6-Gingerol regulates triglyceride and cholesterol biosynthesis to improve hepatic steatosis in MAFLD by activating the AMPK-SREBPs signaling pathway.

Excessive synthesis of triglycerides and cholesterol accelerates the progression of hepatic steatosis in metabolic-associated fatty liver disease (MAFLD). However, the precise mechanism by which 6-gingerol mitigates hepatic steatosis in MAFLD model mice has yet to be fully understood. The present study observed that 6-gingerol administration exhibited significant protective effects against obesity, insulin resistance, and hepatic steatosis in mice subjected to a high-fat diet (HFD), and mitigated lipid accumulation in HepG2 cells treated with palmitate (PA). Following the hepatic lipidomic analysis, we confirmed that the AMPK-SREBPs signaling pathway as the underlying molecular mechanism by which 6-gingerol inhibited triglyceride and cholesterol biosynthesis, both in vivo and in vitro, through Western blot and immunofluorescence assay. Additionally, the application of an AMPK agonist/inhibitor further validated that 6-gingerol promoted AMPK activation by increasing the phosphorylation level of AMPK in vitro. Notably, the inhibitory effect of 6-gingerol on cholesterol biosynthesis, rather than triglyceride biosynthesis, was significantly diminished after silencing SREBP2 using a lentiviral plasmid shRNA in HepG2 cells. Our study demonstrates that 6-gingerol mitigates hepatic triglyceride and cholesterol biosynthesis to alleviate hepatic steatosis by activating the AMPK-SREBPs signaling pathway, indicating that 6-gingerol may be a potential candidate in the therapy of MAFLD.

Reduced Diversities and Clonally Expanded Sequences of T-Cell Receptors in Patients With Essential Hypertension and Subclinical Carotid Atherosclerosis.

BACKGROUND: It has long been hypothesized that the abnormal immune responses contribute to the essential hypertension (EH) and its subclinical target organ damage (STOD). However, the mechanism is unclear. This study aimed at exploring the potential association with abnormal T-cell responses and EH, STOD, and early atherosclerosis in patients with EH. METHODS: This cross-sectional study included 146 patients with EH and 73 age-matched normotensive individuals. The expressed peripheral TCR (T-cell receptor) ß repertoire was analyzed by high through-put sequencing. RESULTS: The TCRß repertoires of the patients with EH were significantly different, with significantly elevated certain TCR beta variable (TRBV) and joint (TRBJ) gene usages, significantly reduced TCRß diversity indexes (diversity 50s) and numbers of total TCRß clonal types, significantly elevated percentages of the biggest TCRß clones and numbers of clones accounting >0.1% sequences, compared with those in the normotensive controls. Decreased diversity 50s and increased biggest TCRß clone percentages were independently correlated with carotid intima-media thickness and subclinical carotid atherosclerosis (SCA) in the patients with EH. Moreover, the diversity 50s were further significantly reduced and the biggest TCRß clone percentages were significantly increased in the patients with EH with SCA (n=89) comparing to the patients with EH/patients without SCA (n=57), and in patients with EH/SCA with carotid plaque (n=22) comparing to patients with EH/SCA/patients without carotid plaque (n=67). Importantly, specific TCRß clones were identified in different subgroups of the patients with EH. CONCLUSIONS: These results reveal that abnormal T-cell responses may play important roles in the progression of EH and its SCA, especially the formation of carotid plaque. REGISTRATION: URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2100054414.

Relationship Between Atherogenic Index of Plasma and Serum Uric Acid in Patients With Untreated Essential Hypertension in China: A Cross-Sectional Study.

