Sweet tea leaves extract improves leptin resistance in diet-induced obese rats

Compound dark tea ameliorates obesity and hepatic steatosis and modulates the gut microbiota in mice

Dark tea is a fermented tea that plays a role in regulating the homeostasis of intestinal microorganisms. Previous studies have found that dark tea can improve obesity and has a lipid-lowering effect. In this study, green tea, Ilex latifolia Thunb (kuding tea) and Momordica grosvenori (Luo Han Guo) were added to a new compound dark tea (CDT), to improve the taste and health of this beverage. High-fat diet-fed C57BL/6J mice were treated with low- (6 mg/mL) or high- (12 mg/mL) concentrations of CDT for 18 weeks to assess their effect on lipid metabolism. Our results suggest that low- and high-concentrations of CDT could reduce body weight by 15 and 16% and by 44 and 38% of body fat, respectively, by attenuating body weight gain and fat accumulation, improving glucose tolerance, alleviating metabolic endotoxemia, and regulating the mRNA expression levels of lipid metabolism-related genes. In addition, low concentrations of CDT were able to reduce the abundance of Desulfovibrio, which is positively associated with obesity, and increase the abundance of Ruminococcus, which are negatively associated with obesity. This study demonstrates the effect of CDT on ameliorating lipid metabolism and provides new insights into the research and development of functional tea beverages.

Integrated transcriptome and metabolome analysis reveals the anthocyanin biosynthesis mechanisms in blueberry (Vaccinium corymbosum L.) leaves under different light qualities

INTRODUCTION

Blueberry (Vaccinium corymbosum L.) is a popular fruit with an abundance of anthocyanins in its leaves and fruits. Light is one of the pivotal environmental elements that affects plant growth and development, but the regulatory mechanism between light quality and anthocyanin formation is poorly understood.

METHODS

An integrated transcriptome and metabolome analysis was performed to investigate the effects of white (control), blue (B), red (R), and red/blue (60R/40B) light on blueberry growth and reveal the potential pathway controlling anthocyanin biosynthesis in blueberry leaves.

RESULTS

The anthocyanin content was significantly improved by the blue and red/blue light when compared with white light, whereas there was a significant reduction in the photosynthesis under the blue light, showing an inverse trend to that of anthocyanin accumulation. Transcriptomic analysis resulted in the assembly of 134,709 unigenes. Of these, 22 were differentially expressed genes (DEGs) that participate in the anthocyanin biosynthesis pathway, with the majority being significantly up-regulated under the blue light. Most of the photosynthesis-related genes that were down-regulated were expressed during anthocyanin accumulation. Targeted metabolome profiling identified 44 metabolites associated with anthocyanin biosynthesis. The contents of most of these metabolites were higher under blue light than the other light conditions, which was consistent with the transcriptome results. The integrated transcriptome and metabolome analysis suggested that, under blue light, leucoanthocyanidin dioxygenase (LDOX), O-methyltransferase (OMT), and UDP-glucose flavonoid glucosyltransferase (UFGT) were the most significantly expressed, and they promoted the synthesis of cyanidin (Cy), malvidin (Mv), and pelargonidin (Pg) anthocyanidins, respectively. The expression levels of dihydroflavonol 4-reductase (DFR) and OMT, as well as the accumulation of delphinidin (Dp), peonidin (Pn), and petunidin (Pt), were significantly increased by the red/blue light.

DISCUSSION

The blue and red/blue lights promoted anthocyanin biosynthesis via inducing the expression of key structural genes and accumulation of metabolites involved in anthocyanin synthesis pathway. Moreover, there was a possible feedback regulating correlation between anthocyanin biosynthesis and photosynthesis under different light qualities in blueberry leaves. This study would provide a theoretical basis for elucidating the underlying regulatory mechanism of anthocyanin biosynthesis of V. corymbosum.

Duyun compound green tea extracts regulate bile acid metabolism on mice induced by high-fat diet

Duyun compound green tea (DCGT) is a healthy beverage with lipid-lowering effect commonly consumed by local people, but its mechanism is not very clear. We evaluated the effect of DCGT treatment on bile acids (BA) metabolism of mice with high-fat diet (HFD) – induced hyperlipidaemia by biochemical indexes and metabolomics and preliminarily determined the potential biomarkers and metabolic pathways of hyperlipidaemia mice treated with DCGT as well as investigated its lipid-lowering mechanism. The results showed that DCGT treatment could reduce HFD – induced gain in weight and improve dyslipidaemia. In addition, a total of ten types of BA were detected, of which seven changed BA metabolites were observed in HFD group mice. After DCGT treatment, glycocholic acid, tauroursodeoxycholic acid and taurochenodeoxycholic acid were significantly down-regulated, while hyodeoxycholic acid, deoxycholic acid and chenodeoxycholic acid were markedly up-regulated. These results demonstrated that DCGT treatment was able to make the BA metabolites in the liver of hyperlipidaemia mice normal and alleviate hyperlipidaemia by regulating the metabolites such as glycocholic acid, tauroursodeoxycholic acid and taurochenodeoxycholic, as well as the BA metabolic pathway and cholesterol metabolic pathway involved.

Consumption of cricket (Acheta domesticus) flour decreases insulin resistance and fat accumulation in rats fed with high-fat and -fructose diet

The consumption of cricket (Acheta domesticus, AD) has recently increased due to its high nutritional and bioactive compound contents. However, limited studies have explored the beneficial effects of AD consumption. Therefore, we aimed to evaluate the protective effect of a diet supplemented with AD flour on obesity control and its complications in an in vivo model. The chemical profiling of the AD showed an important protein content, chitin, and polyunsaturated fatty acids contents. For the in vivo study, a high-fructose and saturated fat diet (HFFD) was supplemented with AD (4% and 8%). The 8% AD supplementation reduced body weight gain (19%) and serum triglycerides (37%) in HFFD-fed rats. These benefits were related to a greater lipid excretion in feces (97%) and the partial inhibition of pancreatic lipase in vitro by the aqueous extract and the hydrolyzed proteins obtained from AD. Additionally, the 8% AD supplementation improved insulin resistance measured by the HOMA index (61%). Thus, 8% AD supplementation to HFFD-fed rats was effective in preventing obesity, dyslipidemia, and insulin resistance. PRACTICAL APPLICATIONS: Obesity is a risk factor for developing insulin resistance and dyslipidemia. Therefore, there is an increasing interest in consuming foods rich in bioactive compounds as therapeutic alternatives for managing the development of obesity and its complications. Edible insects, such as crickets, are attractive for treating obesity due to their content of protein, fiber, and polyunsaturated fatty acids. Studies have explored the effect of glycosaminoglycan (GAG)-enriched extracts from the cricket Gryllus bimaculatus against obesity. However, GAG content in crickets is low, and crickets are commonly consumed whole instead of extracts. The cricket Acheta domesticus (AD) is among the most rearing cricket species as it is easy to farm and has a better flavor. However, limited studies have explored the beneficial effects of AD consumption. This study demonstrates that AD prevents obesity and ameliorates dyslipidemia and insulin resistance. Therefore, AD is a valuable entomotherapeutic strategy to reduce the comorbidities associated with diet-induced obesity.

