Antigenotoxic Effects and Possible Mechanism of Red Yeast (Sporidiobolus pararoseus) on Aflatoxin B1-Induced Mutagenesis

Red yeast (Sporidiobolus pararoseus), obtained from glycerol waste in the biodiesel process, has been used as a mycotoxin sorbent in some agricultural products. This study focused on the antigenotoxic effects of red yeast on aflatoxin B1 (AFB1)-induced mutagenesis, using a Salmonella mutation assay and a rat liver micronucleus test. Red yeast was sequentially extracted to obtain hexane, acetone, hot water, and residue fractions. Carbohydrates were mainly found in hot water extract (HWE), while proteins were observed in the residue fraction. The amount of lycopene in hexane extract (HE) was higher than the amount of β-carotene in HE. All red yeast extracts were not mutagenic in the Salmonella typhimurium strains TA98 and TA100 under the presence and absence of metabolic activation. Among the extracts obtained from red yeast, HE presented the strongest antimutagenicity against AFB1-induced mutagenesis in both strains, but HWE did not show any antimutagenicity. The oral administration of red yeast, HE, and HWE for 28 days was further investigated in rats. These extracts did not induce micronucleated hepatocytes. Furthermore, they modulated the activities of some detoxifying enzymes but did not alter the activities of various cytochrome P450 isozymes. Notably, they significantly decreased hepatic micronucleus formation in AFB1-initiated rats. HE altered the activity of hepatic glutathione-S-transferase but did not affect its protein expression. Taken together, the antigenotoxicity of red yeast against AFB1-induced mutagenesis might be partly due to the modulation of some detoxifying enzymes in AFB1 metabolism. β-Carotene and lycopene might be promising antigenotoxic compounds in red yeast.

DNA PROTECTIVE ACTIVITY OF TWO SPECIES OF THE „SCROPHULARIA“ GENUS 2021ICCBIKG (2021)

Plants from the genus Scrophularia, family Scrophulariaceae have numerous biological activities such as antibacterial, antioxidant, antiprotozoal, antitumor, hepatoprotective, and antidiabetic. However, as far as we know, genotoxic and antigenotoxic effects of these two plant species remain unexplored. The present study aimed to evaluate possible in vivo protective effects of the methanol extracts of two plant species of the Scrophularia genus, Scrophularia canina L. and S. alata Gilib., against carbon tetrachloride (CCl4)-induced DNA damage in albino Wistar rat. A significant increase in total comet score has been shown in animals receiving CCl4 compared with the negative control. Treatment with either S. alata or S. canina extracts reduced CCl4 induced DNA damage as indicated by the percentage of reduction in total comet score with a value above 50%.

Decrease of the DXR-induced genotoxicity and nongenotoxic effects of Theobroma cacao revealed by micronucleus assay

This study evaluated the genotoxicity of lyophilized glycolic extract of Theobroma cacao Linné seeds (TCL), using the micronucleus assay in bone marrow of mice. The interaction between TCL and doxorubicin (DXR) was also analyzed. Experimental groups were evaluated 24-48 h after treatment with N-Nitroso-N-ethylurea (NEU: 50 mg/kg), DXR (5 mg/kg), NaCl (145 mM), TCL (0.5-2 g/kg), and TCL (2 g/kg) in combination with DXR (antigenotoxic assays). Analysis of micronucleated polychromatic erythrocytes (MNPCEs) showed no significant differences between all the treatment doses of TCL and NaCl control. Mice experimentally treated with DXR and NEU significantly induced MNPCEs. However, a significant reduction of MNPCEs was also observed when TCL was administered in combination with the chemotherapeutic agent DXR. The analysis of the PCE/NCE ratio revealed no significant differences between the NaCl control, all doses of TCL, and DXR. However, there were significant differences in the PCE/NCE ratio between positive NEU control and all other treatments. The PCE/NCE ratio observed after treatment with TCL and DXR showed significant differences and intermediate values to controls (NaCl and NEU). This study suggests absence of genotoxicity and cytotoxicity of TCL, regardless of dose, sex, and time. TCL reduced genotoxic effects induced by DXR, suggesting potential antigenotoxic effects.

