Health-benefits of date fruits produced in Saudi Arabia based on in vitro antioxidant, anti-inflammatory and human tumor cell proliferation inhibitory assays

Date fruits are reported to exhibit health-beneficial effects in addition to its nutritional value. Fruits collected from commercial date palm trees were sequentially extracted with water and methanol. All varieties of date fruits contained sugars, phenolics, triterpenoids, triglycerides, fatty acids and steroids, where sugars were the predominant components. Water and methanolic extracts of date fruits were assayed for antioxidant, antiinflammatory and human tumor cell proliferation inhibitory activities. In MTT antioxidant assay, methanolic extracts at 250 μg/mL exhibited moderate activity with absorbance values between 0.14 and 0.41. Water and methanolic extracts at 100 μg/mL inhibited lipid peroxidation (LPO) by 50-67% and 58-82%, respectively. In anti-inflammatory assay using cyclooxygenase enzymes (COX-1 and -2), water and methanolic extracts at 100 μg/mL showed COX-1 enzyme inhibition by 26-36% and 33-41%, and COX-2 by 45-48% and 48-52%, respectively. At 100 μg/mL concentrations, methanolic extracts of all date fruits showed marginal cell proliferation inhibitory activity against human gastric, prostate, colon, breast and lung tumor cell lines. The bioassay results suggest that varietal difference is not a significant factor among the 29 date fruits studied when compared for health-beneficial effects resulting from non-nutritional components present in it.