Antioxidant, anti-inflammatory and anti-proliferative activities of green and yellow zucchini (Courgette)

Epidemiological studies reveal the fact that the risk for the development of chronic diseases including cancer and cardiovascular diseases can be reduced by consuming sufficient quantity of fruits and vegetables in the diet. Phytochemicals are bioactive compounds that are present in fruits and vegetables, which prevent the cells from damage and help in disease prevention. In the present study, seasonal vegetable zucchini ("green" and "yellow") were taken into consideration because of their high medicinal and nutritional value. To evaluate their suitability for use different assays were carried out such as DPPH scavenging assay, hydrogen peroxide scavenging assay, ferric reducing antioxidant power assay and total antioxidant activity assay were performed for the determination of antioxidant activity. Anti-inflammatory capacity was assayed by nitric oxide scavenging assay. Green zucchini exhibits greater scavenging activity of 38% in DPPH assay, 36% in hydrogen peroxide scavenging assay and TAC of 142.55 mg Ascorbic acid equivalent/100 g, whereas yellow zucchini exhibits scavenging activity of 36% in hydrogen peroxide scavenging assay and higher absorbance of 42 in FRAP, 73% scavenging for Nitric oxide radical scavenging assay and TAC of 162.55 mg Ascorbic acid equivalent/100 g. Antibacterial activity was determined against gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). Anti-fungal activity was determined against the fungus Aspergillus niger. Both Green and yellow zucchini exhibit good antibacterial and anti-fungal activity with the zone of inhibition ranges from 15 to 20 mm. Yellow Zuchini extract was found to be toxic to human lung cancer cells at lower concentrations. Thus, bio-components present in zucchini are capable of playing positive role in human health and are safe as evident from their antioxidant, antimicrobial, anti-inflammatory and anti-proliferative activities.