AMELIORATIVE EFFECT OF HIBISCUS SABDARIFFA LINN ON SUBCHRONIC CHLORPYRIFOS-INDUCED ALTERATIONS IN SEX AND THYROID HORMONES IN MALE WISTAR RATS

Abstract

Studies have shown that Chlorpyrifos (CPF), an Organophosphate (OP) insecticide alters both sex and thyroid hormones. Apart from inhibiting Acetylcholinesterase (AChE) activity, CPF has been shown to cause oxidative stress. The antioxidant potentials of many flavonoid-containing plants are increasingly being exploited in the therapy of many infectious and non-infectious diseases. Hibiscus Sabdariffa (HS) is one of the most widely used nutraceuticals that has been used traditionally to combat various illnesses due to its high flavonoid contents. The present study was therefore aimed at evaluating the ameliorative potentials of HS on subchronic chlorpyrifos-evoked alterations in sex and thyroid hormones in male Wistar rats. Forty-two (42) young adult male Wistar rats were divided at random into six groups containing seven (7) rats per group. Group I was administered distilled water (2 mL kg^-1) only while group II received soya oil (2 mL kg^-1), Group III was dosed with only aqueous extract of HS (500 mL kg^-1 ~ 1/10^th of the LD₅₀), while group IV was given CPF (10.6 mL kg^-1 ~ 1/8^th of the LD₅₀). Group V was pretreated with low dose of HS (250 mg kg^-1 ~ 1/20^th of the LD₅₀) and then administered reconstituted CPF (10.6 mg kg^-1), 30 min later. Group VI was pretreated with high dose of the HS (500 mg kg^-1) and then administered CPF (10.6 mg kg^-1), 30 min later. The regimens were administered orally by gavage once daily for a period of 11 weeks. At the end of the treatment period, sera obtained from the blood samples were analyzed for the levels of Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH), testosterone, thyroid hormones (T₃, T₄ and TSH) and AChE. Thyroid and pituitary glands of each rat were also evaluated for Malondialdehyde (MDA) concentration. Results showed a non-significant (p>0.05) decrease in the concentrations of FSH, LH and testosterone in the CPF group relative to the other groups. There was significant decrease (p<0.05) in the concentrations of T₃, T₄ and an increase in TSH in the CPF group relative to the other groups. There were significant increases (p<0.05) in MDA concentrations in the thyroid and pituitary glands in the CPF group compared to the other groups. Pretreatment with aqueous extract of HS demonstrated a dose-dependent amelioration of CPF-induced alterations in the levels of testosterone, LH, FSH, AChE, T₃, T₄ and TSH in the serum and that of pituitary and thyroid glands MDA. This may be partly due to its high level of polyphenolic compounds that confer its antioxidant and possibly AChE restoration activities. It is therefore concluded that pretreatment of individuals who are occupationally exposed to CPF and probably other OPs with the extract of HS may result in protection from the insecticide-induced adverse reproductive health outcomes.