Artesunate Combined With Metformin Ameliorate on Diabetes-Induced Xerostomia by Mitigating Superior Salivatory Nucleus and Salivary Glands Injury in Type 2 Diabetic Rats via the PI3K/AKT Pathway

Agmatine alleviates diabetic-induced hyposalivation in rats: A histological and biochemical study

Diabetic patients commonly experience hyposalivation, which can cause challenges with eating, swallowing, dry mouth, and speaking. It also raises the likelihood of developing periodontal disease. This study aimed to evaluate if agmatine could improve the rate of salivation in rats with hyposalivation induced by streptozotocin (STZ). Five groups of Wistar rats were utilized with 10 animals in each group. They were classified as follows; Negative control group (G1), agmatine (G2) group, and Nicotinamide (NA)-STZ (G3) group; received a single intraperitoneal dose of 65 mg/kg of STZ after NA injection. NA was administered to protect residual β cells and enhance their insulin secretion; NA-STZ + Metformin (G4) Metformin-treated diabetic group; at day 10 diabetic rats received 50mg/kg orally for 28 days, and NA-STZ + Agmatine (G5) at day 10 diabetic rats received a daily intraperitoneal dose of 300 mg/kg Agmatine for 28 days. The salivary flow rate was assessed weekly. Then, the animals were euthanized, both parotid (PG) and submandibular (SMG) salivary glands were dissected, and the following parameters were assessed; salivary glands' histopathology, aquaporin 5 (AQP5), caspase-3, E-cadherin expressions, inflammatory markers and finally, salivary glands' oxidative stress status. Agmatine has alleviated the salivary glands' dysfunction in STZ-induced diabetic rats. It normalized diabetes mellitus-associated salivary glands' abnormalities including histopathological abnormalities, decreased AQP5 and E-cadherin expressions, increased caspase-3 expression, and oxidative stress and inflammatory parameters. Agmatine alleviates diabetes mellitus-associated hyposalivation. It can promote PGs and SMGs function through its histological and AQP5 expression improvements.

Pretreatment of artesunate promoted hepatocyte proliferation by activating the PI3K/Akt/mTOR signaling pathway in mice

PURPOSE

Artesunate (ART) has been implicated in regulating the many processes of liver injury, but its roles in liver regeneration still need to be illustrated.

METHODS

In the present study, ART was used to pretreat hepatocyte cell line NCTC1469 to study the effect of ART on hepatocyte proliferation in vitro. Furthermore, the potency of ART as a regimen to promote liver regeneration and restore liver function was evaluated following partial hepatectomy (PH) on C57BL/6 mice.

RESULTS

ART concentration-dependently promoted hepatocyte proliferation and reduced apoptosis. Cell cycle and Ki-67 immunohistochemical analyses demonstrated that ART supplementation promoted the proliferation of hepatocytes and accelerated liver regeneration. Our results provided evidence that ART improved liver function in a dose-dependent manner, as indicated by decreased serum alanine aminotransferase, aspartate aminotransferase, and increased albumin, and hepatocyte growth factor levels in PH mice. Meanwhile, ART promoted the PI3K/Akt/mTOR signaling in NCTC1469 cells and liver tissue of PH mice. In addition, PI3K inhibitor LY294002 blocked the promotion effect of ART on hepatocyte proliferation and cell cycle progression.

CONCLUSION

ART promoted hepatocyte proliferation via activation of the PI3K/Akt/mTOR pathway, which was beneficial to liver regeneration of PH-induced liver injury.

Allantoin reduces glucotoxicity and lipotoxicity in a type 2 diabetes rat model by modulating the PI3K and MAPK signaling pathways

Objective

The current study aimed to investigate the potential therapeutic impact of allantoin on diabetes produced by a high-fat diet (HFD) and streptozotocin (STZ) in rats.

Subjects and methods

Male Sprague-Dawley rats were fed a high-fat diet to induce insulin resistance, followed by streptozotocin injection to induce diabetes. The effect of oral treatment of allantoin (200, 400 and 800 mg/kg/day) for 8 weeks was evaluated by calculating the alteration in metabolic parameters, biochemical indicators, the oral glucose tolerance tests (OGTT) and hyperinsulinemic-euglycemic clamp tests were performed. Histopathological studies were performed in the liver, kidney and pancreas. Next, the expressions of the MAPK and insulin signaling pathway were measured by Western blot analysis to elucidate the potential mechanism underlying these antidiabetic activities.

