Effects of Heavy Metals and Pesticides on Buffalo (Bubalus bubalis) Spermatozoa Functions In Vitro

Abstract

Industrial toxic metals, pollutants and bio-accumulative pesticides interfere with the male reproductive functions in farm animals. Frozen-thawed semen samples were incubated with heavy metals (cadmium and lead) and pesticides (chlorpyrifos and endosulfan) of different concentrations (0, 0.005, 0.05, 0.02, 0.1, 0.5, 1.0, 2.0 and 4.0 μg/ml) for 1 h, and various spermatozoa functional parameters and in vitro fertilization rates were assessed. Any significant effect was assessed by comparing the 1 h data between the control and treatment groups. Progressive forward motility was significantly (p < 0.05) reduced in spermatozoa exposed to lower concentrations (0.05-0.5 μg/ml) of toxic substances. The straight-line velocity (μm/s) and the average path velocity (μm/s) were significantly (p < 0.05) reduced in spermatozoa exposed to 1.0 and 0.5 μg/ml of cadmium (11.6 ± 1.9 and 16.3 ± 1.9) and chlorpyrifos (10.4 ± 1.5 and 17.1 ± 1.3), respectively, when compared to control (20.4 ± 1.4 and 28.1 ± 1.7). The acrosomal integrity was also significantly (p < 0.05) reduced at 0.05 μg/ml of chlorpyrifos (33.3 ± 1.9), 1.0 μg/ml of cadmium (36.8 ± 3.7), 1.0 μg/ml of lead (39.4 ± 2.8) and 0.5 μg/ml of endosulfan (38.3 ± 3.2), respectively. The spermatozoa chromatin decondensation was significantly (p < 0.05) affected at higher concentrations (>0.5 μg/ml) of these chemicals. The mitochondrial membrane potential (%) was significantly (p < 0.05) reduced at 0.05 μg/ml of cadmium (3.2 ± 0.2) and chlorpyrifos (4.3 ± 0.4), 0.1 μg/ml of lead (3.8 ± 0.3) and 0.5 μg/ml of endosulfan (3.2 ± 0.3) when compared to control (6.7 ± 1.0). The in vitro fertilization capabilities (cleavage percentage) of spermatozoa were significantly reduced at 1.0 μg/ml of cadmium (28.3 ± 2.4) and 2.0 μg/ml of lead (31.1 ± 2.7), chlorpyrifos (29.4 ± 2.2) and endosulfan (32.6 ± 2.5) when compared to control (59.4 ± 4.4). This study suggested that the mitochondrial membrane potential was primarily affected even with lowest doses of toxic chemicals. Cadmium when compared to lead and chlorpyrifos when compared to endosulfan were found to be more toxic to the spermatozoa.

In vitro exposure to CPF affects bovine sperm epigenetic gene methylation pattern and the ability of sperm to support fertilization and embryo development

“…In this study, we have investigated the effects of in vitro exposure to CPF on various functional parameters of bovine spermatozoa (Moce and Graham, ) and examined the possible causes of the alterations observed. Results revealed a significant correlation between in vitro exposure of spermatozoa to CPF and adverse effects on total and progressive motility which are in agreement with sperm reported in humans, bovines and rats (Salazar‐Arredondo et al, ; Selvaraju et al, ; Alaa‐Eldin et al, ).…”

“…In recent years, studies have repeatedly reported that environmental pollutants interfere at different levels with the physiology of organisms, inducing alterations in development and reproduction (Salazar‐Aredondo et al, ; Capriglione et al, ; Perry et al, ; ACOG, ; Tussellino et al, ; Pallotta et al, ). Overexposure to chemical agents, heavy metals and pesticides, present in the environment or introduced into the bodies by feeding, has been demonstrated to reduce sperm quality, acting on spermatozoa counts and lowering percentages of normal mammalian sperm (Selvaraju et al, ; Ebadi Manas, ; Chiu et al, ).…”

“…The high surface area to volume ratio (approximately 50:1) render sperm highly susceptible to the negative effects of pollutants that can impair sperm count, motility, morphology, and fertilization rates (Salazar-Arredondo et al, 2008;Selvaraju et al, 2011;Alaa-Eldin et al, 2017).…”

“…Organophosphorus pesticides (OPs) are among the more commonly found pollutants in human body fluids. Although, OPs are known for their neurotoxic effects through inhibition of acetylcholinesterase (AChE) (Del Pino et al, 2015;Pallotta et al, 2017), recent evidence indicate that they also exert adverse effects upon the mammalian male reproductive system (Selvaraju et al, 2011;Dhanuskae and Peiris, 2017).…”

Protecting Role of Selenium on the Cytotoxic Effect of Profenofos on Rabbit Fertility

“…The presence of pesticide residues in the fluids surrounding spermatozoa have negative influence on sperm quality (Ghuman et al ,2013) as well as alter spermatozoa chromatin and DNA structure and fertilization competence (SalazarArredondo et al ,2008). These pesticides caused spermatozoa dysfunctions due to their cumulative GroupIII(profenofos+selenium)(n=6) ng/ml effect or their chronic exposure (Selvaraju et al, 2011). Exposure to OPI may cause endocrine changes both directly (as hormone agonists or antagonists) and indirectly (altering circulating levels of hormones by influencing rates of hormone synthesis or metabolism), which can severely affect steroid hormone actions (Moustafa et al, 2007).…”