ANTIOXIDANT, ANTIBACTERIAL AND CYTOTOXIC ACTIVITIES OF VARIOUS EXTRACTS OF THYSANOLAENA MAXIMA (ROXB) KUNTZE AVAILABLE IN CHITTAGONG HILL TRACTS OF BANGLADESH

Objective: To evaluate the presence of different phytoconstituents and investigate in vitro bioactivities of petroleum ether, chloroform and methanol extracts of Thysanolaena maxima available in Bangladesh. Methods: Phytochemical screening was conducted using the specific standard procedure. Antioxidant activity of the extracts was evaluated using DPPH radical scavenging assay and reducing power assay. Determination of total phenolic and flavonoid contents was also carried out. Antibacterial and cytotoxic activities were investigated using disc diffusion method and brine shrimp lethality bioassay, respectively. Results : The methanol extract showed highest DPPH radical scavenging activity as well as possessed highest phenolic content (IC 50 value for DPPH is 36.94±0.62 μg/ml and total phenolic content is 74.39±2.87 in mg/g, GAE) compared to the petroleum ether and chloroform extracts. On the other hand, chloroform extract possessed maximum flavonoid content (81±7.542 in mg/g, QE) and highest reducing power compare to other extracts. All the extracts showed mild to moderate in vitro antibacterial activity with a zone of inhibition ranging from 7 mm to 16 mm. In brine shrimp lethality bioassay, the LC 50 values for petroleum ether, chloroform and methanol extracts were found to be 579.05±78.08 μg/ml, 386.92±80.47 μg/ml and 494.29±104.82 μg/ml, respectively which revealed weak cytotoxic potentials of the extracts compared to the positive control. Conclusion : The results indicated that T. maxima could be a very potent source of natural radical scavenger. Isolation of active compounds from this plant responsible for producing such bioactivities is underway. Keywords: Thysanolaena maxima , DPPH, Total phenolic contents, Total flavonoid contents, Reducing power, Cytotoxicity, Antimicrobial activity