Abstract:
Ayurvedic polyherbal formulations are widely recognized for their enhanced therapeutic
efficacy, attributed in part to synergistic interactions among constituent
plant materials. Eranda Sapthakaya is a traditional formulation commonly used
to relieve arthritis-related discomfort. Two of its ingredients, Solanum melongena
(SM) roots and Solanum virginianum (SV) dried aerial parts, are known to possess
antioxidant phytoconstituents, but their potential interactive effects have not
been scientifically evaluated. This study is designed to investigate the synergistic
antioxidant interactions between SM and SV extracts using DPPH assay. Hydroalcoholic
root extract of S. melongena and ethanolic extract of S. virginianum
were prepared via simple maceration. The in vitro antioxidant activities of the individual
plant extracts were assessed using the DPPH assay. The 30% inhibitory
concentrations (IC30) of SM and SV were 58.22 ± 8.66 and 30.39 ± 3.39 μg/mL
respectively, as derived from dose-response curves using linear regression analysis.
The two plant extracts were subsequently combined in their IC30 ratio (1:1.9) to
evaluate the antioxidant potential of the mixture, which demonstrated an IC30
value of 20.95 ± 0.93 μg/mL. The calculated combination index (CI) was 0.47,
indicating a synergistic interaction between the two plant materials. Isobologram
analysis further supported this finding, as the experimental IC30 value fell below
both the additive line and the theoretical IC30 value (44.35 μg/mL). Additionally,
the dose-response curve of the SM-SV combination exhibited a leftward shift compared
to those of the individual plant extracts, indicating enhanced potency and
further confirming the synergistic antioxidant effect of the combination. In conclusion,
SM and SV exhibit significant synergistic antioxidant effects, supporting
their combined use in traditional formulations such as Eranda Sapthakaya and
highlighting their potential for therapeutic applications.
