Therapeutical Effect of Extracts of Terminalia chebula In Inhibiting Human Pathogens and Free Radicals

Abstract

In recent years, multiple drug resistance has been developed due to indiscriminate use of existing antimicrobial drugs in the treatment of infectious diseases. Conventional antibiotics are strong medicines, which if not used in precise way may cause harmful effects. The major thrust is to establish alternative antimicrobial agent in order to treat microbial infections with less or no toxic effect to body and less negligible side effects. The herbal medicines have shown potential to overcome the limitation associated with conventional drugs. However, the appropriate choice of source for herbal medicine is also very important. Terminalia chebula possesses potential pharmaceutical activities and used in several Ayurvedic formulations. The study of solvent-free organic (ethylacetate, acetone, methanol of increasing polarity) and aqueous extracts of the fruits of T. chebula, showed the potential to reduce growth of microorganisms, minimizing the risk of infection, while optimizing the conditions to encourage healing. In our study we found, methanol extract as a potential bactericidal and potent antioxidant while aqueous extract showed the least potential as an antimicrobial agent, though a moderate antioxidant. The finding may provide scientific rationale for the use of crude extract of the plant as a new drug compound as potential antioxidant and antimicrobial agent. Terminalia chebula is used as a mild laxative and as an astringent against wounds and abscesses. Practictioners of folk medicine in India and Southeast Asia use the fruit for homeostatic, laxative and as cardiotonic. It is used as a remedy against a sore throat and cough, against diarrhoea connected with a prolapsed rectum in China and against ulcers and dysentery in Tibet. The antibacterial activity of various extracts of Chebula myrobalan powder was tested against Streptococcus species, Staphylococcus aureus and Pseudomonas aeruginosa. II. MATERIALS T. chebula powder was purchased from local market of Mumbai, India. Pathogens of MTCC grade were obtained from IMTECH (Chandigarh, India). Gallic acid and Glutaraldehyde was purchased from s.d. fine-chemicals limited (Mumbai, India). Gentamicin and 2,4,6-tripyidyl-s-triazine (TPTZ) were procured from Hi-Media(Mumbai,India), 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT, 98%) reagent, 4'-6-diamidino-2-phenylindole (DAPI), propidium iodide (PI) and nystatin was purchased from Sigma (St. Louis, USA). Fetal bovine serum (FBS) and streptomycin-penicillin antibiotic solutions were bought from HyClone (Utah, USA). All other chemicals used were of analytical grade. SIRC (rabbit corneal epithelial cells) cell line was obtained from NCL, Pune, India