Glutathione S-transferase activity and genetic polymorphisms associated with exposure to organochloride pesticides in Todos Santos, BCS, Mexico: a preliminary study

Effect of methoxychlor on liver function, lipid peroxidation, and antioxidants in experimental rats

Background

Methoxychlor (MXC), a widely used pesticide, poses significant toxicological risks to various biological systems. It is an environmental contaminant and the only organochlorine pesticide still using instead of DDT. Endocrine disruption of MXC is also under investigation.This study aimed to investigate the effects of MXC on antioxidant status, lipid peroxidation, and liver metabolism in experimental rats.

Methods

Male Wistar rats were divided into control and treatment groups, with the latter receiving 150 mg/kg and 250 mg/kg body weight (BW) of MXC via oral administration for 30 days. Liver function was assessed by measuring circulating biomarkers, including Alanine Transaminase (ALT), Aspartate Transaminase (AST), and Alkaline Phosphatase (ALP). Oxidative damage was evaluated by determining Thiobarbituric Acid Reactive Substances (TBARS), hydroperoxide (HYP), and other lipid peroxidation markers. Key enzymes involved in antioxidant defense mechanisms were also analyzed in the liver of experimental animals.

Results

Our results demonstrated a significant increase in ALT, AST, and ALP levels in the serum of rats exposed to MXC, indicating impaired liver function. This was accompanied by elevated lipid peroxidation, further emphasizing oxidative stress. Moreover, the activities of antioxidant enzymes such as SOD, GPx, and CAT were markedly reduced in the MXC-exposed groups compared to the controls, suggesting a compromised antioxidant defense system.

Conclusion

These findings suggest that methoxychlor exposure disrupts liver function and induces oxidative stress by enhancing lipid peroxidation, thereby depleting natural antioxidant defenses. This study highlights the potential hepatotoxic effects of methoxychlor and underscores the role of oxidative stress in mediating its toxicity.

GLYPHOSATE IMPACT on human health and the environment: Sustainable alternatives to replace it in Mexico

Glyphosate is a broad-spectrum, non-selective herbicide used to control weeds and protect agricultural crops, and it is classified as potentially carcinogenic by the International Agency for Research on Cancer. In Mexico, the use of pesticides is a common practice, including glyphosate. However, on December 31st, 2020, the Mexican government decreed the prohibition of this herbicide as of January 2024. In this review, we investigate the association between glyphosate and cancer risk and found that most of the studies focused using animals showing negative effects such as genotoxicity, cytotoxicity and neurotoxicity, some studies used cancer cell lines showing proliferative effects due to glyphosate exposure. To our knowledge, in Mexico, there are no scientific reports on the association of glyphosate with any type of cancer. In addition, we reviewed the toxicological effects of the herbicide glyphosate, and the specific case of the current situation of the use and environmental damage of this herbicide in Mexico. We found that few studies have been published on glyphosate, and that the largest number of publications are from the International Agency for Research on Cancer classification to date. Additionally, we provide data on glyphosate stimulation at low doses as a biostimulant in crops and analytical monitoring techniques for the detection of glyphosates in different matrices. Finally, we have tried to summarize the actions of the Mexican government to seek sustainable alternatives and replace the use of glyphosate, to obtain food free of this herbicide and take care of the health of the population and the environment.

Dietary transference of 17α-ethinylestradiol changes the biochemical and behavioral biomarkers in adult zebrafish (Danio rerio)

The endocrine disruptors (ED), even in low concentration, can change the homeostasis of an organism through the biochemical and physiological pathways; and are gaining more relevance due to their well-reported presence in the natural environment. EDs mainly affect non-target animals, which can bioaccumulate, leading to changes in metabolism. Another problem is due to several organisms that compose the aquatic biota serving as a basis of the food chain and transferring it to higher trophic levels. Here we evaluated the dietary transference of 17α-ethinylestradiol (EE2), in adult zebrafish chronically fed by EE2-bioaccumulated brine shrimp (BS). For this, we evaluated behavioral biomarkers such as the novel tank test (NTT), social preference test (SPT), mirror-induced aggressivity (MIA), and biochemical biomarkers such as acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CTL), and glutathione-S-transferase (GST) activity, cortisol, and lipid peroxidation levels in adult zebrafish. The behavioral effects can be explained by the changed effects on acetylcholinesterase activity as well as in the antioxidant system mainly affected by the high levels of EE2 identified by HPLC shown that had occurred during a dietary transfer for fish. EE2 has a potential pattern for bioaccumulation and dietary transfer in biological tissue and EE2 can affect the behavior of fish. The observed effects could be dangerous to the environment, affecting, other animals and even human health.