Rapid monitoring of flavonoid content in sweet tea (Lithocarpus litseifolius (Hance) Chun) leaves using NIR spectroscopy

BACKGROUND

Sweet tea, which functions as tea, sugar and medicine, was listed as a new food resource in 2017. Flavonoids are the main medicinal components in sweet tea and have significant pharmacological activities. Therefore, the quality of sweet tea is related to the content of flavonoids. Flavonoid content in plants is normally determined by time-consuming and expensive chemical analyses. The aim of this study was to develop a methodology to measure three constituents of flavonoids, namely, total flavonoids, phloridin and trilobatin, in sweet tea leaves using near-infrared spectroscopy (NIR).

RESULTS

In this study, we demonstrated that the combination of principal component analysis (PCA) and NIR spectroscopy can distinguish sweet tea from different locations. In addition, different spectral preprocessing methods are used to establish partial least squares (PLS) models between spectral information and the content of the three constituents. The best total flavonoid prediction model was obtained with NIR spectra preprocessed with Savitzky-Golay combined with second derivatives (SG + D2) (R_P² = 0.893, and RMSEP = 0.131). For trilobatin, the model with the best performance was developed with raw NIR spectra (R_P² = 0.902, and RMSEP = 2.993), and for phloridin, the best model was obtained with NIR spectra preprocessed with standard normal variate (SNV) (R_P² = 0.818, and RMSEP = 1.085). The coefficients of determination for all calibration sets, validation sets and prediction sets of the best PLS models were higher than 0.967, 0.858 and 0.818, respectively.

CONCLUSIONS

The conclusion indicated that NIR spectroscopy has the ability to determine the flavonoid content of sweet tea quickly and conveniently.

Discovery of human pancreatic lipase inhibitors from root of Rhodiola Crenulata via integrating bioactivity-guided fractionation, chemical profiling and biochemical assay

Although herbal medicines (HMs) are widely used in the prevention and treatment of obesity and obesity-associated disorders, the key constituents exhibiting anti-obesity activity and their molecular mechanisms are poorly understood. Recently, we assessed the inhibitory potentials of several HMs against human pancreatic lipase (hPL, a key therapeutic target for human obesity), among which the root-extract of Rhodiola crenulata (ERC) showed the most potent anti-hPL activity. In this study, we adopted an integrated strategy, involving bioactivity-guided fractionation techniques, chemical profiling, and biochemical assays, to identify the key anti-hPL constituents in ERC. Nine ERC fractions (retention time = 12.5–35 min), obtained using reverse-phase liquid chromatography, showed strong anti-hPL activity, while the major constituents in these bioactive fractions were subsequently identified using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS/MS). Among the identified ERC constituents, 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranose (PGG) and catechin gallate (CG) showed the most potent anti-hPL activity, with pIC₅₀ values of 7.59 ± 0.03 and 7.68 ± 0.23, respectively. Further investigations revealed that PGG and CG potently inhibited hPL in a non-competitive manner, with inhibition constant (K_i) values of 0.012 and 0.082 μM, respectively. Collectively, our integrative analyses enabled us to efficiently identify and characterize the key anti-obesity constituents in ERC, as well as to elucidate their anti-hPL mechanisms. These findings provide convincing evidence in support of the anti-obesity and lipid-lowering properties of ERC.

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The root-extract of Rhodiola crenulata (ERC) potently inhibits hPL.

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The hPL inhibitors in ERC were characterized using an integrated panel of assays.

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Six constituents in ERC were identified as hPL inhibitors.

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PGG and CG are potent non-competitive hPL inhibitors (K_i < 0.1 μM).

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The binding modes of PGG and CG were examined based on docking simulations.

A Comprehensive Review on Anti-obesity Potential of Medicinal Plants and their Bioactive Compounds

Background:

Obesity is a complex health and global epidemic issue. It is an increasing global health challenge covering significant social and economic costs. Abnormal accumulation of fat in the body may increase the health risks including diabetes, hypertension, osteoarthritis, sleep apnea, cardiovascular diseases, stroke and cancer. Synthetic drugs available on the market reported to have several side effects. Therefore, the management of obesity got to involve the traditional use of medicinal plants which helps to search the new therapeutic targets and supports the research and development of anti-obesity drugs.

Objective:

This review aim to update the data and provide a comprehensive report of currently available knowledge of medicinal plants and phyto-chemical constituents reported for their anti-obesity activity.

Methodology:

An electronic search of the periodical databases like Web of Science, Scopus, PubMed, Scielo, Niscair, ScienceDirect, Springerlink, Wiley, SciFinder and Google Scholar with information reported the period 1991-2019, was used to retrieve published data.

Results:

A comprehensive report of the present review manuscript is an attempt to list the medicinal plants with anti-obesity activity. The review focused on plant extracts, isolated chemical compounds with their mechanism of action and their preclinical experimental model, clinical studies for further scientific research.

Conclusion:

This review is the compilation of the medicinal plants and their constituents reported for the managements of obesity. The data will fascinate the researcher to initiate further research that may lead to the drug for the management of obesity and their associated secondary complications. Several herbal plants and their respective lead constituents were also screened by preclinical In-vitro and In-vivo, clinical trials and are effective in the treatment of obesity. Therefore, there is a need to develop and screen large number of plant extracts and this approach can surely be a driving force for the discovery of anti-obesity drugs from medicinal plants.

Dihydrochalcones from the leaves of Lithocarpus litseifolius

Three new phlorizin derivatives, 6"-O-vanilloylphlorizin (1), 6"-O-(4-hydroxybenzoyl)phlorizin (2), 6"-O-feruloylphlorizin (3), along with four known dihydrochalcones, phlorizin (4), 3-hydroxyphlorizin, trilobatin, and 6"-O-acetylphlorizin were isolated from the leaves of Lithocarpus litseifolius. Their structures were established by analysis of extensive spectroscopic data. The new compounds were shown to be non-cytotoxic when tested against A549, HeLa, HepG2, and MCF-7 cell lines.

The Chemical, Structural, and Biological Properties of Crude Polysaccharides from Sweet Tea (Lithocarpus litseifolius (Hance) Chun) Based on Different Extraction Technologies

Eight extraction technologies were used to extract sweet tea (Lithocarpus litseifolius (Hance) Chun) crude polysaccharides (STPs), and their chemical, structural, and biological properties were studied and compared. Results revealed that the compositions, structures, and biological properties of STPs varied dependent on different extraction technologies. Protein-bound polysaccharides and some hemicellulose could be extracted from sweet tea with diluted alkali solution. STPs extracted by deep-eutectic solvents and diluted alkali solution exhibited the most favorable biological properties. Moreover, according to the heat map, total phenolic content was most strongly correlated with biological properties, indicating that the presence of phenolic compounds in STPs might be the main contributor to their biological properties. To the best of our knowledge, this study reports the chemical, structural, and biological properties of STPs, and the results contribute to understanding the relationship between the chemical composition and biological properties of STPs.

