Aqueous extract of Piper sarmentosum decreases atherosclerotic lesions in high cholesterolemic experimental rabbits

Background: Piper sarmentosum (P.s) has flavonoid component in its leaves which has antioxidative effect. To date, its effect on atherosclerosis has not been studied histologically. Aim: The study aimed to investigate the effect of P.s on atherosclerotic changes in hypercholesterolemic rabbits. Methods: Forty two male New Zealand white rabbits were divided into seven groups. C - control group fed normal rabbit chow, CH - cholesterol diet (1% cholesterol), W1 - 1% cholesterol with water extract of P.s (62.5 mg/kg), W2 - 1% cholesterol with water extract of P.s (125 mg/kg), W3 - 1% cholesterol with water extract of P.s (250 mg/kg), W4 - 1% cholesterol with water extract of P.s (500 mg/kg) and Smv - 1% cholesterol supplemented with simvistatin drug (1.2 mg/ kg). All rabbits were treated for 10 weeks. Following 10 weeks of supplementation, the animals were sacrificed and the aortic tissue was taken for histological study. Results: Rabbits fed only with high cholesterol diet 1% cholesterol (CH) showed focal fatty streak lesions compared to the C group and 1% cholesterol supplemented with simvistatin drug (Smv) group. Atherosclerotic lesions in the 1% cholesterol group supplemented with P.s (500 mg/ kg) i.e. W4 group showed significant reduction (30 +/- 6.0%, p < 0.05) in fatty streak compared to the high cholesterol group (85.6 +/- 4.1%) under Sudan IV stain. The atherosclerotic lesions under transmission electron microscope showed reduction in foam cells in the treatment groups compared to the CH groups. Conclusion: Administration of P.s extract has protective effect against atheroscleros