Results

The administration of allantoin resulted in a significant decrease in fasting blood glucose (FBG) levels, glycogen levels, and glycosylated hemoglobin levels in diabetic rats. Additionally, allantoin therapy led to a dose-dependent increase in body weight growth and serum insulin levels. In addition, the administration of allantoin resulted in a considerable reduction in lipid profile levels and amelioration of histological alterations in rats with diabetes. The administration of allantoin to diabetic rats resulted in a notable decrease in Malondialdehyde (MDA) levels, accompanied by an increase in the activity of antioxidant enzymes in the serum, liver, and kidney. The findings of oral glucose tolerance and hyperinsulinemic-euglycemic clamp tests demonstrated a significant rise in insulin resistance following the administration of allantoin. The upregulation of IRS-2/PI3K/p-Akt/GLUT expression by allantoin suggests a mechanistic relationship between the PI3K/Akt signaling pathway and the antihyperglycemic activity of allantoin. Furthermore, it resulted in a reduction in the levels of TGF-β1/p38MAPK/Caspase-3 expression in the aforementioned rat tissues affected by diabetes.

Conclusions

This study implies that allantoin treats type 2 diabetes by activating PI3K. Additionally, it reduces liver, kidney, and pancreatic apoptosis and inflammation-induced insulin resistance.re.

Artesunate Exerts Organ- and Tissue-Protective Effects by Regulating Oxidative Stress, Inflammation, Autophagy, Apoptosis, and Fibrosis: A Review of Evidence and Mechanisms

The human body comprises numerous organs and tissues operating in synchrony, it facilitates metabolism, circulation, and overall organismal function. Consequently, the well-being of our organs and tissues significantly influences our overall health. In recent years, research on the protective effects of artesunate (AS) on various organ functions, including the heart, liver, brain, lungs, kidneys, gastrointestinal tract, bones, and others has witnessed significant advancements. Findings from in vivo and in vitro studies suggest that AS may emerge as a newfound guardian against organ damage. Its protective mechanisms primarily entail the inhibition of inflammatory factors and affect anti-fibrotic, anti-aging, immune-enhancing, modulation of stem cells, apoptosis, metabolic homeostasis, and autophagy properties. Moreover, AS is attracting a high level of interest because of its obvious antioxidant activities, including the activation of Nrf2 and HO-1 signaling pathways, inhibiting the release of reactive oxygen species, and interfering with the expression of genes and proteins associated with oxidative stress. This review comprehensively outlines the recent strides made by AS in alleviating organismal injuries stemming from various causes and protecting organs, aiming to serve as a reference for further in-depth research and utilization of AS.

Novel artesunate-metformin conjugate inhibits bladder cancer cell growth associated with Clusterin/SREBP1/FASN signaling pathway

Bladder cancer remains the 10th most common cancer worldwide. In recent years, metformin has been found to have potential anti-bladder cancer activity while high concentration of IC50 at millimolar level is needed, which could not be reached by regular oral administration route. Thus, higher efficient agent is urgently demanded for clinically treating bladder cancer. Here, by conjugating artesunate to metformin, a novel artesunate-metformin dimer triazine derivative AM2 was designed and synthesized. The inhibitory effect of AM2 on bladder cancer cell line T24 and the mechanism underlying was determined. Anti-tumor activity of AM2 was assessed by MTT, cloning formation and wound healing assays. Decreasing effect of AM2 on lipogenesis was determined by oil red O staining. The protein expressions of Clusterin, SREBP1 and FASN in T24 cells were evaluated by Western blotting. The results show that AM2 significantly inhibited cell proliferation and migration at micromolar level, much higher than parental metformin. AM2 reduced lipogenesis and down-regulated the expressions of Clusterin, SREBP1 and FASN. These results suggest that AM2 inhibits the growth of bladder cancer cells T24 by inhibiting cellular lipogenesis associated with the Clusterin/SREBP1/FASN signaling pathway.

Improvement effect of gemigliptin on salivary gland dysfunction in exogenous methylglyoxal-injected rats