Hypoglycemic and hypolipidemic activities of phlorizin from Lithocarpus polystachyus Rehd in diabetes rats

The objective of this study was to investigate the hypoglycemic and hypolipidemic effects of phlorizin on sweet tea in rats with diabetes. Diabetic rat model was established by feeding with HFD (high-fat diet) and then treating with intraperitoneal injection of STZ (streptozocin). The experiments were divided into therapeutic and preventive experiments. In both experiments, rats were divided into normal, diabetic control, positive control, and phlorizin groups. Symptoms of diabetes, fasting blood glucose (FBG) levels, serum lipid parameters, and pathological changes in the pancreas and liver were evaluated. It was found that the symptoms of diabetes were improved by phlorizin treatment. In addition, phlorizin could decrease FBG, improve serum lipid levels, protect against damaged pancreas islet, and decrease fat deposition in hepatic cells. These effects of phlorizin can be shown only attain to a certain dosage. It can be concluded that phlorizin has the therapeutic and preventive effects on hyperlipidemia and hyperglycemia in diabetes rats.

Effect of Trilobatin from Lithocarpus polystachyus Rehd on Gut Microbiota of Obese Rats Induced by a High-Fat Diet

Trilobatin was identified as the primary bioactive component in the Lithocarpus polystachyus Rehd (LPR) leaves. This study explored the antiobesity effect of trilobatin from LPR leaves and its influence on gut microbiota in obese rats. Results showed that trilobatin could significantly reduce body and liver weight gain induced by a high-fat diet, and the accumulation of perirenal fat, epididymal fat, and brown fat of SD (Male Sprague–Dawley) obese rats in a dose-independent manner. Short-chain fatty acids (SCFAs) concentrations increased, especially the concentration of butyrate. Trilobatin supplementation could significantly increase the relative abundance of Lactobacillus, Prevotella, CF231, Bacteroides, and Oscillospira, and decrease greatly the abundance of Blautia, Allobaculum, Phascolarctobacterium, and Coprococcus, resulting in an increase of the ratio of Bacteroidetes to Firmicutes (except the genera of Lactobacillus and Oscillospira). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway predicted by the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) indicated the different relative metabolic pathways after trilobatin supplementation. This study may reveal the contribution of gut microbiota to the antiobesity effect of trilobatin from LPR leaves and predict the potential regulatory mechanism for obesity induced by a high-fat diet.

Documenting the heritage along the Silk Road: An ethnobotanical study of medicinal teas used in Southern Xinjiang, China

ETHNOPHARMACOLOGICAL RELEVANCE

People in Southern Xinjiang, China have been consuming medicinal teas for healthcare since before the ancient Silk Road markets began. Several pharmaceutical studies have illustrated the potential healthcare benefits of medicinal teas used in Southern Xinjiang, China. However, little information is available from the literature about the diversity of the species used and related traditional knowledge of these medicinal teas.

AIMS OF THE STUDY

(i) create a comprehensive record of medicinal tea plant species (MTPS) and combinations used with related traditional knowledge for healthcare in Southern Xinjiang, China; (ii) assess safety of MTPS, and (iii) address conservation status for sustainable use of MTPS.

MATERIALS AND METHODS

We employed both field and market surveys from 2014 to 2019 in 10 counties/cities and four main medicinal tea markets by using semi-structured interviews. We interviewed 236 informants and 70 medicinal tea shop vendors. The commonly used MTPS were ranked by Frequency of Citation. Safety issues were assessed based on expert knowledge and with reference to the official list of Medicinal Plants Used as Food. Conservation implications of plant use were assessed as part of the interviews and this was cross referenced with official records.

RESULTS

The surveys revealed 145 different plants from 65 families used for making medicinal teas, expanding the list of known Chinese herbal tea species from 782 to 884. Leguminosae, Rosaceae, Lamiaceae and Apiaceae were dominant families. Herbs (60.7%, 88 species) were the most commonly used plant types; fruits (23.1%, 50 species) and seeds (22.2%, 48 species) were commonly used parts. Nearly half (42.1%) of the plant species were introduced from abroad. Respondents reported more than 50 types of healthcare uses of medicinal teas. Tonic (13.7%, 71 species) and promoting digestion (9.6%, 50 species) were the most frequently mentioned healthcare uses. The majority of commonly used plant species were spices (20 species, 50%) and aromatic plants (10 species, 25%). Cinnamomum cassia (L.) J.Presl, Piper longum L. Syzygium aromaticum (L.) Merr. & L. M. Perry and Gardenia jasminoides J. Ellis were the most cited species. High doses of Piper longum L., Crocus sativus L., Curcuma longa L, and Senna alexandrina Mill. May have negative health implications. Assessments of conservation status and sustainable use of tea species indicate that wild harvesting of Nardostachys jatamansi (D. Don) DC. and Pterocarpus indicus Willd. Should be controlled and cultivation technologies should be improved.

CONCLUSIONS

We found high plant species diversity and rich traditional knowledge of medicinal teas used in Southern Xinjiang, China. The traditional healthcare uses of some of the medicinal teas are also supported by pharmaceutical evidence. Others should be investigated further. Conservation pressures exist for commonly used wild species. China's 'Healthy China 2030' policy should do more to take traditional cultural practices into account. In doing so, both local and national government agendas may seek to promote sustainable harvest and to protect traditional knowledge so that this cultural heritage continues to serve human well-being into the future.

The protective effect of trilobatin against isoflurane-induced neurotoxicity in mouse hippocampal neuronal HT22 cells involves the Nrf2/ARE pathway

Long-term exposure to isoflurane may induce long-term developmental neurotoxicity and cognitive impairments in the neonatal brains. Trilobatin, a leaf extract from the Chinese traditional sweet tea Lithocarpus polystachyus Rehd, possesses various biological properties including anti-inflammatory and anti-oxidant properties. Our study aimed to explore the neuroprotective effect of trilobatin on isoflurane-induced neurotoxicity in mouse hippocampal neuronal HT22 cells. The effects of trilobatin on cell viability, LDH release, apoptosis, and caspase-3/7 activity in isoflurane-induced HT22 cells were explored by CCK-8, LDH release assay, flow cytometry analysis, and caspase-3/7 activity assay, respectively. Oxidative stress was evaluated by measuring the levels of reactive oxygen species (ROS) and malonyldialdehyde (MDA) and activities of superoxide dismutase (SOD) and catalase (CAT). The expression of nuclear erythroid-2 related factor 2 (Nrf2), nuclear Nrf2, heme oxygenase-1 (HO-1), and NAD(P)H: quinone oxidoreductase 1 (NQO1) was determined by western blot and qRT-PCR. Results suggested that exposure to isoflurane significantly reduced cell viability and increased LDH release, apoptotic rate and caspase-3/7 activity in HT22 cells, which were abolished by trilobatin. Trilobatin reversed isoflurane-induced increase of ROS and MDA levels and reduction of SOD and CAT activities in HT22 cells. Additionally, trilobatin promoted the nuclear translocation of Nrf2 as well as the mRNA and protein expression of HO-1 and NQO1 in HT22 cells exposed to isoflurane. Nrf2 knockdown attenuated the effects of trilobatin on isoflurane-induced viability reduction, LDH release, apoptosis, and oxidative stress in HT22 cells. Overall, trilobatin protected HT22 cells against isoflurane-induced neurotoxicity via activating the Nrf2/antioxidant response element (ARE) pathway.