Several studies have reported that the atherogenic index of plasma (AIP) is associated with serum uric acid (SUA) in healthy middle-aged men, kidney transplant patients, and diabetic patients. We assessed the relationship between AIP and SUA in patients with untreated essential hypertension (EH) in China. In the cross-sectional study, we evaluated 5003 patients with untreated EH in China; 1490 were assigned to the hyperuricemia (HUA) group and 3513 to the normouricemia (non-HUA) group according to the diagnostic criteria of HUA (SUA level≥6 mg/dL in females and ≥7 mg/dL in males). A higher AIP level was found in the HUA group (P < .001), and AIP was positively and independently correlated with SUA after adjusting for statistically significant variables (ß = .204, P < .001). Moreover, multivariate logistic regression analysis showed that the AIP was closely and independently related to HUA after adjusting for confounders (odds ratio [OR]: 11.980, 95% confidence interval [CI]: 3.186-45.047, P < .001). Our findings suggested that the AIP was positively and independently associated with SUA, and elevated AIP might be a significant risk factor for HUA in patients with untreated EH in China.

Berberine reduces hepatic ceramide levels to improve insulin resistance in HFD-fed mice by inhibiting HIF-2α.

Several studies have documented the effects of hypoxia and ceramides on lipid and glucose metabolism, resulting in insulin resistance. However, the roles of ceramide in hepatic hypoxia and hepatic insulin resistance remain to be clarified. This study aimed to explore the relationship between hypoxia, ceramide synthesis, and hepatic insulin resistance in high-fat diet (HFD)-fed mice. Given the interaction of hypoxia-inducible factors 2α(HIF-2α) and berberine determined using molecular docking, this study also assessed the pharmacological effects of berberine on the HIF-2α-ceramide-insulin resistance pathway. In the preliminary phase of the study, gradually aggravated hepatic hypoxia and varying levels of ceramides were observed with the development of type 2 diabetes mellitus (T2DM) due to increasing HIF-2α accumulation. Lipidomic analyses of animal and cell models revealed that berberine reduced hypoxia-induced ceramide production and attenuated ceramide-induced insulin resistance. This research provides timely and necessary evidence for the role of ceramide in hypoxia and insulin resistance in the liver. It also contributes to a better understanding of the pharmacological effects of berberine on ameliorating hypoxia and insulin resistance in T2DM therapy.

Prognostic significance of low TSH concentration in patients with COVID-19 presenting with non-thyroidal illness syndrome.

BACKGROUND: Low free triiodothyronine (FT3) levels are related to a poor prognosis deterioration in patients with COVID-19 presenting with non-thyroidal illness syndrome (NTI). This study was designed to explore whether free thyroxin (FT4) or thyroid stimulating hormone (TSH) levels affected the mortality of patients with COVID-19 presenting with NTI. METHODS: Patients with COVID-19 complicated with NTI who were treated at our hospital were included in this retrospective study. Patients were divided into low TSH and normal TSH groups, as well as low and normal-high FT4 group, according to the reference range of TSH or FT4 levels. The 90-day mortality and critical illness rates were compared among patients with low and normal TSH levels, as well as among patients with low FT4 levels and normal-high FT4 levels; in addition, differences in demographic and laboratory data were compared. A Kaplan-Meier analysis and Cox proportional hazards models were used to assess the associations of TSH and FT4 levels with mortality. RESULTS: One hundred fifty patients with low FT3 levels and without a history of thyroid disease were included, 68% of whom had normal FT4 and TSH levels. Critical illness rates (74.07% VS 37.40%, P = 0.001) and mortality rates (51.85% VS 22.76%, P = 0.002) were significantly higher in the low TSH group than in the normal TSH group. Although no significant difference in the critical illness rate was found (P = 0.296), the mortality rate was significantly higher in the low FT4 group (P = 0.038). Low TSH levels were independently related to 90-day mortality (hazard ratio = 2.78, 95% CI:1.42-5.552, P = 0.003). CONCLUSIONS: Low FT4 and TSH concentrations were associated with mortality in patients with COVID-19 presenting with NTI; moreover, low TSH levels were an independent risk factor for mortality in these patients.

