GC-MS Analysis of Anti-Enterobacterial Dichloromethane Fraction of Mandukaparni (Hydrocotyle javanica Thunb.) – A plant from Ayurveda

Background: Mandukaparni (Hydrocotyle javanica Thunb.) is a well known medicinal herb used as folklore medcine in many chronic and infectious gastric and other diseases by the people of Estern Himalayan regions. However, the therapeutic active principles of this plant remained unknown. Objective: The main objective of the study was to characterize antienterobacterial dichloromethane fraction of the volatile oils of it by GC-MS. Materials and Methods: In the present study, dichloromethane (DCM) fraction (MP-DCMf) of Mandukaparni was collected by phase separation of the methanol extract and tested for anti-enterobacterial potentiality against human pathogenic gastrointestinal and food poisoning bacteria by agar well diffusion assay, viability assay and LDH assay and SEM studies. Characterization of the active MP-DCMf fraction was performed by TLC and GC-MS analysis. Results: The MP-DCMf possessed bio-active compounds that have antibacterial potentiality against both the Grampositive and Gram-negative bacteria. The MIC and MBC values were in the range from 1.56 mg/ml to 0.78 mg/ml and 6.25 to 1.56 mg/ml, respectively. The time kill assay showed that at a dose of 3.12 mg/ml of MP-DCMf was lethal to the E. coli MTCC 723 at the 18th hr of treatment. LDH release had moderate positive correlation with the activity index and time of treatment whereas strong negative correlation with CFU count. It caused highest cell disruption in S. mutans. The principal compounds were D-carvon (30.949%);1H-Isoindole-1,3(2H)-dione; 2-(2-chlorophenyl) (28.483%);Cyclohexanone; 2-methyl-5-(1-methylethen) trans (10.04%); D-Limnone (9.256%);2,6-Octadien-1-ol, 3,7-dimethyl- acetate (6.684%); p-Cresol (0.551%), and Thymol (0.118%). Pub-chem database search also supports that these compounds have very strong bactericidal activity by membrane damage as evidenced by LDH and SEM studies. Conclusions: MP-DCMf contains many potential antibacterial compounds that can be used to combat the gastrointestinal and food poising bacterial pathogens.