Antioxidant, antidiarrheal, hypoglycemic and thrombolytic activities of organic and aqueous extracts of Hopea odorata leaves and in silico PASS prediction of its isolated compounds

Hopea Odorata, locally known as Telsur (Bangladesh), has some traditional uses as folk medicine. This study aims to investigate the antioxidant, antidiarrheal, hypoglycemic and thrombolytic activities of H. odorata leaf extracts as new therapeutic prospects predicting the activity of some of the isolated compounds of this plant.

Leaves of Hopea odorata was extracted with pure methanol (MEHO), ethanol (EEHO) and water (AEHO). The extract was tested for antioxidant activity by using reducing power and H₂O₂ scavenging assay. Antidiarrheal effects were assayed by three standard methods of bioassay: Castor oil-induced diarrhea, Castor oil induced enteropooling and gastrointestinal transit test. Hypoglycemic effect was determined by normoglycemic model of mice. Thrombolytic activity was evaluated by clot lyses test for human and mice blood. In silico PASS prediction was applied for phytoconstituents namely Balanocarpol, Hopeaphenol and Ampelopsin H isolated from this plant.

Among the all extracts, MEHO exhibited strong antioxidant activity in both reducing power and H₂O₂ scavenging assay. Phenol content of MEHO was 297.22 ± 0.78 mg/g and flavonol content was 91.53 ± 1.82 mg/g. All the experiment of extracts at dose of 200 and 400 mg/kg and the standard drug loperamide (5 mg/kg) showed significant (p < 0.001) inhibition against castor oil induced diarrhea and castor oil induced enteropooling in mice. There were also significant (p < 0.01) reduction in gastrointestinal motility in the charcoal meal test. Leaf extract showed no significant (P < 0.01) decrease of blood glucose compared to Glibenclamide in normoglycemic mice. Using an in vitro thrombolytic model, MEHO showed the highest and significant clot lysis of human and mice blood compared to Streptokinase. PASS predicted the wide range of antioxidant, free radical scavenger, Nitric oxide scavenger, cardioprotectant, hepatoprotectant, thrombolytic, fibrinolytic, antibacterial, antifungal, anticarcinogenic, anthelmintic and anti-inflammatory activity of examined phytoconstituents.

These findings suggest that the plant may be a potential source of new antidiarrheal, thrombolytic and antioxidative agents but it is found to have no antidiabetic capability. PASS prediction matched with present study for the extracts. Further study needs to identify the PASS predicted biological actions of the phytoconstituents.