Characteristics of Viral Shedding in Respiratory Samples and Specific Antibodies Production in 564 COVID-19 Patients.

Positive nucleic acid (NA) results have been found in recovered and discharged COVID-19 patients, but the proportion is unclear. This study was designed to analyze the recurrent positive rate of NA results after consecutively negative results, and the relationship between the specific antibody production and positive NA rate. According to Strengthening the Reporting of Observational Studies in Epidemiology guidelines, data of inpatients in Sino-French New City Branch of Tongji Hospital between Jan. 28 and Mar. 6, 2020 were collected. A total of 564 COVID-19 patients over 14 years old who received the examinations of NA and antibodies against SARS-CoV-2 were included. Days of viral shedding and specific antibodies were recorded and assessed. Among NA tests in respiratory samples (throat swabs, nasopharyngeal swabs, sputum and flushing fluid in alveoli), the patients with all-negative NA results accounted for 17.20%, those with single-positive results for 46.63%, and those with multiple-positive results for 36.17% respectively. Besides, the recurrent positive NA results after consecutively negative results appeared in 66 patients (11.70%). For multiple-positive patients, median viral shedding duration was 20 days (range: 1 to 57 days). Of the 205 patients who received 2 or more antibody tests, 141 (68.78%) had decreased IgG and IgM concentrations. IgM decreased to normal range in 24 patients, with a median of 44 days from symptom onset. Viral shedding duration was not significantly correlated with gender, age, disease severity, changes in pulmonary imaging, and antibody concentration. It is concluded that antibody level and antibody change had no significant correlation with the positive rate of NA tests and the conversion rate after continuous negative NA tests. In order to reduce the recurrent positive proportion after discharge, 3 or more consecutive negative NA test results with test interval more than 24 h every time are suggested for the discharge or release from quarantine.

Correlation analysis between disease severity and inflammation-related parameters in patients with COVID-19: a retrospective study.

BACKGROUND: COVID-19 is highly contagious, and the crude mortality rate could reach 49% in critical patients. Inflammation concerns on disease progression. This study analyzed blood inflammation indicators among mild, severe and critical patients, helping to identify severe or critical patients early. METHODS: In this cross-sectional study, 100 patients were included and divided into mild, severe or critical groups according to disease condition. Correlation of peripheral blood inflammation-related indicators with disease criticality was analyzed. Cut-off values for critically ill patients were speculated through the ROC curve. RESULTS: Significantly, disease severity was associated with age (R = -0.564, P < 0.001), interleukin-2 receptor (IL2R) (R = -0.534, P < 0.001), interleukin-6 (IL-6) (R = -0.535, P < 0.001), interleukin-8 (IL-8) (R = -0.308, P < 0.001), interleukin-10 (IL-10) (R = -0.422, P < 0.001), tumor necrosis factor α (TNFα) (R = -0.322, P < 0.001), C-reactive protein (CRP) (R = -0.604, P < 0.001), ferroprotein (R = -0.508, P < 0.001), procalcitonin (R = -0.650, P < 0.001), white cell counts (WBC) (R = -0.54, P < 0.001), lymphocyte counts (LC) (R = 0.56, P < 0.001), neutrophil count (NC) (R = -0.585, P < 0.001) and eosinophil counts (EC) (R = 0.299, P < 0.001). With IL2R > 793.5 U/mL or CRP > 30.7 ng/mL, the progress of COVID-19 to critical stage should be closely observed and possibly prevented. CONCLUSIONS: Inflammation is closely related to severity of COVID-19, and IL-6 and TNFα might be promising therapeutic targets.

New role for ceramide in hypoxia and insulin resistance.

