Antidiabetic and Antiobesity Effects of Artemether in db/db Mice

Artemisinin and its derivatives modulate glucose homeostasis and gut microbiota remodeling in a nutritional context

Glucose metabolic disorders, prevalent in numerous metabolic diseases, have become a pressing global public health concern. Artemisinin (ART) and its derivatives, including artesunate (ARTs) and artemether (ARTe), have shown potential as metabolic regulators. However, the specific effects of ART and its derivatives on glucose metabolism under varying nutritional conditions and the associated molecular mechanisms remain largely unexplored. In this study, we examined the impact of ART, ARTs, and ARTe on glucose homeostasis using a mouse model subjected to different dietary regimens. Our findings revealed that ART, ARTs, and ARTe increased blood glucose levels in mice on a normal-chow diet (ND) while mitigating glucose imbalances in high-fat diet (HFD) mice. Notably, treatment with ART, ARTs, and ARTe had contrasting effects on in vivo insulin signaling, impairing it in ND mice and enhancing it in HFD mice. Moreover, the composition of gut microbiota underwent significant alterations following administration of ART and its derivatives. In ND mice, these treatments reduced the populations of bacteria beneficial for improving glucose homeostasis, including Parasutterella, Alloprevotella, Bifidobacterium, Ileibacterium, and Alistipes. In HFD mice, there was an increase in the abundance of beneficial bacteria (Alistipes, Akkermanisia) and a decrease in bacteria known to negatively impact glucose metabolism (Coprobacillus, Helicobacter, Mucispirillum, Enterorhabdus). Altogether, ART, ARTs, and ARTe exhibited distinct effects on the regulation of glucose metabolism, depending on the nutritional context, and these effects were closely associated with modifications in gut microbiota composition.

Dietary interventions improve diabetic kidney disease, but not peripheral neuropathy, in a db/db mouse model of type 2 diabetes

Patients with type 2 diabetes often develop the microvascular complications of diabetic kidney disease (DKD) and diabetic peripheral neuropathy (DPN), which decrease quality of life and increase mortality. Unfortunately, treatment options for DKD and DPN are limited. Lifestyle interventions, such as changes to diet, have been proposed as non-pharmacological treatment options for preventing or improving DKD and DPN. However, there are no reported studies simultaneously evaluating the therapeutic efficacy of varying dietary interventions in a type 2 diabetes mouse model of both DKD and DPN. Therefore, we compared the efficacy of a 12-week regimen of three dietary interventions, low carbohydrate, caloric restriction, and alternate day fasting, for preventing complications in a db/db type 2 diabetes mouse model by performing metabolic, DKD, and DPN phenotyping. All three dietary interventions promoted weight loss, ameliorated glycemic status, and improved DKD, but did not impact percent fat mass and DPN. Multiple regression analysis identified a negative correlation between fat mass and motor nerve conduction velocity. Collectively, our data indicate that these three dietary interventions improved weight and glycemic status and alleviated DKD but not DPN. Moreover, diets that decrease fat mass may be a promising non-pharmacological approach to improve DPN in type 2 diabetes given the negative correlation between fat mass and motor nerve conduction velocity.

Artemisinin attenuates type 2 diabetic cardiomyopathy in rats through modulation of AGE-RAGE/HMGB-1 signaling pathway

Diabetes mellitus is a common metabolic disorder. About two-thirds of diabetic patients develop diabetic cardiomyopathy (DCM), which becomes a challenging issue as it severely threatens the patient's life. Hyperglycemia and the resulting advanced glycated end products (AGE) and their receptor (RAGE)/High Mobility Group Box-1 (HMGB-1) molecular pathway are thought to be key players. Recently, artemisinin (ART) has gained more attention owing to its potent biological activities beyond its antimalarial effect. Herein, we aim to evaluate the effect of ART on DCM and the possible underlying mechanisms. Twenty-four male Sprague-Dawley rats were divided into: control, ART, type 2 diabetic and type 2 diabetic treated with ART groups. At the end of the research, the ECG was recorded, then the heart weight to body weight (HW/BW) ratio, fasting blood glucose, serum insulin and HOMA-IR were evaluated. Cardiac biomarkers (CK-MB and LDH), oxidative stress markers, IL-1β, AGE, RAGE and HMGB-1 expression were also measured. The heart specimens were stained for H&E as well as Masson's trichrome. DCM induced disturbances in all studied parameters; contrary to this, ART improved these insults. Our study concluded that ART could improve DCM through modulation of the AGE-RAGE/HMGB-1 signaling pathway, with subsequent impacts on oxidative stress, inflammation and fibrosis. ART could therefore be a promising therapy for the management of DCM.

Effect of oral cannabis administration on the fat depots of obese and streptozotocin-induced diabetic rats

The prevalence of obesity and insulin-resistance is on the rise, globally. Cannabis have been shown to have anti-diabetic/obesity properties, however, the effect mediated at various fat depots remains to be clarified. The aim of this study was to (1) investigate the anti-diabetic property of an oral cannabis administration in an obese and streptozotocin-induced diabetic rat model and (2) to determine and compare the effect mediated at the peritoneal and intramuscular fat level. Cannabis concentration of 1.25 mg/kg body weight (relative to THC content) was effective in reversing insulin-resistance in the rat model, unlike the other higher cannabinoid concentrations. At the peritoneal fat level, gene expression of fat beigeing markers, namely Cidea and UCP1, were significantly increased compared to the untreated control. At the intramuscular fat level, on the other hand, CE1.25 treatment did not promote fat beigeing but instead significantly increased mitochondrial activity, relative to the untreated control. Therefore, these findings indicate that the mechanism of action of oral cannabis administration, where glucose and lipid homeostasis is restored, is not only dependent on the dosage but also on the type of fat depot investigated.

