Metformin and silymarin afford protection in cyclosporine A induced hepatorenal toxicity in rat by modulating redox status and inflammation

Cyclosporine-induced kidney damage was halted by sitagliptin and hesperidin via increasing Nrf2 and suppressing TNF-α, NF-κB, and Bax

Cyclosporine A (CsA) is employed for organ transplantation and autoimmune disorders. Nephrotoxicity is a serious side effect that hampers the therapeutic use of CsA. Hesperidin and sitagliptin were investigated for their antioxidant, anti-inflammatory, and tissue-protective properties. We aimed to investigate and compare the possible nephroprotective effects of hesperidin and sitagliptin. Male Wistar rats were utilized for induction of CsA nephrotoxicity (20 mg/kg/day, intraperitoneally for 7 days). Animals were treated with sitagliptin (10 mg/kg/day, orally for 14 days) or hesperidin (200 mg/kg/day, orally for 14 days). Blood urea, serum creatinine, albumin, cystatin-C (CYS-C), myeloperoxidase (MPO), and glucose were measured. The renal malondialdehyde (MDA), glutathione (GSH), catalase, and SOD were estimated. Renal TNF-α protein expression was evaluated. Histopathological examination and immunostaining study of Bax, Nrf-2, and NF-κB were performed. Sitagliptin or hesperidin attenuated CsA-mediated elevations of blood urea, serum creatinine, CYS-C, glucose, renal MDA, and MPO, and preserved the serum albumin, renal catalase, SOD, and GSH. They reduced the expressions of TNF-α, Bax, NF-κB, and pathological kidney damage. Nrf2 expression in the kidney was raised. Hesperidin or sitagliptin could protect the kidney against CsA through the mitigation of oxidative stress, apoptosis, and inflammation. Sitagliptin proved to be more beneficial than hesperidin.

Silymarin and Inflammation: Food for Thoughts

Inflammation is a vital defense mechanism, creating hostile conditions for pathogens, preventing the spread of tissue infection and repairing damaged tissues in humans and animals. However, when inflammation resolution is delayed or compromised as a result of its misregulation, the process proceeds from the acute phase to chronic inflammation, leading to the development of various chronic illnesses. It is proven that redox balance disturbances and oxidative stress are among major factors inducing NF-κB and leading to over-inflammation. Therefore, the anti-inflammatory properties of various natural antioxidants have been widely tested in various in vitro and in vivo systems. Accumulating evidence indicates that silymarin (SM) and its main constituent silibinin/silybin (SB) have great potential as an anti-inflammation agent. The main anti-inflammatory mechanism of SM/SB action is attributed to the inhibition of TLR4/NF-κB-mediated signaling pathways and the downregulated expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, IL-12, IL-23, CCL4, CXCL10, etc. Of note, in the same model systems, SM/SB was able to upregulate anti-inflammatory cytokines (IL-4, IL-10, IL-13, TGF-β, etc.) and lipid mediators involved in the resolution of inflammation. The inflammatory properties of SM/SB were clearly demonstrated in model systems based on immune (macrophages and monocytes) and non-immune (epithelial, skin, bone, connective tissue and cancer) cells. At the same time, the anti-inflammatory action of SM/SB was confirmed in a number of in vivo models, including toxicity models, nonalcoholic fatty liver disease, ischemia/reperfusion models, stress-induced injuries, ageing and exercising models, wound healing and many other relevant model systems. It seems likely that the anti-inflammatory activities of SM/SB are key elements on the health-promoting properties of these phytochemicals.

