Genotoxic and antigenotoxic effects of Fucus vesiculosus extract on cultured human lymphocytes using the chromosome aberration and Comet assays

Overview of Natural Supplements for the Management of Diabetes and Obesity

Bioactive compounds found in various natural sources, such as fruits, vegetables, and herbs, have been studied for their potential benefits in managing obesity and diabetes. These compounds include polyphenols, flavonoids, other antioxidants, fiber, and certain fatty acids. Studies have found that these compounds may improve insulin sensitivity, regulate blood sugar levels, and promote weight loss. However, the effects of these compounds can vary depending on the type and amount consumed, as well as individual factors, such as genetics and lifestyle. Nutraceutical substances have multifaceted therapeutic advantages, and they have been reported to have disease-prevention and health-promoting properties. Several clinically used nutraceuticals have been shown to target the pathogenesis of diabetes mellitus, obesity, and metabolic syndrome and their complications and modulate various clinical outcomes favorably. This review aims to highlight and comment on some of the most prominent natural components used as antidiabetics and in managing obesity.

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.

Neuroprotective effect of sodium alginate against chromium-induced brain damage in rats

Oral exposure to chromium hexavalent [Cr(VI)] has disastrous impacts and affects many people worldwide. Cr(VI) triggers neurotoxicity via its high oxidation potential by generating high amount of ROS. Meanwhile, alginates are known by their chelating activity and ability to bind heavy metals and toxins, in addition to their antioxidant, anti-inflammatory, and anti-apoptotic activities. So, this study aimed to explore the neuroprotective potential of sodium alginate (SA) against cellular injury, DNA damage, macromolecule alterations, and apoptosis induced by oral ingestion of Cr. Forty Wistar male rats were divided into 4 groups; group I: standard control ingested with the vehicle solution, group II: Cr-intoxicated group received 10 mg/kg b.w. of potassium dichromate orally by gavage and kept without treatment, group III: SA group in which rats were orally exposed to 200 mg/kg b.w. of SA only, and group IV: SA-treated group that received 200 mg/kg b.w. of SA along with Cr for 28 consecutive days. Neurotransmitters such as Acetyl choline esterase (AchE), Monoamine oxidase A (MAOA) concentrations, Dopamine (DA) and 5-Hydroxytryptamine (5-HT) levels were assessed in brain homogenate tissues. Neurobiochemical markers; NAD⁺ and S100B protein were investigated in the brain tissues and serum, respectively. Levels of HSP70, caspase-3, protein profiling were evaluated. DNA damage was determined using the Comet assay. Results revealed a significant reduction in the AchE and MAOA concentrations, DA, 5-HT, and NAD⁺ levels, with an increase in the S100B protein levels. Cr(VI) altered protein pattern and caused DNA damage. High levels of HSP70 and caspase-3 proteins were observed. Fortunately, oral administration of SA prevented the accumulation of Cr in brain homogenates and significantly improved all investigated parameters. SA attenuated the ROS production and relieved the oxidative stress by its active constituents. SA can protect against cellular and DNA damage and limit apoptosis. SA could be a promising neuroprotective agent against Cr(VI)-inducing toxicity.

In vitro medicinal potentials of Bryum capillare, a moss sample, from Turkey

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This study has highlighted the medicinal importance of Bryum capillare (BC), a moss sample, from Turkey, as a source of compounds with antimicrobial, antibiofilm, antioxidant, antigenotoxic and anticancer properties.

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Even though several studies are present in the literature especially about the antibacterial and antifungal activities of bryophyte samples, very few reports on a wide range of their therapeutic effects were published until now.

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To the best of our knowledge, these results are the first results about the wide range of activities of this bryophyte sample collected from Turkey.

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The data available on bioactive compounds, therapeutic potential of BC suggests that they can be regarded as valuable natural products to moss-based pharmaceuticals that can be used in the prevention and treatment of various diseases.

In this study was conducted the in vitro antimicrobial, antibiofilm, antioxidant, antigenotoxic and anticancer activities investigations on the moss Bryum capillare Hedw (BC). Antimicrobial and antibiofilm activity were tested by MIC and microplate biofilm methods on antibiotic resistant bacteria. While the antioxidant activity of the extract was evaluated by DPPH, metal chelating, plasma lipid peroxidation and total phenolic content, the antigenotoxicity and cytotoxicity were established by Comet test and the WST-1 Cell proliferation assay kit respectively. The MIC values were found to be ≥ 125 µg.mL⁻¹ and a biofilm inhibition of 3–5% against only S. epidermidis was observed. Total phenolic compounds were determined as 23.26 mg/g. The results of DPPH assay, chelating and plasma lipid peroxidation activity were found to be 15%, 3% and 4% respectively. The extract was observed to decrease the affect of H₂O₂ that cause DNA damage. The BC was also determined 60 ± 5% anticancer activity against SKBR 3 and 76 ± 5% anticancer activity against HeLa cells, where this concentration had only 18 ± 5% cytotoxicity against MCF-12A cells. Also, these results have indicated the potential of Bryum capillare for the first time in novel natural compounds search.

