Acute aflatoxin B1-induced gastro-duodenal and hepatic oxidative damage is preceded by time-dependent hyperlactatemia in rats

Antioxidant, anti-inflammatory, and anti-apoptotic effects of genkwanin against aflatoxin B1-induced testicular toxicity

Aflatoxin B1 (AFB1) is the most hazardous aflatoxin that causes significant damage to the male reproductive system. Genkwanin (GNK) is a bioactive flavonoid that shows antioxidant and anti-inflammatory potential. Therefore, the current study was planned to evaluate the effects of GNK against AFB1-induced testicular toxicity. Forty-eight male rats were distributed into four groups (n = 12 rats). AFB1 (50 μg/kg) and GNK (20 mg/kg) were administered to the rats for eight weeks. Results of the current study revealed that AFB1 exposure induced adverse effects on the Nrf2/Keap1 pathway and reduced the expressions and activities of antioxidant enzymes. Additionally, it increased the levels of oxidative stress markers. Furthermore, expressions of steroidogenic enzymes were down-regulated by AFB1 intoxication. Besides, AFB1 exposure reduced the levels of gonadotropins and plasma testosterone, which subsequently reduced the epididymal sperm count, motility, and hypo-osmotic swelled (HOS) sperms, while increasing the number of dead sperms and causing morphological anomalies of the head, midpiece, and tail of the sperms. In addition, AFB1 decreased the activities of testicular function marker enzymes and the levels of inflammatory markers. Moreover, it severely affected the apoptotic profile by up-regulating the expressions of Bax and Casp3, while down-regulating the Bcl2 expression. Besides, AFB1 significantly damaged the histoarchitecture of testicular tissues. However, GNK treatment reversed all the AFB1-induced damages in the rats. Taken together, the current study reports the potential use of GNK as a therapeutic agent to prevent AFB1-induced testicular toxicity due to its antioxidant, anti-inflammatory, and anti-apoptotic properties.

Acute aflatoxin B1-induced hepatic and cardiac oxidative damage in rats: Ameliorative effects of morin

Aflatoxins (AFs) are secondary metabolites produced by the fungus Aspergillus flavus, of which Aflatoxin-B1 (AFB1) appears to be the most cancerogenic and of the highest toxicity. AFB1 causes serious effects on several organs including the liver. Morin is a flavonol that exists in many fruits and plants and has diverse biological properties including anticancer, anti-atherosclerotic, antioxidant, anti-inflammatory, immunomodulatory, and multi-organ protective activities. The present study aims to evaluate the potential protective effects of morin against acute AFB1-induced hepatic and cardiac toxicity in rats. Forty rats were divided into five groups (n = 8) as follows: control received the vehicle, morin was orally administered 30/mg/kg body weight (MRN30), the AFB1 was administered orally at a dose of 2.5 mg/kg, twice on days 12 and 14 of the experiment for the 3rd, 4th, and 5th groups., AFB1-MRN15 was orally given morin at a dose of 15 mg/kg body weight, and AFB1-MRN30 orally received morin at 30 mg/kg body weight. The results indicated a significant decrease in serum AST, ALP, LDH, GGT, CK, CK-MB, 8-OHdG, IL-1β, IL-6, TNF-a levels in MRN30 compared to AFB1, and AFB1-MRN15 groups. However, the results indicated non-significant differences in the serum levels between MRN30, control, and AFB1-MRN30 groups. Meanwhile, regarding the hepatic and cardiac parameters, there were significant differences in the levels of MDA, NO, GSH, GSH-Px, SOD, and CAT in MRN30 compared to AFB1, and AFB1-MRN15 groups, overall implying the protective effects of morin. To conclude, morin at a dose of 30 mg/kg b. wt. showed significant enhancements in acute AFB1-induced hepatic and cardiac toxicity in rats, which could play a role in limiting the public health hazards of AFs.

Environmental Pollutants, Mucosal Barriers, and Pathogen Susceptibility; The Case for Aflatoxin B1 as a Risk Factor for HIV Transmission and Pathogenesis

HIV transmission risk is dependent on the infectivity of the HIV+ partner and personal susceptibility risk factors of the HIV- partner. The mucosal barrier, as the internal gatekeeper between environment and self, concentrates and modulates the internalization of ingested pathogens and pollutants. In this review, we summarize the localized effects of HIV and dietary toxin aflatoxin B1 (AFB1), a common pollutant in high HIV burden regions, e.g., at the mucosal barrier, and evidence for pollutant-viral interactions. We compiled literature on HIV and AFB1 geographic occurrences, mechanisms of action, related co-exposures, personal risk factors, and HIV key determinants of health. AFB1 exposure and HIV sexual transmission hotspots geographically co-localize in many low-income countries. AFB1 distributes to sexual mucosal tissues generating inflammation, microbiome changes and a reduction of mucosal barrier integrity, effects that are risk factors for increasing HIV susceptibility. AFB1 exposure has a positive correlation to HIV viral load, a risk factor for increasing the infectivity of the HIV+ partner. The AFB1 exposure and metabolism generates inflammation that recruits HIV susceptible cells and generates chemokine/cytokine activation in tissues exposed to HIV. Although circumstantial, the available evidence makes a compelling case for studies of AFB1 exposure as a risk factor for HIV transmission, and a modifiable new component for combination HIV prevention efforts.

Aflatoxin B1 and Aflatoxin M1 Induce Compromised Intestinal Integrity through Clathrin-Mediated Endocytosis

With the growing diversity and complexity of diet, humans are at risk of simultaneous exposure to aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1), which are well-known contaminants in dairy and other agricultural products worldwide. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. In vivo, the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth, and distribution pattern of claudin-1 and zonula occluden-1 were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that individual and combined AFB1 (0.5 and 4 μg/mL) and AFM1 (0.5 and 4 μg/mL) decreased cell viability and trans-epithelial electrical resistance values as well as increased paracellular permeability of fluorescein isothiocyanate-dextran in a dose-dependent manner. Furthermore, AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the down-regulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that these toxins are likely to have negative effects on human health.