The controversy about the effects of artemisinins on pancreatic α cell reprogramming and diabetes

It has been reported that artemisinin treatment induces β cell regeneration and alleviates hyperglycemia, although the therapeutic potential and mechanism have been questioned by various groups. We discuss the existing evidence and future plans for studies on artemisinins in the context of diabetes research.

Reduction of NADPH oxidase 4 in adipocytes contributes to the anti-obesity effect of dihydroartemisinin

Artemisinin derivatives have been found to have anti-obesity effects recently, but the mechanism is still controversial. Herein, long-term DHA treatment in obese mice significantly reduced the body weight and improved glucose metabolism. However, short-term DHA treatment did not affect glucose metabolism in obese mice, suggesting that the improved glucose metabolism in mice with DHA treatment could be secondary to body weight reduction. Consistent with previous reports, we observed that DHA inhibited the differentiation of adipocytes. Mechanistically, DHA significantly reduced the expression of NADPH oxidase 4 (NOX4) in white adipose tissue (WAT) of mice and differentiated adipocytes, and using NOX4 siRNA or the NOX4 inhibitor GKT137831 significantly attenuated adipocyte differentiation. Over-expression of NOX4 partially reversed the inhibition effect of DHA on adipogenic differentiation of preadipocytes. In addition, targeted proteomics analysis showed that DHA improved the abnormality of metabolic pathways. In conclusion, DHA significantly reduced fat mass and improved glucose metabolism in obese mice, possibly by inhibiting NOX4 expression to suppress adipocyte differentiation and lipid accumulation in adipocytes.

A Single Strain of Lactobacillus (CGMCC 21661) Exhibits Stable Glucose- and Lipid-Lowering Effects by Regulating Gut Microbiota

Type 2 diabetes (T2D) is usually accompanied by obesity and nonalcoholic fatty-liver-related insulin resistance. The link between T2D and dysbiosis has been receiving increasing attention. Probiotics can improve insulin sensitivity by regulating imbalances in microbiota, but efficacy varies based on the probiotic used. This study screened the main strain in the feces of healthy adult mice and found it to be a new Lactobacillus (abbreviated as Lb., named as CGMCC No. 21661) after genetic testing. We designed the most common Bifidobacterium longum subsp. longum (CGMCC1.2186, abbreviated as B. longum. subsp.), fecal microbiota transplantation (FMT), and Lb. CGMCC No. 21661 protocols to explore the best way for modulating dysbiosis to improve T2D. After 6 weeks of gavage in T2D mice, it was found that all three protocols had a therapeutic alleviating effect. Among them, compared with the B. longum. subsp. and FMT, the Lb. CGMCC No. 21661 showed a 1- to 2-fold decrease in blood glucose (11.84 ± 1.29 mmol/L, p < 0.05), the lowest HOMA-IR (p < 0.05), a 1 fold increase in serum glucagon-like peptide-1 (5.84 ± 1.1 pmol/L, p < 0.05), and lowest blood lipids (total cholesterol, 2.21 ± 0.68 mmol/L, p < 0.01; triglycerides, 0.4 ± 0.15 mmol/L, p < 0.01; Low-density lipoprotein cholesterol, 0.53 ± 0.16 mmol/L, p < 0.01). In addition, tissue staining in the Lb. CGMCC No. 21661 showed a 2- to 3-fold reduction in T2D-induced fatty liver (p < 0.0001), a 1- to 2-fold decrease in pancreatic apoptotic cells (p < 0.05), and a significant increase in colonic mucus layer thickness (p < 0.05) compared with the B. longum. subsp. and FMT. The glucose and lipid lowering effects of this Lb. CGMCC No. 21661 indicate that it may provide new ideas for the treatment of diabetes.

Artemether treatment improves islet function and metabolic homeostasis in diabetic nonhuman primates

Highlights Artemether increased the serum concentration of c‐peptide and decreased the usage of insulin in the diabetic monkey. Artemether downregulated the serum concentration of total cholesterol and low‐density lipoprotein cholesterol in the diabetic monkey. Artemether did not induce dramatic changes of the concentration of liver or kidney damage markers in the serum.

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.