Co-Delivery of Silymarin and Metformin Dual-Loaded in Mesoporous Silica Nanoparticles Synergistically Sensitizes Breast Cancer Cell Line to Mitoxantrone Chemotherapy

The development nano-carriers based therapeutic methods is a potent strategy for enhancing cellular delivery of drugs and therapeutic efficiency in cancer chemotherapy. In the study, silymarin(SLM) and metformin (Met) were co-loaded into mesoporous silica nanoparticles (MSNs) and evaluated the synergistic inhibitory effect of these natural herbal compound in improving chemotherapeutic efficiency against MCF7MX and MCF7 human breast cancer cells. Nanoparticles have been synthesized and characterized by FTIR, BET, TEM, SEM, and X-ray diffraction. Drug loading capacity and release determined. The both single and combined form of SLM and Met (free and loaded MSN) were used for MTT assay, colony formation and real time-PCR in cellular study. The synthesis MSN were uniformity in size and shape with particle size of approximately 100 nm and pore size of approximately 2 nm. The Met-MSNs IC30, SLM -MSNs IC50 and dual-drug loaded MSNs IC50 were much lower than of free-Met IC30, free-SLM IC50 and free Met-SLM IC50 MCF7MX and MCF7cells. The co-loaded MSNs treated cells were increased sensitivity to mitoxantrone with the inhibition of BCRP mRNA expressions and could induce apoptosis in MCF7MX and MCF7 cells in comparison with other groups. Colony numbers were significantly reduced in comparison to with other groups in the co-loaded MSNs -treated cells ( ). Our results indicate that Nano-SLM enhances the anti-cancer effects of SLM against human breast cancer cells. The findings of the present study suggest that the anti-cancer effects of both metformin and silymarin enhances against breast cancer cells when MSNs are used as a drug delivery system.

Metformin beyond an anti-diabetic agent: A comprehensive and mechanistic review on its effects against natural and chemical toxins

In addition to the anti-diabetic effect of metformin, a growing number of studies have shown that metformin has some exciting properties, such as anti-oxidative capabilities, anticancer, genomic stability, anti-inflammation, and anti-fibrosis, which have potent, that can treat other disorders other than diabetes mellitus. We aimed to describe and review the protective and antidotal efficacy of metformin against biologicals, chemicals, natural, medications, pesticides, and radiation-induced toxicities. A comprehensive search has been performed from Scopus, Web of Science, PubMed, and Google Scholar databases from inception to March 8, 2023. All in vitro, in vivo, and clinical studies were considered. Many studies suggest that metformin affects diseases other than diabetes. It is a radioprotective and chemoprotective drug that also affects viral and bacterial diseases. It can be used against inflammation-related and apoptosis-related abnormalities and against toxins to lower their effects. Besides lowering blood sugar, metformin can attenuate the effects of toxins on body weight, inflammation, apoptosis, necrosis, caspase-3 activation, cell viability and survival rate, reactive oxygen species (ROS), NF-κB, TNF-α, many interleukins, lipid profile, and many enzymes activity such as catalase and superoxide dismutase. It also can reduce the histopathological damages induced by many toxins on the kidneys, liver, and colon. However, clinical trials and human studies are needed before using metformin as a therapeutic agent against other diseases.

Metformin attenuates chronic lung allograft dysfunction: evidence in rat models

BACKGROUND

Chronic lung allograft dysfunction (CLAD) directly causes an abysmal long-term prognosis after lung transplantation (LTx), but effective and safe drugs are not available. Metformin exhibits high therapeutic potential due to its antifibrotic and immunomodulatory effects; however, it is unclear whether metformin exerts a therapeutic effect in CLAD. We sought to investigate the effect of metformin on CLAD based on rat models.

METHODS

Allogeneic LTx rats were treated with Cyclosporin A (CsA) in the first week, followed by metformin, CsA, or vehicle treatment. Syngeneic LTx rats received only vehicles. All rats were sacrificed on post-transplant week 4. Pathology of lung graft, spleen, and thymus, extent of lung fibrosis, activity of profibrotic cytokines and signaling pathway, adaptive immunity, and AMPK activity were then studied.

RESULTS

Allogeneic recipients without maintenance CsA treatment manifested CLAD pathological characteristics, but these changes were not observed in rats treated with metformin. For the antifibrotic effect, metformin suppressed the fibrosis extent and profibrotic cytokine expression in lung grafts. Regarding immunomodulatory effect, metformin reduced T- and B-cell infiltration in lung grafts, spleen and thymus weights, the T- and B-cell zone areas in the spleen, and the thymic medullary area. In addition, metformin activated AMPK in lung allografts and in α-SMA⁺ cells and T cells in the lung grafts.