Ceramides are significant metabolic products of sphingolipids in lipid metabolism and are associated with insulin resistance and hepatic steatosis. In chronic inflammatory pathological conditions, hypoxia occurs, the metabolism of ceramide changes, and insulin resistance arises. Hypoxia-inducible factors (HIFs) are a family of transcription factors activated by hypoxia. In hypoxic adipocytes, HIF-1α upregulates pla2g16 (a novel HIF-1α target gene) gene expression to activate the NLRP3 inflammasome pathway and stimulate insulin resistance, and adipocyte-specific Hif1a knockout can ameliorate homocysteine-induced insulin resistance in mice. The study on the HIF-2α-NEU3-ceramide pathway also reveals the role of ceramide in hypoxia and insulin resistance in obese mice. Under obesity-induced intestinal hypoxia, HIF-2α increases the production of ceramide by promoting the expression of the gene Neu3 encoding sialidase 3, which is a key enzyme in ceramide synthesis, resulting in insulin resistance in high-fat diet-induced obese mice. Moreover, genetic and pathophysiologic inhibition of the HIF-2α-NEU3-ceramide pathway can alleviate insulin resistance, suggesting that these could be potential drug targets for the treatment of metabolic diseases. Herein, the effects of hypoxia and ceramide, especially in the intestine, on metabolic diseases are summarized.

Inhibitory effects of berberine on proinflammatory M1 macrophage polarization through interfering with the interaction between TLR4 and MyD88.

BACKGROUNDS: Inflammation is recognized as the key pathological mechanism of type 2 diabetes. The hypoglyceamic effects of berberine (BBR) are related to the inhibition of the inflammatory response, but the mechanism is not completely clear. METHODS: The inflammatory polarization of Raw264.7 cells and primary peritoneal macrophages were induced by LPS, and then effects and underlying mechanisms of BBR were explored. An inflammatory model was established by LPS treatment at different concentrations for different treatment time. An ELISA assay was used to detect the secretions of TNF-α. RT-PCR was applied to detect M1 inflammatory factors. The F4/80+ ratio and CD11c+ ratio of primary peritoneal macrophages were determined by flow cytometry. The expressions of p-AMPK and TLR4 were detected by Western blot. The cytoplasmic and nuclear distributions of NFκB p65 were observed by confocal microscopy. The binding of TLR4 to MyD88 was tested by CoIP, and the affinity of BBR for TLR4 was assessed by molecular docking. RESULTS: Upon exposure to LPS, the secretion of TNF-α and transcription of inflammatory factors in macrophages increased, cell morphology changed and protrusions appeared gradually, the proportion of F4/80+CD11c+ M1 macrophages increased, and the nuclear distribution of NFκB p65 increased. BBR pretreatment partially inhibited the changes mentioned above. However, the expression of TLR4 and p-AMPK did not change significantly after LPS intervention for 3 h. Meanwhile, CoIP showed that the interaction between TLR4 and MyD88 increased, and BBR inhibited the binding. Molecular docking suggested that BBR might interact with TLR4. CONCLUSIONS: Inflammatory changes were induced in macrophages after LPS stimulation for 3 h, and BBR pretreatment inhibited inflammatory polarization. BBR might interact with TLR4 and disturb TLR4/MyD88/NFκB signalling pathway, and it might be the mechanism by which BBR attenuated inflammation in the early phase.

Efficacy and safety of sugarcane policosanol on dyslipidemia: A meta-analysis of randomized controlled trials.

SCOPE: This study aimed to systematically investigate whether sugarcane policosanol was effective and safe on dyslipidemia. METHODS AND RESULTS: A total of 11 databases including the PubMed, Web of science, Embase, Scopus, the Cochrane library and SinoMed databases were searched for available studies investigating the effects of policosanol on dyslipidemia. A total of 22 studies including 1886 subjects were included in the analysis. The pooled results showed that compared with placebo, sugarcane policosanol could significantly reduce total cholesterol (TC, 95% CI: -0.87 to -0.30 mmol/L) and low density lipoprotein cholesterol (LDL-c, 95% CI: -1.02 to -0.40 mmol/L) and increase high density lipoprotein cholesterol; however, no significant effects were observed on triglyceride (TG) and body weight. Subgroup analysis suggested the studies from Cuba obtained more effective data than those outside this country, and the effects were not proportional to the dose. The adverse effects analysis demonstrated that sugarcane policosanol was safer than the control agents. CONCLUSION: The pooled results supported the lipid-lowering effects and safety of policosanol. Because of the high heterogeneity, the better treatment effects observed in the Cuban studies and the inconsistent dose-response relationship, more clinical trials are needed to further confirm the efficacy of policosanol on dyslipidemia.

