Comparative Study of Anti-inflammatory Potency and Acute Toxicity Effects of Aqueous Extracts of Roots and Whole Plants of Alysicarpus vaginalis (L.) DC. and Desmodium gangeticum (L.) DC.

Abstract

Background: Desmodium gangeticum (Shalparni) and Alysicarpus vaginalis (Aswenna) belong to Fabaceae family. Due to the scarcity of Desmodium gangeticum in Sri Lanka, indigenous physicians often use Alysicarpus vaginalis as a substitute in Dashamoola Ayurvedic medicines. Objective: To compare the anti-inflammatory potency and acute toxicity effects of aqueous extracts of roots and whole plants of A. vaginalis and D. gangeticum Methods: Aqueous extracts were obtained from air-dried roots and whole plants through water decoction. Their anti-inflammatory potency was evaluated by heat-induced red blood cell (RBC) membrane stabilization assay and nitric oxide (NO) assay. To assess acute toxicity, Zebrafish embryo acute toxicity assay was conducted, using mortality percentage as the endpoint measure. Results: In RBC assay, D. gangeticum showed the highest anti-inflammatory potency (IC50 47.86 µg/mL) compared to reference drug, diclofenac sodium (IC50 741.31 µg/mL). In NO assay, reference drug, quercetin (IC50 285.01 µg/mL) outperformed four plant extracts. However, according to both assays, D. gangeticum whole plant demonstrated the strongest anti inflammatory potency (IC50 47.86 µg/mL in RBC assay and 2080.03 µg/mL in NO assay). A. vaginalis root exhibited the lowest efficacy (IC50 1380.38 µg/mL in RBC assay and 8150.09 µg/ml in NO assay). D. gangeticum root had higher potency than A. vaginalis root and whole plant in both assays. In acute toxicity testing, 50% ethanol (reference drug) demonstrated 100% mortality whereas all plant extracts showed reduced toxicity. Between plant extracts, D. gangeticum root exhibited the lowest toxicity (LC50 3801.89 µg/mL) while A. vaginalis whole plant exhibited the highest (LC50 1348.96 µg/mL). Statistical analysis revealed significant differences (p<0.05) between plant extracts and reference drugs in all assays. Conclusions: Comparing IC50 and LC50 values, it suggests D. gangeticum offers better anti inflammatory potency with lower toxicity than A. vaginalis. Therefore, the use of D. gangeticum is more suitable than A. vaginalis, suggesting that the Sri Lankan practice is not optimal.