Case report evidence of relationships between hepatocellular carcinoma and ochratoxicosis

Toxicogenic fungal profile, Ochratoxin A exposure and cancer risk characterization through maize (Zea mays) consumed by different age populations in the Volta region of Ghana

Maize (Zea mays) is an important staple food crop for the majority of Ghanaians. Maize is mostly contaminated by fungal species and particularly mycotoxins. This work aimed to identify and quantify the incidence of fungal infection and exposure to Ochratoxin A (OTA) as well as the health risk characterization in different age populations due to maize consumption in the Volta region. Maize samples were plated on Dichloran Rose Bengal Chloramphenicol (DRBC) agar, and Oxytetracycline Glucose Yeast Extract (OGYE) agar. All media were prepared in accordance with the manufacturers' instructions. The plates were incubated at 28 ± 2 °C for 5-7 days. High-Performance Liquid Chromatography connected to a fluorescence detector (HPLC-FLD) was used to analyze the ochratoxin A (OTA) levels in maize. Cancer risk assessments were also conducted using models prescribed by the Joint FAO/WHO Expert Committee on Additives (JECFA). The maize samples collected from the Volta region contained fungal population between the range of 3.08-4.58 log10 CFU/g. Eight (8) genera were recorded belonging to Aspergillus, Trichoderma, Penicillium, Fusarium, Saccharomyces, Mucor, Rhodotorula and Rhizopus. The species diversity includes A. flavus, A. niger, T. harzianum, P. verrucosum, F. oxysporum, Yeast, F. verticillioides, Rhodotorulla sp, A. fumigatus, R. stolonifer, M. racemosus species. Additionally, the ochratoxins level contained in the samples were very noteworthy and ranged from 1.22 to 28.17 μg/kg. Cancer risk assessments of OTA produced outcomes also ranged between 2.15 and 524.54 ng/kg bw/day, 0.03-8.31, 0.0323, and 0.07-16.94 for cases/100,000 person/yr for Estimated Daily Intake (EDI), Margin of Exposure (MOE), Average Potency, and Cancer Risks respectively for all age categories investigated. There was very high mycoflora load on the maize sampled from the Volta region, likewise the range of mycotoxins present in the maize grains, suggesting the potential to pose some adverse health effects with the populace of the Volta region.

Mycotoxin Occurrence, Exposure and Health Implications in Infants and Young Children in Sub-Saharan Africa: A Review

Infants and young children (IYC) remain the most vulnerable population group to environmental hazards worldwide, especially in economically developing regions such as sub-Saharan Africa (SSA). As a result, several governmental and non-governmental institutions including health, environmental and food safety networks and researchers have been proactive toward protecting this group. Mycotoxins, toxic secondary fungal metabolites, contribute largely to the health risks of this young population. In SSA, the scenario is worsened by socioeconomic status, poor agricultural and storage practices, and low level of awareness, as well as the non-establishment and lack of enforcement of regulatory limits in the region. Studies have revealed mycotoxin occurrence in breast milk and other weaning foods. Of concern is the early exposure of infants to mycotoxins through transplacental transfer and breast milk as a consequence of maternal exposure, which may result in adverse health effects. The current paper presents an overview of mycotoxin occurrence in foods intended for IYC in SSA. It discusses the imperative evidence of mycotoxin exposure of this population group in SSA, taking into account consumption data and the occurrence of mycotoxins in food, as well as biomonitoring approaches. Additionally, it discusses the health implications associated with IYC exposure to mycotoxins in SSA.

Risk assessment of ochratoxin A in food

The European Commission asked EFSA to update their 2006 opinion on ochratoxin A (OTA) in food. OTA is produced by fungi of the genus Aspergillus and Penicillium and found as a contaminant in various foods. OTA causes kidney toxicity in different animal species and kidney tumours in rodents. OTA is genotoxic both in vitro and in vivo; however, the mechanisms of genotoxicity are unclear. Direct and indirect genotoxic and non-genotoxic modes of action might each contribute to tumour formation. Since recent studies have raised uncertainty regarding the mode of action for kidney carcinogenicity, it is inappropriate to establish a health-based guidance value (HBGV) and a margin of exposure (MOE) approach was applied. For the characterisation of non-neoplastic effects, a BMDL 10 of 4.73 μg/kg body weight (bw) per day was calculated from kidney lesions observed in pigs. For characterisation of neoplastic effects, a BMDL 10 of 14.5 μg/kg bw per day was calculated from kidney tumours seen in rats. The estimation of chronic dietary exposure resulted in mean and 95th percentile levels ranging from 0.6 to 17.8 and from 2.4 to 51.7 ng/kg bw per day, respectively. Median OTA exposures in breastfed infants ranged from 1.7 to 2.6 ng/kg bw per day, 95th percentile exposures from 5.6 to 8.5 ng/kg bw per day in average/high breast milk consuming infants, respectively. Comparison of exposures with the BMDL 10 based on the non-neoplastic endpoint resulted in MOEs of more than 200 in most consumer groups, indicating a low health concern with the exception of MOEs for high consumers in the younger age groups, indicating a possible health concern. When compared with the BMDL 10 based on the neoplastic endpoint, MOEs were lower than 10,000 for almost all exposure scenarios, including breastfed infants. This would indicate a possible health concern if genotoxicity is direct. Uncertainty in this assessment is high and risk may be overestimated.