Effect of Anoectochilus roxburghii flavonoids extract on H2O2 - Induced oxidative stress in LO2 cells and D-gal induced aging mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Anoectochilus roxburghii (A. roxburghii) is a popular folk medicine in many Asian countries, which has been used traditionally for treatment of some diseases such as diabetes, tumors, hyperlipemia, and hepatitis. The ethanol extract from A. roxburghii was recently shown to exert better ability to scavenge free radicals in vitro and possess antioxidant on natural aging mice in vivo.

AIM OF THE STUDY

This study is to characterize the chemical composition, and investigate the protective effect of the A. roxburghii flavonoids extract (ARF) against hydrogen peroxide (H₂O₂)-induced oxidative stress in LO2 cells in vitro and D-galactose (D-gal)-induced aging mice model in vivo, and explore the underlying mechanisms.

MATERIALS AND METHODS

The chemical components of the flavonoids extract fromA. roxburghii were detected by ultraperformance lipid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS/MS). H₂O₂ was used to establish an oxidative stress model in LO2 cells. Cytotoxic and protective effects of ARF on the LO2 cells were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Moreover, the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA) in cell supernatants were measured by commercial reagent kits. Kun-Ming mice were induced to aging with D-gal (400 mg/kg, BW) by subcutaneous injection for 58 days. From the 28th day to the 58th day of D-gal treatment, ARF (122.5, 245 and 490 mg/kg, BW) and vitamin E (100 mg/kg, BW) were orally administrated to aging mice once a day for consecutive 30 days. After 25 days of the treatment with ARF, learning and memory were assessed using Morris Water Maze (MWM). At the end of the test period, the animals were euthanized by cervical dislocation, and the levels of SOD, GSH-PX, and MDA in serum, liver homogenates and brain homogenates were measured. The levels of monoamine oxidase (MAO) and acetylcholinesterase (AchE) were determined in brain homogenates. Skin and liver histopathological morphology were observed by H&E staining. Furthermore, antioxidant-related gene expression levels in the liver were carried out by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Nine flavonoids were identified in the extracts of A. roxburghii. In vitro assay, a high concentration of ARF (>612.5 μg/ml) reduced the survival rate and had toxic effects on LO2 cells. In addition, ARF (245 μg/ml, 490 μg/ml) and Vitamin C (200 μg/ml) markedly inhibited generations of MDA and increased activities of SOD, GSH-PX in H₂O₂-induced LO2 cells supernatants. In vivo assay, ARF (122.5 mg/kg, 245 mg/kg and 490 mg/kg) and Vitamin E (100 mg/kg) not only ameliorated learning and memory ability but also improved skin and liver pathological alterations. Strikingly, ARF significantly decreased MDA and MAO levels, markedly enhanced antioxidant enzyme (SOD and GSH-PX) activities. Further, compared to the D-gal group, ARF could obviously up-regulate glutathione peroxidase-1 (GPx-1) and glutathione peroxidase-4 (GPx-4) mRNA levels.

CONCLUSIONS

These findings suggested that ARF protects LO2 cells against H₂O₂-induced oxidative stress and exerts the potent anti-aging effects in D-gal aging mice model, which may be related to the inhibition of oxidative stress. Flavonoid compounds may contribute to the anti-oxidative capability and modulating aging.

The PI3K/Akt and NF-κB signaling pathways are involved in the protective effects of Lithocarpus polystachyus (sweet tea) on APAP-induced oxidative stress injury in mice

Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity. The leaves of Lithocarpus polystachyus Rehd. (named as “sweet tea”, ST) usually serve as tea drink and folk medicine for healthcare in the southwest part of China. In previous reports, it has been proven to protect various animal models, except for APAP-induced liver injury model. Therefore, this study initially explored the protective effect of ST leaf extract (STL-E) on hepatotoxicity induced by APAP in ICR mice. STL-E of 50 and 100 mg kg⁻¹ were given to each group for 7 days. ALI was intraperitoneally induced by APAP treatment (i.p. 250 mg per kg body weight). Biochemical markers, levels of inflammatory factors, histopathological staining and western blotting were used to analyze the inflammation and apoptosis of liver tissues. Interestingly, the treatment with STL-E significantly attenuated APAP-induced liver injury (p < 0.05). Moreover, STL-E partially mitigated APAP-induced liver injury by effectively activating the PI3K/Akt pathway and inhibiting the NF-κB pathway. In a word, STL-E protected liver against APAP-induced hepatotoxicity by inhibiting the PI3K/Akt-mediated apoptosis signal pathway and inhibiting the NF-κB-mediated signaling pathway.

Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity.

Purified Phlorizin from DocynIa Indica (Wall.) Decne by HSCCC, Compared with Whole Extract, Phlorizin and Non-Phlorizin Fragment Ameliorate Obesity, Insulin Resistance, and Improves Intestinal Barrier Function in High-Fat-Diet-Fed Mice

Natural products generally contain complex and multiple bioactive compounds that are responsible for the effects on health through complicated synergistic and/or suppressive actions. As an important raw material of local ethnic minority tea, ethnomedicines and food supplements in southwestern areas of China, Docynia indica (Wall.) Decne (DID) mainly consists of phlorizin (PHZ), which is the main active component. In this study, the holistic activities and the interactions of components of PHZ, non-phlorizin (NP) in the DID extract (DIDE) were evaluated. A rapid and effective high-speed counter-current chromatography (HSCCC) was performed to knock out PHZ from DIDE and the purity of PHZ was 96.01% determined by HPLC, with a recovery rate of 96.76%. After 13 weeks of treatment course in a high-fat diet (HFD)-induced obese mice model, the results revealed that the DIDE and PHZ significantly decreased weight gain, blood lipid levels, hyperplasia of adipocytes and alleviated inflammation (p < 0.05). Both DIDE and PHZ improves insulin resistance (p < 0.001). Meanwhile, the intestinal barrier function was improved compared to HFD group, through the determination of serum lipopolysaccharides (LPS), glucagon-likepeptide-2 (GLP-2) and hematoxylin-eosin staining of jejunum. Interestingly, after NP treatment, the metabolic syndrome of the HFD-induced obesity appeared to have a similar improvement. All the experiments showed that there is a synergistic weakening phenomenon when PHZ and NP interact with each other in the mixed state. In conclusion, for the PHZ and NP showing a good effect on anti-obesity, anti-inflammation, and intestinal barrier function, DIDE could be a good source of functional food to prevent obesity.

