Spirulina platensis protects against microcystin-LR-induced toxicity in rats

CXCL1/IGHG1 signaling enhances crosstalk between tumor cells and tumor-associated macrophages to promote MC-LR-induced colorectal cancer progression

Microcystin-leucine arginine (MC-LR) is a common cyantotoxin produced by hazardous cyanobacterial blooms, and eutrophication is increasing the contamination level of MC-LR in drinking water supplies and aquatic foods. MC-LR has been linked to colorectal cancer (CRC) progression associated with tumor microenvironment, however, the underlying mechanism is not clearly understood. In present study, by using GEO, KEGG, GESA and ImmPort database, MC-LR related differentially expressed genes (DEGs) and pathway- and gene set-enrichment analysis were performed. Of the three identified DEGs (CXCL1, GUCA2A and GDF15), CXCL1 was shown a positive association with tumor infiltration, and was validated to have a dominantly higher upregulation in MC-LR-treated tumor-associated macrophages (TAMs) rather than in MC-LR-treated CRC cells. Both CRC cell/macrophage co-culture and xenograft mouse models indicated that MC-LR stimulated TAMs to secrete CXCL1 resulting in promoted proliferation, migration, and invasion capability of CRC cells. Furtherly, IP-MS assay found that interaction between TAMs-derived CXCL1 and CRC cell-derived IGHG1 may enhance CRC cell proliferation and migration after MC-LR treatment, and this effect can be attenuated by silencing IGHG1 in CRC cell. In addition, molecular docking analysis, co-immunoprecipitation and immunofluorescence further proved the interactions between CXCL1 and IGHG1. In conclusion, CXCL1 secreted by TAMs can trigger IGHG1 expression in CRC cells, which provides a new clue in elucidating the mechanism of MC-LR-mediated CRC progression.

Alleviation of microcystin-leucine arginine -induced hepatotoxicity: An updated overview

OBJECTIVES

Contamination of surface waters is a major health threat for all living creatures. Some types of blue-green algae that naturally occur in fresh water, are able to produce various toxins, like Microcystins (MCs). Microcystin-leucine arginine (MC-LR) produced by Microcystis aeruginosa is the most toxic and abundant isoforms of MCs, and it causes hepatotoxicity. The present article reviews preclinical experiments examined different treatments, including herbal derivatives, dietary supplements and drugs against MC-LR hepatotoxicity.

METHODS

We searched scientific databases Web of Science, Embase, Medline (PubMed), Scopus, and Google Scholar using relevant keywords to find suitable studies until November 2023.

RESULTS

MC-LR through Organic anion transporting polypeptide superfamily transporters (OATPs) penetrates and accumulates in hepatocytes, and it inhibits protein phosphatases (PP1 and PP2A). Consequently, MC-LR disturbs many signaling pathways and induces oxidative stress thus damages cellular macromolecules. Some protective agents, especially plants rich in flavonoids, and natural supplements, as well as chemoprotectants were shown to diminish MC-LR hepatotoxicity.

CONCLUSION

The reviewed agents through blocking the OATP transporters (nontoxic nostocyclopeptide-M1, captopril, and naringin), then inhibition of MC-LR uptake (naringin, rifampin, cyclosporin-A, silymarin and captopril), and finally at restoration of PPAse activity (silybin, quercetin, morin, naringin, rifampin, captopril, azo dyes) exert hepatoprotective effect against MC-LR.

