Determination of in vitro effects of aqueous extract of camellia sinensis on human sperm functions

Abstract

Infertility, defined as the inability to conceive following one year of unprotected sexual intercourse, respectively affects 25% of couples globally. Oxidative stress (OS) has been greatly related to the idiopathic cause of infertility and Camellia sinensis contains antioxidants that may enhance reproductive functions. This study focussed on the effects of Camellia sinensis (green and black tea) on human sperm functions in both normal and abnormal samples. Semen samples (n= 59) collected from donors were liquefied, analysed, and classified as normal (n=40) and abnormal (n= 19) using the WHO criteria. Samples were washed and exposed to aqueous leaf extracts of green and black tea (0, 0.4, 4, 40, 405 μg/ml) for 1 hour. Human Tubular Fluid (HTF) served as the control. The respective sperm parameters were analysed (sperm motility, vitality, DNA fragmentation, mitochondrial membrane potential (MMP), capacitation and acrosome reaction (CTC) and reactive oxygen species (ROS). Green and black tea significantly increased vitality, and intact MMP, while it significantly reduced, CTC, and intracellular ROS as well as DNA fragmented spermatozoa in both normal and abnormal samples compared to the control (p<0.05). A significant increase in sperm CTC, ROS, with a decrease in sperm vitality, and intact MMP was observed in the abnormal compared to the normal samples (p<0.05). No significant change in motility was observed between normal and abnormal samples compared to their respective controls, in both green and black tea (p>0.05). Camellia sinensis improved human sperm function in vitro and may be attributed to its antioxidant activity.