Lithocarpus polystachyus Rehd. leaves aqueous extract protects against hydrogen peroxide‑induced SH-SY5Y cells injury through activation of Sirt3 signaling pathway

Lithocarpus polystachyus Rehd. (sweet tea; ST) leaves is a type of Chinese folkloric medicine from southern China. The purpose of the present study was to explore the neuroprotective effect of ST, and to explore its underlying mechanisms in hydrogen peroxide (H2O2)‑induced neuronal cell injury in cultured human neuroblastoma. H2O2 was used as oxidant inducer and human SH‑SY5Y neuroblastoma cells were treated with various concentrations of ST. Cell viability and cell death were detected using MTT and LDH assays, respectively. Additionally, the production of intracellular and mitochondrial reactive oxygen species (ROS) were determined by 2',7'‑dichlorodihydrofluorescein diacetate (DCFH‑DA) and MitoSOX Red, respectively. The production of malondialdehyde (MDA), reduced glutathione (GSH) level, glutathione peroxidase (GSH‑Px), superoxide dismutase (SOD) activities, and NAD+/NADH ratio were confirmed using relevant kits. The expression of adenosine monophosphate‑activated protein kinase (AMPK), peroxisome proliferator‑activated receptor coactivator (PGC)‑1α, Sirt3, isocitrate dehydrogenase (IDH)2, forkhead boxO3a (Foxo3a), and SOD2 were analyzed by western blot analysis. It was demonstrated that pre‑treatment with ST enhanced cell viability and repressed cell death, and it also reduced intracellular and mitochondrial ROS accumulation. Additionally, ST attenuated MDA production and enhanced GSH level, GSH‑Px and SOD activities. Furthermore, ST not only increased NAD+/NADH ratio, but also inhibited the decrease of AMPK, PGC‑1α, Sirt3, IDH2, Foxo3a, and SOD2. The present study revealed that ST exerts protective effects against oxidative stress‑induced SH‑SY5Y cells injury, and the underlying mechanisms are, at least partly, associated with its antioxidant capacity and function through mitochondrial Sirt3 signaling pathway.

A billion cups: The diversity, traditional uses, safety issues and potential of Chinese herbal teas

ETHNOPHARMACOLOGICAL RELEVANCE

Herbal teas have long been consumed by Chinese people for preventive and/or therapeutic healthcare. Although herbal teas are widely consumed by many cultural groups in different regions of China, no thorough review has been undertaken to assess the diversity of the country's herbal tea usage. This literature review, complemented by a quantitative survey in an important tea market in Kunming, begins to fill this knowledge gap.

AIMS OF THE STUDY

The study aims to summarize the current knowledge of plant species used as herbal teas by different cultural groups in different regions of China, with a focus on the teas' perceived traditional healthcare functions, related phytochemical/pharmaceutical research, and safety issues.

MATERIALS AND METHODS

The study involved a comprehensive literature review and a market survey. The literature review was based on published ethnobotanical studies of herbal teas in China. We searched the Web of Science™, ELSEVIER, the China National Knowledge Infrastructure (CNKI) and the China Science and Technology Journal Database to locate relevant studies (including journal articles, Masters/PhD dissertations and books) that were published before March 2017. A species list was compiled based on the review and supplemented with information retrieved from the Scifinder database (https://scifinder.cas.org) and the Chinese Pharmacopoeia (2010). A Use Value Index was employed for ranking the most cited species. Based on the 29 most cited species, we discussed the current research status in relation to healthcare benefits and safety concerns of herbal teas in China. To better understand the current status of the herbal tea market in China, we also surveyed 136 tea vendors at the Xiongda Tea Market in Kunming. Information gathered from the survey included the species sold, the sale prices and the form of the herbal tea product.

RESULTS

The literature identified 759 plant species used as herbal tea in China and the market survey identified an additional 23 species. Most of the species used were from the Leguminosae, Compositae and Lamiaceae families. Twenty two provinces and fourteen ethnic minority groups have records on the consumption of herbal teas. Southern China uses up to 82% of the total species, and 211 out of 759 species are used by minority groups. Thirty categories of traditional healthcare functions are linked with herbal teas, with clearing away heat, relieving toxicity and suppressing cough being the most important functions. There is phytochemical/pharmaceutical evidence to support the claimed healthcare benefits of some Chinese herbal teas. Although Chinese herbal teas are generally safe to consume, overdoses of some herbal teas and some unapproved mixtures of species may cause health risks. Based on our market survey, the prices of most herbal teas range between 100 and 200 RMB (US$15-30) per kg.

CONCLUSIONS

A rich array of herbal tea species with various traditional healthcare functions have long been used in China, and as such there is a huge market potential for Chinese herbal teas. More pharmaceutical/phytochemical research is needed to assess a wide range of perceived healthcare benefits of Chinese herbal teas. Our research highlights the need to study herbal teas through an ethnopharmacological perspective and by employing a holistic approach, which requires greater consideration of traditional knowledge in the pharmacological research design. Product safety and sustainability issues should also be considered, so the traditional applications of herbal teas can be transformed to efficient health boosting functional products.

Trilobatin Protects Against Oxidative Injury in Neuronal PC12 Cells Through Regulating Mitochondrial ROS Homeostasis Mediated by AMPK/Nrf2/Sirt3 Signaling Pathway

