Author(s)

Shakil Ahmed Polash¹, Tanushree Saha², Md. Sharif Hossain¹, Satya Ranjan Sarker^1*

¹Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Jahangirnagar University, Dhaka, Bangladesh.
²Department of Textile Engineering, Dhaka University of Engineering and Technology, Gazipur, Bangladesh.

Andrographis paniculata (Kalmegh) has been considered as a medicinal shrub and used as a medicinal plant in the remote areas of Bangladesh. A. paniculata leaf and stem extracts were prepared using the polar (i.e., water, and 70% ethanol) and nonpolar (i.e., hexane) solvents. The phytochemical contents, total phenol contents (TPC), antioxidant activity, and antibacterial activity of all the extracts of A. paniculata leaf and stem were investigated. Both the gram-positive (i.e., Bacillus subtillis) and gram-negative (i.e., E. coli, and Salmonella typhi) strains of bacteria were used for the antibacterial activity assay of the sample extracts. The ethanolic stem extracts contained the maximum amount of TPC when compared to that of the leaf extracts. However, the aqueous stem extracts had the highest free radical scavenging activity in vitro. The extracts prepared from A. paniculata stem showed better antibacterial activity against all the strains of bacteria (i.e., E. coli, S. typhi, and B. subtillis) when compared to that of the leaf extracts. More specifically, the aqueous stem extract showed superior antibacterial effect against E. coli, and B. subtillis, and the zones of inhibition were 21 mm, and 29 mm in diameter, respectively. On the other hand, the ethanolic stem extract showed the maximum antibacterial activity against S. typhi and the zone of inhibition was 8.15 mm. The minimum inhibitory concentration (MIC) value and IC₅₀ value for all the A. paniculata extracts were ~0.05 μg/μL, and ~1 μg/μL, respectively.

Andrographis paniculata, Total Phenol Content, Antioxidant, Antimicrobial, Zone of Inhibition

Polash, S. , Saha, T. , Hossain, M. and Sarker, S. (2017) Investigation of the Phytochemicals, Antioxidant, and Antimicrobial Activity of the Andrographis paniculata Leaf and Stem Extracts. Advances in Bioscience and Biotechnology, 8, 149-162. doi: 10.4236/abb.2017.85012.