Propoxur-induced oxidative DNA damage in human peripheral blood mononuclear cells: protective effects of curcumin and α-tocopherol

Pesticides: An alarming detrimental to health and environment

Pesticides are chemical substances of natural or synthetic origin that are used to eradicate pests and insects. These are indispensable in the agricultural processes for better crop production. Pesticide use aims to promote crop yield and protect the crops from diseases and damage. Pesticides must be handled carefully and disposed of appropriately because they are dangerous to people and other species by default. Environmental pollution occurs when pesticide contamination spreads away from the intended plants. Older pesticides such as lindane and dichlorodiphenyltrichloroethane (DDT) may remain in water and soil for a longer time. These accumulate in various parts of the food chain and cause damage to the ecosystem. Biological techniques in the management of pest control such as importation, augmentation, and conservation, and the accompanying procedures are more efficient, less expensive, and ecologically sound than other ways. This review mainly focuses on the consequences on the targeted and non-targeted organisms including the health and well-being of humans by the use of pesticides and their toxicity. The side effects that occur when a pesticide's LD50 exceeds the accepted limit through oral or skin penetration due to their binding to various receptors such as estrogen receptors, GABA, EGFR, and others. These pesticide classes include carbamates, pyrethroids, organochlorides, organophosphorus, and others. The current study seeks to highlight the urgent requirement for a novel agricultural concept that includes a major reduction in the use of chemical pesticides.

Vitamin E and conflicting understandings in noncommunicable diseases: Is it worth supplementing?

Vitamin E is a lipid-soluble nutrient found mainly in vegetable oils and oilseeds. It is divided into eight homologous compounds; however, only α-tocopherol exhibits vitamin activity. Many advantages are related to these compounds, including cellular protection through antioxidant and anti-inflammatory activity, and improving lipid metabolism. Physiopathology of many diseases incepts with reduced antioxidant defense, characterized by an increased reactive oxygen species production and activation of transcription factors involved in inflammation, such as nuclear factor-kappa B (NF-κB), that can be linked to oxidative stress. Moreover, disorders of lipid metabolism can increase the risk of cardiovascular diseases. In addition, intestinal dysbiosis plays a vital role in developing chronic non-communicable diseases. In this regard, vitamin E can be considered to mitigate those disorders, but data still needs to be more conclusive. This narrative review aims to elucidate the mechanisms of action of vitamin E and if supplementation can be beneficial in a disease scenario regarding non-communicable diseases.

A symbiotic gut bacterium enhances Aedes albopictus resistance to insecticide

BACKGROUND

The increasing insecticide resistance of Aedes albopictus puts many countries in Asia and Africa, including China, at great risk of a mosquito-borne virus epidemic. To date, a growing number of researches have focused on the relationship between intestinal symbiotic bacteria and their hosts' resistance to insecticides. This provides a novel aspect to the study of resistant mechanisms.

METHODS/FINDINGS

This study reveals significant composition and dynamic changes in the intestinal symbiotic bacteria of Ae. albopictus between the resistant and susceptible strains based on full-length sequencing technology. The relative abundance of Serratia oryzae was significantly higher in the resistance strain than in the susceptible strains; also, the relative abundance of S. oryzae was significantly higher in deltamethrin-induced Ae. albopictus than in their counterpart. These suggested that S. oryzae may be involved in the development of insecticide resistance in Ae. albopictus. To explore the insecticide resistance mechanism, adult mosquitoes were fed with GFP-tagged S. oryzae, which resulted in stable bacterial enrichment in the mosquito gut without affecting the normal physiology, longevity, oviposition, and hatching rates of the host. The resistance measurements were made based on bioassays as per the WHO guidelines. The results showed that the survival rate of S. oryzae-enriched Ae. albopictus was significantly higher than the untreated mosquitoes, indicating the enhanced resistance of S. oryzae-enriched Ae. albopictus. Also, the activities of three metabolic detoxification enzymes in S. oryzae-enriched mosquitoes were increased to varying degrees. Meanwhile, the activity of extracellular enzymes released by S. oryzae was measured, but only carboxylesterase activity was detected. HPLC and UHPLC were respectively used to measure deltamethrin residue concentration and metabolite qualitative analysis, showing that the deltamethrin degradation efficiency of S. oryzae was positively correlated with time and bacterial amount. Deltamethrin was broken down into 1-Oleoyl-2-hydroxy-sn-glycero-3-PE and 2',2'-Dibromo-2'-deoxyguanosine. Transcriptome analysis revealed that 9 cytochrome P450s, 8 GSTs and 7 CarEs genes were significantly upregulated.