Oxidative stress-induced neuronal cell damage is a crucial factor in the pathogenesis of mitochondria-associated neurological diseases. Therefore, elimination of overproduction of mitochondrial reactive oxygen species (mtROS) may be a potential strategy for prevention and treatment of neurological diseases. In the present study, the neuroprotective effects of trilobatin (TLB), a novel small molecule monomer derived from Lithocarpus polystachyus Rehd, and its underlying mechanisms were investigated in vitro using hydrogen peroxide (H₂O₂)-induced oxidative stress model in a neuron-like PC12 cell. The findings revealed that pre-treatment with TLB dramatically concentration-dependently suppressed H₂O₂-induced PC12 cells damage by enhancing cell viability, repressed reduction of mitochondrial membrane potential (MMP) and decreased mtROS overgeneration, thereby deferring cell apoptosis. Further study demonstrated that TLB not only increased the enzymatic activities of glutathione peroxidase (GPx), isocitrate dehydrogenase 2 (IDH2),superoxide dismutase 2 (SOD2) and deacetylation of SOD2, but also activated silent mating-type information regulation 2 homolog 3 (Sirt3) within the mitochondria and thereby upregulating forkheadboxO3a (FoxO3a), which regulated mitochondrial DNA genes, then led to improving complex I activity and adenosine triphosphate (ATP) synthesis. What’s more, TLB up-regulated p-adenosine monophosphate-activated protein kinase (AMPK) level, the expression of peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α), and ERRα. Intriguingly, TLB failed to mitigate H₂O₂-induced PC12 injury in the presence of the AMPK inhibitor (Compound C), indicating that the beneficial effects of TLB on the regulation of mtROS homeostasis were reliance on AMPK -Sirt3 signaling pathway. Moreover, TLB also facilitated nuclear factor erythroid 2-related factor 2 (Nrf2) and promoted antioxidant gene expression in turn, and knockdown of Nrf2 by siRNA dramatically reduced the neuroprotective effects of TLB. Notably, AMPK inhibitor abolished the activation of Nrf2 and Sirt3, whereas, knockdown of Nrf2 blocked the upregulation of Sirt3, but it did not affect p-AMPK level. In conclusion, our findings demonstrate that TLB protects against oxidative injury in neuronal PC12 cells through regulating mtROS homeostasis in the first time, which is, at least partly, mediated through the AMPK/Nrf2/Sirt3 signaling pathway.

Optimization of the ultrasound-assisted extraction of antioxidant phloridzin from Lithocarpus polystachyus Rehd. using response surface methodology

The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box-Behnken design was used to analyze the effects of ethanol concentration, liquid-solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high-performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1-,diphenyl-2-picrylhydrazyl, hydroxyl radical scavenging test and reduction force). The optimal parameters obtained by response surface methodology were a volume fraction of ethanol of 64%, a liquid-solid ratio of 37:1, a soaking time of 35 h and a sonication time of 38 min. The proportion of the extraction of phloridzin from L. polystachyus under these industrial process conditions was 3.83%. According to the obtained results, response surface methodology could be suggested as an adequate model for optimizing the extraction process of phloridzin from L. polystachyus. Ultrasound extraction significantly increased the extraction rate of phloridzin, which could be used as an antioxidant in pharmaceutical and food products.

Obesity-alleviating potential of asiatic acid and its effects on ACC1, UCP2, and CPT1 mRNA expression in high fat diet-induced obese Sprague-Dawley rats

The present study evaluated the effects of asiatic acid (AA), a pentacyclic triterpenoid from Centella asiatica on lipid metabolism parameters in a rat model of obesity induced using a high fat diet (HFD) for 42 days. AA (20 mg/kg body weight [BW]) was administered orally once daily for 42 days, and an orlistat-treated group of rats (10 mg/kg BW) was included for comparison. Changes in BW, blood glucose levels, insulin resistance and leptin, adiponectin, amylase, and lipase levels in the blood; lipid profiles of plasma; liver antioxidants levels; and acetyl CoA carboxylase(ACC), uncoupling protein-2 (UCP2), and carnitine palmitoyltransferase-1 (CPT1) mRNA expression were observed in the experimental rats. Our results revealed that AA (20 mg/kg BW), similar to orlistat, reduced the increase in BW; increased bone mineral contents and bone mineral densities; reduced blood glucose levels, insulin resistance, leptin, plasma lipid levels; increased adiponectin, amylase, lipase levels in the blood; showed antioxidant activity; and altered mRNA expression of lipid metabolism-related genes, including ACC, UCP 2, and CPT 1, in the HFD-fed rats. From these results, we concluded that AA possesses significant anti-obesity potential through the suppression of BW gain, lipid lowering action, development of insulin and leptin sensitivity, antioxidant activity, and increased mRNA expression of lipid metabolism-related genes.

Ethanolic Fraction of Terminalia tomentosa Attenuates Biochemical and Physiological Derangements in Diet Induced Obese Rat Model by Regulating Key Lipid Metabolizing Enzymes and Adipokines

The prevalence of overweight-obesity and associated comorbidities have reached alarming levels necessitating the need to explore effective therapeutics. In the present work, we demonstrated the promising antiobesity activity of ethanolic fraction of Terminalia tomentosa bark (EFTT) in diet induced obese rat model. High Fat Diet (HFD)-fed obese rats were orally administered with EFTT (50, 100 and 200 mg/kg body weight). Changes in body weight, body composition, bone mineral concentration, bone mineral density, plasma glucose, insulin, leptin, adiponectin, circulatory and tissue lipid profiles, and the activities of liver antioxidant enzymes, key lipid metabolic enzymes and mRNA expressions of fatty acid synthase (FAS), peroxisome proliferator-activated receptor gamma (PPAR-γ), leptin and tumor necrosis factor alpha (TNF-α) were assessed in experimental rats in the presence and absence of EFTT. At a dose of 200 mg/kg b.wt, EFTT has substantially attenuated body weight and related patho-physiological alterations in HFD-induced obese rats. These findings were correlated with histological observations of adipose tissue. The therapeutic activity of EFTT could be possibly through restoration of antioxidants status, regulation of key lipid metabolizing enzymes, expression of FAS, leptin, PPAR-γ and by synchronized control of energy metabolism in liver and adipose tissue.

Leaf Extract from Lithocarpus polystachyus Rehd. Promote Glycogen Synthesis in T2DM Mice

The purpose of this study was to investigate the effects of leaf extract from Lithocarpus polystachyus Rehd. on type II diabetes mellitus (T2DM) and the active ingredients of this effect. In addition, this study determined, for the first time, the underlying molecular and pharmacological mechanisms of the extracts on hyperglycemia using long-term double high diet-fed and streptozotocin (STZ) induced type II diabetic mice. In the present study, leaf extract, phloridzin and trilobatin were assessed in vivo (gavage) and in vitro (non-invasive micro-test technique, NMT) in experimental T2DM mice. The biochemical parameters were measured including blood glucose and blood lipid level, liver biochemical indexes, and hepatic glycogen. The relative expression of glycometabolism-related genes was detected. The effect of leaf extracts on physiological glucose flux in liver tissue from control and T2DM mice was also investigated. Body weight of experimental T2DM mice increased significantly after the first week, but stabilized over the subsequent three weeks; body weight of all other groups did not change during the four weeks’ study. After four weeks, all treatment groups decreased blood glucose, and treatment with leaf extract had numerous positive effects: a) promoted in glucose uptake in liver, b) increased synthesis of liver glycogen, c) reduced oxidative stress, d) up-regulation of glucokinase (GK), glucose transporter 2 (GLUT2), insulin receptor (IR) and insulin receptor substrate (IRS) expression in liver, e) down-regulation of glucose-6-phosphatase (G-6-P) expression, and f) ameliorated blood lipid levels. Both treatment with trilobatin or phloridzin accelerated liver glycogen synthesis, decreased oxidative stress and increased expression of GK. IRS and phosphoenolpyruvate carboxykinase (PEPCK) were both up-regulated after treatment with trilobatin. Expression of GLUT2, PEPCK and G-6-P were also increased in liver tissue after treatment with phloridzin. Our data indicate that leaf extract from L. polystachyus Rehd. has a preferable hypoglycemic effects than trilobatin or phloridzin alone. Leaf extract significantly increased glucose uptake and hepatic glycogen synthesis while also inducing a decline of hepatic gluconeogenesis and oxidative stress in T2DM mice. From this study, we draw conclusions that L. polystachyus promoted glycogen synthesis in T2DM mice, and that the active compounds were not only the trilobatin or phloridzin.