Microcystin-LR improves anti-tumor efficacy of oxaliplatin through induction of M1 macrophage polarization

Tumor-associated macrophages within the tumor microenvironment play an immunosuppressive role by promoting tumor growth and immune evasion. Macrophages are highly plastic and can be stimulated to adopt an anti-tumor M1 phenotype. In this study, we used microcystin-LR (MC-LR), a cyclic heptapeptide produced by cyanobacteria, to induce in vitro macrophage innate immunity and transition into the anti-tumor M1 phenotype. MC-LR was also tested in vivo in a mouse model of colorectal cancer. An intraperitoneal injection of MC-LR increased the proportion of CD86⁺ M1 macrophages and triggered the maturation of CD11c⁺ dendritic cells within tumor tissues. MC-LR combined with the chemotherapeutic drug oxaliplatin significantly inhibited tumor growth in vivo. Flow cytometry analysis revealed increased infiltration of activated cytotoxic (CD8⁺, PD-1⁺) T-cells and anti-tumor cytokines (IFNγ and Granzyme B) in the tumor tissues of the combination therapy group, suggesting that this may be the primary mechanism behind the anti-tumor effect of the combination treatment. These findings indicate that MC-LR regulates the immune stimulation of macrophage polarization and dendritic cell maturation, effectively reversing tumor immunosuppression, activating an anti-tumor immune response, and enhancing tumor therapy.

Antioxidant and anti-inflammatory potential of spirulina and thymoquinone mitigate the methotrexate-induced neurotoxicity

The objective of this study was to investigate whether the neurotoxic effects caused by methotrexate (MTX), a frequently used chemotherapy drug, could be improved by administering Spirulina platensis (SP) and/or thymoquinone (TQ). Seven groups of seven rats were assigned randomly for duration of 21 days. The groups consisted of a control group that was given saline only. The second group was given 500 mg/kg of SP orally; the third group was given 10 mg/kg of TQ orally. The fourth group was given a single IP dose of 20 mg/kg of MTX on the 15th day of the experiment. The fifth group was given both SP and MTX, the sixth group was given both TQ and MTX, and the seventh group was given SP, TQ, and MTX. After MTX exposure, the study found that AChE inhibition, depletion of glutathione, and increased levels of MDA occurred. MTX also decreased the activity of SOD and CAT, as well as the levels of inflammatory mediators such as IL-1, IL-6, and tumor necrosis factor-α. MTX induced apoptosis in brain tissue. However, when MTX was combined with either SP or TQ, the harmful effects on the body were significantly reduced. This combination treatment resulted in a faster return to normal levels of biochemical, oxidative markers, inflammatory responses, and cell death. In conclusion, supplementation with SP or TQ could potentially alleviate MTX-induced neuronal injury, likely due to their antioxidant, anti-inflammatory, and anti-apoptotic effects.

Effects of testosterone replacement on lipid profile, hepatotoxicity, oxidative stress, and cognitive performance in castrated wistar rats

OBJECTIVE

Androgen deficiency is associated with multiple biochemical and behavioral disorders. This study investigated the effects of testosterone replacement and Spirulina Platensis association on testosterone deficiency-induced metabolic disorders and memory impairment.

METHODS

Adult male rats were randomly and equally divided into four groups and received the following treatments for 20 consecutive days.

CONTROL GROUP

non-castrated rats received distilled water. Castrated group received distilled water. Testosterone treated group: castrated rats received 0.20 mg of testosterone dissolved in corn oil by subcutaneous injection (i.p.). Spirulina co-treated group: castrated rats received 0.20 mg of testosterone (i.p.) dissolved in corn oil followed by 1000 mg/kg of Spirulina per os.

RESULTS

Data showed that castration induced an increase in plasma ALT, AST, alkaline phosphatase (PAL), cholesterol, and triglycerides level. Castrated rats showed a great elevation in SOD and CAT activities and MDA and H2O2 levels in the prostate, seminal vesicles, and brain. Testosterone deficiency was also associated with alteration of the spatial memory and exploratory behaviour. Testosterone replacement either alone or with Spirulina combination efficiently improved most of these biochemical parameters and ameliorated cognitive abilities in castrated rats.

CONCLUSIONS

Testosterone replacement either alone or in combination with Spirulina improved castration-induced metabolic, oxidative, and cognitive alterations.

