Exploring the Synergistic Antioxidant Potential of Four Phytotherapeutic Extracts: Coriandrum sativum, Aloe barbadensis, Solanum nigrum and Glycyrrhiza glabra

Oxidative stress is implicated in numerous chronic diseases, promoting increased awareness of plant-based antioxidants as safer substitutes for synthetic ones. While Coriandrum sativum, Aloe barbadensis, Solanum nigrum, and Glycyrrhiza glabra are known for individual antioxidant potential, their combined synergistic effects remain underexplored.

The purpose of this study was to use the DPPH radical scavenging assay to assess the in vitro antioxidant activity of ethanolic extracts of these four herbs, both alone and in combination (CGSA).

Ethanol extracts were prepared via Soxhlet extraction after defatting with petroleum ether. Samples were tested at concentrations ranging from 62.5 to 1000μg/mL. Radical scavenging activity (%RSA) was measured spectrophotometrically at 517nm, and IC₅₀ values were calculated using regression analysis. Ascorbic acid was used as the standard.

Among all test samples, the polyherbal formulation CGSA showed the strongest free radical scavenging activity with an IC₅₀ of 819.13± 2.79μg/mL, outperforming individual extracts: Solanum nigrum (867.71μg/mL), Coriandrum sativum (846.73 μg/mL), Aloe barbadensis (1053.57μg/mL), and Glycyrrhiza glabra (2554.25μg/mL). Ascorbic acid, used as a positive control, had an IC₅₀ of 16.15μg/mL.

The results support a partial synergistic antioxidant effect in the CGSA combination, suggesting enhanced radical scavenging efficiency compared to individual plant extracts. These findings support the development of polyherbal formulations as potential natural antioxidants for managing oxidative stress.