Therapeutic role of Artemether in the prevention of hepatic steatosis through miR‐34a‐5p/PPARα pathway

Artemether (ATM) is a natural antimalarial drug that can also regulate glucose and lipid metabolism. However, little is known regarding its pharmacological action in metabolic dysfunction-associated fatty liver disease (MAFLD), and the underlying mechanisms remain undetermined. The aim of this study was to explore the therapeutic effects of ATM against hepatic steatosis and the possible mechanisms. ATM significantly decreased blood glucose levels, improved glucose tolerance, reduced inflammatory response, and alleviated hepatic steatosis in the ob/ob mouse model as well as the high-fat diet-fed mice. ATM also inhibited lipid accumulation in murine hepatocytes in vitro. Using RNA sequencing, miR-34a-5p and peroxisome proliferator-activated receptor-α (PPARα) were identified as important regulators during ATM treatment. ATM administration downregulated miR-34a-5p expression and miR-34a-5p abrogated the inhibitory effects of ATM on PO (palmitate + oleate)-induced lipid accumulation as well as triglycerides levels in murine hepatocytes. Furthermore, the expression of PPARα, a target gene of miR-34a-5p, was upregulated by ATM and PPARα inhibitor MK-886 abolished the positive effect of ATM. Consequently, PPARα agonist fenofibrate reversed the decreased mitochondrial fatty acid β-oxidation induced by miR-34a-5p mimics after ATM treatment, thereby leading to attenuation of intracellular lipid accumulation. Taken together, ATM is a promising therapeutic agent against MAFLD that reduces lipid deposition by suppressing miR-34a-5p and upregulating PPARα.

Artemisia annua L. Extracts Improved Insulin Resistance via Changing Adiponectin, Leptin and Resistin Production in HFD/STZ Diabetic Mice

Objectives

Insulin resistance (IR) is major cause of type 2 diabetes (T2D), and adipokines (e.g., adiponectin, leptin, and resistin) play an important role in insulin sensitivity. Medicinal plants are frequently used for T2D treatment. This study investigates the effect of Artemisia annua L. (AA) extracts on adipokines in mice with high-fat-diet (HFD)/streptozotocin (STZ)-induced T2D.

Methods

We divided 60 mice into 12 groups (n = 5 per group) control, untreated T2D, treated T2D, and 9 other groups. T2D was induced in all groups, except controls, by 8 weeks of HFD and STZ injection. The treated T2D group was administered 250 mg/kg of metformin (MTF), while the nine other groups were treated with 100, 200, and 400 mg/kg of hot-water extract (HWE), cold-water extract (CWE), and alcoholic extract (ALE) of AA (daily oral gavage) along with 250 mg/kg of MTF for 4 weeks. The intraperitoneal glucose tolerance test (IPGTT) was performed, and the homeostasis model assessment of adiponectin (HOMA-AD) index and blood glucose and serum insulin, leptin, adiponectin, and resistin levels were measured.

Results

Similar to MTF, all three types of AA extracts (HWEs, CWEs, and ALEs) significantly (p < 0.0001) decreased the area under the curve (AUC) of glucose during the IPGTT, the HOMA-AD index, blood glucose levels, and serum insulin, leptin, and resistin levels and increased serum adiponectin levels in the MTF group compared to the T2D group (p < 0.0001). The HWEs affected adipokine release, while the CWEs and ALEs decreased leptin and resistin production.

Conclusion

Water and alcoholic AA extracts have an antihyperglycemic and antihyperinsulinemic effect on HFD/STZ diabetic mice. In addition, they decrease IR by reducing leptin and resistin production and increasing adiponectin secretion from adipocytes.

Artemether Ameliorates Non-Alcoholic Steatohepatitis by Repressing Lipogenesis, Inflammation, and Fibrosis in Mice

Background: Non-alcoholic fatty liver disease (NAFLD) is a widespread disease, but no recognized drug treatment exists. Previous studies have shown that artemether (Art) can ameliorate carbon tetrachloride (CCl₄)–induced liver fibrosis in mice. This study sets out to observe the therapeutic impact of Art on non-alcoholic steatohepatitis (NASH).

Methods: Model mice were provided with a methionine- and choline-deficient (MCD) diet for 4 weeks or a high-fat diet (HFD) for 28 weeks, respectively, and then treated with Art. RNA sequencing (RNA-Seq) analyzed gene expression changes caused by Art treatment. The molecular mechanism of the therapeutic effects of Art on NASH was studied in the mouse liver and HepG2 cells.

Results: Art treatment significantly attenuated hepatic lipid accumulation and liver damage in MCD diet– or HFD-induced NASH mice. The RNA-Seq analysis revealed lipid metabolism as a major pathway suppressed by Art administration, in addition to the regulation of inflammation pathways. Mechanistically, Art reduced lipid accumulation by repressing de novo lipogenesis of sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD1), promoting lipolysis of peroxisome proliferator–activated receptor-γ co-activator-1α (PGC1α), adipose triglyceride lipase (ATGL), and carnitine palmitoyltransferase I (CPT-1a) in NASH mouse liver and HepG2 cells. In addition, Art inhibited the secretion of pro-inflammatory factors and reduced inflammatory infiltration by effectively inhibiting M1 macrophage activation. Furthermore, Art inhibited transforming growth factor-beta 1 (TGF-β), and the SMAD signaling pathway mediates the development of liver fibrosis.

Inclusion: Art improved fat deposition by repressing de novo lipogenesis and promoting lipolysis in vivo and in vitro. Furthermore, Art improved inflammation and fibrosis with a significant effect. It is a prospective therapeutic agent for NASH.

Effect of artemisinin on improving islet function in rats fed with maternal high-fat diet

BACKGROUND

Maternal high-fat diet (HFD) is a detrimental factor in developing glucose intolerance, obesity, and islet dysfunction. However, the effect of artemisinin on maternal HFD and whether it is related to the alterations of islet function is seldom studied since artemisinin treatments not only attenuate insulin resistance (IR) and restore islet ß cell function in Diabetes mellitus type 2.