Effect of Lactobacillus brevis (MG000874) on antioxidant-related gene expression of the liver and kidney in D-galactose-induced oxidative stress mice model

Oxidative stress (OS) is a phenomenon induced by excessive production and accumulation of reactive oxygen species (ROS) in living cells. These increased ROS productions connected, coupled with many neurological and physiological diseases. Several antioxidants were utilized recently to combat OS, and lactic acid bacteria have a potent radical-scavenging activity to minimize OS. The present work was designed to find out the protective effects of Lactobacillus brevis MG000874 (L. brevis MG000874) against oxidative injuries induced by D-galactose (D-gal) in vivo and to explore the gene expression of OS-related gene mice. Sixty male mice were randomly split into six groups. The first four groups were different control groups as no treatment (N), positive (G), probiotic (B), and ascorbic acid (A); the remaining two groups were treatment groups such as probiotic treatment (BG) and ascorbic acid treatment (AG). L. brevis MG000874 (0.2 ml of 10¹⁰ CFU/ml) and ascorbic acid (0.2 ml of 25 mg/ml) were administered orally daily for 5 weeks. It was revealed that these significantly affect the weight of treated mice: 40.22 ± 1.5 and 33.0 ± 0.57 g on days 0 and 36, respectively. D-gal induction in mice declined the levels of SOD and CAT determined by spectrophotometer. Administration of L. brevis MG000874 improved the antioxidant status of the stress mice and recovered the antioxidant activities of SOD and CAT enzymes. In addition, L. brevis MG000874-altered gene expression of OS marker at the messenger RNA (mRNA) levels was determined by RT-PCR in the mouse model. L. brevis MG000874 significantly improved the GST, GPX, SOD, CAT, and ß-actin levels in the kidney and the liver of the D-gal-induced mice (p < 0.05). Moreover, the histological investigation indicated that L. brevis MG000874 mitigated damage to the kidney and liver effectively in mice induced by D-gal. Therefore, it could be concluded from the current results that L. brevis MG000874 may act as a powerful antioxidant agent, and this study can provide the baseline data for drug development against OS-linked diseases.

Reproductive and metabolic toxic effects of polystyrene microplastics in adult female Wistar rats: a mechanistic study

Microplastics, such as polystyrene microplastics (PS-MPs), have become an emerging environmental hazard for animals and humans. Long-term exposure to PS-MPs has led to neurotoxicity, reproductive dysfunction, and carcinogenesis. The goal of this study was to evaluate the effect of sub-chronic exposure of PS-MPs on metabolic and reproductive functions in female rats. The PS-MPs were prepared by cryogenic technique. The PS-MPs were given orally to female Wistar rats for 45 days at 2.5, 5, and 10 mg/kg/day. The average PS-MPs' size diameter was 876 nm. The PS-MPs administration resulted in a significant decrease in the activity of superoxide dismutase and catalase in the liver and ovary. The effect of PS-MPs on reduced glutathione and lipid peroxidation in the liver and ovarian tissues of rats was statistically insignificant. The PS-MP exposure exhibited an increase in the levels of triglycerides, total cholesterol, and low-density lipoprotein and decrease in high-density lipoprotein. The PS-MPs caused glucose intolerance and increase in insulin. Moreover, the PS-MP exposure increased follicle stimulating hormone, estradiol, and testosterone. Serum level of interleukin-6 and nuclear factor kappa B (NF-κB) was elevated in animals treated with PS-MPs. The PS-MP exposed rats showed normal ovarian histology, but activated hepatic stellate cells and liver fibrosis. It is concluded that the sub-chronic exposure to PS-MPs resulted in metabolic and endocrine disruption in female rats through oxidative damage, hormonal imbalance, and chronic inflammation.

