Caffeine increased progressive motility of human spermatozoa in normozoospermic and asthenozoospermic semen samples and enhanced activity of seminal creatine kinase

How Food Choices Impact on Male Fertility

PURPOSE OF REVIEW

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting an association between nutrition and male fertility. Here, we have highlighted the impact of the various food groups on reproductive hormones and on spermatogenesis, and the effects of classical and latest dietary patterns such as Mediterranean diet, Western diet, intermittent fasting, ketogenic diet, and vegan/vegetarian diet on male fertility.

RECENT FINDINGS

Nutrients are the precursors of molecules involved in various body's reactions; therefore, their balance is essential to ensure the correct regulation of different systems including the endocrine system. Hormones are strongly influenced by the nutritional status of the individual, and their alteration can lead to dysfunctions or diseases like infertility. In addition, nutrients affect sperm production and spermatogenesis, controlling sexual development, and maintaining secondary sexual characteristics and behaviors. The consumption of fruit, vegetables, fish, processed meats, dairy products, sugars, alcohol, and caffeine importantly impact on male fertility. Among dietary patterns, the Mediterranean diet and the Western diet are most strongly associated with the quality of semen. Nutrients, dietary patterns, and hormonal levels have an impact on male infertility. Therefore, understanding how these factors interact with each other is important for strategies to improve male fertility.

In vitro exposure to environmentally relevant concentrations of norgestrel affects sperm physiology and reproductive success of the Pacific oyster Crassostrea gigas

Progestins in aquatic environments are of increasing concern, as shown by the results of toxicological studies on adult invertebrates with external fertilization. However, their potential effects on the gametes and reproductive success of such animals remain largely unknown. Thus, the current study assessed the effect of in vitro exposure of environmentally relevant concentrations (10 ng/L and 1000 ng/L) of norgestrel (NGT) on the sperm of Pacific oyster Crassostrea gigas, analyzing sperm motility, ultrastructure, mitochondrial function, ATP status, characteristic enzyme activities, and DNA integrity underlying fertilization and hatching success. The results showed that NGT increased the percentage of motile sperm by elevating intracellular Ca²⁺ levels, Ca²⁺-ATPase activity, creatine kinase activity, and ATP content. Although superoxide dismutase activity was enhanced to eliminate reactive oxygen species generated by NGT, oxidative stress occurred, as indicated by the increase in malonaldehyde content and damage to plasma membranes and DNA. As a consequence, fertilization rates decreased. However, hatching rates did not alter significantly, possibly as a result of DNA repair processes. This study demonstrates oyster sperm as a useful, sensitive tool for toxicological research of progestins and provides ecologically relevant information on reproductive disturbance in oysters resulting from exposure to NGT.

The effects of caffeine on the motility and viability of stallion spermatozoa at different temperature conditions

The purpose of this study was to evaluate the dose- and time-dependent effect of caffeine treatment on the motility and viability of stallion spermatozoa at different temperatures. Six dose groups (A to F) were established with changing caffeine concentrations (from 0.625 to 10 mg/mL). The control samples were prepared by diluting the ejaculate only with physiological salt solution. The samples were examined after 0, 1, 2 and 3 h of incubation at 5 °C and 37 °C. The motility parameters were evaluated by Computer Assisted Semen Analyzer (CASA) system, and the viability was assessed by the mitochondrial toxicity test at the end of the incubation. A positive effect of the lowest tested caffeine concentration on the motility parameters was observed throughout the incubation period at 5 °C. At the end of the 3h incubation, the viability in every sample in these groups, treated with any caffeine concentration, showed lower values compared to the control. At the higher incubation temperature (37 °C), caffeine positively affected the motility in samples B (P < 0.05) and D, E, F (P < 0.001) after 3 h of incubation; however, the viability showed a slightly decreasing tendency. Our results suggest that caffeine, in an optimal concentration, may be used as a component of stallion semen extenders.

Ranitidine decreases human sperm motility and vitality and increases the activity of seminal creatine kinase

Ranitidine (brand name: Zantac), an acid reducer, belongs to histamine-2 receptor antagonists. Since 1981, even though several adverse effects of this drug were reported in the body, still, its effects on human sperm parameters have yet to be confirmed. In this work, we attempted to measure sperm motility, sperm vitality and activity of seminal creatine kinase in the ejaculated human semen (n = 31) in the presence of ranitidine at a range of concentrations (0.1, 0.3, 0.6, 0.9 and 1.2 μg/ml) compared with control (without ranitidine). Sperm motility was measured using the Makler counter, whilst sperm vitality was assessed using the Eosin test. Creatine kinase activity was measured using the kinetic spectrophotometric method. Sperm motility (total and progressive) as well as sperm vitality was significantly (p < .05) reduced in the presence of ranitidine in human semen, particularly at the higher tested concentrations (0.6-1.2 μg/ml) compared with the control. On the other hand, creatine kinase activity was significantly increased (p < .05) in the presence of ranitidine at 0.6, 0.9 and 1.2 μg/ml. In conclusion, ranitidine at 0.6-1.2 μg/ml reduced sperm motility and vitality, but increased the activity of creatine kinase in ejaculated human semen.