Wu-Mei-Wan Reduces Insulin Resistance via Inhibition of NLRP3 Inflammasome Activation in HepG2 Cells.

Wu-Mei-Wan (WMW) is a Chinese herbal formula used to treat type 2 diabetes. In this study, we aimed to explore the effects and mechanisms of WMW on insulin resistance in HepG2 cells. HepG2 cells were pretreated with palmitate (0.25 mM) to impair the insulin signaling pathway. Then, they were treated with different doses of WMW-containing medicated serum and stimulated with 100 nM insulin. Results showed that palmitate could reduce the glucose consumption rate in HepG2 cells and impair insulin signaling related to phosphorylation of insulin receptor (IR) and insulin receptor substrate-1 (IRS-1), thereby regulating the downstream signaling pathways. However, medicated serum of WMW restored impaired insulin signaling, upregulated the expression of phospho-IR (pIR), phosphatidylinositol 3-kinase p85 subunit, phosphoprotein kinase B, and glucose transporter 4, and decreased IRS serine phosphorylation. In addition, it decreased the expression of interleukin-1ß and tumor necrosis factor-α, which are the key proinflammatory cytokines involved in insulin resistance; besides, it reduced the expression of NLRP3 inflammasome. These results suggested that WMW could alleviate palmitate-induced insulin resistance in HepG2 cells via inhibition of NLRP3 inflammasome and reduction of proinflammatory cytokine production.

Berberine Attenuates Intestinal Mucosal Barrier Dysfunction in Type 2 Diabetic Rats.

Background: Intestinal mucosal barrier dysfunction plays an important role in the development of diabetes mellitus (DM). Berberine (BBR), a kind of isoquinoline alkaloid, is widely known to be effective for both DM and diarrhea. Here, we explored whether the anti-diabetic effect of BBR was related to the intestine mucosal barrier. Methods and Results: The rat model of T2DM was established by high glucose and fat diet feeding and intravenous injection of streptozocin. Then, those diabetic rats were treated with BBR at different concentrations for 9 weeks. The results showed, in addition to hyperglycemia and hyperlipidemia, diabetic rats were also characterized by proinflammatory intestinal changes, altered gut-derived hormones, and 2.77-fold increase in intestinal permeability. However, the treatment with BBR significantly reversed the above changes in diabetic rats, presenting as the improvement of the high glucose and triglyceride levels, the relief of the inflammatory changes of intestinal immune system, and the attenuation of the intestinal barrier damage. BBR treatment at a high concentration also decreased the intestinal permeability by 27.5% in diabetic rats. Furthermore, BBR regulated the expressions of the molecules involved in TLR4/MyD88/NF-κB signaling pathways in intestinal tissue of diabetic rats. Conclusion: The hypoglycemic effects of BBR might be related to the improvement in gut-derived hormones and the attenuation of intestinal mucosal mechanic and immune barrier damages.

Inhibition of proprotein convertase subtilisin/kexin type 9: a novel mechanism of berberine and 8-hydroxy dihydroberberine against hyperlipidemia.

