Aqueous Hypoestes rosea Leaf extract Ameliorates Lead-Acetate-Induced Thyroid Hormones Disruption in Albino Wistar Rats

Abstract

Aim: To evaluate the effect of aqueous extract of Hypoestes rosea (AEHR) leaf extract on thyroid hormones in lead-acetate-induced Albino Rats. Study design: Experimental study. Place and Duration of Study: Department of Pharmacology, University of Port Harcourt and Department of Chemical Pathology, University of Port Harcourt, between October, 2019 and March, 2020. Methodology: A total of 140 albino Wistar rats were used for the study. The animals were divided into 26 groups (6 post-treatment and 6 pre-treatment groups for female rats and the same number for male rats). Each group contained 5 rats for both sexes in both pre- and post-treatments groups, except the positive control groups that had 10 animals for both sexes. The study was carried out for 21 days in each sex. The negative control groups received rat feed only, the extract control (EC) group received 100mg/kg bwt/day for 21 days, the positive control (PC) group received 60mg/kg b.wt per day of lead acetate for 7 days. The other 3 groups received 100mgkg, 200mg/kg and 300mg/kg b.wt respectively for 14 days either as pre-treatment or post treatment, for both sexes of the albino rats. At the end of the experimental periods, the rats were sacrificed under chloroform anaesthesia and samples were taken through the jugular vein. Thyroid hormone levels (thyroid stimulating hormone (TSH), tri-iodothyronine (T3) and tetra-iodothyronine (T4)) were estimated using the Enzyme linked immunosorbent assay methods. Statistical analysis was done using Statistical Analysis System (SAS), STAT 15.1 and p values less than 0.05 were considered statistically significant. Results: The results showed that the administration of lead acetate in male and female rats caused significant (p<0.05) fall in the levels of TSH, fT3 and fT4. The plant in a dose dependent pattern was able to significantly (p<0.05), reverse the effect of lead acetate in the post treatment phase and also protect the endocrine system from the deleterious effect of lead acetate in the pre-treatment phase. Conclusion: This study shows that the consumption of AEHR by albino rats could help protect the endocrine system against endocrine disruptors.