Effect of CuO nanoparticles on polyphenols content and antioxidant activity in Ashwagandha (Withania somnifera L. Dunal)

TLDR: In this article, the effect of CuO nanoparticles on polyphenols content in treated plants at different dates of sampling was investigated and the results showed that the elicitation effect of the nanoparticles in Withania somnifera L. L. 20 days after treatment was significant.

Abstract: In the present investigation CuO nanoparticles significantly enhanced the polyphenols content in treated plants at different dates of sampling. Highest total phenol content i.e., 27.215±0.73 and 26.455±0.365 mg gallic acid equivalents/g extract, was observed 20 days after treatment in shoots and roots of treated plants, respectively. No significant difference (p≤0.05) in flavonoid content within shoots of treated plants was observed 15 and 20 DAT, respectively. Highest flavonoid content i.e., 23.076±5.128 mg quercetin equivalents/g extract was observed in roots of treated plants 20 days after treatment. Significantly higher tannin content was also observed in roots of treated plants20 DAT. Higher total antioxidant activity i.e., 55.797±1.924 and 56.811±3.012mg ascorbic acid equivalents/g extract was observed in shoots and roots of treated plants, respectively 20 days after treatment. Higher DPPH radical scavenging activity as observed by lower IC50 values i.e., 336.234±5.187 and 473.88±8.834 µg/ml in shoots and roots of treated plants, respectively was observed 20 days after treatment. Total antioxidant activity in shoots showed a significant (p≤0.05) positive correlation with phenol and tannin content within the shoots i.e., 0.618 and 0.693, respectively. Total antioxidant activity in roots also showed significant positive correlation with total phenol, flavonoid and tannin content within roots i.e., 0.416, 0.683 and 0.891, respectively. DPPH radical scavenging activity within shoots (-0.888) and roots (-0.851) showed a significant negative correlation with total phenol and flavonoid content in shoots and roots, respectively. Thus the findings of the present investigation clearly shows, the elicitation effect of CuO nanoparticles in Withania somnifera L.