Antioxidant, Anti-α-amylase and Antimicrobial Activities of Doum (Hyphaene thebaica) and Argun (Medemia argun) Fruit Parts

Background and Objectives: Doum (Hyphaene thebaica) is a common palm tree in Egypt and produce an edible fresh fruits or dried in refreshment drinks. Another relative desert uncommon palm, Argun (Medemia argun) deserves extra focus as its fruits were found reserved in Pharaohs tombs. This study is designated to examine the phytochemicals, nutrient content, antioxidant and antimicrobial inhibitions activities of fruit parts of H thebaica (HT) and M argun (MAR). Materials and Methods: The total phenolic and flavonoid contents of fruit parts (mesocarp (M), coat (C) and seed endocarp (E)) were investigated spectrophotometrically. Antioxidant properties were measured as total antioxidant capacity, DPPH and H2O2 scavenging. The nutritional values determined as carbohydrates, proteins contents and anti-alpha-amylase activities. A bioassay based on inhibition zone on agar plate was applied to evaluate the antibiotic activity of the HT and MAR metabolites against 4 pathogenic bacterial strains. Results:The results displayed that antioxidant, antibacterial activities and nutritional values differ significantly in the endocarp, mesocarp and coat samples of both fruits. Flavonoids and phenolics content are high in endocarp of each fruit and low in mesocarp. Total phenolics from fruits parts ranged between 40.65-327.48 mg GAE g(-1) of dry sample. The IC50 values for radical scavenging of DPPH of MARE, MARM, MARC, HTE, HTM and HTC were 55.01, >500, 293.36, 53.76, >500 and 137.89 mu g mL(-1), respectively. The hydrogen peroxide scavenging efficacy of the various extracts obtained from HT and MAR was in the order of HTE>MARE>MARC>HTC>HTM>MARM. IC50 inhibitory activity of alpha-amylase showed the maximum in HT mesocarp, followed by HT coat and HT endocarp. At the concentrations of 100, 200, 300, 400 and 500 mu g mL(-1), HT mesocarp (HTM) showed inhibitory activity of 61.57, 85.67, 86.93, 83.97 and 85.20%, respectively and while MAR mesocarp (MARM) was 60.67, 64.13, 83.83, 82.23 and 82.27%, respectively. HTE and MARE extracts possess potential antioxidant and antibacterial properties followed by HT coat (HTC) and MAR coat (MARC). Conclusion: Argun fruit has strong biological activities similar to doum fruits and potentially can be used as food dietary supplement to cure cancer and diabetic diseases.