CONCLUSIONS

Metformin attenuates CLAD in rat models, which could be attributed to the antifibrotic and immunomodulatory effects. AMPK activation suggests the potential molecular mechanism. Our study provides an experimental rationale for further clinical trials.

Gallic acid and metformin co-administration reduce oxidative stress, apoptosis and inflammation via Fas/caspase-3 and NF-κB signaling pathways in thioacetamide-induced acute hepatic encephalopathy in rats

BACKGROUND

Hepatic encephalopathy (HE) is a consequence of chronic or acute liver diseases. This study evaluates the combined effect of gallic acid (GA), and metformin (Met) on the liver and brain damage associated with HE.

METHODS

Acute HE was induced by a single dose of thioacetamide (TAA) (300 mg/kg) as an I.P. injection. Treated groups received GA group (100 mg/kg/day, p.o), Met (200 mg/kg/day, p.o), or their combination for 25 consecutive days before TAA injection.

RESULTS

The administration of TAA induced various biochemical and histopathological alterations. In contrast, treatment with GA either alone or combined with Met resulted in improved liver functions by the significant reduction in serum ALT, AST, and ALP activities, and ammonia levels. Inflammatory mediators; TNF-α, IL-6, and NFkβ levels were decreased by these treatments as well as apoptotic cascade via down-regulation of FAS and caspase-3 (CASP-3) expression in hepatic tissues. Furthermore, GA and Met either alone or combined protected the liver and brain tissues from damage by increased glutathione concentration while decreasing malondialdehyde. In addition, it was accompanied by the improvement of the brain neurotransmitter profile via the restoration of norepinephrine, dopamine, and serotonin levels. Based on our data, this is the first study to report a novel combined hepatoprotective and cognitive enhancing effect of GA and Met against TAA-induced acute liver and brain injury.

CONCLUSION

GA and Met combination resulted in a prominent improvement in HE complications, relative to monotherapy. Both agents potentiated the antioxidant, anti-inflammatory, and anti-apoptotic effects of each other.

Niclosamide modulates cyclosporin A-induced hepatotoxicity in a mouse model: PPAR-γ and Wnt/β-catenin crosstalk

OBJECTIVES

The aim of this study was to evaluate whether: 1) Wnt/β-catenin signaling is involved in cyclosporin A (CsA)-induced hepatotoxicity, and 2) knockdown of this pathway by niclosamide (NCL) attenuate CsA-induced hepatotoxicity.

METHODS

The experiment was accomplished in 21 days. Adult male mice were randomly distributed into five groups: control group, CsA (25 mg/kg/day) group, CsA + NCL (2.5 mg/kg/day) group, CsA + NCL (5 mg/kg/day) group, and NCL (5 mg/kg/day) group.

RESULTS

NCL showed marked hepatoprotection by significantly decreasing liver enzymes activities and ameliorating the histopathological alterations induced by CsA. Besides, NCL alleviated oxidative stress and inflammation. NCL-treated groups (2.5 and 5 mg/kg) displayed rise in the expression of hepatic peroxisome proliferator-activated receptor-γ (PPAR-γ) by 2.1- and 2.5-fold, respectively. Notably, NCL (2.5 and 5 mg/kg) significantly inhibited Wnt/β-catenin signaling, evidenced by a marked decrease in the hepatic expression of Wnt3a by 54 % and 50 %, frizzled-7 receptor by 50 % and 50 %, β-catenin by 22 % and 49 %, and c-myc by 50 % and 50 %, respectively.

CONCLUSIONS

NCL can be regarded as a potential agent to mitigate CsA-induced hepatotoxicity.