Preparative isolation, quantification and antioxidant activity of dihydrochalcones from Sweet Tea (Lithocarpus polystachyus Rehd.)

Dihydrochalcones are the main active components of Lithocarpus polystachyus Rehd. (Sweet Tea), they are directly related to the sweet tonic beverage and traditional herb. In this work, two runs of preparative high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/water (1:4:3:4, v/v) were employed to separate three dihydrochalcones (phloridzin, trilobatin and phloretin) from Sweet Tea. About 6.4mg of phloridzin, 48.4mg of trilobatin, and 4.7mg of phloretin with purities of 96.7%, 98.4% and 98.1% were obtained from 130mg of the crude Sweet Tea extract. Phloridzin, trilobatin, and phloretin had effective radical scavenging activities, with IC50 values of 866.80, 20.16 and 179.47μg/mL, respectively, in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method. The contents of phloridzin, trilobatin and phloretin in dried old leaves and tender leaves of tea were in the range of 10.1-18.0, 113.7-128.8, 3.6-4.3mg/g and 9.3-9.8, 82.9-103.1, 1.9-2.5mg/g, respectively. The results indicated that the HPLC had good precision, accuracy and repeatability for the determination of three dihydrochalcones in samples.

Correlation between tea consumption and prevalence of hypertension among Singaporean Chinese residents aged ⩾40 years

By a cross-sectional epidemiology study, we attempted to correlate the consumption of tea and/or health supplements, living habits and socio-demographic factors to the prevalence of hypertension among Singaporean Chinese residents. Singaporean Chinese residents aged ⩾40 years were randomly selected and interviewed face-to-face by clinical research assistants. Hypertension was defined as measured systolic blood pressure at least 140 mm Hg and/or diastolic blood pressure at least 90  mmHg or self-reported history/treatment for hypertension. The prevalence of hypertension among the whole investigated population (N=1184, 58.27% females) was 49.73% and the prevalence increased to 66.47% in the sub-population aged ⩾60 years. High risk of hypertension was associated with age ⩾60 years (odds ratio (OR): 4.15-4.19, P<0.01), obesity (body mass index >25 kg m(-2), OR: 2.10-2.11, P<0.01), family history of hypertension (OR: 2.69-2.76, P<0.01), diabetes history (OR: 2.29-2.33, P<0.01), hyperlipidemia history (OR: 1.79-1.80, P<0.01), male (OR: 1.56-1.59, P<0.01) and coffee intake (OR: 1.44-1.46, P<0.05). In contrast, drinking green tea at least 150 ml per week was associated with lower hypertension risk (OR: 0.63, 95% confidence interval (CI): 0.43-0.91, P<0.05). Drinking combination of green tea and British tea was associated with higher reduction in the risk of hypertension (OR: 0.58, 95% CI: 0.39-0.85, P<0.05). This cross-sectional study suggests that consumption of tea, especially green tea and British tea, was associated with lowering the risk of hypertension. On the other hand, consumption of coffee could be a risk factor of hypertension. These findings may provide useful information for health promotion to reduce risk of hypertension and warrant further study to confirm and elucidate such association.

Lithocarpic Acids A-N, 3,4-seco-Cycloartane Derivatives from the Cupules of Lithocarpus polystachyus

Fourteen new 3,4-seco-cycloartane-type triterpenes, lithocarpic acids A-N (1-14), together with one known compound, coccinetane E (15), were identified from the cupules of Lithocarpus polystachyus. The structures of 1-14 were determined by spectroscopic data analysis and chemical methods, and the absolute configurations of 1 and 4 were defined unequivocally by X-ray crystallography using Cu Kα radiation. Compounds 1-15 are the first examples of 3,4-seco-cycloartane derivatives isolated from the genus Lithocarpus. Among them, compounds 1 and 2, 9 and 10, and 11 and 12 were found to be three pairs of C-24 epimers, while compounds 7 and 8 represent the first examples of 3,4-seco-norcycloartane-type triterpenes. Compound 1, as the major component of the plant extract, showed potent antibacterial activity against Micrococcus luteus and Bacillus subtilis, with MIC values of 3.1 and 6.3 μg/mL, respectively, as well as inhibitory activity against human and mouse 11β-hydroxysteroid dehydrogenase type 1, with IC50 values of 1.9 and 0.24 μM, respectively.

Identification of the bioactive components of orally administered Lithocarpus polystachyus Rehd and their metabolites in rats by liquid chromatography coupled to LTQ Orbitrap mass spectrometry

A rapid, sensitive and selective UPLC/MS method using LTQ Orbitrap mass spectrometry was established for the analysis and characterization of the main biological components and their metabolites in rat plasma, urine and feces following oral administration of Lithocarpus polystachyus extract. In vivo, 22 flavonoid metabolites were observed in rat plasma, and 13 metabolites were detected in rat urine, whereas just two aglycones of dihydrochalcone (3-hydroxy phloretin and phloretin) could be detected in rat feces. Among these metabolites, one new and a known dihydrochalcone metabolite were isolated and definitely identified. Besides, five dihydrochalcone metabolites were tentatively identified as new compounds. A metabolism study of 3-hydroxyphlorizin and phloridzin was also conducted. Glucuronidation was the main metabolic pathway of phloridzin, whereas glucuronidation and sulfonation were the main metabolic pathway of 3-hydroxyphlorizin. These results provided a basis for evaluating the bioactive components of a complex natural medicine and their mechanisms of actions.

New Dihydrochalcone and Propenamide from Lithocarpus polystachyus

Two new compounds, (E)-4-(3, 4-dihydroxyphenyl)-N-(1-hydroxy-2-(4-hydroxyphenyl) ethyl)-2-oxobut-3-enamide (1) and phloretin2-O-β-D-apiofuranosyl (1→6)-β-D-glucopyranoside (2) were isolated from Lithocarpus polystachyus Rehd. Their structures were determined on the basis of analysis of their 1D and 2D NMR spectroscopic and mass spectral data.

