Astaxanthin and Docosahexaenoic Acid Reverse the Toxicity of the Maxi-K (BK) Channel Antagonist Mycotoxin Penitrem A.

Penitrem A (PA) is a food mycotoxin produced by several terrestrial and few marine Penicillium species. PA is a potent tremorgen through selective antagonism of the calcium-dependent potassium BK (Maxi-K) channels. Discovery of natural products that can prevent the toxic effects of PA is important for food safety. Astaxanthin (AST) is a marine natural xanthophyll carotenoid with documented antioxidant activity. Unlike other common antioxidants, AST can cross blood brain barriers (BBBs), inducing neuroprotective effects. Docosahexaenoic acid (DHA) is polyunsaturated ω-3 fatty acid naturally occurring in fish and algae. DHA is essential for normal neurological and cellular development. This study evaluated the protective activity of AST and DHA against PA-induced toxicity, in vitro on Schwann cells CRL-2765 and in vivo in the worm Caenorhbitidis elegans and Sprague Dawley rat models. PA inhibited the viability of Schwann cells, with an IC50 of 22.6 µM. Dose-dependent treatments with 10-100 µM DHA significantly reversed the PA toxicity at its IC50 dose, and improved the survival of Schwann cells to 70.5%-98.8%. Similarly, dose-dependent treatments with 10-20 µM AST reversed the PA toxicity at its IC50 dose and raised these cells' survival to 61.7%-70.5%. BK channel inhibition in the nematode C. elegans is associated with abnormal reversal locomotion. DHA and AST counteracted the in vivo PA BK channel antagonistic activity in the C. elegans model. Rats fed a PA-contaminated diet showed high levels of glutamate (GLU), aspartate (ASP), and gamma amino butyric acid (GABA), with observed necrosis or absence of Purkinjie neurons, typical of PA-induced neurotoxicity. Dopamine (DA), serotonin (5-HT), and norepinephrine (NE) levels were abnormal, Nitric Oxide (NO) and Malondialdehyde (MDA) levels were significantly increased, and total antioxidant capacity (TAC) level in serum and brain homogenates was significantly decreased in PA-treated rats. DHA and AST treatments effectively counteracted the toxic effects of PA and normalized most biochemical parameters in rats. DHA and AST can be useful food additives to prevent and reverse PA food-induced toxicity.

Changing pattern of hepatocellular carcinoma (HCC) and its risk factors in Egypt: possibilities for prevention.

The burden of hepatocellular carcinoma (HCC) has been increasing in Egypt with a doubling in the incidence rate in the past 10 years. This has been attributed to several biological (e.g. hepatitis B and C virus infection) and environmental factors (e.g. aflatoxin, AF). Other factors such as cigarette smoking, occupational exposure to chemicals such as pesticides, and endemic infections in the community, such as schistosomiasis, may have additional roles in the etiology or progression of the disease. Estimates of the burden of cancer caused by these factors provide an opportunity for prevention. Previously, there was strong evidence that hepatitis B virus (HBV) was the major cause of HCC in Egypt, but more recently HCV has become the predominant factor associated with the more recent epidemic of HCC. It has been well documented that Egypt has one of the highest prevalence rates of HCV infection in the world. The natural history of HCV infection and disease progression, however, are influenced by additional factors such as duration of infection, age at infection, sex, co-infection with HBV, the level of HCV viraemia and its genotype. The role of exposure to aflatoxins and development of HCC in Egypt was historically less clear. Nevertheless, recent food sampling surveys and population-based studies indicated that exposure to aflatoxins in Egypt may have been underestimated in the past. Recent results indicated that both local and imported samples were positive for aflatoxin B1 (AFB1, 17.5% and 20%, respectively), with concentrations ranging from 3 to 25 microg/kg. The level of AFB1 was dependent on the area of collection as well as the season of the year. In a population-based study, the level and frequency of aflatoxin M1 (AFM1, a major metabolite of aflatoxin B1 excreted in breast milk) was assessed as a biomarker of maternal exposure. The samples were collected from a selected group of 388 Egyptian lactating mothers during May-September 2003. Non-working status, obesity, high corn oil consumption, and the number of offspring contributed to the variability in occurrence of AFM1 in breast milk. Prevention and intervention approaches directed to risk factors of HCC can play a critical role in its prevention. In the case of HCV infection a prevention programme can be achieved by changing personal behaviors and/or cultural habits which are risk factors for HCV transmission, such as injection with contaminated syringes, blood transfusion, surgical operations, venous catheterization, use of common syringes, dental treatment and circumcision at home. Prevention of exposure to aflatoxins can be achieved either at community (via good agriculture practices) or individual levels (treatment or dietary interventions). In conclusion, due to the alarming increase in the incidence of HCC in Egypt, there is a need to further investigate the contribution of these emerging risk factors to the development of HCC in Egypt. This may enable us to determine the susceptibility to HCC among high-risk groups and to provide these individuals with effective measures for early prevention or intervention.

Efficacy of royal jelly against the oxidative stress of fumonisin in rats.

Fumonisins (FB) are mycotoxins produced by Fusarium verticillioides, frequently associated with corn. It produces toxicity, including teratogenicity, equine leukoencephalomalacia, porcine pulmonary edema, hepatic or renal damage in most animal species and perturb sphingolipid metabolism. The aim of the present study was to evaluate the protective effects of royal jelly (RJ) against FB toxicity. Sixty male Sprague-Dawley rats were divided into six treatment groups including the control group; group fed FB-contaminated diet (200mg/kg diet) and the groups treated orally with RJ (100 or 150mg/kg body weight) with or without FB for 3 weeks. FB alone decreased body weight gain, feed intake, GPX and SOD. Whereas it increased in ALT, AST, triglycerides, cholesterol, HDL, LDL, createnine and uric acid levels. Animals received FB showed severe histological and histochemical changes in liver and kidney tissues. Cotreatment with FB plus RJ resulted in a significant improvement in all the tested parameters and the histological and histochemical pictures of the liver and kidney. These improvements were pronounced in animals fed FB-contaminated diet plus the high dose of RJ. It could be concluded that RJ have a protective effects against FB toxicity and this protection was dose dependent.