Synergistic effect: An in vitro based evaluation for the enhanced biocontrol activities of combined extracts of Allium sativum and Curcuma longa
Abstract
The present study dealt with the extraction of phytochemicals from the rhizome samples of Allium sativum and Curcuma longa collected from Annamalai Nagar market, Chidambaram, Tamilnadu using different solvents such as hexane, ethyl acetate and methanol. Preliminary phytochemical analysis in the rhizomes solvent extracts revealed the presence of alkaloids, flavonoids, tannins, saponin, carbohydrates, terpenoids and phenols. The quantitative phytochemical analysis in the combined complex ethyl acetate extracts of A. sativum and C. longa showed a highest total phenolic content yield of 51.220.52mg GAE/g and total flavonoid yield of 37.480.50mg QE/g. TLC analysis of the crude extract showed compounds with different Rf values ranged from 0.2-0.8. When testing for the antibacterial activities of the crude extracts against Gram positive bacterial strains like Staphylococcus aureus, Bacillus subtilis and Methicillin resistant Staphylococcus aureus (MRSA) and Gram negative strains like Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa; they displayed excellent wide range of activities against both groups. Among the three different solvent extracts tested; the zone of inhibition was ranged from 7.0 0.2 to 22.5 0.4 mm where, the highest mean zone of inhibition of 18.3 0.7 at 200?l/ml was observed with ethyl acetate extract followed by methanol and hexane. These crude extracts also had excellent DPPH free radical scavenging activity, total antioxidant activity and reducing power. This study evidenced that the rhizomes extracts of A. sativum and C. longa had bioactive compounds with excellent antibacterial and antioxidant activity potentials with high IC50 values ranged from 116.7-476.2g/ml.