Medicinal plants have been used to cure diseases for thousands of years, including to treat male reproductive problems such as male infertility, impotence, etc. Their utilization in treating various ailments has grown in popularity within the last decade. Several plants such as Chlorophytum borivilianum, Turnera diffusa, Smilax china, and Eurycoma longifolia have been claimed to have beneficial effects in combating andrological problems. This chapter addresses the beneficial effects of these selected medicinal plants in treating male reproductive problems, including abnormal sperm parameters, deranged male reproductive hormones' profile, and male reproductive senescence as well as their roles as potential male contraceptives. This chapter also provides a quick overview and a detailed evaluation of these natural herbs and their potential benefits on men's health as well as their use as herbal components in assisted reproduction.
TopIntroduction
The male reproductive system is a complex network of organs and structures that work together to facilitate spermatogenesis, steroidogenesis, and the delivery of sperm for fertilization (Obukohwo et al., 2021). It includes external organs such as the penis and scrotum, as well as internal organs like the testes, epididymis, vas deferens, prostate gland, seminal vesicles, bulbourethral glands, and ejaculatory duct (Sajjad et al., 2018). These organs are essential for maintaining male reproductive health and function.
Spermatogenesis is the process of producing mature spermatozoa from primordial germ cells. These germ cells migrate to the gonads during embryogenesis and develop into spermatogonia, which remain inactive until adolescence (Shalet, 2009). Puberty triggers spermatogenesis through increased levels of gonadotropins and testosterone. Hormones like androgen, estrogen, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) play vital roles in regulating this process. Spermatogenesis involves mitosis, meiosis, and spermiogenesis. Mitosis divides diploid spermatogonia, ensuring a continuous supply of germ cells. Meiosis I and II transform primary spermatocytes into haploid secondary spermatocytes and then spermatids (Shalet, 2009). Spermiogenesis is the maturation of spermatids into functional spermatozoa. Disruptions to spermatogenesis can lead to male infertility and impact reproductive capacity.
Male infertility is a prevalent issue worldwide, affecting a significant number of couples of reproductive ages. According to the World Health Organization (WHO), male factor infertility accounts for approximately 20-30% of all infertility cases. The global prevalence of male infertility is estimated to be around 8%, although rates can vary across different countries and populations (Agarwal et al., 2021). Various factors contribute to male infertility, including defects in spermatogenesis, abnormalities in semen parameters, sperm morphology abnormalities, oxidative stress and DNA damage, genetic factors, and lifestyle choices (Sengupta & Cho, 2019). Spermatogenesis defects can occur due to genetic mutations, hormonal imbalances, or disruptions in signaling pathways involved in sperm development and maturation. Semen abnormalities, such as reduced sperm concentration or poor sperm motility, can be caused by abnormalities in the testicular environment, impaired sperm production, or blockages in reproductive ducts. Structural abnormalities, impaired energy production, or disruptions in signaling pathways can lead to defects in sperm motility and function. Genetic factors, including chromosomal abnormalities and gene mutations, can also contribute to male infertility. Oxidative stress, characterized by an imbalance between reactive oxygen species (ROS) and antioxidant defenses, plays a significant role in male infertility (Dutta et al., 2021). ROS can damage sperm cells, affecting their viability, motility, and DNA integrity. Inflammation resulting from oxidative stress further exacerbates reproductive dysfunction. Genetic abnormalities, lifestyle factors such as smoking, alcohol consumption, drug abuse, obesity, and exposure to environmental toxins also contribute to male infertility by impairing sperm production, quality, and function. Besides, diabetes mellitus (DM) and obesity negatively impact testicular health, leading to testicular cell degeneration, disrupted glucose metabolism in Sertoli cells, impaired blood-testis barrier, Leydig cell dysfunction (including testosterone production and secretion), and issues with ejaculation and male libido (Leslie et al., 2023). These effects are associated with increased inflammation and oxidative damage due to long-term hyperglycemia (Leslie et al., 2023).