Thiamethoxam Evoked Neural Oxido-inflammatory Stress in Male Rats Through Modulation of Nrf2/NF-kB/iNOS Signaling and Inflammatory Cytokines: Neuroprotective Effect of Silymarin

Thiamethoxam (TMX), a neonicotinoid insecticide, is a widely used insecticide with neurotoxic potential. Silymarin (SM), a milk thistle-derived flavonoid, is known with its promising biological activities. This study explored the neuroprotective effects of SM against TMX-triggered cortical injury in male rats. Animals were divided into four groups and treated daily either with SM (150mg/kg), TMX (78.15mg/kg), or both at the aforementioned doses for 28 days. Our results revealed marked declines in cortical SOD and CAT activities with elevations in MDA, IL-1b and TNF-α levels in TMX-treated rats. Further, TMX induced down-regulation in the gene expressions of Sod, Cat, Gpx, and Nrf-2, with up-regulation in the gene expressions of IL-1b, IL-6, iNOS, TNF-α and NF-kB. Interestingly, pre-treatment with SM provided a notable neuroprotective action against TMX-mediated cortical damage that indicates its promising antioxidant and anti-inflammatory activities. This effect may be mediated by Nrf2/NF-kB/iNOS signalling and suppression of excess free radicals and production of inflammatory cytokines. In brief, SM could be a promising therapeutic agent against TMX-mediated neural complication via its antioxidant and anti-inflammatory properties. PRACTICAL APPLICATIONS: The using of neonicotinoids as thiamethoxam is recently increased and is associated with brain damage. TMX induced excessive oxidative and inflammatory damage. Therefore, new therapeutic approaches are needed to counteract its adverse effects on the nervous system. SM, a flavonoid, is extracted from the seeds and fruits of milk thistle. Due to its potent antioxidative activity, SM have been applied to mitigate the oxidative stress as well as inflammatory disorders. Herein, we examined the potential therapeutic role of SM against TMX-induced brain oxidative stress and inflammation in rats through evaluating oxidative markers, inflammatory response, and histopathological changes in the brain cortical tissue.

Modulatory Role of Autophagy in Metformin Therapeutic Activity toward Doxorubicin-Induced Nephrotoxicity

Doxorubicin (DOX) is a frequent chemotherapeutic drug used to treat various malignant tumors. One of the key factors that diminish its therapeutic importance is DOX-induced nephrotoxicity. The first-line oral antidiabetic drug is metformin (Met), which also has antioxidant properties. The purpose of our study was to investigate the underlying molecular mechanisms for the potential protective effects of Met on DOX-triggered nephrotoxicity. Four animal groups were assigned as follows; animals received vehicle (control group), 200 mg/kg Met (Met group), DOX 15 mg/kg DOX (DOX group), and a combination of DOX and Met (DOX/Met group). Our results demonstrated that DOX administration caused marked histological alterations of widespread inflammation and tubular degeneration. Notably, the DOX-induced dramatic up-regulation of the nuclear factor-kappa B/P65 (NF-κB/P65), microtubule-associated protein light chain 3B (LC3B), neutrophil gelatinase-associated lipocalin (NGAL), interleukin-1beta (IL-1β), 8-hydroxy-2' -deoxyguanosine (8-OHdG), and Beclin-1 in renal tissue. A marked increase in the malondialdehyde (MDA) tissue level and a decrease in the total antioxidant capacity (TAC) were also recorded in DOX-exposed animals. Interestingly, Met could minimize all histopathological changes as well as the disruptions caused by DOX in the aforementioned measures. Thus, Met provided a workable method for suppressing the nephrotoxicity that occurred during the DOX regimen via the deactivation of the Beclin-1/LC3B pathway.

Silymarin Protects against Acute Liver Injury Induced by Acetaminophen by Downregulating the Expression and Activity of the CYP2E1 Enzyme

Previous studies have shown that silymarin protects against various types of drug-induced liver injury, but whether the protective mechanism of silymarin against acetaminophen-induced liver injury is related to the CYP2E1 enzyme remains unclear. In this study, we investigated the effect of silymarin on the activity and expression of CYP2E1 in vitro and in vivo. The results of in vitro studies showed that silymarin not only inhibited the activity of CYP2E1 in human and rat liver microsomes but also reduced the expression of CYP2E1 in HepG2 cells. In vivo studies showed that silymarin pretreatment significantly reduced the conversion of chlorzoxazone to its metabolite 6-OH-CLX and significantly increased the t_1/2, area under the curve (AUC) and mean residence time (MRT) of chlorzoxazone. In addition, silymarin pretreatment significantly inhibited the upregulation of Cyp2e1 expression, reduced the production of 3-cysteinylacetaminophen trifluoroacetic acid salt (APAP-CYS), and restored the liver glutathione level. The results of our study show that silymarin plays an important protective role in the early stage of acetaminophen-induced acute liver injury by reducing the activity and expression of CYP2E1, reducing the generation of toxic metabolites, and alleviating liver injury.

