SCREENING OF PHYTOCHEMICALS AND DETERMINATION OF TOTAL PHENOLIC CONTENT, ANTI-OXIDANT AND ANTIMICROBIAL ACTIVITY OF METHANOLIC EXTRACT OF PIPER NIGRUM LEAVES
Redina Sapam, Partha Pratim Kalita, Manash Pratim Sarma, Nayan Talukdar, Harajyoti Das
Assam Down Town University, Panikhaiti,Guwahati- 26, Assam, India.
The study involves two methods of methanolic extraction of the powdered leaves, which ensure all the plant components of the extracted for better results. Phytochemical analysis from the extracts was performed by using standard protocols. Total phenolic content was determined by Folin–Ciocalteau’s (FC) method. The antimicrobial susceptibility of the extracts was tested against E coli, Pseudomonas and Klebsilla sp. using agar disc diffusion method. Antioxidant property of the plant was evaluated using DPPH Method. The plant extracts were used at varying concentrations to ensure which plant extract and concentration causes the most inhibition. Phytochemical analysis of the extract indicated the present of phenol, tannin, terpenoid(except in heat extraction method of methanol extract) and carbohydrates while protein, flavonoid, steroidwere absent. The phenolic content in cold extraction of methanol extract is 360?g/ml of GAE or 0.36mg of phenolic compound and in heat extraction of methanol extract is 340?g/ml of GAE or 0.34mg of phenol compound were present. The cold extraction of methanol extract demonstrated the maximum zone of inhibition against Pseudomonas followed by E. coli and Klebsiella sp. In case of heat extraction of methanol extract the maximum zone of inhibition against Pseudomonas followed by E.coli and Klebsiella sp. were seen respectively. The plant showed a significant activity with both methods. Out of the two extracts cold extraction showed the maximum antioxidant activity (78.81% inhibition in 200?g/ml) with increase in concentration. The heat extraction method showed the maximum of 77.62% inhibition in 200?g/ml concentration which reveals the dose dependent increase in percentage of inhibitory activity.