ABSTRACT
The increasing reliance on drugs from natural sources has led to the extraction and development of several drugs and chemotherapeutic agents from traditional herbs. Many foods present antibiotics function that are often unknown to the eater and these foods limit the growth of bacteria in the consumer’s body. Phytochemicals are chemicals that are derived from plant. Phytochemicals are found in fruits, vegetable, grains, legumes and green tea. The antibacterial activity of plant extracts is linked to the presence of phytochemicals in them. Some people have started using herbs due to the high cost of synthetic drugs. This study aimed at analysing the phytochemical and antibacterial properties of garlic (Allium sativum L.) against clinical some isolates.
The plant (Allium sativum L.) bulb was collected from Oba Market in Edo State, Nigeria and identified in the Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Benin, Nigeria. The test organismswere obtained from the Department of Medical Microbiology Laboratory, University of Benin Teaching Hospital, Benin City. The ethanol and aqueous extracts of Allium sativum were tested on bacterial isolates to determine the antibacterial effects. Quantitative phytochemical constituents were carried out on the aqueous and ethanolic peeled garlic extract using standard phytochemical procedures. Antibiotic sensitivity test was done using disc diffusion method.
Phytoconstituents identified in both aqueous and ethanolic extracts of Allium sativum were phlobatannins, tannins, flavonoids, alkaloids, saponins, steroids, glycosideand terpenoids. Quantitative analysis revealed saponins having the highest concentration (41.90±1.2 mg/100g) on ethanolic extract while tannins had the least concentration (15.40±1.0 mg/100g). There was a significant difference between all quantitative phytochemical identified (p<0.05) except for steroids and glycoside which were not significantly different (p>0.05). Salmonella entericahad the highest susceptibility (24±1.00 mm and 18±1.00 mm) both in the aqueous and ethanolic extracts at 100 mg/ml. The minimum inhibitory concentration of the ethanol extract ranged from 25-75 mg/ml and minimum bactericidal concentration ranging from 75-100 mg/ml on the tested organisms. The aqueous extract had its minimum inhibitory concentration ranging from 50-75 mg/ml and minimum bactericidal concentration at 100 mg/ml. Bacillus cereus, Streptococcus pnuemoniae and Staphylococcus aureus were susceptible to ciprofloxacin, erythromycin and resistant to rocephin, Escherichia coli, Salmonella enterica and Shigella dysentariae were resistant to sparfloxacin, amoxicillin and susceptible to gentamycin, ofloxacin and chloramphenicol. E. coli had the highest multiple antibiotic resistance index of 0.5, Shigella dysentariae had the least multiple antibiotic resistance index (0.2). The antibacterial activities of Allium sativum provides a basis for the development of new pharmaceuticals from Allium sativum.
