Evaluation of in vitro antioxidant and in vivo Pharmacological activity of leaf extracts of Hoya parasitica (Wall.)

Abstract

In present study, leaf extract of Hoya parasitica Wall. was evaluated for in vitro antioxidant and membrane stabilizing activity along with in vivo gastro intestinal motility and acute toxicity. Five different assays were performed to evaluate antioxidant activity. In DPPH free radical scavenging activity, methanol, ethanol and chloroform extract exhibited IC50 value similar to standard ascorbic acid. The presence of flavonoid and phenolic contents was also similar in all the plant extracts. However, chloroform extract showed remarkable reducing power capacity (69.10% at 200μg/mL). In case of membrane stabilization, the chloroform extract showed maximum inhibition (32.62 %) of haemolysis, whereas the ethanol extract showed a significant (p<0.001) human RBC membrane stabilizing effect. In vivo gastrointestinal motility test indicates significant (p<0.001) increase in gastrointestinal motility by Methanol extract (100 and 200 mg/kg b.w.) and ethanol extract (200 mg/kg b.w.) compared to standard. Highest dose introduced as 1000, 2000 and 3000 mg/kg body weight of each extracts in acute toxicity study and did not shown any sign of toxicity in Swiss albino mice. The result obtained from this study, can be considered as preliminary and further sophisticated investigation is needed to isolate new bioactive compounds that might act as led compounds in future.