Comparative evaluation of anti-inflammatory activity and acute toxicity of Alysicarpus vaginalis (L.) DC. and Desmodium gangeticum (L.) DC. whole plants and their roots

Abstract

Background: The root of Desmodium gangeticum, a key component of “Dashamoola,” is a significant Ayurveda remedy for inflammatory conditions. Due to the less availability of D. gangeticum in Sri Lanka, indigenous physicians often substitute Alysicarpus vaginalis root without scientific validation. Further, no comparative study has been conducted on the whole plants of these species. This research is focused on comparing the aqueous extracts of roots and whole plants of A. vaginalis and D. gangeticum for anti-inflammatory activity, acute toxicity, and to quantify major phytochemicals. Methods: Freeze-dried aqueous extracts were prepared and assessed for anti-inflammatory potency using the egg albumin denaturation assay, heat-induced red blood cell membrane stabilization assay, and nitric oxide assay. Acute toxicity was evaluated using the zebrafish embryo assay, and major phytochemicals, were quantitatively screened. Results: In egg albumin denaturation assay, D. gangeticum whole plant (IC50 107.89 ± 0.71 μg/mL) and root (IC50 210.37 ± 0.39 μg/mL) exhibited superior anti-inflammatory potency compared to diclofenac sodium (IC50 826.04 ± 0.27 μg/mL) and A. vaginalis (whole plant IC50 1,336 μg/mL, root IC50 3,162.28 μg/mL). In red blood cell membrane stabilization assay, D. gangeticum (whole plant IC50 47.86 ± 0.52 μg/mL, root IC50 331.13 ± 0.83 μg/mL) showed the highest activity. Quercetin (IC50 285.01 μg/mL) was the most potent, with D. gangeticum (IC50 2,080.03 μg/mL) and A. vaginalis (IC50 7,183.87 μg/mL) showing weaker inhibition in the nitric oxide assay. Regarding toxicity, lower toxicity showed for D. gangeticum (LC50 2,570.39 μg/mL) compared to A. vaginalis (LC50 1,348.96 μg/mL). In phytochemical analysis, phenols, flavonoids, tannins, alkaloids and saponins were quantified. Statistical analysis revealed significant differences between effects of all extracts and reference drugs (P < 0.05). Conclusion: Comparative analysis revealed, D. gangeticum has higher anti-inflammatory activity and lower toxicity than A. vaginalis, suggesting its suitability over A. vaginalis in Sri Lankan practices.