In vivo evaluation of the antimutagenic and antigenotoxic effects of β-glucan extracted from Saccharomyces cerevisiae in acute treatment with multiple doses

β-Glucan Regulates Lipopolysaccharide Induced Genotoxic Damage to The Liver through The Induction of BRCA1 Protein Expression

OBJECTIVE

The present study aims to investigate the role of breast cancer-susceptibility gene 1 (BRCA1) protein in the β-Glucan (βG) molecule mediated regulation of lipopolysaccharide (LPS)-induced liver genotoxicity.

MATERIALS AND METHODS

In this experimental study, totally, 32 male Swiss Albino mice were randomly divided into 4 equal groups: control (C), LPS-administered (LPS), βG-administered (βG) and βG-pre-administered/LPS-administered (βG+LPS). The βG was injected at the dose of 150 mg/kg/day intraperitoneally (i.p.) for 3 days. A single dose of 4 mg/ kg (i.p.) LPS was administered 24 hours after the last βG injection. BRCA1 expression was determined by western blot analysis and confirmed by quantitative immunofluorescence. Proliferating cell nuclear antigen (PCNA), nuclear factor erythroid 2-related factor (Nrf2) and 8-OHdG protein levels were also determined by the immunofluorescence analysis. The alkaline comet assay was performed. superoxide dismutase (SOD), catalase (CAT) and membrane lipid peroxidation were biochemically measured, and light microscopic histology was evaluated.

RESULTS

The BRCA1 expression level was significantly decreased in the LPS group. However, in the βG+LPS group, expression of BRCA1 protein was over 2 folds higher than the control. After the LPS induction, the DNA strand breaks, oxidative DNA lesions and abnormal proliferation of the liver cells were almost entirely suppressed in βG preadministrated animals, indicating the BRCA1 mediated ubiquitination of PCNA and activation of the DNA damage repair pathways. Activation of Nrf2 in the βG+LPS group resulted in an increase in the levels of Nrf2 pathway dependent antioxidant enzymes SOD and CAT, prevented the peroxidation of membrane lipids and maintained the histological architecture of the liver.

CONCLUSION

The results manifested that the βG is a strong inducer of the BRCA1 protein expression in the LPSinduced hepatic stress and the protein constitutes the key component of a βG mediated liver protection against an LPS-induced genotoxic and pathological damage.

Protective potential of sulfated polysaccharides from tropical seaweeds against alkylating- and oxidizing-induced genotoxicity

Sulfated polysaccharides (SPs) from seaweeds are potential bioactive natural compounds, but their DNA protective activity is poorly explored. This article aimed to evaluate the genotoxic/antigenotoxic potentials of a sulfated heterofucan from brown seaweed Spatoglossum schröederi (Fucan A - FA) and a sulfated galactan from green seaweed Codium isthomocladum (3G4S) using in vitro Comet assay (alkaline and oxidative versions) with HepG2 cells. The antioxidant activity of these SPs was evaluated by total antioxidant capacity, radical scavenging, metal chelating, and antioxidant enzyme activity assays. Both SPs were not genotoxic. FA and 3G4S displayed strong antigenotoxic activity against oxidizing chemical (H₂O₂) but not against alkylating chemical (MMS). The DNA damage reduction after a pre-treatment of 72 h with these SPs was 81.42% to FA and 81.38% to 3G4S. In simultaneous exposure to FA or 3G4S with H₂O₂, HepG2 cells presented 48.04% and 55.41% of DNA damage reduction compared with the control, respectively. The antigenotoxicity of these SPs relates to direct antioxidant activity by blockage of the initiation step of the oxidative chain reaction. Therefore, we conclude that FA and 3G4S could be explored as functional natural compounds with antigenotoxic activity due to their great protection against oxidative DNA damage.

Evaluation of the genotoxic and antigenotoxic effects of exopolysaccharide pullulan in human lymphocytes in vitro

