Drought Stress Modulates Antioxidant Defense, Phytochemical Composition, and Anti-Inflammatory Activity in Physalis minima Linn.

Abstract

Drought is one of the abiotic stress factors that may affect plant metabolism, antioxidant defense mechanisms and biosynthesis of biologically active substance. “In the present study, the effects of drought stress on the phytochemical characteristics, activity of antioxidant enzymes and anti-inflammatory properties of Physalis minima was investigated. Methanolic extract was prepared from both control and drought stressed plants subjected to the qualitative phytochemical screening, catalase (CAT) and superoxide dismutase (SOD) activity assays, in vitro anti-inflammatory test with membrane stabilization method and protein denaturation method. The phytochemical qualitative test showed the presence of tannins, flavonoids, proteins and phenolic compound in both control and drought treated plants. On the other hand, there was no qualitative difference observed for phytochemical constituents of drought treated and non-drought treated since no presence of saponins, alkaloids, steroids, terpenoids, quinones and cardiac glycosides was observed in both. Drought exposure led to higher catalase activity owing to lower half maximal effective concentration (EC₅₀) value (46.4 µg protein vs. 49.1 µg protein for control). A better ability to neutralize hydrogen peroxide exists in drought-exposed plants. Drought stress did show a slight decrease in SOD activity with the drought stress extract background to have a higher IC50 value of 56.3 μg/mL than the control extract which was 53.6 μg/mL. The membrane stabilization test revealed a little more anti-inflammatory activity in control plants compared with drought treated P. minima and albumin denaturation revealed more anti-inflammatory activity in drought stress P. minima at higher concentration. In general, drought stress triggered significant biochemical reactions in P. minima, which amounted to a rise in catalase activity and protein solubilization and not significant changes in the qualitative compound type of phytochemicals. Overall, the results indicate that P. minima possess a potent antioxidant and anti-inflammatory defense system that is activated during water deficiency and that the plant may be used for medical purposes in the future to help cope with abiotic stresses.