Nicotine mediates some of the injurious effects caused by consuming tobacco products. The aim of this work is to investigate the protective effects of Mentha spicata extract (ME) supplementation on the testis and brain of nicotine-induced oxidative damage rats. ME extract showed interesting hydrogen peroxide-scavenging activity. HPLC-DAD analysis of ME revealed the presence of nine compounds among them gallic acid was the major one (165.44 µg/g ME). Thirty-two rats were randomly divided into four groups: control, a nicotine-treated group (1 mg/kg i.p.), a group receiving ME (100 mg/kg), and a group receiving both ME (100 mg/kg) and nicotine (1 mg/kg).
After 2 months of treatment, the in vivo results showed that nicotine exhibited an increase in the body, brain, testis and accessory sex organ weights, sperm count and sperm motility. In addition, exposure to nicotine significantly (p < 0.01) increased acetylcholinesterase level (AChE) in brain, lipid peroxidation level in brain and testis as compared to control group. The antioxidant enzymes results showed that nicotine treatment induced a significant decrease (p < 0.01) in brain and testis antioxidant enzymes such as catalase, superoxide dismutase and glutathione peroxidase as compared to control group. Interestingly, pretreatment with ME significantly (p < 0.01) restored the majority of these biological parameters to normal levels, as well as a histological improvement. Obtained results suggest that ME contains promising substances that counteract the nicotine-intoxication and can be efficient in the prevention of brain and testis toxicity complications.
Keywords: HPLC analysis; Mentha spicata; Nicotine; Oxidative stress; Phytochemical; Protective effect; Rats.