Abstract
Grape seeds extract has therapeutic values including antimicrobial activity, antioxidant effect, wound healing and prevention of cardiovascular diseases. This study aimed to evaluate and compare antibacterial activity of different species of grape seed) Vitis labrusca, Vitis vinifera and Vitis vinifera( against some bacterial strains (Staphylococcus aureus, Streptococcus pneumonia, Acinetobacter Calcoaceticus, Klebsiella pneumoniae and Escherichia coli). Determine antioxidant effect of grape seed extracts (qualitatively). Antibacterial effects was performed using agar cup cut diffusion method for all bacterial species, followed by using minimum inhibitory concentration MIC for the species showed to be inhibited by grape seeds extracts. Antioxidant assay was done using DPPH scavenging test, methanolic solution of each grape seeds was spotted on TLC paper, sprayed with 0.2 % methanolic solution of diphenyl picryl hydrazyl (DPPH) reagent. Vitamin C was used as positive control. From the results, all grape species didn’t have any effect on K. pneumonia and E. coli, red and black grape seeds showed the highest inhibition zone (20 mm) on Staph. Aureus agar plate, green grape had the highest effect on Sterp. Pneumonia agar plate (20 mm). The lowest effect was for the red grape seeds extract (13 mm) on Acinetobacter calciaceticus. In general the three grape seeds extract had effect on Staph. aureus, Sterp. pneumonia and Acinetobacter calciaceticus. The red and black grape seed extract was effective against Sterp. pneumonia strain at MIC values of 7.8 mg/mL and black grape seeds extract had MIC at 7.8 mg/mL on Staph. aureus. However, the test for MIC of seeds extracts for the rest of bacterial species ranged between 15.62 and 87.5 mg/mL. The result showed that black grape seeds extract had the largest spot change in color indicating strong antioxidant effect. The lowest effect was by red grape seeds. From this result black grape showed to be the best grape seeds extract among the three chosen species in its antibacterial and antioxidant efficacy.