Evaluation of Membrane Stabilizing, Thrombolytic, Anti-Diarrheal and Antipyretic Activities of Ethanolic Extracts of Hoya Parasitica variegata and Crotalaria pallida Aiton

Hoya parasitica Variegata (Apocynaceae) and Crotalaria pallida Aiton (Fabaceae)are traditionally used to treat pain, fever, and urinary disorders, but scientific1reports are limited or lacking on their antipyretic, antidiarrheal, thrombolytic, and membrane-stabilizing activities. The study evaluated the membrane-stabilizing, thrombolytic, anti-diarrheal, and antipyretic activities of crude extracts from H. parasitica and C. pallida using various animal models. In the in vitro thrombolytic test, assessing clot lysis, the extracts of H. parasitica and C. pallida showed thrombolytic activity with clot lysis of 75.93% and 73.64%, respectively, compared to streptokinase, which achieved 85.17% clot lysis. In the hypotonic buffer-induced hemolysis test, the ethanolic extracts of H. parasitica and C. pallida inhibited hemolysis of red blood cells (RBC) by 64.53%and 68.23%, respectively, which is close to the inhibition rate of acetyl salicylic acid (79.68%). Similarly, in the heat-induced hemolysis test, the extracts inhibited RBC hemolysis by 62.89% and 68.14%, compared to the 74.49% inhibition observed with acetyl salicylic acid. In the castor oil-induced diarrhea, the ethanolic extracts of H. parasitica and C. pallida leaves at doses of 100,150, and 200 mg/kg body weight significantly (P<0.05) reduced the number of diarrheal faeces compared to the negative control. Additionally, in the brewer's yeast-induced pyrexia test, these extracts at the same doses elevated temperatures in mice in a dose-dependent manner, with significant (P<0.05) reductions observed at the 21st, 22nd, and 23rd hours of treatment. These results indicate that the ethanol extracts of H. parasitica and C. pallida exhibit notable thrombolytic, membrane-stabilizing, anti-diarrheal, and antipyretic properties.