Crocin treatment exerts anti-inflammatory and anti-oxidative effects in liver tissue damage of pinealectomized diabetic rats

Diabetes mellitus (DM) is a chronic metabolic disorder with an increasing global prevalence that leads to significant morbidity and mortality. The liver plays a vital role in glycemic regulation in physiological and pathological conditions such as DM. Free radical formation and inhibition of antioxidant defense systems play a role in the liver damage pathogenesis in diabetic patients The antioxidant, anti-diabetic, anti-inflammatory, and radical scavenging properties of crocin are known. This study was designed to determine the possible protective effects of crocin against liver tissue damage in pinealectomized diabetic rats. Sixty rats were divided into six groups: Control, Sham+streptozotocin (STZ), Pinealectomy (PINX), PINX+STZ, PINX+Crocin, and PINX+STZ+Crocin. PNX procedure was carried out on the first day of the experiment. Intraperitoneal (i.p.) injection of 50 mg/kg STZ was performed on the 30th day of the experiment to induce DM. Crocin (50 mg/kg; i.p.) was applied for 15 days after the pinealectomy procedure and induction of DM. Crocin decreased the markers (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), interleukin-1β (IL-1β), and malondialdehyde (MDA)) of liver damage and increased antioxidant enzyme levels and tissue total antioxidant status. Histological results showed that the administration of crocin exhibited a protective effect against liver damage caused by STZ. These results indicate that crocin evidence protection against liver injury caused by STZ.

Protective effect of quercetin against 5-fluorouracil-induced cardiac impairments through activating Nrf2 and inhibiting NF-κB and caspase-3 activities

5-Fluorouracil (5-FU) is a chemotherapy used to treat many types of cancer. Cardiotoxicity is one of the common drawbacks of 5-FU therapy. Quercetin (Qu) is a bioflavonoid with striking biological activities. This research aimed to assess the ameliorative effect of Qu against 5-FU-mediated cardiotoxicity. Thirty-five rats were allocated into five groups: control group (normal saline), 5-FU group (30 mg/kg, intraperitoneally), Qu group (50 mg/kg, oral), 25 mg/kg Qu+5-FU group, and 50 mg/kg Qu+5-FU. The experimental animals were received the above-mentioned drugs for 21 days. Results showed that 5-FU significantly elevated creatine kinase, lactate dehydrogenase, serum cholesterol and triglyceride, and upregulated troponin and renin mRNA expression. Additionally, cardiac oxidant/antioxidant imbalance was evident in elevated oxidants (malondialdehyde and nitric oxide) and depleted antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione). 5-FU also downregulated the gene expression of nuclear factor erythroid 2-related factor 2. Furthermore, 5-FU significantly increased cardiac pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-1 beta) and upregulated gene expression of nuclear factor kappa-B. 5-FU significantly enhanced cardiac apoptosis through upregulating caspase-3 expression and downregulating B-cell lymphoma 2. Immunohistochemical and histopathological examinations verified the above-mentioned findings. However, all these changes were significantly ameliorated in Qu pre-administered rats. Conclusively, Qu counteracted 5-FU-mediated cardiotoxicity through potent antioxidant, anti-inflammatory, and anti-apoptotic effects.

Monosodium glutamate induces cortical oxidative, apoptotic, and inflammatory challenges in rats: the potential neuroprotective role of apigenin

Monosodium glutamate (MSG) is used as a flavor, and a taste enhancer was reported to evoke marked neuronal impairments. This study investigated the neuroprotective ability of flavonoid apigenin against neural damage in MSG-administered rats. Adult male rats were allocated into four groups: control, apigenin (20 mg/kg b.wt, orally), MSG (4 g/kg b.wt, orally), and apigenin + MSG at the aforementioned doses for 30 days. Regarding the levels of neurotransmitters, our results revealed that apigenin augmented the activity of acetylcholinesterase (AChE) markedly, and levels of brain monoamines (dopamine, norepinephrine, and serotonin) accompanied by lessening the activity of monoamine oxidase (MAO) as compared to MSG treatment. Moreover, apigenin counteracted the MSG-mediated oxidative stress by decreasing the malondialdehyde (MDA) levels together with elevating the glutathione (GSH) levels. In addition, pretreatment with apigenin induced notable increases in the activities of cortical superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Furthermore, apigenin attenuated the cortical inflammatory stress as indicated by lower levels of pro-inflammatory mediators such as interleukin-1 b (IL-1b), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) as well as downregulated inducible nitric oxide synthase (iNOS) expression levels. Histopathological screening validated the abovementioned results and revealed that apigenin restored the distorted cytoarchitecture of the brain cortex. Thus, the present findings collectively suggest that apigenin exerted significant protection against MSG-induced neurotoxicity by enhancing the cellular antioxidant response and attenuating inflammatory machineries in the rat brain cortex.