Phytochemistry, Antioxidant, and Hepatoprotective Potential of Acanthospermum hispidum DC Extracts against Diethylnitrosamine-Induced Hepatotoxicity in Rats

Background: Burkina Faso is classified among the countries with a high prevalence (˃12%) of hepatitis. Hepatic diseases, such as cirrhosis—related to alcoholism—and hepatitis B and C, are the cause of the increase in cases of liver cancer. They promote the development of cancer by decreasing the natural cell death, causing problems with DNA repair, or by increasing the production of free radical toxins to the cell. According to the World Health Organization (WHO), there were nearly 639,000 deaths from liver cancer worldwide in 2014, hence the need to search for natural hepatoprotective molecules. Objective: To evaluate the hepatoprotective potential of Acanthospermum hispidum extracts on rats and the antioxidant capacity of extracts in vitro and in vivo, and to perform phytochemistry. Methods: The ethanolic and aqueous extracts of the whole Acanthospermum hispidum plant were used to evaluate hepatoprotection. The hepatotoxin used in our case was diethylenitrosamine. The animals were divided into groups of six. The sera of the treated animals were used for the determination of transaminases, and the liver homogenates were used for the determination of antioxidant. The total phenol and flavonoid contents, and the antioxidant properties of the extracts, were evaluated in vitro. Results: The results of the in vitro antioxidant tests showed good antioxidant activity of the ethanolic extract, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test (0.08 ± 0.0018 μg/mL) and 2,2′-azinobis (3-ethylbenzolin-6-sulphonate) (ABTS) (246.05 ± 1.55 mmol TE/g). The in vivo tests showed, through the evaluation of the antioxidant in vivo and the biochemical parameters, that the ethanolic extract with the highest phenolic content had a good hepatoprotective capacity. Conclusions: The antioxidant activity of Acanthopermum hispidum extracts would justify the observed hepatoprotective activity. These results confirmed that the plant is used in the treatment of liver diseases in traditional medicine in Burkina Faso.

Diet contaminated with ochratoxin A at the highest level allowed by EU recommendation disturbs liver metabolism in weaned piglets

Ochratoxins, are toxic fungal metabolites produced by certain moulds of the genera Aspergillus and Penicillium that grow on a wide range of raw food commodities. The most relevant toxin is ochratoxin A (OTA) and the European Commission has established guidance values for OTA concerning complementary and complete feeding stuff recommending that for pigs a maximum concentration of 0.05 mg/kg. These guidance values represent only a recommendation of the Commission and the establishment of a legal regulation needs additional toxicological data generated from farm animal experiments. The aim of this paper was to investigate the effect of OTA – at the recommended EU guidance value of 0.05 mg/kg – on liver health. For this purpose, twelve crossbred, weaned piglets were fed for 33 days a maize-soybean-meal-based diet contaminated or not with 0.05 mg/kg OTA. Blood plasma samples were collected at the end of this period and subjected to biochemical analyses, whereas liver samples were analysed for cytokine concentration (ELISA), enzyme activity and expression of selected genes (qRT-PCR) involved in liver metabolism. Exposure to OTA resulted in a significant decrease in the concentrations of total protein, albumin and nitric oxide in plasma, and interleukin-6 in the liver. OTA exposure also resulted in a significant increase of alanine aminotransferase and triglycerides in plasma and of superoxide dismutase in the liver. In conclusion, the administration of 0.05 mg/kg of OTA, to weaned piglets for a period of 33 days caused measurable hepatocellular injury in the toxin-exposed. Additional in vivo studies should be performed with larger numbers of animals in order to confirm our results and to provide robust data for the establishment of safe concentrations of OTA in swine feeds.

Ochratoxin A induces cytotoxicity, DNA damage and apoptosis in rat hepatocyte primary cell culture at nanomolar concentration

Ochratoxin A (OTA), a mycotoxin produced by several species of Aspergillus and Penicillum, is widely found as a contaminant of food. OTA exhibits a wide range of toxic activities, including nephro- and hepatotoxicity. Although the mechanisms of its genotoxicity and carcinogenicity have been studied before, many controversial results have been published. In addition, the studies were mostly conducted with kidney cells. Therefore, the present study used a primary culture of Wistar rat hepatocytes incubated with increasing concentrations of OTA (2.0-6.0 nanomolar). OTA treatment showed dose-dependent cytotoxicity and DNA damage. Further, flow cytometric analysis of hepatocytes showed dose-dependent apoptosis, suggesting that OTA-induced hepatotoxicity is, may be partly, mediated by apoptosis. Vascular endothelial growth factor gene, a potent pro-angiogenic in hepatocellular carcinoma and responsible for hepatocyte regeneration, did not show any change with OTA treatment, as analysed by reverse transcription polymerase chain reaction. Thus, the present data indicated OTA-induced rat hepatotoxicity in vitro at nanomolar concentration, which inferred a major possible target other than kidney cells.