Researchers conducted a systematic review of studies on the effects of natural products and dietary supplements on aflatoxin-Induced nephropathy, or kidney failure. They found that the antioxidant effects of these products could improve the management of kidney disease associated with aflatoxin exposure.
“The natural products and dietary supplements mentioned in this review may reverse the effects of AFB1 on kidney function,” wrote the researchers in International Journal of Molecular Sciences.
The dangers of aflatoxins
There are six types of aflatoxins, and aflatoxin B1 (AFB1) is the most carcinogenic. Enzymes in the liver metabolise AFB1 to the carcinogen aflatoxin B1-8,9-epoxide, which ultimately leads to cancerous effects.
AFB1 can also be converted to aflatoxin M1 (AFM1), which can be detected in dairy products from animals that have consumed food contaminated with AFB1. In addition, contamination of food or poultry feed with fungal toxins reduces poultry safety and quality, putting consumers at risk and causing a huge economic loss at the industrial level. The International Agency for Research on Cancer (IARC) has classified AFB1 and AFM1 as group 1 and group 2B human carcinogens, respectively. Hence, chronic aflatoxin toxicity is a global problem.
Aflatoxins are highly toxic metabolites that occur naturally and are estimated to contaminate 25% of cereals worldwide. Under optimum temperature conditions of between 24–27 °C and humidity levels above 62%, fungi can grow and produce aflatoxin on all agricultural commodities. The degree of contamination varies depending on geographical location, food storage procedures, and processing methods. It is abundant in developing countries where safety regulations for agricultural commodities are often ignored.
Additionally, oxidative stress is associated with the progression of kidney disease. Research has demonstrated that oxidative stress is a critical risk factor for aflatoxin toxicity, and that exposure to aflatoxin leads to oxidative stress-induced kidney injury.
“As a result, reducing oxidative stress is emphasised as a useful way to treat aflatoxin nephrotoxicity,” said the researchers.
Nephrotoxicity is kidney damage caused by a drug, chemical or toxin, resulting in possible chronic kidney disease.
Despite significant advancements in kidney disease treatment, effective medications remain few. The high cost of medication, along with the severe side effects, has led to the search for natural remedies, particularly those produced from plants and spices.
Research on natural remedies for renal disease prevention and treatment has gained popularity due to their antioxidant and anti-inflammatory properties, which can alleviate toxin-induced nephrotoxicity and prevent tissue damage. However, researchers and medical professionals have not fully understood how these therapies work because they affect many different parts of the body in various ways.
Therefore, the researchers wanted to analyse how some natural products and dietary supplements could be used to treat aflatoxin-induced nephrotoxicity.
The study
Articles published in the last decade (from 2010 to 2023) were searched in electronic databases such as PubMed, Google Scholar, and Embase.
"The literature suggests that natural remedies may reduce AFB1-induced toxicity by increasing antioxidant and anti-inflammatory capabilities and modulating gene expression of detoxifying enzymes, thereby limiting toxicity and tissue damage,” said the researchers.
Natural products and dietary supplements are also important in aflatoxin research because of their antioxidant properties and their role in producing glutathione. Glutathione binds to harmful aflatoxin compounds such as aflatoxin-8,9 epoxide, preventing them from damaging DNA, which is a key detoxification process.
“This implies that the primary approach to ameliorate the harmful aflatoxin-8,9 epoxide is to increase the levels of intrinsic antioxidants,” said the researchers.
The researchers also observed antioxidant effects of natural products such as gallic acid, caffeic acid, apigenin, and 3-indole propionic acid, against AFB1-induced hepato-renal effects. Other natural products and dietary supplements that contain ingredients with antioxidant effects – such as curcumin, resveratrol, diosmin, morin, esculin, fucoidans, selenomethionine, vitamin E, and lycopene, as well as some herbal formulations and probiotics – have also been found to lessen AFB1-induced kidney damage.
Previous clinical studies have demonstrated that natural products and dietary supplements possess antioxidant properties that could help manage chronic kidney disease in patients. Research on animals has confirmed their effectiveness in, for example, reducing kidney cell death, DNA damage, and enhancing cellular antioxidants.
While the researchers acknowledged that further studies are needed to understand exactly how the natural products and dietary supplements work at the molecular level, they concluded that the information provided in this review may improve the management of kidney disease associated with mycotoxins, which is the broader category of fungal toxins that includes aflatoxins.
“This study has so far highlighted some active compounds, crude extracts, herbal formulations, and probiotics with various bioactive ingredients against aflatoxin-induced renal dysfunction and illuminated their mechanisms of action in both in vitro and in vivo studies, which could be further explored. The natural products and dietary supplements mentioned in this review target renal oxidative stress, inflammation, tissue damage, and kidney function markers induced by aflatoxin, and could be considered in wide experimental studies for the prevention of renal damage induced by fungal toxins and other nephrotoxic agents,” said the researchers.
Source: International Journal of Molecular Sciences
“Therapeutic Effect of Natural Products and Dietary Supplements on Aflatoxin-Induced Nephropathy”
Authors: Ebenezer Ofori-Attah, Mai Hashimoto et al.