Hplc Quantification And Antimicrobial Activity Trends Of Allyl Thiosulphinate Upon Chromatographic Fractionation Of Allium Sativum Extracts

Abstract

Allium sativum extracts have continually been used as herbal therapy for a variety of bacterial, fungal and viral infections. There is however reports of contraindications leading to adverse effects like ulcerations associated with use of these garlic herbal concoctions as medication. The main purpose of this study was therefore to quantitatively determine allicin and alliin by HPLC and investigate antimicrobial activity trends of allyl thiosulphinate (allicin) upon chromatographic fractionation of Allium sativum (garlic) constituents. The objectives were to develop and validate HPLC analysis method for quantification of allicin and alliin, to determine allyl thiosulphinate content in garlic obtained, to evaluate antimicrobial activity trends of Allium sativum extracts on chromatographic fractionation and model the antimicrobial trends. Experimental research design was adopted for this study using garlic juice. Two garlic bulbs sample categories were obtained, one from Kenyan cultivation regions while the other purchased from importing commercial stores which were separately blended to afford garlic juice for analysis. Extraction was performed using the soxhlet and maceration methods with ethanol and methanol solvents. Synergistic trend was evaluated using Disc-diffusion assays for antibacterial, antifungal activities of crude extracts, column chromatography fractions and HPLC eluents while determining their content of diallyl thiosulfinate and allylsulfinyl-L-alanine through High Performance Liquid Chromatographic (HPLC) quantification of allicin and alliin in the fractions of Allium sativum extracts. Extractions yielded up to 0.9% and 1.3% for the ethanol and methanol solvents respectively. The HPLC method developed and validated for determination of allicin displayed high accuracy and precision from the percent recoveries of 96.09+1.09% and Relative standard deviations ranging from 1.63 to 4.01 for intraday and 0.08 to 3.40 for inter day precision statistical assays. Inter- and intra-day consistency was depicted. Bioassays reported inhibition zones of 10mm to 18mm and finally 5mm (antibacterial) while 12mm to 28.4mm and finally 5mm (antifungal) from crude extract to column fraction and finally HPLC eluents respectively. In conclusion, antimicrobial trends indicate a rise and later a drop in activity moving from crude extract to column fraction and finally HPLC eluents. The developed and validated HPLC method is substantial for satisfactory performance in ethno pharmacovigilance of traditional medicine agents. Use of Garlic concoctions should be checked for standardization of constituents as these determines the efficacy.