Studies on antibacterial activity of Teriminalia dafeuillana plant extract against Vibrio species reared from Penaeus monodon hatchery

Objective: The emergence of microbial diseases in the field of aquaculture implies serious financial loss. Application of antibiotics for the treatment of diseases results undesirable side effects. Certain herbal plant compounds are having potent effect on growth and survival as well as antimicrobial properties of aquatic organisms. In this study the chemical composition and antibacterial activity of different compounds from Terminalia dafeuillana plant was analyzed. The chromatographic separation of the hexane extract from bark, seeds of Terminalia dafeuillana lead in the isolation of five compounds Friedelin, β-sitosterol, D-manitol, Lupeol and (+)-sesamin. The structure was determined by using spectroscopic methods. Method & Materials: Terminalia dafeuillana plant material was collected from various regions of Chitoor and East Godavari districts, Andhra Pradesh, India. Instruments: I R Spectra was recorded on shimadzu QP-500C spectrometer. 1H and 13C spectra were recorded in CDCl3 solution on a Jeol JNM-Ex90A spectrometer with TMS as a internal standard. Silica gel 60H (70-230 and 230-400mesh) was used for column chromatography. The Vibrio strains like V. harveyi, V. parahaemolyticus, V. vulnificus and V. alginolyticus were used. The minimal inhibitory concentrations (MICs) of all the isolated compounds were determined by micro dilutions techniques. Results & Conclusion: The total four compounds are identified from the Terminalia dafeuillana compounds from bark extract: 1. Friedelin 2. β- sitosterol 3. Dmannitol Compounds from dry seed extract: 4. lupeol 5. (+) – Sesamin. The compounds isolated from the seeds of Terminalia dafeuillana displayed good, moderate and poor level of antibacterial activity. The compound (+) - sesamin is quite effective against V. parahaemolyticus with MIC of 31.5μg/ml, 62.5μg/ml against V. harveyi, V. alginolyticus species, and moderate level of (125μg) antibacterial activity against V. vulnificus. Friedelin compound from bark extract exhibits moderate level of activity i.e. 125μg/ml against V. harveyi, V. vulnificus and V. alginolyticus species and poor activity 250μg/ml against V. parahaemolyticus. β-sistosterol and Lupeol compounds were similar in antibacterial activity and represents poor level of inhibition. D-mannitol displays moderate level of MIC value i.e. 125μg/ml against tested parahaemolyticus strains, upon remaining strains it reveals poor activity. The results of the present investigation shows that Terminalia dafeuillana can act against Vibrio species even at low concentration and hence the use could be very cost effective. It is biodegradable and hence environment friendly.

کلیدواژه ها:

Terminalia dafeuillana ، antibacterial activity ، Vibrio species