts of B. monosperma.

Figure 3. Time course of 20 individual EPR spectra obtained for samples of various extracts of B. monosperma dissolved in DMSO. All sets of 20 EPR spectra of DMPO adducts monitored during the thermal (333 K) decomposition of K₂S₂O₈ in the presence of DMSO extracts were taken for 22 minutes under the same experimental conditions as for reference sample (DMSO, instead of DMSO bark extracts). Extracts concentrations: methanol I.P., acetone I.P. & D.P. (100 mg ml⁻¹) and methanol D.P. (500 mg ml⁻¹).

Figure 4. (a) Time course of EPR integral intensities of DMPO adducts recorded during the first 22 minutes of the thermal decomposition of K₂S₂O₈ in the presence of DMSO extracts of B. monosperma bark and (b) radical scavenging capacities equated to actual dry weight of the extracts and expressed as TEAC g⁻¹ of extracts.