METHODS

Female rats were randomly fed a HFD (45% kcal from fat), HFD + artemisinin, or a regular chow diet (RCD) before pregnancy and during gestation. Glucose metabolism and the β cell phenotypes were assessed.

RESULTS

Maternal HFD increased islet load in female rats, proliferation of pancreatic β cells, increased insulinogen, and decreased insulin secretion response to high glucose stimulation with delayed insulin release, increased fasting glucose, and glucose area under the curve compared with the general diet group. HFD inhibited expression of Foxo1 and PAX6 in female rats. Under the effect of both HFD and pregnancy, islet load was further increased, insulinogen was further increased, and fasting insulin level and fasting glucose were higher than RCD fed general-pregnancy group. ALDH1a3 transdifferentiation and PAX6, Foxo1, and PDX1 expression were increased in islets of high-fat pregnant rats. When adding artemisinin in HFD treated pregnant rats, islet function was significantly improved.

CONCLUSIONS

Intervention with artemisinin in maternal HFD resulted in reduced islet size, decreased number of β-cells and improved islet microcirculation, insulin processing shear process, decreased insulinogen/insulin ratio, and restored islet function through increased expression of PC1/3.

Combination therapy with artemether and enalapril improves type 1 diabetic nephropathy through enhancing antioxidant defense

Previous studies have demonstrated that both artemether and enalapril are effective in treating diabetic nephropathy (DN). However, the effects and underlying mechanisms of their combination in treating DN remain unknown. The experimental DN model was induced by injecting streptozotocin (STZ) into male C57BL/6J mice. Mice were randomly allocated to the Type 1 diabetes control (T1D-ctrl), STZ, STZ + artemether (STZ + Art), STZ + enalapril (STZ + ACEi), or STZ + artemether + enalapril (STZ + Art + ACEi) group. The interventions lasted for 8 weeks. At the end of the experiment, related urine and serum biochemical values, such as urinary albumin excretion (UAE) and fasting blood glucose (FBG), were measured. In addition, blood pressure (BP) and kidney morphologic changes were also evaluated. The expression of oxidative stress related molecules, such as catalase, acetylated SOD2 (k68) and acetylated SOD2 (k122) in the kidney were measured. Results: combination therapy showed more pronounced effects in reducing UAE, FBG, and BP than any single drug. Typical diabetic kidney injuries, such as heavier kidney weight, and glomerular and tubular hypertrophy, were also further alleviated by combination therapy. Combination therapy also up-regulated the expression of catalase and down-regulated the expression of acetylated SOD2 (k68) and acetylated SOD2 (k122). Combination therapy with artemether and enalapril exhibited renoprotective effects in STZ-induced T1D mice superior to a single drug. The mechanism might be associated with their synergistic effects in enhancing antioxidant defense.

Artemisinin relieves myocardial ischemia-reperfusion injury via modulating miR-29b-3p and hemicentin 1

Objective: To explore the impact of artemisinin (ARS) on myocardial ischemia-reperfusion (I/R) injury and the underlying mechanism. Methods: Myocardial I/R rat model and cell model were used in this study. The cell viability, morphological changes, apoptosis, and oxidative stress were evaluated in cardiomyocytes H9c2 cells in vitro by using cell counting kit-8, microscope, flow cytometry, and commercial kits. High throughput sequencing is used to identify molecular targets of ARS on myocardial I/R injury, and then the gene-gene interaction network was constructed. MiR-29b-3p, hemicentin 1 (HMCN1), and apoptosis-related genes were tested by qRT-PCR and Western blotting. In the myocardial I/R rat model, echocardiography, (Triphenyl tetrazolium chloride) TTC staining, Hematoxylin-eosin (H&E) staining, Masson Trichrome staining, and TUNEL staining are applied to evaluate the protective effect of ARS on the myocardial injury. Results: In vitro, we demonstrated that ARS alleviated H₂O₂-induced myocardial I/R injury, manifested by increased H9c2 viability, decreased pathological changes, apoptosis, and oxidative stress biomarker ROS, LDH, and CK-MB. Then, sequencing analysis revealed that miR-29b-3p/HMCN1 was the target of ARS for myocardial I/R injury. Notably, rescue experiments indicated that ARS inhibited myocardial I/R injury through targeted regulation miR-29b-3p/HMCN1. In vivo, we confirmed that ARS reduced myocardial injury, fibrosis, and apoptosis via modulation of miR-29b-3p/HMCN1. Conclusion: This study demonstrated the functional role of the ARS/miR-29b-3p/HMCN1 axis in alleviating myocardial I/R injury, which provided a new direction for myocardial I/R injury therapy.

