Endocrine Function in Acute Triton-induced Hyperlipidaemic Rats after Being Administered Aqueous Fruit Extract of Solanum macrocarpum, alpha-Solanidine and Standard Hypolipidaemic Agents

Abstract

Experimental studies were carried out on the effect of Solanum macrocarpum, ?-Solanidine (a glycoalkaloid found in the Solanaceae), three antihyperlipidaemic drugs (nicotinic aid, simvastin and cholestyramine) on forty two (42) male rats made hyperlipidaemic by treating them with 400 mg/kg triton-X for 7 days. The rats were divided into 7 groups of 6 rats each. At 24 h, 48 h and 72h respectively, the rats in each group were humanely sacrificed and blood samples collected for endocrine function analysis which included thyroid hormones (thyroxine or T4, 3, 5, 3 – triiodothyronine or T3 and thyroid stimulating hormone or TSH), sex hormones (testosterone and 17? oestradiol) and the pancreatic hormone, insulin. Changes in T3, T4, oestradiol, testosterone and insulin were significant (p< 0.05) throughout the period of study. There was no change in the TSH values (p> 0.05) throughout the period of study. For the extract, T3 significantly increased (p< 0.05) from 0.60±0.14ng/mL to 0.65±0.13 ng/mL and then decreased to 0.55±0.21ng/mL at 24h, 48h and 72h respectively. For ?-Solanidine and the three hypolipidaemic drugs, T3 values were too small to be measured i.e. < 0.20 ng/mL. For the extract, T4 significantly increased (P< 0.05) from 3.60±0.5 µg/dL to 4.30±0.43 µg/dL and then decreased to 3.80±0.28 µg/dL at 24h, 48h and 72h respectively. For ?-solanidine and the three hypolipidaemic drugs, the T4 values at 24h were 4.00±0.00 µg/dL, whilst the values remained the same at 48h and 72h i.e. there was no change. For testosterone, oestradiol and insulin, the values of the negative control were higher than those of the positive control. For the extract, the oestradiol values significantly increased (P< 0.05) from 18.00 ±4.24 pg/mL to 19.50±4.24pg/mL, then decreased to 15.04±4.24 pg/mL at 24h, 48h and 72h respectively. For ?-solanidine and the three hypolipidaemic drugs, the values of oestradiol were too small to be measured i.e. < 5.00 pg/mL. For the extract, the testosterone level was 0.20±0.07 ng/mL at 24h, 0.20±0.00 ng/mL at 48h and < 0.20 mg/mL at 72h, i.e. the value could not be measured. For the other four agents, the level of testosterone was < 0.20 ng/mL i.e. too low to be measured. For the extract, the insulin values significantly decreased (p< 0.05) from 2.00±0.00 µU/mL to 1.00±0.00 µU/mL and <1.00 µU/mL (i.e. too low to be measured) at 24h, 48h and 72h respectively. On administration of ?-solanidine, NA, cholestyramine and simvastatin the insulin levels remained almost constant throughout the period of study. For ?-solanidine, the values were 1.50±0.00 µU/mL, 2.00±0.00 µU/mL and 2.00±0.00 µU/mL at 24h, 48h and 72h respectively. For NA, the insulin level remained at 2.00±0.00 µU/mL throughout the study period, for cholestyramine, the insulin values were 2.00±0.00 µU/mL and 1.00±0.00 µU/mL at 24h, 48h and 72h respectively whilst simvastatin had insulin values of 1.50±0.00 µU/mL, 2.00±0.00 µU/mL and 2.25±0.50 µU/mL at 24h, 48h and 72h respectively. The aqueous fruit extract of S. macrocarpum when compared to ?-solanidine, cholestyramine, simvastatin and NA under the condition of study, was probably more effective in lowering hyperlipidaemia in triton-induced hyperlipidaemic rats as the fruit is a combination of active principles whilst the other four (4) substances single entities.