Evaluation of phytochemical and pharmacological properties of seeds of Nephelium lappaceum L.

This study aimed to evaluate the antioxidant, analgesic, neuropharmacological, antihyperglycemic, anti-inflammatory, and antidiarrheal properties of the methanolic extract of Nephelium lappaceum L. seeds (MSNL). In vitro antioxidant was determined using the DPPH free radical scavenging test. Analgesic, antihyperglycemic, antidiarrheal, and anti-inflammatory activities were evaluated using the acetic acid-induced writhing test, oral glucose tolerance test, castor oil-induced diarrhea, and carrageenan-induced paw edema, respectively, using rodents. Neuropharmacological activity was investigated in mice using both open-field and hole-cross methods. MSNL demonstrated strong DPPH scavenging capacity (IC50 = 53.92 μg/mL) compared to standard ascorbic acid (IC50 = 41.10 μg/mL). In the acetic acid-induced writhing test, the highest dose (600 mg/kg) showed 59.89% inhibition of abdominal constrictions compared to indomethacin (81.97%). MSNL showed a significant (P<0.05, P<0.01) diminution in the locomotion of rodents in both open field, and hole cross methods at the highest dose compared to the control group. MSNL significantly reduced blood glucose levels in mice (P<0.01, P<0.05) in a dose-dependent manner. The highest dose 600 mg/kg of MSNL showed a significant 53.46% reduction in diarrhea. MSNL 600 mg/kg displayed significant inhibition of inflammation at the 3rd hour (65.22%). The findings demonstrated that the extract has potential bioactivities and can be considered as the benchmark for the isolation of pure bioactive compounds from this plant to discover new drugs.