OBJECTIVE: To investigate the effect and molecular mechanisms of different doses of 8-hydroxy dihydroberberine (Hdber) for the treatment of hyperlipidemia in rats. METHODS: A rat model of hyperlipidemia was established by feeding rats a high-fat diet for 4 weeks in 70 rats of 80 animals, and 10 rats were randomly selected as control group. The hyperlipidemic rats were then randomly divided into the following groups: a model group (MOD); a berberine group [BBR, 156 mg/(kg day)]; Hdber groups, which were treated with different doses of Hdber [78, 39 and 19.5 mg/(kg day)]; and a simvastatin group [SIM, 4 mg/(kg day)]. The corresponding therapy was administered to the rats of each treatment via gastric tubes. Normal animals were used as a control group. The blood levels of various lipids, including total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, free fatty acid (FFA), apolipoprotein AI(Apo-AI) and apolipoprotein B (Apo-B) were examined. The protein expressions of low-density lipoprotein receptor (LDL-R), sterol regulatory element-binding protein 2 (SREBP-2), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and proprotein convertase subtilisin/kexin type 9 (PCSK-9) in liver tissues were determined by Western blot analysis. RESULTS: Compared with the control group of rats, the model group demonstrated a deteriorated blood lipid profile and exhibited increased expression levels of PCSK-9 protein in their liver tissues (P<0.01). In addition, the high-fat diet decreased the expression levels of LDL-R, SREBP-2 and HMGCR proteins in murine liver tissues. However, the addition of berberine or Hdber reversed the blood lipid profile changes (P<0.05 or P<0.01), decreased the expression levels of PCSK-9 proteins (P<0.01), and increased the expression levels of LDL-R proteins in the hyperlipidemic rats (P<0.01). These compounds did not significantly influence the expression levels of SREBP-2 and HMGCR proteins in the hyperlipidemic rats. CONCLUSIONS: Hdber is effective in the treatment of hyperlipidemia in rats. The therapeutic mechanisms of Hdber may be associated with increasing the expression of LDL-R protein and decreasing the expression of PCSK-9 protein in liver tissues.

Berberine ameliorates collagen-induced arthritis in rats associated with anti-inflammatory and anti-angiogenic effects.

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by inflammation and joint destruction. In this study, we explored the effect of berberine on rats with bovine type II collagen-induced arthritis (CIA), an animal model for RA. Following treatment, berberine attenuates arthritic scores and suppresses collagen-specific immune responses in CIA rats. Compared with the un-treated CIA group, berberine reversed pathological changes, which showed a significant improvement in synovial hyperplasia and inflammatory infiltration. The expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-17 and vascular endothelial growth factor (VEGF) were obviously reduced in the sera of berberine-treated rats (all P<0.05). Moreover, berberine showed marked inhibition of the expression of VEGF and CD34 (all P<0.05). Interestingly, berberine significantly suppresses p-ERK, p-p38 and p-JNK activation (all P<0.05), which may partially explain the anti-RA activity of berberine. These results suggest that berberine ameliorates CIA in rats associated with anti-inflammatory and anti-angiogenic effects, which might be of great therapeutic value for RA.

Antimicrobial effect of bayberry leaf extract for the preservation of large yellow croaker (Pseudosciaena crocea).

BACKGROUND: Chemical preservatives have been widely used to keep large yellow croaker fresh. However, the potential harm to human health cannot be ignored. This study was undertaken to investigate the antimicrobial effect of bayberry leaf extract and to evaluate the efficacy of this natural product on the preservation of large yellow croaker. RESULTS: The minimum inhibitory concentration (MIC) values of bayberry leaf extract against bacteria were 1.0 mg mL⁻¹ for Micrococcus luteus, 0.5 mg mL⁻¹ for Staphylococcus aureus, 0.25 mg mL⁻¹ for Escherichia coli, 0.5 mg mL⁻¹ for Pseudomonas aeruginosa, 0.0625 mg mL⁻¹ for Vibrio parahaemolyticus, and 0.03125 mg mL⁻¹ for Listeria monocytogenes, respectively. This result was confirmed by the diameters of inhibition zone (DIZ) assay. Further studies showed that the bacterial growth was significantly retarded when large yellow croaker was pretreated with bayberry leaf extract (2 g L⁻¹) compared to that in the control group. Moreover, the generation of total volatile basic nitrogenous compounds (TVB-N), ATP degradation products (K-value) and thiobarbituric acid-reactive substances (TBARS) were significantly reduced compared to that in the control group. CONCLUSION: Our results demonstrated that the shelf life of large yellow croaker can be extended when supplemented with bayberry leaf extract, which might have implications for natural preservatives.