The symptom of hyposalivation associated with hypofunction of the salivary glands is a common feature of diabetes. Inadequate saliva production can cause tissue damage in the mouth, making it susceptible to infections and leading to oral health diseases. Previous studies have highlighted the harmful effects of methylglyoxal (MGO) and MGO-derived advanced glycation end products (AGEs) in diabetes. In this study, we investigated the protective effects of gemigliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, against MGO-induced salivary gland dysfunction. MGO treatment of immortalized human salivary gland acinar cells induced apoptosis via reactive oxygen species (ROS)-mediated pathways, but this effect was mitigated by gemigliptin. In vivo experiments involved the simultaneous administration of MGO (17.25 mg/kg) with aminoguanidine (100 mg/kg) and gemigliptin (10 and 100 mg/kg) daily to rats for two weeks. Gemigliptin increased the saliva volume and amylase levels in MGO-injected rats. Gemigliptin reduced the DPP-4 activity in both the salivary glands and serum of MGO-injected rats. Furthermore, gemigliptin exerted anti-glycation effects by reducing the accumulation of AGEs in the saliva, salivary glands, and serum and suppressing the expression of the receptor for AGEs. These actions protected the salivary gland cells from ROS-mediated apoptosis. Overall, gemigliptin protected the salivary gland cells from ROS-mediated cell death, reduced the accumulation of amylase and mucins in the salivary glands, and enhanced the salivary function by upregulating aquaporin 5 expression, and it exerted protective effects against MGO-induced salivary gland dysfunction by enhancing the anti-glycation, antioxidant, and salivary secretion activities. Our findings suggest gemigliptin as a potential therapeutic for patients with salivary gland dysfunction caused by the complications of diabetes.

Artesunate Alleviates Kidney Fibrosis in Type 1 Diabetes with Periodontitis Rats via Promoting Autophagy and Suppression of Inflammation

To explore the effect of periodontal disease on the progression of diabetic kidney disease (DKD), to observe the effects of artesunate (ART) intervention on periodontal and kidney tissues in type 1 diabetic rats with periodontitis, and to explore the possibility of ART for the treatment of DKD. Rat models of diabetes mellitus, periodontitis, and diabetes mellitus with periodontitis were established through streptozotocin (STZ) intraperitoneal injection, maxillary first molar ligation, and P. gingivalis ligation applied sequentially. Ten weeks after modeling, ART gavage treatment was given for 4 weeks. Immunohistochemistry, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and Western blot were used to investigate the inflammatory factors, fibrogenisis, autophagy-related factors, and proteins in periodontal and kidney tissues, and 16S rDNA sequencing was used to detect the changes in dental plaque fluid and kidney tissue flora. Compared to the control group, the protein expression levels of transforming growth factor β1 (TGF-β1) and COL-IV in the periodontal disease (PD) group were increased. The protein expression of TGF-β1, Smad3, and COL-IV increased in the DM group and the DM + PD group, and the expression of TGF-β1, Smad3, and COL-IV was upregulated in the DM + PD group. These results suggest that periodontal disease enhances renal fibrosis and that this process is related to the TGF-β1/Smad/COL-IV signaling pathway. Among the top five dominant bacteria in the kidney of the DM + PD group, the abundance of Proteobacteria increased most significantly, followed by Actinobacteria and Firmicutes with mild increases. The relative abundance of Proteobacteria, Actinobacteria, and Firmicutes in the kidney tissues of DM and PD groups also showed an increasing trend compared with the CON group. Proteobacteria and Firmicutes in the kidney of the PD group and DM + PD group showed an increasing trend, which may mediate the increase of oxidative stress in the kidney and promote the occurrence and development of DN. Periodontal disease may lead to an imbalance of renal flora, aggravate renal damage in T1DM, cause glomerular inflammation and renal tubulointerstitial fibrosis, and reduce the level of autophagy. ART delays the process of renal fibrosis by inhibiting the TGF-β-Smad signaling pathway.

Modes and Mechanisms of Salivary Gland Epithelial Cell Death in Sjogren's Syndrome

Sjogren's syndrome is an autoimmune disease in middle and old-aged women with a dry mucosal surface, which is caused by the dysfunction of secretory glands, such as the oral cavity, eyeballs, and pharynx. Pathologically, Sjogren's syndrome are characterized by lymphocyte infiltration into the exocrine glands and epithelial cell destruction caused by autoantibodies Ro/SSA and La/SSB. At present, the exact pathogenesis of Sjogren's syndrome is unclear. Evidence suggests epithelial cell death and the subsequent dysfunction of salivary glands as the main causes of xerostomia. This review summarizes the modes of salivary gland epithelial cell death and their role in Sjogren's syndrome progression. The molecular mechanisms involved in salivary gland epithelial cell death during Sjogren's syndrome as potential leads to treating the disease are also discussed.

Effect of artesunate on cardiovascular complications in periodontitis in a type I diabetes rat model and related mechanisms

PURPOSE

Both cardiovascular disease and periodontitis are complications of diabetes that have a great impact on human life and health. Our previous research found that artesunate can effectively improve cardiovascular disease in diabetes and has an inhibitory effect on periodontal disease. Therefore, the present study aimed to explore the potential therapeutic possibility of artesunate in the protection against cardiovascular complications in periodontitis with type I diabetes rats and to elucidate the possible underlying mechanisms.

