Phytochemical studies and antioxidant activity of ashwagandha (Withania somnifera L.)
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Date
2015
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The present study was undertaken for phytochemical studies and antioxidant activity of Ashwagandha
(Withania somnifera L.) roots of promising genotypes viz. HWS-08-14, HWS-08-18, HWS-1228, HWS-1229 and Selection-2B & varieties JA-20 and RVA-100 grown at Research Farm of Chaudhary Charan
Singh Haryana Agricultural University, Hisar. Chemical parameters viz. crude fibre, minerals (Fe, Cu,
Zn, Mn), starch, total sugars, reducing sugars, non-reducing sugars were analysed in ashwagandha roots.
Crude fibre ranged from 17.4 to 37.3%, Fe content range d from 595.83 to 983.33 ppm, Cu content ranged
from 8.40 to 13.72 ppm, Zn content ranged from 16.33 to 41.00 ppm and Mn content ranged from 16.80
to 33.46 ppm. Starch, total sugars, reducing sugars and non-reducing sugars content ranged from 7.61 to
8.22 mg/g, 5.33 to 6.89 mg/g, 0.40 to 0.64 mg/g and 4.87 to 6.33 mg/g, respectively. Phytochemical
parameters viz. total alkaloids, tannins, total phenolics and total flavonoids were also analysed. Total
alkaloids and tannins content ranged from 0.26 to 0.31% an d 0.66 to 0.84 mg/g, respectively. Total
phenolics and flavonoids were extracted with two solvents namely aqueous and ethanol. Extract yield of
aqueous extracts of ashwagandha roots ranged from 7.32 to 13.65 g/100g in comparison to ethanol
extracts ranging from 2.66 to 4.84 g/100g showing that aqueous extracts had higher extract yield than
ethanol extracts. Total phenolics content (mg GAE/g) in aqueous extracts of ashwagandha roots ranged
from 2.41 to 5.37 mg GAE/g d.w.b. and in ethanol extracts ranged from 1.70 to 3.36 mg GAE/g d.w.b.
Total flavonoids content (mg CE/g) in aqueous extracts of ashwagandha roots ranged from 0.64 to 1.10
and in ethanol extracts ranged from 0.96 to 1.59 mg CE/g d.w.b. DPPH free radical scavenging activity
(%) increased with increase of concentration levels. In aqueous extracts, DPPH free radical scavenging
activity of genotype HWS-08-14 was highest ranging from 10.40 to 90.34 (IC
50
1140.5 µg/mL) followed
by genotype HWS-08-18 ranging from 6.72 to 87.39 (IC
50 1385.7 µg/mL), genotype HWS-1229 ranging
from 7.40 to 76.30 (IC50
1497.8 µg/mL), genotype Selection-2B ranging from 7.23 to 75.49 (IC
50
1856.5
µg/mL), genotype HWS-1228 ranging from 2.09 to 77.64 (IC
50 2463.2 µg/mL) in comparison to varieties
JA-20 ranging from 2.82 to 87.32 (IC
50 1578.6 µg/mL) and RVA-100 ranging from 4.47 to 77.27 (IC
50
2615.9 µg/mL) at concentrations levels 100 to 5000 µg/mL. In ethanol extracts, DPPH free radical
scavenging activity of genotype HWS-1229 was highest ranging from 5.98 to 72.84 (IC
50
1507.1
µg/mL), genotype HWS-08-14 ranging from 1.98 to 85.11 (IC
50
1533.9 µg/mL), genotype HWS-08-18
ranging from 2.73 to 76.59 (IC 50
1627.9 µg/mL), genotype Selection-2B ranging from 1.54 to 72.80 (IC
50
2632.3 µg/mL) genotype HWS-1228 ranging from 1.40 to 68.01 (IC
50
2648.1 µg/mL) in comparison to
varieties JA-20 ranging from 2.48 to 82.27 (IC
50 2384.1 µg/mL) and RVA-100 ranging from 1.42 to
72.22 (IC
50
3307.9 µg/mL) at concentrations levels 100 to 5000 µg/mL. Among aqueous and ethanol
extracts, aqueous extracts contained higher amounts of total phenolics and also exhibited higher
antioxidant activity. Hence, aqueous extracts of ashwagandha roots are better source of antioxidants in
comparison to ethanol extracts.
Description
Keywords
Genotypes, Extraction, Vegetative propagation, Alcohols, Withania somnifera, Aromatic compounds, Antioxidants, Phenols, Sugar, Planting