Pullulan is a biocompatible and water-soluble exo-polysaccharide produced by primary strains of the fungus Aureobasidium pullulans. It is frequently used in the pharmaceutical and food industries. In this study, possible cytotoxic effect of pullulan was assessed using the MTT assay in the human breast cancer (MCF-7) cell line. Micronucleus (MN), micronucleus-FISH (MN-FISH), random amplified polymorphic DNA (RAPD-PCR), and comet assays were used to investigate genotoxic and antigenotoxic effects of pullulan against mitomycin C (MMC) (at MN assay) and hydrogen peroxide (at comet assay) in human lymphocytes. Antigenotoxicity was determined using two different applications: 1 h pretreatment and simultaneous treatment. In the MTT assay, pullulan significantly reduced the cell viability at 15.6-2000 μg/mL compared to the control. No significant alterations in MN rates were found in human lymphocytes treated with different concentrations of pullulan compared to the control. In contrast, co-treatment of pullulan and MMC decreased the frequency of MN in almost all the treatment concentrations and durations compared to the MMC. No significant change was observed in the frequency of the centromere-positive C + or negative C- MNi compared to the positive control. In comet assay, pullulan did not affect comet tail intensity compared to the negative control. On the contrary, pullulan in combination with H₂O₂ significantly decreased tail intensity at almost all the concentrations compared to the positive control. The changes occurring in RAPD-PCR profiles following pullulan treatments included an increase or decrease in band intensity and gain or loss of bands. These results indicate that exopolysaccharide Pullulan is not genotoxic; moreover, it possesses a protective effect against MMC and H₂O₂ induced genotoxicity. In breast cancer cells, pullulan induced cytotoxic/anti-proliferative effect.

Assessment of toxicological potential of sodium carboxymethyl beta-glucan, a novel beta-glucan

In this experimental work, sodium carboxymethyl beta-glucan (CMBG), a chemically altered beta-glucan, is evaluated for mutagenicity and sub-acute oral toxicity. Specifically, the tested material was CM-Glucan Nu, a food grade powder ≥90% CMBG derived from Saccharomyces cerevisiae. A bacterial reverse mutation test was performed and resulted in no mutagenicity. A 28-day, repeated-dose, oral (gavage) toxicity test on rats was performed at dose levels of 0, 500, 1000, and 2000 mg/kg bw/day. No mortality, target organs or other treatment related effects were observed. The no observed adverse effect level (NOAEL) was 2000 mg/kg bw/day, the highest dose tested, for both male and female Han:WIST rats.

The protective role of spirulina and β-glucan in African catfish (Clarias gariepinus) against chronic toxicity of chlorpyrifos: hemato-biochemistry, histopathology, and oxidative stress traits

Chlorpyrifos (CPF) is an insecticide that is commonly applied in the agriculture sector. However, little is known about the protective role of Spirulina platensis (SP) and/or β-glucan (BG) on African catfish exposed to chronic CPF toxicity. The fish (95 ± 5 g, initial weight) were assigned to 5 fiberglass tanks (500 L, 50 fish/tank) where the 1st and 2nd fed the basal diet, while the 3rd, 4th, and 5th fed diets with SP, BG, and SP+BG at 0.5%, respectively. Fish in 2nd, 3rd, 4th, and 5th groups were exposed to CPF at a dose of 1.5 mg/L and fed the respective diets for 60 days. In comparison with the control group, CPF-exposed fish exhibited significantly lower (P ≤ 0.05) body weights, feed intake, red blood cells count, hemoglobin concentration, packed cell volume (PCV) (%), lymphocytes, monocytes, phagocytic activity, and phagocytic index, while feed conversion ratio, white blood cell count, and neutrophils count were significantly increased. Fish exposed to CPF also revealed a significant elevation in aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, triglycerides, low-density lipoproteins (LDL), very-low-density lipoproteins (vLDL), glucose concentration, urea, and creatinine as well as low total proteins, albumin, globulins, and high-density lipoprotein (HDL) concentration. Fish exposed to CPF also exhibited a high concentration of malondialdehyde while glutathione content, glutathione peroxidase, and catalase activities were significantly decreased in the liver, gills, brain, and intestine tissues. Moreover, exposure to CPF resulted in higher transcription of cytochrome P450 (CYP1A-P450) gene expression than the 1st group. Histopathological investigations revealed various degrees of pathological lesions in different organs like the liver, kidney, brain, spleen, and intestine tissues. Interestingly, dietary SP supplementation either alone or combined with BG significantly ameliorated the alterations mitigated by CPF-induced organ injuries and genotoxicity. Therefore, it could be concluded that SP or/and BG are able to induce the protective consequences on health status, immunity, and antioxidative response of African catfish exposed to CPF.

Antimutagenic action of the live yeast can be transmitted to the offspring of Drosophila melanogaster. A genetic study using the wing spot assay

The present study evaluates whether the protective effect of live yeast (LY) against direct and indirect mutagenic agents, persists in the offspring from individuals fed with LY. The wing-spot test in Drosophila was used; four different mates were performed: a) neither females nor males were fed with LY-enriched food (NLYxNLY); b) only females were fed (LYxNLY); c) males were fed (NLYxLY) or d) both progenitors were fed (LYxLY). Results confirm that LY strongly stimulates fecundity in females but not in males and provides strength to the egg for survive. A greater reduction in mutation rate was observed when females were feed, in the following relationship: LYxNLY>LYxLY>NLYxLY. No protection was found against action in any of the promutagens tested. Results suggest that LY has a very powerful antimutagenic action, predominantly against the action of ionizing radiation and Chromium trioxide that can be transmitted mainly through the female.

