Antibacterial Activity with Bacterial Growth Kinetics and GC-MS Studies on Leaf and Tuber Extracts of Arisaema tortuosum (Wall.) Schott

Abstract:

Background: Pathogenic bacteria (Gram positive/Gram negative) are serving as a vital precursor for the development of infectious diseases in humans. Arisaema tortuosum (Wall.) Schott (ATWS), a famous folklore medicine of Asian region has documented for great medicinal values. Objective: To evaluate the ATWS extracts and their fractions (leaf and tuber part) for antibacterial potential against human pathogens and to probably examine the phytochemicals existing in promising extracts via gas chromatographymass spectroscopy (GC-MS). Methods: The dried young leaves and tubers of ATWS was extracted using C₂H₅OH:H₂O (95:5, v/v) and further fractionated with n-hexane, chloroform, ethyl acetate and butanol, respectively. The antibacterial activity was carried out using agar well diffusion method. Furthermore, the antibacterial kinetic curve of capable extracts/fractions was too studied using time killing assay. Results: Overall, leaves extracts exhibited greater and varying level of Minimum Inhibitory Concentration (MIC)/ Zone of Inhibition (ZOI) against tested bacterial strains: Staphylococcus aureus (Sa), Bacillus subtilis (Bs), Escherichia coli (Ec) and Salmonella typhimurium (St). Additionally, extracts (Ethanolic for St and Bs, n-hexane for Sa and chloroform for Ec) have mostly inhibited the growth of test organisms for approximate 24 hr. The common tentative compounds like phytol, neophytadiene, octadecane, hexahydrofarnesyl acetone etc. were confirmed qualitatively by GC-MS. Conclusion: The antibacterial finding reveals that the leaves of ATWS have considerable antibacterial activity might be due to the presence of various chemical constituents. The tentative compounds confirmed by GCMS from different extracts may further act as a valuable tool for future researchers against various bacterial illnesses.

Key words: Arisaema tortuosum, Leaf, Tuber, Extracts, Antibacterial activity, GC-MS analysis.