METHODS

Sprague‒Dawley rats were randomly divided into the healthy, diabetic, periodontitis, diabetic with periodontitis, and artesunate treatment groups (10, 30, and 60 mg/kg, i.g.). After artesunate treatment, oral swabs were collected and used to determine changes in the oral flora. Micro-CT was performed to observe changes in alveolar bone. Blood samples were processed to measure various parameters, while cardiovascular tissues were evaluated by haematoxylin-eosin, Masson, Sirius red, and TUNEL staining to observe fibrosis and apoptosis. The protein and mRNA expression levels in the alveolar bone and cardiovascular tissues were detected using immunohistochemistry and RT‒PCR.

RESULTS

Diabetic rats with periodontitis and cardiovascular complications maintained heart and body weight but exhibited reduced blood glucose levels, and they were able to regulate blood lipid indicators at normal levels after artesunate treatment. The staining assays suggested that treatment with 60 mg/kg artesunate has a significant therapeutic effect on myocardial apoptotic fibrosis. The high expression of NF-κB, TLR4, VEGF, ICAM-1, p38 MAPK, TGF-β, Smad2, and MMP9 in the alveolar bone and cardiovascular tissue in the type I diabetes and type I diabetes with periodontitis rat models was reduced after treatment with artesunate in a concentration-dependent manner. Micro-CT showed that treatment with 60 mg/kg artesunate effectively alleviated alveolar bone resorption and density reduction. The sequencing results suggested that each model group of rats had vascular and oral flora dysbiosis, but artesunate treatment could correct the dysbacteriosis.

CONCLUSIONS

Periodontitis-related pathogenic bacteria cause dysbiosis of the oral and intravascular flora in type I diabetes and aggravate cardiovascular complications. The mechanism by which periodontitis aggravates cardiovascular complications involves the NF-κB pathway, which induces myocardial apoptosis, fibrosis, and vascular inflammation.

Role of artesunate in autoimmune diseases and signaling pathways

Artesunate (ART) is a derivative of artemisinin. Compared with artemisinin, ART has excellent water solubility, high stability and oral bioavailability. In this review, the application of ART in classic autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and ulcerative colitis is summarized. ART exhibited similar or even better efficacy than other highly effective immunosuppressive agents, such as methotrexate and cyclophosphamide. In addition, ART exerts its pharmacological effects mainly by inhibiting the production of inflammatory factors, reactive oxygen species, autoantibodies and the migration of cells to reduce damage to tissues or organs. Moreover, ART widely affected the NF-κB, PI3K/Akt, JAK/STAT and MAPK pathways to exert pharmacological effects.

Role of Fibrinogen in Type-2 Diabetes Mellitus with Diabetic Neuropathy and its Preliminary Mechanism

INTRODUCTION

Diabetic peripheral neuropathy (DN) is the most common complication of type 2 diabetes mellitus (T2DM).

OBJECTIVE

This study aimed to explore the role of fibrinogen (FIB) in T2DM neuropathy and its preliminary mechanism.

METHODS

Ten male Sprague-Dawley rats were divided into a normal control group (NC group) and a T2DM neuropathy model group (DN group). The DN group was given a high-energy diet and streptozotocin, while the NC group was given a normal diet and a citric acid buffer. The expression levels of related proteins were analysed.

RESULTS

Electrophysiology: Compared with the NC group, the conduction latency of the somatosensory-evoked potential and nerve conduction velocity was prolonged in the DN group, while the motor nerve action potential was decreased. As seen under a light microscope, the peripheral nerve fibres in the DN group were swollen, and the nerve fibres in the posterior funiculus of the spinal cord were loose or missing. Moreover, as seen under an electron microscope, the peripheral nerve demyelination of the DN group was severe, with microvascular blood coagulation, luminal stenosis, and collapse. Compared with the NC group, in the DN group, the expression of FIB was positively correlated with the expression of both ionised calcium-binding adaptor molecule-1 and glial fibrillary acidic protein. Compared with the NC group, in the DN group, the expression of platelet/endothelial cell adhesion molecule-1 and B-cell lymphoma 2 was negatively correlated.

CONCLUSION

The increased concentration of FIB may be the cause of neuropathy, and its mechanism may be related to its promotion of inflammatory response, blood coagulation, and vascular stenosis.