Advances in understanding the interrelations between leptin resistance and obesity

Obesity, which has developed into a global epidemic, is a risk factor in most chronic diseases and some forms of malignancy. The discovery of leptin in 1994 has opened a new field in obesity research. Currently, we know that leptin is the primary signal from energy stores and exerts negative feedback effects on energy intake. However, most individuals with diet-induced obesity (DIO) develop leptin resistance, which is characterized by elevated circulating leptin levels and decreased leptin sensitivity. To date, though various mechanisms have been proposed to explain leptin resistance, the exact mechanisms of leptin resistance in obesity are poorly understood. Consequently, it's an important issue worth discussing regarding what the exact interrelations between leptin resistance and obesity are. Here, we review the latest advancements in the molecular mechanisms of leptin resistance and the exact interrelations between leptin resistance, obesity, and obesity-related diseases, in order to supply new ideas for the study of obesity.

Treatment with a SOD mimetic reduces visceral adiposity, adipocyte death, and adipose tissue inflammation in high fat-fed mice

OBJECTIVE

Obesity is associated with enhanced reactive oxygen species (ROS) accumulation in adipose tissue. However, a causal role for ROS in adipose tissue expansion after high fat feeding is not established. The aim of this study is to investigate the effect of the cell permeable superoxide dismutase mimetic and peroxynitrite scavenger Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (MnTBAP) on adipose tissue expansion and remodeling in response to high fat diet (HFD) in mice.

DESIGN AND METHODS

Male C57BL/6j mice were fed normal chow or high fat diet (HFD) and treated with saline or MnTBAP for 5 weeks. The effects of MnTBAP on body weights, whole body energy expenditure, adipose tissue morphology, and gene expression were determined.

RESULTS

MnTBAP attenuated weight gain and adiposity through a reduction in adipocyte hypertrophy, adipogenesis, and fatty acid uptake in epididymal (eWAT) but not in inguinal (iWAT) white adipose tissue. Furthermore, MnTBAP reduced adipocyte death and inflammation in eWAT and diminished circulating levels of free fatty acids and leptin. Despite these improvements, the development of systemic insulin resistance and diabetes after HFD was not prevented with MnTBAP treatment.

CONCLUSIONS

Taken together, these data suggest a causal role for ROS in the development of diet-induced visceral adiposity but not in the development of insulin resistance and type 2 diabetes.

Regulation effects of TZQ-F on adipocyte differentiation and insulin action

ETHNOPHARMACOLOGICAL RELEVANCE

TZQ has been used in traditional Chineses medicine for treating diabetes. Based on the recipe of traditional anti-diabetic formula TZQ, we have developed TZQ-F which has been in phase 2 clinical trails. To study the mechanisms by which TZQ-F ameliorates diabetes, we examined whether treatment with TZQ-F improves hyperinsulinemia, hyperglycemia and obesity in type 2 diabetic KKA(y) mice and whether this is associated with an improvement of adipocyte differentiation and insulin action.

METHODS

TZQ-F, fenofibrate, rosiglitazone or distilled water was administered to 7-week-old diabetic KKA(y) and nondiabetic C57BL/6J mice for 8 weeks. Insulin resistance index, body weight and levels of serum blood glucose, leptin, insulin and adiponectin were evaluated. The expression of peroxisome proliferator-activated receptor γ (PPARγ) in skeletal muscle and liver tissues were determined with real-time PCR and western boltting. The mRNA expressions of insulin receptor (InsR), insulin receptor substrate-1 (IRS-1), insulin receptor substrate-2 (IRS-2), glucose transporter-1 (Glut-1) and Phosphoenolpyruvate 3-kinases (PI3K) in skeletal muscle and liver tissues were determined with real-time PCR. Histopathology of liver has been observed.

RESULTS

Treatment of TZQ-F for 8 weeks ameliorated hyperglycemia, hyperinsulinemia, hyperleptinemia and hypoadiponectinemia in KKA(y) mice. TZQ-F also up-regulated expression of PPARγ in liver tissue. However, it had no effect on regulation of expression of PPARγ in muscle tissue. In addition, TZQ-F upregulates InsR, IRS-1, IRS-2, Glut-1, and PI3K mRNA expression. Consistent with the in vivo results, histology study demonstrated that TZQ-F alleviated pathologic changes of the liver induced by high-fat diet.

CONCLUSIONS

These results first indicate that TZQ-F can be beneficial for reducing hyperinsulinemia, hyperglycemia and obesity through its potency of regulating adipocyte differentiation and insulin action.

Antiadipogenic Effects of Aster glehni Extract: In Vivo and In Vitro Effects

Aster glehni (AG) is a Korean traditional herb that grows in Ulleungdo Island, Republic of Korea. None of the several reports on AG include a determination of the effect of AG on adipogenesis. The primary aim of this study was to determine whether AG attenuates adipogenesis in mouse 3T3-L1 cells and epididymal fat tissue. AG blocked the differentiation of 3T3-L1 preadipocytes in a concentration-dependent manner and suppressed the expression of adipogenesis-related genes such as PPARγ, C/EBPα, and SREBP1c, the master regulators of adipogenesis. Male C57BL/6J mice were divided randomly and equally into 4 diet groups: control diet (CON), high-fat diet (HFD), HFD with 1% AG extract added (AG1), and HFD with 5% AG extract added (AG5). The experimental animals were fed HFD and the 2 combinations for 10 weeks. Mice fed HFD with AG gained less body weight and visceral fat-pad weight than did the mice fed HFD alone. Moreover, AG inhibited the expression of important adipogenic genes such as PPARγ, C/EBPα, SREBP1c, LXR, and leptin in the epididymal adipose tissue of the mice treated with AG1 and AG5. These findings indicate antiadipogenic and antiobesity effects of AG and suggest its therapeutic potential in obesity and obesity-related diseases.

Antiobesity Effect of Codonopsis lanceolata in High-Calorie/High-Fat-Diet-Induced Obese Rats

The antiobesity effects of Codonopsis lanceolata (CL) were evaluated in a high-calorie/high-fat-diet (HFD-) induced obesity rat model and 3T3-L1 cells. The Sprague-Dawley male rats were fed a normal diet (ND) or a HFD for a period of 12 weeks. The rats were subdivided into groups: ND, ND + wild Codonopsis lanceolata (wCL) (900 mg/kg/day, p.o.), ND + cultivated Codonopsis lanceolata (cCL) (900 mg/kg/day, p.o.), HFD, HFD + wCL (100, 300, or 900 mg/kg/day, p.o.), HFD + cCL (100, 300, or 900 mg/kg/day, p.o.), and HFD + sibutramine. The body weight gains of the administered HFD + CL (wCL or CCL) were lower than those of the rats fed with only the HFD group. Moreover, the weight of adipose pads and the serum levels of triglycerides, total cholesterol, and low density lipoprotein cholesterol in the group administered HDL + CL were significantly lower than in the HFD group. The inhibitory effect of lipid accumulation in 3T3-L1 cells was measured by Oil Red O staining and reverse transcription-polymerase chain reaction (RT-PCR). Treatment of 3T3-L1 cells with wCL inhibited lipid accumulation and expression of C/EBPα and PPARγ. These results suggest that CL has a great potential as a functional food with anti-obesity effects and as a therapeutic alternative in the treatment of obesity.