Green tea (Camellia sinensis) aqueous extract improved human spermatozoa functions in vitro

Abstract

Background: Idiopathic causes of infertility is associated with oxidative stress. Antioxidants are known to scavenge the excessive production of reactive oxygen species (ROS). Green tea (Camellia sinensis) contains polyphenols that enhance its antioxidant potential.Aim: This study focused on the impact of aqueous green tea extract on normozoospermic human spermatozoa.Setting: Department of Medical Biosciences, University of the Western Cape (UWC), South Africa.Methods: Semen samples obtained using masturbation method following three to five days of sexual abstinence from consenting men (n = 59) at the University of the Western Cape (UWC) were liquefied and analysed. Normozoospermic samples were selected according to the World Health Organization (WHO) 5th guideline. Thereafter, semen samples (7.5 × 106 /mL) were washed in human tubular fluid (HTF; 10 min at 300 ×g) and exposed to aqueous extracts of green tea (0 μg/mL, 0.4 μg/mL, 4 μg/mL, 40 μg/mL, 405 μg/mL) for 1 h with various sperm parameters analyzed. Human tubular fluid supplemented with bovine serum albumin (HTF-BSA; 10%) served as control.Results: Sperm motility, reactive oxygen species production, across some reaction and deoxyribonucleic acid (DNA) fragmentation decreased significantly, particularly at the highest concentration (405 μg/mL; p 0.001). A substantial increase in the percentage of viable spermatozoa and those with intact mitochondrial membrane potential (MMP) were observed (p 0.001).Conclusion: Aqueous extract of green tea prolonged sperm viability and MMP while reducing sperm intracellular ROS production, capacitation and across some reaction and DNA fragmentation, and may be attributed to its antioxidant potential. However, a high concentration of the extract appears to be detrimental to the functioning of human spermatozoa.

Black Tea Aqueous Extracts Improve Human Sperm Functions: An In Vitro Study

“…Collection of Plant Extract and Preparation. As described by Setumo [32], an aqueous extract of black tea was prepared by infusing 2 g of the leaves in freshly boiled (100 ml) for 5 min, filtered using a vacuum filtration system, and cooled to room temperature [31]. The filtrate was freeze-dried (with an average yield of 3.60 g/l) and kept in a cool, dry place until use.…”

“…Afterwards, the World Health Organization (WHO) [34] guidelines classified the samples as normal or abnormal. A normal semen sample is defined as having sperm concentrations > 15 million/ml, progressive motility > 32%, and total motility > 40%; an abnormal semen sample is defined as having sperm concentrations < 15 × 10 6 /ml, progressive motility < 32%, and total motility < 40% [32]. For a semen sample to be classified as normal, it must meet all three criteria; otherwise, it is classified as an abnormal sample.…”

“…The washed samples were incubated with black tea aqueous extract (0.4, 4.0, 40, and 405 μg/ml) for 1 hr at 37°C. Additional sperm parameters, sperm motility, vitality, mitochondrial membrane potential (MMP), ROS production, DNA fragmentation, capacitation, and acrosome reaction, were analyzed as previously described [32,[35][36][37][38]. The control contained only HTF-BSA.…”

“…The SCA was used to assess the motility of treated sperm suspension (2 μl) on Leja slides and incubated at 37°C. Moreover, analysis was done on the following: beat cross frequency (BCF), linearity (LIN), straightness (STR), amplitude of lateral head displacement (ALH), wobble (WOB), average velocity path (VAP), velocity curve line (VCL), velocity straight line (VSL), and total motility [32,37].…”

“…The chlortetracycline fluorescence assay protocol was utilized to evaluate the capacitation and acrosome reaction [40]. Using a fluorescence microscope with a 488 nm excitation filter (Zeiss, Oberkochen, Germany), 200 spermatozoa were assessed based on the presence or absence of fluorescence and classified as acrosome reacted, capacitated acrosome intact or noncapacitated, acrosome intact cell [32,38].…”