Efficacy of artemisinin and its derivatives in animal models of type 2 diabetes mellitus: A systematic review and meta-analysis

Although current evidence suggests that artemisinin and its derivatives play a multitarget therapeutic role in type 2 diabetes mellitus (T2DM), their efficacy and safety remain under debate. This meta-analysis aimed to evaluate the effects and safety of artemisinin and its derivatives in T2DM animal models. Preclinical studies that met the inclusion criteria were retrieved from PubMed, Embase, Web of Science, Scopus, CINAHL, OpenGrey, Google Scholar, Psyclnfo, British Library Ethos, ProQuest Dissertations & Theses, China National Knowledge Internet, VIP Information Chinese Periodical Service Platform, Chinese Biomedicine Literature Database, and Wanfang Data Knowledge Service Platform. Twenty-two studies involving 526 animals were included in the meta-analysis. The RevMan 5.3 and Stata 15.0, were used to perform the statistical analyses. The overall results showed that artemisinin or its derivatives could significantly reduce fasting plasma glucose, 2-h plasma glucose (2hPG) in the intraperitoneal glucose tolerance test (IPGTT), 2hPG in the intraperitoneal insulin tolerance test (IPITT), glycated hemoglobin A1c, under the curve in the IPGTT/IPITT, total cholesterol, triglyceride, low-density lipoprotein cholesterol, free fatty acid, and urine volume. Although increase in body weight was observed due to administration of the compounds, no significant effect was observed regarding serum insulin. In terms of adverse reactions, only two of the included studies reported that high-dose artemether may cause digestive inhibition in mice. Our results suggest that artemisinins could improve several parameters related to glycolipid metabolism in T2DM animal models. However, to evaluate the antidiabetic effects and safety of artemisinins in a more accurate manner, additional preclinical studies are necessary.

Aqueous and alcoholic extracts of Artemisia annua L. improved insulin resistance via decreasing TNF-alpha, IL-6 and free fatty acids in high-fat diet/streptozotocin-induced diabetic mice

Objective:

Type 2 diabetes mellitus (T2DM) is a metabolic disease that influences many people worldwide. Management of insulin resistance in T2DM without side effects of chemical drugs, is the ultimate goal of the medical community. Artemisia annua L. is used for the treatment of diabetes in folkloric medicine. The present study investigated the effects of aqueous and alcoholic extracts of A. annua (AA) on insulin resistance in high-fat diet/STZ-induced diabetic mice.

Material and Methods:

Mice were divided into groups including control with a normal diet, un-treated high-fat diet/streptozotocin-induced diabetic mice, and diabetic mice treated by oral administration of 100, 200, and 400 mg/kg body weight of water (hot and cold) and alcoholic extracts of AA. After four weeks of treatment with AA, blood sampling was carried out to measure factors involved in insulin resistance such as low-density lipoprotein/ High-density lipoprotein (LDL/HDL) ratio, free fatty acids, Tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and homeostasis model assessment of insulin resistance (HOMA-IR) as an index of insulin resistance.

Results:

The results showed that all AA extracts (100, 200, and 400 mg/kg) and metformin (250 mg/kg) significantly reduced the serum levels of free fatty acids, TNF-alpha, IL-6, LDL/HDL ratio, and HOMA-IR in diabetic mice compared to untreated diabetic mice (p<0.0001). Notably, the 400 mg/kg dose of cold-water extract was more effective than metformin in reduction of TNF-alpha and IL-6 (p<0.01 and p<0.05, respectively).

Conclusion:

These data illustrated that AA extracts attenuated insulin resistance by reducing the lipid profile and adipocytokines.

Acetone Ingestion Mimics a Fasting State to Improve Glucose Tolerance in a Mouse Model of Gestational Hyperglycemia

Gestational diabetes mellitus results, in part, from a sub-optimal β-cell mass (BCM) during pregnancy. Artemisinins were reported to increase BCM in models of diabetes by α- to β-cell conversion leading to enhanced glucose tolerance. We used a mouse model of gestational glucose intolerance to compare the effects of an artemisinin (artesunate) on glycemia of pregnant mice with vehicle treatment (acetone) or no treatment. Animals were treated daily from gestational days (GD) 0.5 to 6.5. An intraperitoneal glucose tolerance test was performed prior to euthanasia at GD18.5 or post-partum. Glucose tolerance was significantly improved in both pregnant and non-pregnant mice with both artesunate and vehicle-alone treatment, suggesting the outcome was primarily due to the acetone vehicle. In non-pregnant, acetone-treated animals, improved glucose tolerance was associated with a higher BCM and a significant increase in bihormonal insulin and glucagon-containing pancreatic islet cells, suggesting α- to β-cell conversion. BCM did not differ with treatment during pregnancy or post-partum. However, placental weight was higher in acetone-treated animals and was associated with an upregulation of apelinergic genes. Acetone-treated animals had reduced weight gain during treatment despite comparable food consumption to non-treated mice, suggesting transient effects on nutrient uptake. The mean duodenal and ileum villus height was reduced following exposure to acetone. We conclude that acetone treatment may mimic transient fasting, resulting in a subsequent improvement in glucose tolerance during pregnancy.

