Bioassay guided fractionation of Cyclea peltata using in vitro RAW 264.7 cell culture, antioxidant assays and isolation of bioactive compound tetrandrine

ABSTRACT

Background: Cyclea peltata is one of the herbs mentioned in ancient scriptures of Ayurveda and is used indifferent types of Ayurvedic gritham preparations. Moreover, in traditional/tribal medicine C. peltata isused as digestive, anti-inflammatory, diuretic and to treat jaundice, digestive disorders, etc.Objective: Activity guided fractionation of C. peltata and in correlation with the levels of bioactivecompound tetrandrine.Materials and methods: Preliminary phytochemical screening, estimation of total alkaloid content,preparation of different extracts of C. peltata (crude extract CP, hexane extract HCP, chloroform extractCCP, methanol extract MCP, alkaloid fraction ACP). In vitro anti-inflammatory studies using RAW264.7 cells and in vitro antioxidant assays of the different extracts of C. peltata. HPTLC estimation oftetrandrine (TET) was carried out using solvent system toluene ethyl acetate diethylamine (7.2 2 0.8)and isolation of TET from ACP.Results: Preliminary phytochemical studies of C. peltata showed the presence of alkaloid content in allextracts. Whereas, saponins, steroids and terpenoids were detected in CP and CCP. ACP and TET showedsignificant in vitro anti-inflammatory and antioxidant activity when compared to other extracts. ACP andTET (100 mg/ml) treatment significantly inhibited the mRNA expression of iNOS, COX-2, TNF-a in LPStreated RAW 264.7 cells. HPTLC estimation of bioactive compound tetrandrine was highest in ACP228.4 mg/mg followed by CP-29.62 mg/mg, CCP-23.46 mg/mg, MCP-18.82 mg/mg and HCP-1.25 mg/mg. TEThas been isolated from ACP.Conclusion: The results of the present in vitro assays revealed that the alkaloid fraction (ACP) is the mostactive fraction when compared to other extracts and has a positive correlation with the levels of bioactivecompound tetrandrine.