Protective effects of fucoidan against 4-nitroquinolin-1-oxide provoked genetic damage in mouse bone marrow cells

Fucoidan is a unique bioactive and dietary polymer enriched mainly in the cell wall matrix of the brown seaweeds. This present study was intended to reveal the antigenotoxicity effect of fucoidan on 4-nitroquinolin-1-oxide (4-NQO) induced genetics damage and apoptosis in mice bone marrow cells. The 4-NQO caused genetic damages in the form of chromosome/chromatic breakage was estimated by micronuclei assay whereas apoptosis by annexin-V FITC kit and DNA damage by comet assay kit. In addition, oxidative damage in terms of plasma lipid peroxidation (LPO) and 8-OHdG was also estimated. In the experimental regime, six groups with each in five either sex of mice were used. Fucoidan constituted (50,100,200 mg/kg bwt) by orally for 5 days consequently and on 6th day, 4-NQO was administered (7.5 mg/kg bwt) by i.p. The results clearly show that negative control (H2O) and fucoidan alone constituted mice were not exhibited significant effect on LPO, genetic damages whereas positive control group (4-NQO 7.5 mg/kg bwt, i.p.) showed significant effect on genetic damage by showing increased level of LPO (6.25 vs 1.3 μM MDA), 8-OHdG (12 vs 4%), micronuclei about six-fold, 5-fold of comet, and 4-fold of apoptosis when compared with negative control, 11.6 ± 2.07, 5.00 ± 1.58, and 4.14 ± 0.65 respectively. Fucoidan pretreatment significantly protected the 4-NQO-induced genetic damage by 77% decreased level of micronuclei and 96% comet at dose of 200 mg/kg bwt over the positive control whereas LPO, 8-OHdG, and apoptosis were restored as equal to negative control. This study found as fucoidan possessing significant antigenotoxicity property by protecting 4-NQO-induced genetic damage in mice bone marrow cells as dose dependent manner suggest as valuable food supplements and medicine for mankind from environmental toxicants.

Searching for antigenotoxic properties of marine macroalgae dietary supplementation against endogenous and exogenous challenges

The functional characterization of marine macroalgae toward their potential to strength genome protection is still scarce. Hence, the aim of this study was to assess the antigenotoxic potential of Ulva rigida, Fucus vesiculosus, and Gracilaria species in Drosophila melanogaster following dietary exposure and adopting the somatic mutation and recombination test (SMART). All macroalgae displayed a genoprotection activity, namely against an exogenous challenge (streptonigrin). The action against subtler endogenous pressures was also noted indicating that supplementation level is a critical factor. Gracilaria species provided ambivalent indications, since 10% of G. vermiculophylla inhibited the egg laying and/or larvae development, while 10% of G. gracilis promoted spontaneous genotoxicity. The effects of U. rigida were modulated (in intensity) by the growing conditions, demonstrating higher genoprotection against streptonigrin-induced damage when grown in an aquaculture-controlled system, while the effectiveness against spontaneous genotoxicity was more apparent in specimens grown under wild conditions. In contrast, F. vesiculosus did not produce significant differences in its potential under varying growing conditions. Overall, these findings shed some light on the macroalgae ability toward genome protection, contributing to the development of algaculture industry, and reinforcing the concept of functional food and its benefits.

Attenuation of doxorubicin-induced cardiotoxicity and genotoxicity by an indole-based natural compound 3,3'-diindolylmethane (DIM) through activation of Nrf2/ARE signaling pathways and inhibiting apoptosis

The most crucial complication related to doxorubicin (DOX) therapy is nonspecific cytotoxic effect on healthy normal cells. The clinical use of this broad-spectrum chemotherapeutic agent is restricted due to development of severe form of cardiotoxicity, myelosuppression, and genotoxicity which interfere with therapeutic schedule, compromise treatment outcome and may lead to secondary malignancy. 3,3'-diindolylmethane (DIM) is a naturally occurring plant alkaloid formed by the hydrolysis of indolylmethyl glucosinolate (glucobrassicin). Therefore, the present study was undertaken to investigate the protective role of DIM against DOX-induced toxicity in mice. DOX was administered (5 mg/kg b.w., i.p.) and DIM was administered (25 mg/kg b.w., p.o.) in concomitant and 15 days pretreatment schedule. Results showed that DIM significantly attenuated DOX-induced oxidative stress in the cardiac tissues by reducing the levels of free radicals and lipid peroxidation, and by enhancing the level of glutathione (reduced) and the activity of antioxidant enzymes. The chemoprotective potential of DIM was confirmed by histopathological evaluation of heart and bone marrow niche. Moreover, DIM considerably mitigated DOX-induced clastogenicity, DNA damage, apoptosis, and myeloid hyperplasia in bone marrow niche. In addition, oral administration of DIM significantly (p < .05) stimulated the Nrf2-mediated activation of antioxidant response element (ARE) pathway and promoted expression of ARE-driven cytoprotective proteins, HO-1, NQO1, and glutathione-S-transferase (GST). In connection with that, DIM significantly attenuated DOX-induced apoptosis by upregulation of Bcl-2 expression and downregulation of Bax and caspase-3 expression. Thus, this study suggests that DIM has promising chemoprotective efficacy against DOX-induced toxicity and indicates its future use as an adjuvant in chemotherapy.