Artemisinin derivatives inhibit adipogenic differentiation of 3T3-L1 preadipocytes through upregulation of CHOP

Artemisinin derivatives could inhibit adipogenic differentiation of 3T3-L1 preadipocytes and prevent obesity in mice. However, the molecular mechanism remains largely unclear. Our research was designed to investigate the specific molecular target of artemisinin derivatives in adipogenic differentiation of 3T3-L1 preadipocytes. Here, we revealed that in response to dihydroartemisinin (DHA) or artesunate (ATS), intracellular lipid was decreased in a concentration dependent manner as shown by BODIPY staining. Quantitative PCR analysis showed that expression of Cebpa, Pparg, Fabp4 and Plin was significantly decreased by DHA treatment in a concentration and time dependent manner. Also, DHA treatment remarkably downregulated expression of CCAAT/enhancer-binding protein α (C/EBPα) and nuclear receptor peroxisome proliferation-activated receptor γ (PPARγ) of adipogenic induced 3T3-L1 cells as assayed by western blotting. RNA-seq analysis identified thousands of differential expression genes (DEGs), among which CHOP expression was significantly improved in DHA treated cells. Upregulation of CHOP was verified by quantitative PCR and western blotting, respectively. Knockdown of CHOP by the specific shRNA revealed that the inhibition of adipogenesis by DHA was strongly blocked, resulting in restored lipid accumulation and expression of adipogenic molecules. In conclusions, the inhibitory effect of DHA on adipogenic differentiation of 3T3-L1 preadipocytes was exerted in a concentration and time dependent manner, which was mediated by expression of CHOP.

The potential of Artemisia species for use as broad-spectrum agents in the management of metabolic syndrome: a review

Although the prevalence of metabolic syndrome (MetS), a cluster of cardiometabolic risk factors that predispose to the development of type 2 diabetes mellitus and cardiovascular diseases, is increasing globally, there is no broad-spectrum agent for its holistic treatment. Natural plant-derived products with a wide spectrum of biological activities are currently being explored as alternatives in the management of diseases. Artemisia species are a heterozygous group of plants of the Compositae family that possess several health benefits. Here we highlight their antidiabetic, anti-obesity, anti-hyperlipidaemic, hepatoprotective and cardioprotective properties among others. These activities have been linked to the presence of phytochemicals that act on several molecular targets to exert their effects and the species of Artemisia are considered to be relatively safe. Artemisia species offer significant anti-MetS activity and thus are strong therapeutic candidates for the effective management of MetS.

Exploration of artemisinin derivatives and synthetic peroxides in antimalarial drug discovery research

Malaria is a life-threatening infectious disease caused by protozoal parasites belonging to the genus Plasmodium. It caused an estimated 405,000 deaths and 228 million malaria cases globally in 2018 as per the World Malaria Report released by World Health Organization (WHO) in 2019. Artemisinin (ART), a "Nobel medicine" and its derivatives have proven potential application in antimalarial drug discovery programs. In this review, antimalarial activity of the most active artemisinin derivatives modified at C-10/C-11/C-16/C-6 positions and synthetic peroxides (endoperoxides, 1,2,4-trioxolanes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes) are systematically summarized. The developmental trend of ART derivatives, and cyclic peroxides along with their antimalarial activity and how the activity is affected by structural variations on different sites of the compounds are discussed. This compilation would be very useful towards scaffold hopping aimed at avoiding the unnecessary complexity in cyclic peroxides, and ultimately act as a handy resource for the development of potential chemotherapeutics against Plasmodium species.

Artemisinin and dihydroartemisinin promote β-cell apoptosis induced by palmitate via enhancing ER stress

Artemisinin (ART) and dihydroartemisinin (DHA) are first-line antimalarial drugs and have been reported to have anti-obesity effects. Hyperlipidemia is associated with β-cell damage in obese subjects, which could contribute to the pathogenesis of type 2 diabetes. In addition to their anti-obesity effects, ART and DHA also have protective roles in some diseases. Thus, we investigated the effects of ART and DHA in palmitate-induced β-cell apoptosis and the underlying mechanism. In this study, the rat pancreatic β-cell line INS-1 and mouse pancreatic β-cell line MIN6 were cultured with palmitate (PA) (0.1 mM) to induce cell apoptosis in the presence or absence of ART or DHA. Cell apoptosis was investigated by using flow cytometry, and the expression of ER stress markers, including CHOP, GRP78 and PDI, was detected by Western blotting and/or qRT-PCR. The results showed that ART and DHA significantly increased the apoptosis of β-cells induced by PA and exacerbated the ER stress caused by PA. An inhibitor of ER stress, 4-phenylbutyric acid (4-PBA), significantly ameliorated cell apoptosis caused by ART and DHA in PA-treated β-cells, consistent with the inhibition of ER stress. Together, the findings from the current study suggested that ART and DHA may promote lipid disorder-associated β-cell injury via enhancing ER stress when they were used to treat obesity.

The Potential Roles of Artemisinin and Its Derivatives in the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic disease that has become a global public health problem. Studies on T2DM prevention and treatment mostly focus on discovering therapeutic drugs. Artemisinin and its derivatives were originally used as antimalarial treatments. In recent years, the roles of artemisinins in T2DM have attracted much attention. Artemisinin treatments not only attenuate insulin resistance and restore islet ß-cell function in T2DM but also have potential therapeutic effects on diabetic complications, including diabetic kidney disease, cognitive impairment, diabetic retinopathy, and diabetic cardiovascular disease. Many in vitro and in vivo experiments have confirmed the therapeutic utility of artemisinin and its derivatives on T2DM, but no article has systematically demonstrated the specific role artemisinin plays in the treatment of T2DM. This review summarizes the potential therapeutic effects and mechanism of artemisinin and its derivatives in T2DM and associated complications, providing a reference for subsequent related research.