The protective effects of topiramate and spirulina against doxorubicin-induced cardiotoxicity in rats

Doxorubicin (DOX) is a widely used chemotherapy drug that can cause significant cardiotoxicity, limiting its clinical application. This study aimed to investigate the potential protective effects of topiramate (TPM) and spirulina (SP), either alone or in combination, in preventing DOX-induced cardiotoxicity. Adult Sprague Dawley rats were divided into five groups, including a normal control group and groups receiving DOX alone, DOX with TPM, DOX with SP, or DOX with a combination of TPM and SP. Cardiotoxicity was induced by administering DOX intraperitoneally at a cumulative dose of 16 mg/kg over 4 weeks. TPM and/or SP administration started 1 week before DOX treatment and continued for 35 days. Body weight, serum markers of cardiac damage, oxidative stress and inflammatory parameters were assessed. Histopathological and immunohistochemical examinations were performed on cardiac tissues. Results showed that TPM and SP monotherapy led to significant improvements in serum levels of cardiac markers, decreased oxidative stress, reduced fibrosis-related growth factor levels, increased antioxidant levels, and improved histopathological features. SP demonstrated more prominent effects in comparison to TPM, and the combination of TPM and SP exhibited even more pronounced effects. In conclusion, TPM and SP, either alone or in combination, hold promise as therapeutic interventions for mitigating DOX-induced cardiotoxicity.

Therapeutic antischizophrenic activity of prodigiosin and selenium co-supplementation against amphetamine hydrochloride-induced behavioural changes and oxidative, inflammatory, and apoptotic challenges in rats

Schizophrenia (SCZ), a multifactorial neuropsychiatric disorder, is treated with inefficient antipsychotics and linked to poor treatment outcomes. This study, therefore, investigated the combined administration of prodigiosin (PDG) and selenium (Na₂SeO₃) against SCZ induced by amphetamine (AMPH) in rats. Animals were allocated into four groups corresponding to their respective 7-day treatments: control, AMPH (2 mg/kg), PDG (300 mg/kg) + Na₂SeO₃ (2 mg/kg), and AMPH + PDG + Na₂SeO₃. The model group exhibited biochemical, molecular, and histopathological changes similar to those of the SCZ group. Contrastingly, co-administration of PDG and Na₂SeO₃ significantly increased the time for social interaction and decreased AChE and dopamine. It also downregulated the gene expression of NMDAR1 and restored neurotrophin (BDNF and NGF) levels. Further, PDG combined with Na₂SeO₃ improved the antioxidant defence of the hippocampus by boosting the activities of SOD, CAT, GPx, and GR. These findings were accompanied by an increased GSH, alongside decreased MDA and NO levels. Furthermore, schizophrenic rats having received PDG and Na₂SeO₃ displayed markedly lower IL-1β and TNF-α levels compared to the model group. Interestingly, remarkable declines in the Bax (pro-apoptotic) and increases in Bcl-2 (anti-apoptotic) levels were observed in the SCZ group that received PDG and Na₂SeO₃. The hippocampal histological examination confirmed these changes. Collectively, these findings show that the co-administration of PDG and Na₂SeO₃ may have a promising therapeutic effect for SCZ. This is mediated by mechanisms related to the modulation of cholinergic, dopaminergic, and glutaric neurotransmission and neurotrophic factors, alongside the suppression of oxidative damage, neuroinflammation, and apoptosis machinery.