Assessment of mutagenic effect of G. acerosa and S. wightii in S. typhimurium (TA 98, TA 100, and TA 1538 strains) and evaluation of their cytotoxic and genotoxic effect in human mononuclear cells: a non-clinical study

The marine red algae (Gelidiella acerosa and Sargassum wightii) possessing excellent antioxidant and anticholinesterase activity were subjected to toxicity evaluation for a deeper understanding of other bioprotective properties of seaweeds. Cytotoxic evaluation was done by trypan blue exclusion, and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays using human PBMC (peripheral blood mononuclear cells) and RBC (red blood cells) lysis assay using human erythrocytes. Mutagenicity of the seaweeds was analyzed by Ames salmonella mutagenicity test with the histidine dependent mutant strains TA 98, TA100 and TA 1538. Genotoxic activity was verified in PBMC by comet assay. The results suggest that benzene extract of G. acerosa (BEGA) and dichloromethane extract of S. wightii (DMESW) did not show cytotoxic effect both in PBMC and erythrocytes. Evaluation of mutagenic activity suggests that the seaweeds did not cause any mutagenic effects both in the absence and the presence of S9 microsomal fraction in all the three Salmonella mutant strains. Results of genotoxic study showed that PBMC treated with seaweed extracts (1 mg/mL) exhibit less or no damage to cells, thus proving the non-genotoxic effect of the extract. Since these in vitro non-clinical studies clearly demonstrate the non-toxic nature of the seaweeds, they could be exploited for further characterization, which would result in development of novel and safe therapeutic entities.

Herb-drug interaction of Fucus vesiculosus extract and amiodarone in rats: a potential risk for reduced bioavailability of amiodarone in clinical practice

Fucus vesiculosus is a seaweed claimed to be useful for obesity management. Therefore, considering the relationship between obesity and cardiovascular diseases, this work aimed to assess the potential for an herb-drug interaction among a standardized F. vesiculosus extract (GMP certificate) and amiodarone (a narrow therapeutic index drug) in rats. In a first pharmacokinetic study, rats were simultaneously co-administered with a single-dose of F. vesiculosus (575 mg/kg, p.o.) and amiodarone (50 mg/kg, p.o.); in a second study, rats were pre-treated during 14 days with F. vesiculosus (575 mg/kg/day, p.o.) and received amiodarone (50 mg/kg, p.o.) on the 15th day. Rats of the control groups received the corresponding volume of vehicle. After analysis of the pharmacokinetic data it deserves to be highlighted the significant decrease in the peak plasma concentration of amiodarone (55.4%) as well as the reduction of systemic exposure to the parent drug (~30%) following the simultaneous co-administration of F. vesiculosus extract and amiodarone. This paper reports, for the first time, the herb-drug interaction between F. vesiculosus and amiodarone, which determined a considerable decrease on amiodarone bioavailability in rats. Therefore, the therapeutic efficacy of amiodarone may be compromised by the concurrent administration of herbal slimming medicines/dietary supplements containing F. vesiculosus.

A core in vitro genotoxicity battery comprising the Ames test plus the in vitro micronucleus test is sufficient to detect rodent carcinogens and in vivo genotoxins

In vitro genotoxicity testing needs to include tests in both bacterial and mammalian cells, and be able to detect gene mutations, chromosomal damage and aneuploidy. This may be achieved by a combination of the Ames test (detects gene mutations) and the in vitro micronucleus test (MNvit), since the latter detects both chromosomal aberrations and aneuploidy. In this paper we therefore present an analysis of an existing database of rodent carcinogens and a new database of in vivo genotoxins in terms of the in vitro genotoxicity tests needed to detect their in vivo activity. Published in vitro data from at least one test system (most were from the Ames test) were available for 557 carcinogens and 405 in vivo genotoxins. Because there are fewer publications on the MNvit than for other mammalian cell tests, and because the concordance between the MNvit and the in vitro chromosomal aberration (CAvit) test is so high for clastogenic activity, positive results in the CAvit test were taken as indicative of a positive result in the MNvit where there were no, or only inadequate data for the latter. Also, because Hprt and Tk loci both detect gene-mutation activity, a positive Hprt test was taken as indicative of a mouse-lymphoma Tk assay (MLA)-positive, where there were no data for the latter. Almost all of the 962 rodent carcinogens and in vivo genotoxins were detected by an in vitro battery comprising Ames+MNvit. An additional 11 carcinogens and six in vivo genotoxins would apparently be detected by the MLA, but many of these had not been tested in the MNvit or CAvit tests. Only four chemicals emerge as potentially being more readily detected in MLA than in Ames+MNvit--benzyl acetate, toluene, morphine and thiabendazole--and none of these are convincing cases to argue for the inclusion of the MLA in addition to Ames+MNvit. Thus, there is no convincing evidence that any genotoxic rodent carcinogens or in vivo genotoxins would remain undetected in an in vitro test battery consisting of Ames+MNvit.