The potential of artemisinins as anti-obesity agents via modulating the immune system

Artemisinin and its derivatives are the most effective antimalarial drugs. Besides anti-malarial activity, artemisinin and its derivatives have displayed wide-spectrum bioactivities such as anti-parasite, anti-tumor, and anti-obesity effects. Obesity is an epidemic worldwide which is a big threat to human health, but there are only a few approved anti-obesity drugs in the world. Also, these drugs are efficient to limited patients partly because their safety and efficacy are questioned. Anti-inflammatory therapies may be valuable in obesity treatment since growing evidence shows chronic metabolic inflammation is implicated in metabolic disease pathogenesis. As artemisinin and its derivatives display effective anti-inflammatory and immunoregulatory properties with less toxicity, it provides an insight for novel drug development in obesity therapeutic strategies via immune-regulatory mechanisms. In this review, the potential of artemisinin and its derivatives to treat various metabolic diseases such as obesity and diabetes is discussed.

Single-cell RNA-seq with spike-in cells enables accurate quantification of cell-specific drug effects in pancreatic islets

BACKGROUND

Single-cell RNA-seq (scRNA-seq) is emerging as a powerful tool to dissect cell-specific effects of drug treatment in complex tissues. This application requires high levels of precision, robustness, and quantitative accuracy-beyond those achievable with existing methods for mainly qualitative single-cell analysis. Here, we establish the use of standardized reference cells as spike-in controls for accurate and robust dissection of single-cell drug responses.

RESULTS

We find that contamination by cell-free RNA can constitute up to 20% of reads in human primary tissue samples, and we show that the ensuing biases can be removed effectively using a novel bioinformatics algorithm. Applying our method to both human and mouse pancreatic islets treated ex vivo, we obtain an accurate and quantitative assessment of cell-specific drug effects on the transcriptome. We observe that FOXO inhibition induces dedifferentiation of both alpha and beta cells, while artemether treatment upregulates insulin and other beta cell marker genes in a subset of alpha cells. In beta cells, dedifferentiation and insulin repression upon artemether treatment occurs predominantly in mouse but not in human samples.

CONCLUSIONS

This new method for quantitative, error-correcting, scRNA-seq data normalization using spike-in reference cells helps clarify complex cell-specific effects of pharmacological perturbations with single-cell resolution and high quantitative accuracy.

Antidiabetic Effect of Artemether in Db/Db Mice Involves Regulation of AMPK and PI3K/Akt Pathways

The traditional Chinese medicine has long been used in the treatment of diabetes, one major disease threatening the public health. It has been reported that artemether exerts antidiabetic effects on type 2 diabetes in db/db mice, however the underlying mechanisms remain unknown. In the present study, we show that artemether regulates expression of related enzymes participating in the glucose and lipid metabolism in the liver of db/db mice, which could at least partly explain the improved glucose and lipid metabolism in artemether-treated mice. Additionally, artemether also regulates expression of glycogen synthesis related enzymes in the skeletal muscle of db/db mice, supporting its promotive role in glycogen synthesis. Mechanistically, artemether activates AMPK pathway as well as PI3K/Akt pathway in the liver and skeletal muscle of db/db mice, suggesting that these two signaling pathways are both involved in the antidiabetic effects of artemether on type 2 diabetes in db/db mice. In conclusion, our study connects the antidiabetic effects of artemether to the regulation of metabolic enzymes and signaling pathways, and also provides molecular basis for the potential application of artemether in treating type 2 diabetes.

Artemether Regulates Metaflammation to Improve Glycolipid Metabolism in db/db Mice

BACKGROUND

Artemether, a commonly used artemisinin derivative, has been shown to possess potential antidiabetic activities. However, only limited information is available on the mechanisms of artemether in type 2 diabetes. Therefore, in this study, we examined some of the possible mechanisms of artemether (ATM) upon glycolipid metabolism in the db/db mouse model of diabetes.

MATERIALS AND METHODS

Male C57BL/KsJ-db/db and C57BL/KsJ-db/+ mice at 4 weeks of age were divided into four groups (N=6/group): (1) NC (normal control - db/+ mice, 1% methylcellulose, intragastric administration), (2) DM (diabetic model - db/db mice, 1% methylcellulose, intragastric administration), (3) ATM 100 (DM + 100 mg/kg of artemether) and (4) ATM 200 (DM + 200 mg/kg of artemether). A number of assays related to diabetes were then performed following a 4-week period of these treatments.

RESULTS

Artemether at both doses significantly reduced rates of weight gain and fasting blood glucose levels, improved islet function and insulin resistance and reduced serum lipid levels to varying degrees in db/db mice. Artemether exerted a positive effect on islet vacuolar degeneration and hepatic steatosis, and increased expressions of AMP-activated protein kinase, glucose transporter 4 and Insulin receptor β protein in the liver of these db/db mice. With the use of liver protein chip detection, we found that artemether significantly improved the immune microenvironment, down-regulated the expression of inflammatory factors and activated the cytokine-mediated signaling pathway through cytokine-cytokine receptor interactions.

CONCLUSION

Artemether may regulate glycolipid metabolism in db/db mice by improving the immune microenvironment. The results of this study provide important new information that can serve as the foundation for future research into the use of artemether as a means to improve glycolipid metabolism.

Retrospective study of small pet tumors treated with Artemisia annua and iron

Artemisinin from Artemisia annua L. and its derivatives are well-known antimalarial drugs. In addition, in vitro studies, in vivo studies and clinical trials have demonstrated that these drugs exhibit anticancer activity in human patients with cancer. Therefore, the aim of the present study was to investigate whether a phytotherapeutic A. annua preparation exerts anticancer activity in veterinary tumors of small pets. Dogs and cats with spontaneous cancer (n=20) were treated with standard therapy plus a commercial A. annua preparation (Luparte^®) and compared with a control group treated with standard therapy alone (n=11). Immunohistochemical analyses were performed with formalin-fixed paraffin-embedded tumor biopsies to analyze the expression of transferrin receptor (TfR) and the proliferation marker Ki-67 as possible biomarkers to assess treatment response of tumors to A. annua. Finally, the expression levels of TfR and Ki-67 were compared with the IC₅₀ values towards artemisinin in two dog tumor cells lines (DH82 and DGBM) and a panel of 54 human tumor cell lines. Retrospectively, the present study assessed the survival times of small animals treated by standard therapy with or without A. annua. A. annua treatment was associated with a significantly higher number of animals surviving >18 months compared with animals without A. annua treatment (P=0.0331). Using a second set of small pet tumors, a significant correlation was identified between TfR and Ki-67 expression by immunohistochemistry (P=0.025). To further assess the association of transferrin and Ki-67 expression with cellular response to artemisinin, the present study compared the expression of these two biomarkers and the IC₅₀ values for artemisinin in National Cancer Institute tumor cell lines in vitro. Both markers were inversely associated with artemisinin response (P<0.05), and the expression levels of TfR and Ki-67 were significantly correlated (P=0.008). In conclusion, the promising results of the present retrospective study warrant further confirmation by prospective studies in the future.

Protective mechanism of artemisinin on rat bone marrow-derived mesenchymal stem cells against apoptosis induced by hydrogen peroxide via activation of c-Raf-Erk1/2-p90rsk-CREB pathway

Background

Bone marrow-derived mesenchymal stem cell (BMSC) transplantation is one of the new therapeutic strategies for treating ischemic brain and heart tissues. However, the poor survival rate of transplanted BMSCs in ischemic tissue, due to high levels of reactive oxygen species (ROS), limits the therapeutic efficacy of this approach. Considering that BMSC survival may greatly enhance the effectiveness of transplantation therapy, development of effective therapeutics capable of mitigating oxidative stress-induced BMSC apoptosis is an important unmet clinical need.

Methods

BMSCs were isolated from the 4-week-old male Sprague Dawley rats by whole bone marrow adherent culturing, and the characteristics were verified by morphology, immunophenotype, adipogenic, and osteogenic differentiation potential. BMSCs were pretreated with artemisinin, and H₂O₂ was used to induce apoptosis. Cell viability was detected by MTT, FACS, LDH, and Hoechst 33342 staining assays. Mitochondrial membrane potential (ΔΨm) was measured by JC-1 assay. The apoptosis was analyzed by Annexin V-FITC/PI and Caspase 3 Activity Assay kits. ROS level was evaluated by using CellROX® Deep Red Reagent. SOD, CAT, and GPx enzymatic activities were assessed separately using Cu/Zn-SOD and Mn-SOD Assay Kit with WST-8, Catalase Assay Kit, and Total Glutathione Peroxidase Assay Kit. The effects of artemisinin on protein expression of BMSCs including p-Erk1/2, t-Erk1/2, p-c-Raf, p-p90^rsk, p-CREB, BCL-2, Bax, p-Akt, t-Akt, β-actin, and GAPDH were measured by western blotting.

Results

We characterized for the first time the protective effect of artemisinin, an anti-malaria drug, using oxidative stress-induced apoptosis in vitro, in rat BMSC cultures. We found that artemisinin, at clinically relevant concentrations, improved BMSC survival by reduction of ROS production, increase of antioxidant enzyme activities including SOD, CAT, and GPx, in correlation with decreased Caspase 3 activation, lactate dehydrogenase (LDH) release and apoptosis, all induced by H₂O₂. Artemisinin significantly increased extracellular-signal-regulated kinase 1/2 (Erk1/2) phosphorylation, in a concentration- and time-dependent manner. PD98059, the specific inhibitor of the Erk1/2 pathway, blocked Erk1/2 phosphorylation and artemisinin protection. Similarly, decreased expression of Erk1/2 by siRNA attenuated the protective effect of artemisinin. Additionally, when the upstream activator KRAS was knocked down by siRNA, the protective effect of artemisinin was also blocked. These data strongly indicated the involvement of the Erk1/2 pathway. Consistent with this hypothesis, artemisinin increased the phosphorylation of Erk1/2 upstream kinases proto-oncogene c-RAF serine/threonine-protein kinase (c-Raf) and of Erk1/2 downstream targets p90 ribosomal s6 kinase (p90^rsk) and cAMP response element binding protein (CREB). In addition, we found that the expression of anti-apoptotic protein B cell lymphoma 2 protein (BcL-2) was also upregulated by artemisinin.

Conclusion

These studies demonstrate the proof of concept of artemisinin therapeutic potential to improve survival in vitro of BMSCs exposed to ROS-induced apoptosis and suggest that artemisinin-mediated protection occurs via the activation of c-Raf-Erk1/2-p90^rsk-CREB signaling pathway.