Avocado Seeds-Mediated Alleviation of Cyclosporine A-Induced Hepatotoxicity Involves the Inhibition of Oxidative Stress and Proapoptotic Endoplasmic Reticulum Stress

Previous studies reported disrupted hepatic function and structure following the administration of cyclosporine A (CsA) in humans and animals. Recently, we found that avocado seeds (AvS) ameliorated CsA-induced nephrotoxicity in rats. As a continuation, herein we checked whether AvS could also attenuate CsA-induced hepatotoxicity in rats. Subcutaneous injection of CsA (5 mg/kg) for 7 days triggered hepatotoxicity in rats, as indicated by liver dysfunction, redox imbalance, and histopathological changes. Oral administration of 5% AvS powder for 4 weeks ameliorated CsA-induced hepatotoxicity, as evidenced by (1) decreased levels of liver damage parameters (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and bilirubin), (2) resumed redox balance in the liver (reduced malondialdehyde (MDA) and increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)), (3) downregulated hepatic expression of endoplasmic reticulum (ER) stress-related genes (X-box binding protein 1 (XBP1), binding immunoglobulin protein (BIP), C/EBP homologous protein (CHOP)), and apoptosis-related genes (Bax and Casp3), (4) upregulated expression of the anti-apoptotic gene Bcl2, (5) reduced DNA damage, and (6) improved liver histology. These results highlight the ability of AvS to ameliorate CsA-induced hepatotoxicity via the inhibition of oxidative stress and proapoptotic ER stress.

α-Lipoic Acid Protects against Cyclosporine A-Induced Hepatic Toxicity in Rats: Effect on Oxidative Stress, Inflammation, and Apoptosis

The clinical application of cyclosporine A (CsA) as an immunosuppressive agent is limited by its organ toxicity. We aimed to evaluate the effectiveness of α-lipoic acid against CsA-induced hepatotoxicity and to delineate the underlying molecular mechanisms. Male Wistar rats (n = 24, 8 per each group) received the vehicle, CsA (25 mg/kg) and/or ALA (100 mg/kg, p.o.) for 3 weeks. Biochemical markers of liver function (serum ALT, AST, ALP < GGT), oxidative stress (MDA, TAC, SOD, GSH, Nrf2/HO-1), inflammation (NF-κB, CD68, iNOS, NO, COX-2), and apoptosis (caspase-3) were assessed in serum and tissue. Liver histological analysis using H&E and Sirius red was performed. The development of liver injury in CsA-treated animals was indicated by elevated levels of liver enzymes, oxidants/antioxidants imbalance, inflammatory cells infiltration, up-regulated expression of inflammatory mediators, and apoptosis. These changes were associated with altered architecture of hepatic cells and fibrous connective tissue. ALA co-administration protected against CsA-induced liver damage and ameliorated biochemical changes and cellular injury. In conclusion, ALA demonstrated hepatoprotective potential against CsA-induced liver injury through combating oxidative stress, inflammation, and apoptosis, highlighting ALA as a valuable adjunct to CsA therapy.

