Preventing male infertility by marjoram and sage essential oils through modulating testicular lipid accumulation and androgens biosynthesis disruption in a rat model of dietary obesity

• Male infertility is mostly associated with increased occurrence of obesity.
• Obese men have poorer outcomes after medicinal treatments.
• This encouraged us to examine the effect of sage and marjoram oil extracts.
• Both oils showed marked improving effect against male infertility.
• Responsible mechanism based on preventing relevant hormonal and metabolic changes.

Obesity has been recognized as a leading cause for male infertility. This study aimed to investigate reproductive disorders caused by obesity and the possible prevention through the use of marjoram and sage oil extracts. Obesity was achieved in adult male rats by feeding high fat diet (HFD) for 12 weeks, while marjoram (0.16 ml/kg b.wt) and sage (0.05 ml/kg b.wt) oils were given orally for the same duration. HFD-fed rats exhibited marked obesity features indicated by increased adiposity index, with higher weight gain compared to control rats. This goes with increased lipid accumulation in testis and serum of the obese rats. Increased serum levels of leptin, prolactinL (PRL) and estrogen (E2), with reduced serum androgens; dehydroepiandrosterone (DHEA), testosterone (T) and T/E2 ratio were also observed. Additionally, the results showed significant reduction in epididymal sperm count, as well as in steriodogenic enzymes; 3β-hydroxysteroid dehydrogenase (3β-HSD), alkaline phosphatase (ALP), and acid phosphatase (ACP), with marked elevation in aromatase activity in testis of the obese rats. Histopathological alterations, including degenerative changes in seminiferous tubules, with sloughing, vacuolization and reduction of spermatogenic cells were also detected. Oral administration of marjoram or sage oil extracts, along with HFD seemed to prevent overall mentioned alterations, as evident by reduced testicular lipid accumulation, elevated androgens and sperm count, in addition to improved testicular structure. Results thus suggested that both oils should be considered in future therapeutic approaches for controlling adverse impact of obesity on male fertility.