In vivo chemotherapeutic insight of a novel isocoumarin (3-hexyl-5,7-dimethoxy-isochromen-1-one): Genotoxicity, cell death induction, leukometry and phagocytic evaluation

Chemotherapy is one of the major approaches for the treatment of cancer. Therefore, the development of new chemotherapy drugs is an important aspect of medicinal chemistry. Chemotherapeutic agents include isocoumarins, which are privileged structures with potential antitumoral activity. Herein, a new 3-substituted isocoumarin was synthesized from 2-iodo-3,5-dimethoxy-benzoic acid and oct-1-yne in a cross-coupling Sonogashira reaction followed by a copper iodide-catalyzed intramolecular cyclization as key step using MeOH/Et₃N as the solvent system. The present study also evaluated the leukometry, phagocytic activity, genotoxic potential and cell death induction of three different doses (5 mg/kg, 10 mg/kg and 20 mg/kg) of this newly synthesized isocoumarin, alone and in combination with the commercial chemotherapeutic agents cyclophosphamide (100 mg/kg) and cisplatin (6 mg/kg) in male Swiss mice. The results suggest that the isocoumarin has genotoxicity and causes cell death. Noteworthy, this new compound can increase splenic phagocytosis and lymphocyte frequency, which are related to immunomodulatory activity. When combined with either cyclophosphamide or cisplatin, chemopreventive activity led to a reduction in the effects of both chemotherapeutic drugs. Thus, the new isocoumarin is not a candidate for chemotherapeutic adjuvant in treatments using cyclophosphamide or cisplatin. Nevertheless, the compound itself is an important prototype for the development of new antitumor drugs.

Cellular and molecular effects of yeast probiotics on cancer

The cancer is one of the main causes of human deaths worldwide. The exact mechanisms of initiation and progression of malignancies are not clear yet, but there is a common agreement about the role of colonic microbiota in the etiology of different cancers. Probiotics have been examined for their anti-cancer effects, and different mechanisms have been suggested about their antitumor functions. Nonpathogenic yeasts, as members of probiotics family, can be effective on gut microbiota dysbiosis. Generally safe yeasts have shown so many beneficial effects on human health. Probiotic yeasts influence physiology, metabolism, and immune homeostasis in the colon and contribute to cancer treatment due to possessing anti-inflammatory, anti-proliferative and anti-cancer properties. This study reviews some of the health-beneficial effects of probiotic yeasts and their biological substances like folic acid and β-glucan on cancer and focuses on the possible cellular and molecular mechanisms of probiotic yeasts such as influencing pathogenic bacteria, inactivation of carcinogenic compounds, especially those derived from food, improvement of intestinal barrier function, modulation of immune responses, antitoxic function, apoptosis, and anti-proliferative effects.

Cardanol: toxicogenetic assessment and its effects when combined with cyclophosphamide

Cardanol is an effective antioxidant and is a compound with antimutagenic and antitumoral activity. Here, we evaluated the genotoxic and mutagenic potential of saturated side chain cardanol and its effects in combination with cyclophosphamide in preventing DNA damage, apoptosis, and immunomodulation. Swiss mice were treated with cardanol (2.5, 5 and 10 mg/kg) alone or in combination with cyclophosphamide (100 mg/kg). The results showed that cardanol is an effective chemopreventive compound, with damage reduction percentages that ranged from 18.9 to 31.76% in the comet assay and from 45 to 97% in the micronucleus assay. Moreover, cardanol has the ability to reduce the frequency of apoptosis induced by cyclophosphamide. The compound did not show immunomodulatory activity. A final interpretation of the data showed that, despite its chemoprotective capacity, cardanol has a tendency to induce DNA damage. Hence, caution is needed if this compound is used as a chemopreventive agent. Also, this compound is likely not suitable as an adjuvant in chemotherapy treatments that use cyclophosphamide.

Protective effects of the exopolysaccharide Lasiodiplodan against DNA damage and inflammation induced by doxorubicin in rats: Cytogenetic and gene expression assays