Jiao tai wan attenuates hepatic lipid accumulation in type 2 diabetes mellitus.

Jiao Tai Wan (JTW), a Chinese herbal formula containing Rhizoma Coptidis and Cortex Cinnamomi, has been used for diabetic treatment for many years. The aim of this study was to determine the main components in JTW and to investigate the effects of JTW on hepatic lipid accumulation in diabetic rats and humans. JTW extract was prepared and the main components were assayed by HPLC. An animal model of diabetes mellitus was established and JTW was administered intragastrically. In the clinical study, diabetic patients with poor glycemic control were treated with JTW. Blood glucose and lipid parameters, liver histology, hepatic triglyceride content and lipogenic gene expression were examined. Our data demonstrated that JTW significantly improved hyperglycemia, hyperlipidemia and hepatic lipid accumulation in diabetic rats. This was accompanied by the down-regulation of acetyl coenzyme A carboxylase (ACC) and fatty acid synthase (FAS) protein expressions, and the up-regulation of AMP-activated protein kinase (AMPK) and phosphorylated-ACC (pACC) protein expressions in the liver tissues. Diabetic patients also exhibited decreases in their hepatic triglyceride content. The results suggest that JTW attenuates hepatic lipid accumulation in diabetic rats and humans. These beneficial effects are possibly associated with the inhibition of lipogenic gene expression in the liver.

Effects of Chinese Fructus Mume formula and its separated prescription extract on insulin resistance in type 2 diabetic rats.

The effect of Fructus Mume formula and its separated prescription extract on insulin resistance in type 2 diabetic rats was investigated. The rat model of type 2 diabetes was established by feeding on a high-fat diet for 8 weeks and by subsequently intravenous injection of small doses of streptozotocin. Rats in treatment groups, including the Fructus Mume formula treatment group (FM), the cold property herbs of Fructus Mume formula treatment group (CFM), the warm property herbs of Fructus Mume formula treatment group (WFM), were administrated with Fructus Mume formula and its separated prescription extract by gavage, while the rats in diabetic model group (DM) and metformin group (MET) were given by gavage with normal saline and metformin correspondingly. The body weight before and after treatment was measured, and the oral glucose tolerance test (OGTT) and the insulin release test (IRT) were performed. The homeostasis model assessment-insulin resistance index (HOMA-IR) was calculated. The protein and mRNA expression levels of Insr, ß-arrestin-2, Irs-1 and Glut-4 in the liver, skeletal muscle and fat tissues were detected by using Western blotting and RT-PCR respectively. The results demonstrated that, as compared with DM group, OGTT, IRT (0 h, 1 h) levels and HOMR-IR in treatment groups were all reduced, meanwhile their protein and mRNA expression levels of Insr, Irs-1 and Glut-4 in the liver, skeletal muscle and fat tissues were obviously increased, and their protein and mRNA expression levels of ß-arrestin-2 in the liver and skeletal muscle tissues were also markedly increased. It was suggested that the Fructus Mume formula and its separated prescription extracts could effectively improve insulin resistance in type 2 diabetic rats, which might be related to the up-regulated expression of Insr, Irs-1 and Glut-4 in the liver, skeletal muscle and fat tissues, and ß-arrestin-2 in the liver and skeletal muscle tissues.

The anti-diabetic effects and pharmacokinetic profiles of berberine in mice treated with Jiao-Tai-Wan and its compatibility.