Evaluation of the antioxidant activity and mutagenicity of Brazil nut (Bertholletia excelsa Bonpl.).

This study evaluated the antioxidant capacity and the genotoxic and antigenotoxic effects of the fixed oil of B. excelsa Bonpl. in peripheral blood of Swiss mice. For the antioxidant capacity, were used the β-carotene/linoleic acid and DPPH methods. In the genotoxicity assay, were used healthy, 6-7 week old male Swiss mice, and there were six animals per group. For the genotoxic test, animals were treated with different concentrations of B. excelsa (500, 1.000 and 2.000 mg/kg body weight bw) in 0.5 mL orally. For the antigenotoxic test, animals were treated with predetermined concentrations, followed by intraperitoneal injection of doxorubicin (DXR 15 mg/kg bw) in 0.3 ml, in addition to the negative group (water) and dimethylsulfoxide (200 μL). Peripheral blood samples were collected 24 and 48 hours after the treatments. The frequency of micronucleated polychromatic erythrocytes (MNPCEs) was obtained from the analysis of 2.000 MNPCEs/animal. After data analysis, the conclusion was that the fixed oil of B. excelsa showed excellent protective activity by the β-carotene/linoleic acid method, demonstrated absence of genotoxic effect, and significant antigenotoxic effect according to the protocols and treatments performed in this study.

Antioxidant and Antigenotoxic Potential of Infundibulicybe geotropa Mushroom Collected from Northwestern Turkey

Infundibulicybe geotropa (Bull.) Harmaja is an edible mushroom found in Bolu province in northwestern Turkey. The chemical composition and bioactivity of these mushrooms has not been previously investigated. We examined the phenolic composition, elemental content, and antioxidant and antigenotoxic effects of methanol extracts of fruiting bodies. The phenolic compounds in the fungal samples were determined using high-performance liquid chromatography (HPLC), and element content was determined using atomic absorption spectrophotometry. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were determined using the commercially available Rel assay kit. The antigenotoxic effects of the extract were determined using the MTT assay to assess cell viability and the alkaline single-cell gel electrophoresis assay (Comet assay). The total phenolic content (ppm) of I. geotropa was found to be catechin (361±2.31), clorogenic acid (553.54±5.06), and coumaric acid (9.93±0.25). The TAS, TOS, and OSI of the extract were 1.854±0.051 mmol/L, 30.385±0.399 μmol/L, and 1.639±0.067, respectively. The elemental levels were within “normal” range. In HT22 mouse hippocampal neuronal cells, the extract (100 and 200 μg/ml) showed no genotoxic potential and ameliorated hydrogen peroxide- (H2O2-) induced oxidative DNA damage. I. geotropa may be considered a good nutrient due to its phenolic constituents and antioxidant potential.

Antigenotoxic Effects of Biochaga and Dihydroquercetin (Taxifolin) on H2O2-Induced DNA Damage in Human Whole Blood Cells

The health benefits of natural products have long been recognized. Consumption of dietary compounds such as supplements provides an alternative source of natural products to those obtained from the diet. There is a growing concern regarding the possible side effects of using different food supplements simultaneously, since their possible interactions are less known. For the first time, we have tested genotoxic and antigenotoxic effects of Biochaga, in combination with dihydroquercetin. No genotoxic effect on whole blood cells was observed within individual treatment of Biochaga (250 μg/mL, 500 μg/mL and 1000 μg/mL) and dihydroquercetin (100 μg/mL, 250 μg/mL and 500 μg/mL), nor in combination. Afterwards, antigenotoxic potency of both supplements against hydrogen peroxide- (H2O2-) induced DNA damage to whole blood cells (WBC) was assessed, using the comet assay. Biochaga and dihydroquercetin displayed a strong potential to attenuate H2O2-induced damage on DNA in cells at all tested concentrations, with a statistical significance (p<0.05), whereas Biochaga at the dose of 500 μg/mL in combination with dihydroquercetin 500 μg/mL was most prominent. Biochaga in combination with dihydroquercetin is able to protect genomic material from oxidative damage induced by hydrogen peroxide in vitro.