Therapeutic potential of artemisinin and its derivatives in managing kidney diseases

Artemisinin, an antimalarial traditional Chinese herb, is isolated from Artemisia annua. L, and has shown fewer side effects. Several pieces of evidence have demonstrated that artemisinin and its derivatives exhibited therapeutic effects on diseases like malaria, cancer, immune disorders, and inflammatory diseases. Additionally, the antimalarial drugs demonstrated antioxidant and anti-inflammatory activities, regulating the immune system and autophagy and modulating glycolipid metabolism properties, suggesting an alternative for managing kidney disease. This review assessed the pharmacological activities of artemisinin. It summarized the critical outcomes and probable mechanism of artemisinins in treating kidney diseases, including inflammatory, oxidative stress, autophagy, mitochondrial homeostasis, endoplasmic reticulum stress, glycolipid metabolism, insulin resistance, diabetic nephropathy, lupus nephritis, membranous nephropathy, IgA nephropathy, and acute kidney injury, suggesting the therapeutic potential of artemisinin and its derivatives in managing kidney diseases, especially the podocyte-associated kidney diseases.

Monomethyl lithospermate alleviates ischemic stroke injury in middle cerebral artery occlusion mice in vivo and protects oxygen glucose deprivation/reoxygenation induced SHSY-5Y cells in vitro via activation of PI3K/Akt signaling

Stroke is a fatal neurological disease, which seriously threatens human health and life. Ischemic stroke (IS) is the most common type of stroke in clinic. Its pathogenesis is very complex, mainly caused by nerve damage caused by brain blood supply disorder. Previous studies have confirmed that natural products play important roles in improving neurological disorders. Furthermore, our previous results also suggested that Shenxiong Tongmai granule, a clinically used herbal medicines’ prescription, has a good ameliorating effect on IS. In the present study, we found that Monomethyl lithospermate (MOL), a constituent of Shenxiong Tongmai granule, significantly improved the neurological damage in middle cerebral artery occlusion (MCAO) rats. MOL can significantly improve the neurological deficit score of MCAO rats, and improve the damage of hippocampal neurons caused by ischemia-reperfusion (IR). At the same time, we also found that MOL could reduce the level of oxidative stress in the brain tissues of MCAO rats. Furthermore, the oxygen and glucose deprivation/Reoxygenation (OGD/R)-induced SHSY-5Y cell model was established in vitro to investigate the pharmacological activity and molecular mechanisms of MOL in improving the nerve injury of IS rats. The results showed that MOL could increase the cell viability of SHSY-5Y cells, inhibit the mitochondrial membrane potential (MMOP) collapse and suppress apoptosis. In addition, MOL also ameliorated the elevated oxidative stress level caused by OGR/R treatment in SHSY-5Y cells. Further mechanistic studies showed that MOL could activate the PI3K/AKT pathway via promoting the phosphorylation of PI3K and AKT in MCAO rats and OGR/R-induced SHSY-5Y cells, which could be partially blocked by addition of PI3K/AKT pathway inhibitor of LY294002. Taken together, our current study suggested that MOL exerts a protective effect against neural damage caused by IS in vivo and in vitro by activating the PI3K/AKT pathway.

Profiling the lncRNA-miRNA-mRNA interaction network in the submandibular gland of diabetic mice

BACKGROUND

Hyposalivation is one of the common symptoms of diabetes. Although long non-coding RNAs (lncRNAs) have recently been reported to play important roles in the pathogenesis of diabetes, the role of lncRNAs in diabetes-induced hyposalivation remains unknown.

METHODS

The present study aimed to explore the function of lncRNA-microRNA-mRNA regulatory network in the submandibular gland (SMGs) under the context of diabetes. LncRNA expression profile of the SMGs was analyzed using microarray technology. Differentially expressed lncRNAs were confirmed using real-time quantitative PCR. Bioinformatics analyses were performed, and Coding-non-coding gene co-expression (CNC) and competing endogenous RNA (ceRNA) networks were constructed to explore the potential mechanisms of diabetes-induced hyposalivation.

RESULTS

A total of 1273 differentially expressed lncRNAs (536 up-regulated and 737 downregulated) were identified in the SMGs tissues of db/db mice. CNC and ceRNA network analyses were performed based on five differentially expressed lncRNAs validated by real-time quantitative PCR. Gene Ontology analysis of target genes of CNC network revealed that "calcium ion binding" was a highly enriched molecular function. Kyoto Encyclopedia of Genes and Genomes pathway analysis of target genes of ceRNA network revealed that the "mammalian target of rapamycin signaling pathway" was significantly enriched.

CONCLUSIONS

On the whole, the findings of the present study may provide insight into the possible mechanism of diabetes-induced hyposalivation.