Jiao-Tai-Wan (JTW), a classical Chinese prescription, has been clinically employed to treat diabetes mellitus in recent years. To investigate the comparative evaluations on anti-diabetic effects and pharmacokinetics of the active ingredient berberine in mice treated with JTW in various combinations of its constituent herbs. In our study, the anti-diabetic study was carried out in diabetic mice induced by intraperitoneal injection of streptozotocin. The diabetic mice were randomly assigned to three therapy groups and orally administered with different prescription proportions of Rhizoma Coptidis and Cinnamomum cassia respectively. The level of plasma glucose, lipid profile and parameters related to oxidative stress were determined. The concentrations of berberine in non-diabetic mice plasma were determined using HPLC, and main pharmacokinetic parameters were investigated. The results indicated that the compatibility effects of ingredients present in Cinnamomum cassia could affect the anti-diabetic ability and pharmacokinetics of berberine in JTW.

Hispidin produced from Phellinus linteus protects against peroxynitrite-mediated DNA damage and hydroxyl radical generation.

Oxidative stress plays an important role in the progression of many chronic diseases including cardiovascular diseases, diabetes, cancer and neurodegenerative disorders. One such mediator of oxidative stress is peroxynitrite, which is highly toxic to cultured neurons and astrocytes, and has been reported to be involved in the pathogenesis of various types of neuronal diseases. Therefore, searching for natural compounds with peroxynitrite-scavenging activity might be an effective therapy for peroxynitrite-mediated cytotoxicity. Hispidin, a phenolic compound from Phellinus linteus (a medicinal mushroom), has been shown to possess strong antioxidant, anticancer, and antidiabetic properties. However, the astrocyte protective efficacy of hispidin has been not examined. This study was undertaken to investigate whether the astrocyte protective effect of hispidin is associated with inhibition of peroxynitrite-induced DNA damage, a critical event leading to peroxynitrite-mediated cytotoxicity. Our results showed that peroxynitrite can cause DNA damage in φX-174 plasmid DNA and rat primary astrocytes. The presence of hispidin (10-20 µg/ml) was found to significantly inhibit peroxynitrite-induced DNA damage and cytotoxicity. EPR spectroscopy demonstrated that the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from peroxynitrite, and that hispidin potently diminished the adduct signal in a concentration-dependent manner. Taken together, these results demonstrate for the first time that hispidin can protect against peroxynitrite-mediated cytotoxicity, DNA damage and hydroxyl radical formation.

Effects of cinnamon granules on pharmacokinetics of berberine in Rhizoma Coptidis granules in healthy male volunteers.

The effects of Cinnamon granules on pharmacokinetics of berberine in Rhizoma Coptidis granules in healthy male volunteers, and the compatibility mechanism of Jiao-Tai-Wan (JTW) composed of Rhizoma Coptidis granules and Cinnamon granules were investigated. The concentration of berberine in plasma of healthy male volunteers was determined directly by high performance liquid chromatography (HPLC) after an oral administration of Rhizoma Coptidis granules alone or combined with Cinnamon granules (JTW). The plasma concentration-time curves of berberine were plotted. The data were analyzed with Drug and Statistics (DAS) 2.0 pharmacokinetic program (Chinese Pharmacology Society) to obtain the main pharmacokinetic parameters. The results showed that the plasma concentration-time curve of berberine was described by a two-compartment model. The C(max), T(max), t(1/2) and CLz/F of berberine in Rhizoma Coptidis granules were 360.883 µg/L, 2.0 h, 3.882 h, 119.320 L·h(-1)·kg(-1) respectively, and those of berberine in JTW were 396.124 µg/L, 1.5 h, 4.727 h, 57.709 L·h(-1)·kg(-1) respectively. It was suggested that Rhizoma Coptidis granules combined with Cinnamon granules could increase the plasma concentration of berberine, promote berberine absorption and lengthen the detention time of berberine in healthy male volunteers.