Effect of Solvents on Extraction of Bioactive Substances from CITRULLUS COLOCYNTHIS and Their Antioxidant, Antimicrobial and Antiglycation Activities

Citrullus colocynthis has been used for treating ailments since ages. The ability of plant extracts obtained using various solvents to exhibit pharmacological effects was evaluated. To check for the antioxidant potential of whole plant and fruits of C. colocynthis, conventional antioxidant assays such as DPPH radical scavenging capacity were carried out, total content of flavonoids and phenolics was determined, and reducing power was estimated. The antimicrobial activity was evaluated using 96-well plate technique and Alamar Blue assay and the potential of plant extracts as antioxidant agents was evaluated using oxidative burst assay with chemiluminescent indicators. The highest phenolic content was obtained using 50% ethyl acetate, while highest total flavonoid content was provided by extraction with methanol. Aqueous extracts showed highest DPPH radical scavenging activity, while methanolic extracts showed maximum reducing power potential at different concentrations. Whole plant extracts of C. colocynthis showed higher antioxidant potential than fruit extracts only. For both in-vitro and in-vivo anti-inflammatory activity, the maximum inhibition of reactive oxygen species (ROS) was produced by 50% methanol whole plant extract. Among the five test bacterial strains used, namely Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi, the antibacterial activity of extracts showed more pronounced growth inhibition of S. aureus and minimum effect upon E. coli. All extracts tested rendered zero potential as antiglycation agents.