PROTECTIVE EFFECT OF SAPONIN EXTRACT FROM LOCUST BEANS (Parkia biglobosa) IN TRITON-WR-1339-INDUCED HYPERLIPIDEMIC RATS

Abstract

The present study was conducted to investigate the serum lipid-lowering activities of saponin isolated from crude methanolic extract of Parkia biglobosa leaves in Triton-WR-1339 induced hyperlipidemia using thirty-six (36) albino rats. The crude methanolic extract was screened for phytochemicals while saponin was isolated by subjecting the crude methanolic extract to n-hexane and then n-butanol extractions. Thin layer Chromatography of both the crude and the isolate was run. A total of 36 male Wistar albino rats (180-250 g), divided into 6 groups of 6 animals each were used for the bioassay. While the control (group 1) was given normal saline orally for the duration of the experiment (4 days), group 2 was given Triton-WR-1339 (350 mg/kg) intraperitoneally on the 4th day in addition to the daily administration of normal saline to serve as the induced group. Group 3 was daily pretreated with nicotinic acid (500 mg/kg) while groups 4 and 5 were daily pretreated with saponin (30 and 60 mg/kg) respectively prior to the intraperitoneal administration of Triton-WR-1339 (350 mg/kg) on the 4th day to group 3, 4 and 5. Group 6 received saponin (40 mg/kg) for the 4-day period. Animals were sacrificed 20 h after the last dose and the serum was analyzed for some lipid parameters. Phytochemical screening indicated that flavonoids, terpenoids, saponins, and cardiac glycosides were present while alkaloids, tannins, anthraquinones, and phlobatannins were absent in the crude methanolic extract. Triton-WR-1339 (350 mg/kg) caused significant elevation in the levels of cholesterol, triglycerides, low density lipoprotein (LDL) and the ratio of low density lipoprotein to high density lipoprotein (LDL:HDL) while there was a significant reduction in the level of HDL. These effects were countered by pretreatments with saponin (30 and 60 mg/kg) in the lipid profile; saponin appears to be more effective than the standard compound, nicotinic acid (500 mg/kg). However, saponin at the lower dosage of 30 mg/kg appears to be more effective than the higher dosage of 60 mg/kg. Hence saponin isolated from the methanolic extract of Parkia biglobosa at this dosage of 30 mg/kg promises to be a future good antidote against hyperlipidemia and the corresponding pathologies