Abstract

5-Isopropyl-2-methylphenol, a monoterpene found in essential oils from various plants, has been shown to have anti-inflammatory, antioxidant, vasorelaxant, and hypotensive effects. The current study looked at the effects of 5-isopropyl-2-methylphenol on male hypertensive rats with erectile dysfunction. During 4 weeks, 12-week-old spontaneously hypertensive rats (SHR) were given intragastrically with saline, 5-Isopropyl-2-methylphenol (50 or 100 mg/kg/day), or sildenafil (1.5 mg/kg/day). Wistar Kyoto rats were utilized as normotensive controls. All the drugs examined throughout the treatment period lowered systolic blood pressure. Treatments with 5-isopropyl- 2-methylphenol and sildenafil enhanced the intracavernosal pressure/mean arterial pressure ratio in hypertensive rats. The acetylcholine sodium nitroprusside-induced relaxation responses in isolated rat corpora cavernosa were considerably improved by sildenafil or 5-isopropyl-2-methylphenol treatments—treatment with 5-isopropyl- 2-methylphenol reduced hypercontractility produced by phenylephrine or electric field stimulation in corpora cavernosa SHR. The contractile response of rats treated with 5-isopropyl-2-methylphenol was not affected in the presence of tempol. The fluorescence intensity emitted by the dihydroethidium probe in rat corpora cavernosa was considerably lower in SHR-treated groups compared to SHR-control. The present study suggests that 5-isopropyl- 2-methylphenol enhances SHR erectile performance while decreasing endothelial dysfunction, smooth muscle cell hypercontractility, and superoxide anion production.

Key words: corpus cavernosum, erectile dysfunction, reactive oxygen species, SHR