Hepato-protective effects of Glossogyne tenuifolia in Streptozotocin-nicotinamide-induced diabetic rats on high fat diet

Essential Oil from Glossogyne tenuifolia Inhibits Lipopolysaccharide-Induced Inflammation-Associated Genes in Macro-Phage Cells via Suppression of NF-κB Signaling Pathway

Glossogyne tenuifolia Cassini (Hsiang-Ju in Chinese) is a perennial herb native to Taiwan. It was used in traditional Chinese medicine (TCM) as an antipyretic, anti-inflammatory, and hepatoprotective agent. Recent studies have shown that extracts of G. tenuifolia possess various bioactivities, including anti-oxidant, anti-inflammatory, immunomodulation, and anti-cancer properties. However, the pharmacological activities of G. tenuifolia essential oils have not been studied. In this study, we extracted essential oil from air-dried G. tenuifolia plants, then investigated the anti-inflammatory potential of G. tenuifolia essential oil (GTEO) on lipopolysaccharide (LPS)-induced inflammation in murine macrophage cells (RAW 264.7) in vitro. Treatment with GTEO (25, 50, and 100 μg/mL) significantly as well as dose-dependently inhibited LPS-induced pro-inflammatory molecules, such as nitric oxide (NO) and prostaglandin E₂ (PGE₂) production, without causing cytotoxicity. Q-PCR and immunoblotting analysis revealed that the inhibition of NO and PGE₂ was caused by downregulation of their corresponding mediator genes, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), respectively. Immunofluorescence and luciferase reporter assays revealed that the inhibition of iNOS and COX-2 genes by GTEO was associated with the suppression of nuclear export and transcriptional activation of the redox-sensitive transcription factor, nuclear factor -κB (NF-κB). In addition, GTEO treatment significantly inhibited phosphorylation and proteosomal degradation of the inhibitor of NF-κB (I-κBα), an endogenous repressor of NF-κB. Moreover, treatment with GTEO significantly blocked the LPS-mediated activation of inhibitory κB kinase α (IKKα), an upstream kinase of the I-κBα. Furthermore, p-cymene, β-myrcene, β-cedrene, cis-β-ocimene, α-pinene, and _D-limonene were represented as major components of GTEO. We found that treatment with p-cymene, α-pinene, and _D-limonene were significantly inhibiting LPS-induced NO production in RAW 264.7 cells. Taken together, these results strongly suggest that GTEO inhibits inflammation through the downregulation of NF-κB-mediated inflammatory genes and pro-inflammatory molecules in macrophage cells.

The protective effect of green tea on diabetes-induced hepato-renal pathological changes: a histological and biochemical study

We investigated the protective effect of green tea on diabetic hepato-renal complications. Thirty male Wistar rats were randomly divided into five equal groups: normal control, diabetic control, glibenclamide-treated, green tea-treated, and combined therapy-treated groups; ethical approval number "BERC-014-01-20." After eight weeks, animals were sacrificed by CO₂ euthanasia method, liver and kidney tissues were processed and stained for pathological changes, and blood samples were collected for biochemical analysis. Diabetic rats showed multiple hepato-renal morphological and apoptotic changes associated with significantly increased some biochemical parameters, while serum albumin and HDL decreased significantly compared to normal control (p < .05). Monotherapy can induce significant improvements in pathological and biochemical changes but has not been able to achieve normal patterns. In conclusion, green tea alone has a poor hypoglycaemic effect but can reduce diabetic complications, whereas glibenclamide cannot prevent diabetic complications. The addition of green tea to oral hypoglycaemic therapy has shown a potent synergistic effect.

Anti-Fatigue and Exercise Performance Improvement Effect of Glossogyne tenuifolia Extract in Mice

Glossogyne tenuifolia (GT) is a native perennial plant growing across the coastline areas in Taiwan. The current study aimed to examine the efficacy of GT extract in ameliorating physical fatigue during exercise and increasing exercise performance. Fifty male Institute of Cancer Research (ICR) mice were randomly segregated into five groups (n = 10) to GT extract orally for 4 weeks, at different concentrations (50, 100, 250, and 500 mg/kg BW/day): LGT 1X, MGT 2X, HGT 5X, and HGT 10X groups. Forelimb grip strength, endurance swimming time, serum biochemical marker levels, blood lipid profile and histological analysis of various organs were performed to assess the anti-fatigue effect and exercise performance of GT extract. The forelimb-grips strength and endurance-swimming time of GT-administered mice were increased significantly in a dose-dependent manner when compared to the control. Serum glucose, creatine kinase, and lactate levels were increased significantly in the HGT 10X group. Liver marker serum glutamic-oxaloacetic transaminase (GOT) was increased in the HGT 5X and HGT 10X groups, whereas Serum Glutamic Pyruvic Transaminase (GPT) was not altered. Renal markers, creatinine and uric acid levels, were not altered. Muscle and hepatic glycogen levels, which are essential for energy sources during exercise, were also significantly increased in a dose-dependent manner in all GT extract groups. No visible histological aberrations were observed in the vital organs after GT extract administration. The supplementation with GT extract could have beneficial effects on exercise performance and anti-fatigue function without toxicity at a higher dose.

