Late-onset hypogonadism(LOH) in men is a syndrome characterized by an age-related decline in testosterone levels accompanied by various clinical symptoms. Mentha suaveolens Ehrh. has been reported to exert antioxidant, anti-inflammatory, and antimicro...
Late-onset hypogonadism(LOH) in men is a syndrome characterized by an age-related decline in testosterone levels accompanied by various clinical symptoms. Mentha suaveolens Ehrh. has been reported to exert antioxidant, anti-inflammatory, and antimicrobial effects and is known to be rich in phenolic compounds. However, its influence on male reproductive function, particularly testosterone biosynthesis, remains unclear. This study aimed to evaluate the effects of Mentha suaveolens Ehrh. extract(MSE) on testosterone regulation and clinical symptoms associated with LOH using both in vitro and in vivo models. In this study, hCG stimulated TM3 cells(mouse Leydig cell line) were pretreated with MSE(50, 100, and 200 μg/mL) and subsequently exposed to H2O2 to establish an in vitro model of LOH. In vitro, MSE significantly upregulated the expression of key steroidogenic genes, including StAR and 17β-HSD3, while downregulating CYP19A1 and SRD5A2, resulting in a 1-fold and 2.67-fold increase in testosterone levels at 100 and 200 μg/mL, respectively(P<0.001). To further validate these findings, in vivo studies were subsequently performed using 34-week-old male C57BL/6 mice. In vivo models were administered low and high doses of MSE(MSE-L and MSE-H) daily for 6 weeks. After 6 weeks, the MSE-H group exhibited increased LHR expression, which enhanced LH/LHR binding. Consistent with the in vitro findings, the expression of StAR and 17β-HSD3 was also elevated. Although CYP11A1 did not show significant changes, downstream enzymes involved in testosterone synthesis(CYP17A1, 3β-HSD2, 17β-HSD3) were upregulated, leading to a significant 1.34-fold increase in serum total testosterone levels(P<0.05). Furthermore, MSE also restored skeletal muscle mass and improved grip strength(P<0.05), and the MSE-H group increased FSHR gene and protein expression, leading to a significant elevation of sperm count(P<0.05). HPLC analysis revealed that MSE contained 45.292 mg/g of rosmarinic acid, suggesting it as a major bioactive compound of MSE. Finally, these findings demonstrate that MSE enhances testosterone biosynthesis and ameliorates LOH-associated symptoms(reductions in skeletal muscle mass and reproductive dysfunction), supporting its potential as a natural therapeutic candidate for late-onset hypogonadism.