Metformin alleviates chronic obstructive pulmonary disease and cigarette smoke extract-induced glucocorticoid resistance by activating the nuclear factor E2-related factor 2/heme oxygenase-1 signaling pathway

Chronic obstructive pulmonary disease (COPD) is an important healthcare problem worldwide. Often, glucocorticoid (GC) resistance develops during COPD treatment. As a classic hypoglycemic drug, metformin (MET) can be used as a treatment strategy for COPD due to its anti-inflammatory and antioxidant effects, but its specific mechanism of action is not known. We aimed to clarify the role of MET on COPD and cigarette smoke extract (CSE)-induced GC resistance. Through establishment of a COPD model in rats, we found that MET could improve lung function, reduce pathological injury, as well as reduce the level of inflammation and oxidative stress in COPD, and upregulate expression of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), multidrug resistance protein 1 (MRP1), and histone deacetylase 2 (HDAC2). By establishing a model of GC resistance in human bronchial epithelial cells stimulated by CSE, we found that MET reduced secretion of interleukin-8, and could upregulate expression of Nrf2, HO-1, MRP1, and HDAC2. MET could also increase the inhibition of MRP1 efflux by MK571 significantly, and increase expression of HDAC2 mRNA and protein. In conclusion, MET may upregulate MRP1 expression by activating the Nrf2/HO-1 signaling pathway, and then regulate expression of HDAC2 protein to reduce GC resistance.

Inhibition of oxidative stress and apoptosis by camel milk mitigates cyclosporine-induced nephrotoxicity: Targeting Nrf2/HO-1 and AKT/eNOS/NO pathways

Cyclosporine (CsA) is a widely used immunosuppressive agent that incurs marked nephrotoxicity in the clinical setting. Thus, there is a need for finding safe/effective agents that can attenuate CsA-induced kidney injury. Meanwhile, the underlying mechanisms for CsA-associated nephrotoxicity are inadequately investigated, in particular, the AKT/eNOS/NO pathway. Here, the present work aimed to explore the potential of camel milk, a natural product with distinguished antioxidant/anti-inflammatory actions, to ameliorate CsA-induced nephrotoxicity in rats. The molecular mechanisms related to renal oxidative aberrations and apoptosis were studied, including Nrf2/HO-1 and AKT/eNOS/NO pathways. The kidney tissues were inspected using histopathology, ELISA, Western blotting, and immunohistochemistry. The present findings demonstrated that camel milk (10 ml/kg) significantly lowered creatine, BUN, and NGAL nephrotoxicity markers and the aberrant histopathology, with similar efficacy to the reference quercetin. Moreover, camel milk suppressed the renal oxidative stress, as evidenced by significantly lowering NOX-1 and lipid peroxides and significantly augmenting the renal antioxidant moieties (GSH, GPx, and SOD), thereby, driving the restoration of Nrf2/HO-1 pathway. Meanwhile, camel milk counteracted the pro-apoptotic reactions by significantly lowering Bax protein expression, caspase-3 activity/cleavage, and PARP cleavage, alongside significantly increasing the expression of the proliferation signal PCNA. Regarding the anti-apoptotic AKT/eNOS/NO pathway, camel milk activated its signaling by significantly increasing the protein expression of PI3Kp110, p-AKT(Ser473)/total AKT, and p-eNOS (Ser1177)/total eNOS besides significantly boosting the renoprotective NO levels. In conclusion, these findings reveal that camel milk may be a promising candidate for the alleviation of CsA-induced nephrotoxicity.

Metformin: A Novel Weapon Against Inflammation

It has become widely accepted that inflammation is a driving force behind a variety of chronic diseases, such as cardiovascular disease, diabetes, kidney disease, cancer, neurodegenerative disorders, etc. However, the existing nonsteroidal anti-inflammatory drugs show a limited utility in clinical patients. Therefore, the novel agents with different inflammation-inhibitory mechanisms are worth pursuing. Metformin, a synthetic derivative of guanidine, has a history of more than 50 years of clinical experience in treating patients with type 2 diabetes. Intense research efforts have been dedicated to proving metformin’s inflammation-inhibitory effects in cells, animal models, patient records, and randomized clinical trials. The emerging evidence also indicates its therapeutic potential in clinical domains other than type 2 diabetes. Herein, this article appraises current pre-clinical and clinical findings, emphasizing metformin’s anti-inflammatory properties under individual pathophysiological scenarios. In summary, the anti-inflammatory effects of metformin are evident in pre-clinical models. By comparison, there are still clinical perplexities to be addressed in repurposing metformin to inflammation-driven chronic diseases. Future randomized controlled trials, incorporating better stratification/targeting, would establish metformin’s utility in this clinical setting.