CONCLUSIONS

S. oryzae can be accumulated into adult Ae. albopictus by artificial feeding, which enhances deltamethrin resistance by inducing the metabolic detoxification genes and autocrine metabolic enzymes. S. oryzae is vertically transmitted in Ae. albopictus population. Importantly, S. oryzae can degrade deltamethrin in vitro, and use deltamethrin as the sole carbon source for their growths. Therefore, in the future, S. oryzae may also be commercially used to break down the residual insecticides in the farmland and lakes to protect the environment.

Methomyl-induced nephrotoxicity and protective effect of curcumin in male rats

We investigated the ameliorative effect of the curcumin against methomyl-induced potential nephrotoxicity in Wistar albino male rats. In the present study, curcumin (100 mg kg^-1 bw), methomyl (0,8 mg kg^-1 bw) and methomyl plus curcumin were given to rats by oral for 28 days (for subacute examination). Concentrations of blood urea nitrogen, uric acid and creatinine in serum and malondialdehyde level and activities of antioxidant enzyme (superoxide dismutase, catalase, glutathione peroxidase and glutathione S transferase) and histopathological alterations in kidney tissues were studied. Methomyl caused an increment in the concentrations of blood urea nitrogen, creatinine, uric acid and MDA levels. In addition, methomyl caused a diminution in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione S transferase. Tubular and glomerular degenerations occurred in the kidney tissues of methomyl-received rats. However, coadministration of curcumin with methomyl significantly minimized the adverse effects of methomyl on kidney function parameters, lipid peroxidation and antioxidant enzyme activities and histological structure of kidney tissue. The results showed that curcumin significantly mitigated methomyl-induced nephrotoxicity in rats.

The genotoxic effects of perchloroethylene in human peripheral blood lymphocytes and the possible ameliorative role of α-tocopherol

Perchloroethylene (PCE), also known as tetrachloroethylene, is a commercially important chlorinated solvent commonly used in dry cleaning, textile processing, and metal degreasing industries. According to the available studies, the potential genotoxic impacts of this chlorinated solvent on human beings are still controversial. The present work was carried out to determine the genotoxic effects of PCE on human peripheral blood lymphocytes (PBLs) using chromosome aberrations (CAs) and cytokinesis-block micronucleus (CBMN) tests. Additionally, the antigenotoxic potential of α-tocopherol (α-Toc), a well-known antioxidant agent, on human lymphocytes treated with PCE in vitro was assessed. The cells were exposed for 48 h to PCE (25, 50, 100, and 150 μg/mL) alone as well as in combination with α-Toc (100 μg/mL). The findings of the study suggested that, relative to solvent control, PCE significantly increased the structural CA and MN formation for all concentrations. However, simultaneous treatment of PCE and α-Toc caused a significant reduction of CAs and MNi as compared to cultures treated with PCE alone. Besides, the results showed that PCE has cytotoxic effects on human PBLs as indicated by the significant decrease in mitotic index (MI) and nuclear division index (NDI). Nevertheless, the co-treatment of α-Toc with PCE did not reduce the cytotoxicity of PCE at a significant level. In conclusion, it can be suggested that PCE is genotoxic and cytotoxic in human PBLs, and α-Toc has an antigenotoxic effect on PCE-induced genotoxicity but has no significant effect on the cytotoxicity triggered by PCE.