RESUMEN
The combined Bi-herbal ethanolic extract (BHE) made up of equal quantities of leaves of Pisonia grandis and Cardiospermum halicacabum was evaluated for its synergistic in vitro and in vivo Anti-arthritic effects and was compared with its individual ethanolic extracts of Pisonia grandis (EPG) and Cardiospermum halicacabum (ECH). The inhibition of protein denaturation, membrane stabilization and proteinase enzyme inhibition were studied as in vitro and Freund’s adjuvant arthritis model in Wistar rats was used to study the in vivo Anti-arthritic activity. The three extracts (BHE, EPG, and ECH) at the dose level of 300mg/kg b.w.in 2%CMC were ingested orally to the CFA treated rats once daily for 40 days and the percentage inhibition of the paw volume increase due to the drug treatment was calculated. All the three plant extracts exhibited dose dependent stabilization of the RBC membranes, inhibition of protein denaturation and protease inhibition. The BHE has got a significant reduction in the paw volume and oedema when comparable to EPG and ECH in these intoxicant treated animals. These observed effects may be due to its inhibition of free radical production due to the immunological and inflammatory reactions or minimizing protein denaturation or proteinase enzyme or stabilizing the membranes.