The lasiodiplodan (LS) is a β-(1→6)-d-glucan produced by the fungus Lasiodiplodia theobromae and some of the biological activities of LS were reported as hypoglycemic, anticoagulant, anti-proliferative and anticancer action; however, its effects on DNA instability and modulation of gene expression are still unclear. Aims of study were investigate the genotoxic effects of lasiodiplodan, and its protective activity against DNA damage induced by doxorubicin (DXR) and its impact on the expression of genes associated with DNA damage and inflammatory response pathways. Therefore, Wistar rats were treated (15 days) orally with LS (5.0; 10 and 20mg/kg bw) alone and in combination with DXR (15mg/kg bw; administrated intraperitoneally on 14th day) as well as their respective controls: distilled water and DXR. Monitoring of DNA damage was assessed by comet and micronucleus (MN) assays and gene expression was evaluated by PCR-Arrays. Treatments with LS alone did not induce disturbances on DNA; when LS was given in combination with DXR, comet and MN formations were reduced to those found in the respective controls. Moreover, LS was able to reduce the disturbances on gene expressions induced by DXR treatment, since the animals that receive LS associated with DXR showed no alteration in the expression of genes related to DNA damage response. Also, DXR induced several up- and down-regulation of several genes associated to inflammatory process, while the animals that received LS+DXR had their gene expression patterns similar to those found in the control group. In conclusion, our results showed that LS did not induce disturbances on DNA stability and significantly reduce the DNA damage and inflammation caused by DXR exposure. In addition, we give further information concerning the molecular mechanisms associated to LS protective effects which seems to be a promising nutraceutical with chemopreventive potential.

Analysis of the anti-inflammatory and chemopreventive potential and description of the antimutagenic mode of action of the Annona crassiflora methanolic extract

CONTEXT

Annona crassiflora Mart. (Annonaceae) is a medicinal plant that is widely used in folk medicine, which leads to its investigation as a potential source of new pharmacological principles.

OBJECTIVE

This study describes the anti-inflammatory, antiallodynic, and antimutagenic/chemopreventive activities of the leaves A. crassiflora methanolic extract. Its antimutagenic mode of action was analyzed in a plant or animal experimental model.

MATERIALS AND METHODS

Total flavonoids were quantified by spectrophotometry at 415 nm and its composition was analyzed by (1)H NMR spectra. Animals received orally, 30, 100, and 300 mg/kg of extract in both tests, carrageenan-induced paw edema and myeloperoxidase activity. Animals were treated with 100 and 300 mg/kg, in all the analyzed tests, pleural cell migration and protein exudation, carrageenan-induced cell migration into the pouch, induction of joint inflammation and carrageenan-induced allodynia response in the mouse paw. To evaluate the antimutagenic/chemopreventive activity through the Allium cepa test, we used 5, 10, and 15 mg/L of extract, and for the micronucleus test in the peripheral blood, we used the dose of 15 mg/kg.

RESULTS

The fractionation of the ethyl acetate (EA) fraction, resulting from the partition of the methanol extract of the A. crassiflora, afforded through chromatographic methods resulted in the isolation of kaempferol 3-O-β-glucoside and kaempferol 3-O-β-diglucoside. Oral treatment with 100 and 300 mg/kg of extract significantly inhibited the carrageenan-induced edema formation, with inhibitions of 53 ± 7% and 47 ± 10%; in MPO activity, the observed inhibitions were 60 ± 7% for 100 mg/kg treatment and 63 ± 7% for 300 mg/kg. The ACME reduced significantly the total leukocytes (an inhibition of 78 ± 9% with 100 mg/kg and 90 ± 7% with 300 mg/kg) and protein levels (approximately 100% inhibition with both doses) in the pleurisy model. In carrageenan-induced leukocyte migration into the pouch, the extract inhibited leukocyte migration only when administered 300 mg/kg per dose (the reduction was 43 ± 5%). Pretreatment with extract failed to reduce the zymosan-induced edema formation and did not inhibit the carrageenan-induced mechanical allodynia. Damage reduction in Allium cepa tested with different concentrations (5, 10, and 15 mg/L) was 66.17, 75.75, and 69.19% for the pre-treatment; 72.72, 33.33, and 22.22% for the simple simultaneous treatment; 100.50, 93.93, and 102.52% for the simultaneous treatment with pre-incubation; 89.39, 79.79, and 84.34%; for the post-treatment, and 86.36, 81.31, and 93.43% for the continuous treatment. The antimutagenic evaluation in the micronucleous test showed a damage reduction of 75.00 and 64.58% for the pre-treatment and simultaneous protocols, respectively. The post-treatment protocol increased the cyclophosphamide effects in 45.83%.

CONCLUSION

These results suggest that this medicinal plant has chemopreventive and anti-inflammatory therapeutic potential.

Effects of glucan on bone marrow

Bone marrow damage represents a significant problem in cancer treatment. Therefore, it is clear that the pharmacologic protection against bone marrow damage is of considerable interest, since the development of novel and effective medical approaches to combat radiation or cytotoxic damage are of major importance not only to the medical field but also to several industries and the military. This review represents a summary of our knowledge of the effects of various glucans on bone marrow protection.

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63–116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20–52.54% and −0.95–62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide.