Neurobehavioral and biochemical responses to artemisinin-based drug and aflatoxin B1 co-exposure in rats.

Populations in malaria endemic areas are frequently exposed to mycotoxin-contaminated diets. The possible toxicological outcome of co-exposure to dietary aflatoxin B1 (AFB1) and artemisinin-based combination therapy warrants investigation to ascertain amplification or attenuation of cellular injury. Here, we investigated the neurobehavioral and biochemical responses associated with co-exposure to anti-malarial drug coartem, an artemether-lumefantrine combination (5 mg/kg body weight, twice a day and 3 days per week) and AFB1 (35 and 70 µg/kg body weight) in rats. Motor deficits, locomotor incompetence, and anxiogenic-like behavior induced by low AFB1 dose were significantly (p < 0.05) assuaged by coartem but failed to rescue these behavioral abnormalities in high AFB1-dosed group. Coartem administration did not alter exploratory deficits typified by reduced track plot densities and greater heat map intensity in high AFB1-dosed animals. Furthermore, the reduction in cerebral and cerebellar acetylcholinesterase activity, anti-oxidant enzyme activities, and glutathione and thiol levels were markedly assuaged by coartem administration in low AFB1 group but not in high AFB1-dosed animals. The significant attenuation of cerebral and cerebellar oxidative stress indices namely reactive oxygen and nitrogen species, xanthine oxidase activity, and lipid peroxidation by coartem administration was evident in low AFB1 group but not high AFB1 dose. Although coartem administration abated nitric oxide level, activities of myeloperoxidase, caspase-9, and caspase-3 in animals exposed to both doses of AFB1, these indices were significantly higher than the control. Coartem administration ameliorated histopathological and mophometrical changes due to low AFB1 exposure but not in high AFB1 exposure. In conclusion, contrary to AFB1 alone, behavioral and biochemical responses were not altered in animals singly exposed to coartem. Co-exposure to coartem and AFB1 elicited no additional risk but partially lessened neurotoxicity associated with AFB1 exposure.

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 ß-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.

Effects of artemether on pancreatic islet morphology, islet cell turnover and α-cell transdifferentiation in insulin-deficient GluCreERT2;ROSA26-eYFP diabetic mice.

OBJECTIVES: The antimalarial drug artemether is suggested to effect pancreatic islet cell transdifferentiation, presumably through activation γ-aminobutyric acid receptors, but this biological action is contested. METHODS: We have investigated changes in α-cell lineage in response to 10-days treatment with artemether (100 mg/kg oral, once daily) on a background of ß-cell stress induced by multiple low-dose streptozotocin (STZ) injection in GluCreERT2; ROSA26-eYFP transgenic mice. KEY FINDINGS: Artemether intervention did not affect the actions of STZ on body weight, food and fluid intake or blood glucose. Circulating insulin and glucagon were reduced by STZ treatment, with a corresponding decline in pancreatic insulin content, which were not altered by artemether. The detrimental changes to pancreatic islet morphology induced by STZ were also evident in artemether-treated mice. Tracing of α-cell lineage, through co-staining for glucagon and yellow fluorescent protein (YFP), revealed a significant decrease of the proportion of glucagon+YFP- cells in STZ-diabetic mice, which was reversed by artemether. However, artemether had no effect on transdifferentiation of α-cells into ß-cells and failed to augment the number of bi-hormonal, insulin+glucagon+, islet cells. CONCLUSIONS: Our observations confirm that artemisinin derivatives do not impart meaningful benefits on islet cell lineage transition events or pancreatic islet morphology.

Artemether and aspterric acid induce pancreatic alpha cells to transdifferentiate into beta cells in zebrafish.

BACKGROUND AND PURPOSE: Recently, the antimalarial drug, artemether and the neurotransmitter GABA were identified to convert alpha cells into beta-like cells in vivo. However, some of these observations were challenged by other studies. To help address the controversy, we took advantage of zebrafish as a model to perform this study. EXPERIMENTAL APPROACH: First, we performed a small-molecule screening for artemether and its skeleton analogues. Second, we used the Cre-LoxP system for lineage tracing to indicate the conversion of alpha cells into beta cells in vivo. The stable transgenic ins2:eGFP αTC1-6-cell line was used for evaluation of alpha-cell transdifferentiation in vitro. We further used multiple zebrafish transgenic and mutation lines to demonstrate beta-cell differentiation, beta-cell ablation and alpha-cell hyperplasia in this study. KEY RESULTS: We showed that artemether and another sesquiterpene, aspterric acid, induced alpha-cell transdifferentiation into beta cells, both in zebrafish as well as using αTC1-6 cells. Furthermore, these two compounds also converted alpha cells into beta cells when beta cells were lost or alpha cells were hyperplastic in zebrafish. Unlike the previous report, the conversion of alpha cells to beta cells was mediated by increasing Pax4 expression, but not suppression of Arx expression. CONCLUSION AND IMPLICATIONS: Our data suggest that in zebrafish and αTC1-6 cells, both artemether and aspterric acid induce alpha-cell transdifferentiation. Our data, along with those of Li et al. (2017), suggested that artemether and aspterric acid were able to induce alpha-cell transdifferentiation, at least in zebrafish and αTC1-6 cells.

Synthesis of Nanostructured Lipid Carriers Loaded Chitosan/ Carbopol Hybrid Nanocomposite Gel for Oral Delivery of Artemether and Curcumin.

BACKGROUND: Antimalarial therapy remains the utmost effective means for the management of malarial parasites in the liver and red blood cells. The application of these therapeutic agents is hampered by their improper application, hepato-toxicity caused by their continuous use, and degradation by hepatic enzymes. METHODS: Recent advancements in drug delivery applications have shown potential in improving the pharmacological properties of artemether. Nanostructured lipid carriers (NLCs) loaded chitosan (CH)/Carbopol (CB) hybrid gel was prepared using glycerol monostearate (GMS) as solid lipid and clove oil as a liquid lipid for artemether (ART) and curcumin (CR) for its localized effect on the liver. RESULTS: The smaller particle size (~118 ± 1.0 nm) and high zeta potential (- 41.1 ± 6.46 mV) confirm the formulation and stability of NLCs. On the other hand, the shape and morphology of prepared NLCs and gel showed a spherical and wrinkled surface with a size range of 150-250 nm. The release studies of the NLC's showed a controlled release of artemether (~ 92%) and curcumin (~ 83%) for up to 30 h. Photostability data showed that, approximately, ~86.5 ± 0.3% and ~60 ± 0.9% of nanoencapsulated artemether and curcumin were still detected on exposure to sunlight, respectively. It has been found from the permeation study that 69.8% and 49.1% of the drug was permeated across the mucus membrane in 24 h with a significant increase (P < 0.05) in flux as well as permeability coefficients. CONCLUSION: The overall results showed that prepared CH/CB/NLCs hybrid gel could be a promising vehicle for the effective delivery of ART and CR for the management of malarial parasites. Lay Summary: Antimalarial therapy remains the utmost effective means for the management of malarial parasites in liver and red blood cells. Recent advancements in drug delivery applications have shown potential in improving the pharmacological properties of artemether. Application of these therapeutic agents hampered by their improper application, hepato-toxicity caused by their continuous use and degradation by hepatic enzymes. To manage the above issues, we synthesize nanostructured lipid carriers (NLC's) loaded chitosan (CH)/Carbopol (CB) hybrid gel using glycerol monostearate (GMS) as solid lipid and clove oil as liquid lipid for artemether (ATR) and curcumin (CR) for its local action in liver and the major criteria were to find a protective barrier with hepatoprotective nature of the curcumin.

Folate receptor alpha targeted delivery of artemether to breast cancer cells with folate-decorated human serum albumin nanoparticles.

The pharmaceutical application of artemether (ARM) as an anticancer natural agent is hampered due to its poor solubility and bioavailability. In the present study, ARM was encapsulated in human serum albumin nanoparticles (HSA NPs) via desolvation method led to improvement of the water solubility by 50 folds. In further, folate-decorated ARM-HSA NPs (F-ARM-HSA NPs) were developed to enhance targeted delivery to folate receptor alpha (FRα)-overexpressing breast cancer cells. The hydrodynamic diameter and the zeta potential value of F-ARM-HSA NPs were 198 ± 11.22 nm and -23 ± 0.88 mV, respectively. Fluorescent microscopy demonstrated an enhanced cellular uptake of F-ARM-HSA NPs by high FRα-expressing MDA-MB-231 breast cancer cells compared to low FRα-expressing SK-BR-3 breast cancer cells. Cytotoxicity assay revealed a small significant difference between cytotoxicity effect of targeted and non-targeted NPs in SK-BR-3 cells. However, in MDA-MB-231 cells due to FRα-mediated endocytosis, the F-conjugated NPs had less inhibitory concentration (IC50) value (19.82 µg/mL) and higher cytotoxicity after 72 h compared to non-targeted ARM-HSA NPs. Flow cytometry analysis indicated a more potent drug-induced apoptosis rather than necrosis. The results suggest that our novel F-ARM-HSA NPs are likely to be recommended as a promising candidate for combination therapy of FRα-overexpressing breast cancer cells.

Improvement of solubility, dissolution and stability profile of artemether solid dispersions and self emulsified solid dispersions by solvent evaporation method.

The purpose of this study was to investigate changes in the water solubility of artemether; a poorly soluble drug used for the treatment of malaria. Different solid dispersions (SDs) of artemether were prepared using artemether and polyethylene glycol 6000 at ratio 12:88 (Group 1), self-emulsified solid dispersions (SESDs) containing artemether, polyethylene glycol 6000, cremophor-A-25, olive oil, hydroxypropylmethylcellulose and transcutol in the ratio 12:75:5:4:2:2, respectively (Group 2). SESDs were also prepared by substituting cremophor-A-25 in Group 2 with poloxamer 188 (noted as Group 3). Each of these preparations was formulated using physical mixing and the solvent evaporation method. Aqueous solubility of artemether improved 11-, 95- and 102-fold, while dissolution (in simulated gastric fluid) increased 3-, 13- and 14-fold, for formulation groups 1, 2 and 3, respectively. X-ray diffraction patterns of SDs indicated a decrease in peak intensities at 10° implying reduced artemether crystallinity. Scanning electron micrographs invariably revealed embedment of artemether by various excipients and a glassy appearance for solvent evaporated mixtures for all three formulation Groups. Our findings indicate improved hydrophilic interactions for drug particles yield greater solubility and dissolution in the following order for artemether formulating methods: solvent evaporation mixtures > physical mixtures > pure artemether.