Bee venom ameliorates cardiac dysfunction in diabetic hyperlipidemic rats

High levels of blood glucose and lipids are well-known risk factors for heart diseases. Bee venom is a natural product that has a potent hypoglycemic, hypolipidemic, anti-inflammatory, and antioxidant effects. The current study aimed to determine the bee venom effects on cardiac dysfunction compared to combined therapy of metformin and atorvastatin in diabetic hyperlipidemic rats. The median lethal dose of bee venom was estimated, and then 50 adult male albino rats were categorized into five groups. One group was fed a standard diet and served as a negative control, while the other groups were given nicotinamide and streptozotocin injections to induce type 2 diabetes. After confirming diabetes, the rats were fed a high-fat diet for four weeks. The four groups were divided as follows: one group served as a positive control, whereas the other three groups were treated with bee venom (0.5 mg/kg), bee venom (1.23 mg/kg), and combined therapy of metformin (60 mg/kg) and atorvastatin (10 mg/kg), respectively, for four weeks. Upon termination of the experiment, blood samples and heart tissue were obtained. Administration of bee venom using both doses (0.5 and 1.23 mg/kg) and combined therapy of metformin and atorvastatin revealed a significant decrease in the concentrations of glucose, total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, troponin I, creatine kinase, and lactate dehydrogenase activities. Moreover, a significant decrease had been detedcted in malondialdehyde, nuclear factor-kappa-β levels, and relative mRNA expression of vascular cell adhesion molecule-1 and galectin-3 in heart tissue compared to the positive control (P < 0.0001). Furthermore, there was a significant increase in bodyweight levels of insulin, high-density lipoprotein cholesterol, and total antioxidant capacity in heart tissue compared to the positive control (P < 0.0001). The results indicate that bee venom can ameliorate cardiac dysfunction through attenuating oxidative stress and downregulating the NF-κβ signaling pathway.

Nicotinamide and ascorbic acid nanoparticles against the hepatic insult induced in rats by high fat high fructose diet: A comparative study

AIMS

Non-alcoholic fatty liver disease (NAFLD) caused by consumption of high levels of fat and sugars (HFHS) in diet is considered one of the most dangerous medical complications among children and adolescents. Nicotinamide is among the promising candidates in ameliorating HFHS diet-induced NAFLD, but its use is limited by the possibility of prompting hepatotoxicity in high doses. Ascorbic acid is another promising candidate, however its use as a hepatoprotective agent is limited by its chemical instability. Therefore, the aim of the study was to overcome their delivery limitations and enhance their hepatoprotective activity by loading into nanoparticles.

KEY FINDINGS

In the present study, upon incorporating nicotinamide or ascorbic acid in chitosan nanoparticles, they ameliorated the insulin-resistant status induced in rats by a high-fat-high-fructose (HFHF) diet. Both formulae decreased serum level of ALT and AST, as well as liver tissue total cholesterol, triglycerides and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. They also decreased oxidative and nitrosative stresses along with a significant increase in the hepatocellular energy. The biochemical findings were further confirmed by histopathological examination. Finally from the obtained data it could be concluded that chitosan nicotinamide nanoparticles at a dose level (10 mg/kg, p.o.) demonstrated beneficial pharmacological effect with safer toxicity profile than chitosan ascorbic acid nanoparticles.

SIGNIFICANCE

Nicotinamide chitosan nanoparticles could be recommended as daily supplement in the recovery from NAFLD.

Brain-derived neurotrophic factor alleviates diabetes mellitus-accelerated atherosclerosis by promoting M2 polarization of macrophages through repressing the STAT3 pathway

Diabetes mellitus-accelerated atherosclerosis (DMAS) is one of the vascular complications of diabetes. Brain-derived neurotrophic factor (BDNF) plays a critical role in diabetes mellitus. However, the mechanism by which BDNF is involved in DMAS remains unknown. This study investigates the effect of BDNF on the progression of DMAS as well as the underlying mechanism of action. The levels of BDNF in serum and peripheral blood mononuclear cells (PBMCs) from patients with DMAS and health controls were measured as well as the expression of inflammatory cytokines (IL-1β, TNF-α, IL-10, TGF-β and IL-13). The effects of BDNF restoration on cytokine release, macrophage differentiation and the formation of atherosclerotic plaques were evaluated both in vitro and in vivo using the DMAS mouse model. Downregulation of BDNF was identified in the serum and PBMCs of patients with DMAS. Elevation of BDNF contributed to a reduction in the AS lesion area in low-density lipoprotein receptor^-/- mice, inactivated the STAT3 pathway, decreased pro-inflammatory cytokines IL-1β and TNF-α, and increased IL-10, TGF-β and IL-13. BDNF overexpression also increased the proportion of M2 macrophages and alleviated atherosclerotic lesions. Our findings demonstrate that BDNF overexpression promotes M2 macrophage polarization, which represses the development of DMAS by inactivating the STAT3 pathway.