Fruit of Hovenia dulcis Thunb. Induces Nonshivering Thermogenesis through Mitochondrial Biogenesis and Activation by SIRT1 in High-Fat Diet-Fed Obese Mice and Primary Cultured Brown Adipocytes

Anti-obesity effects of a standardized ethanol extract of Eisenia bicyclis by regulating the AMPK signaling pathway in 3T3-L1 cells and HFD-induced mice

Obesity requires treatment to mitigate the potential development of further metabolic disorders, including diabetes, hyperlipidemia, tumor growth, and non-alcoholic fatty liver disease. We investigated the anti-obesity effect of a 30% ethanol extract of Eisenia bicyclis (Kjellman) Setchell (EEB) on 3T3-L1 preadipocytes and high-fat diet (HFD)-induced obese C57BL/6 mice. Adipogenesis transcription factors including peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer-binding protein-alpha (C/EBPα), and sterol regulatory element-binding protein-1 (SREBP-1) were ameliorated through the AMP-activated protein kinase (AMPK) pathway by EEB treatment in differentiated 3T3-L1 cells. EEB attenuated mitotic clonal expansion by upregulating cyclin-dependent kinase inhibitors (CDKIs) while downregulating cyclins and CDKs. In HFD-fed mice, EEB significantly decreased the total body weight, fat tissue weight, and fat in the tissue. The protein expression of PPARγ, C/EBPα, and SREBP-1 was increased in the subcutaneous fat and liver tissues, while EEB decreased the expression levels of these transcription factors. EEB also inhibited lipogenesis by downregulating acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) expression in the subcutaneous fat and liver tissues. Moreover, the phosphorylation of AMPK and ACC was downregulated in the HFD-induced mouse group, whereas the administration of EEB improved AMPK and ACC phosphorylation; thus, EEB treatment may be related to the AMPK pathway. Histological analysis showed that EEB reduced the adipocyte size and fat accumulation in subcutaneous fat and liver tissues, respectively. EEB promotes thermogenesis in brown adipose tissue and improves insulin and leptin levels and blood lipid profiles. Our results suggest that EEB could be used as a potential agent to prevent obesity.

Effects of Hovenia dulcis fruit and peduncle extract on alcohol metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit and peduncle of Hovenia dulcis Thunberg (Rhamnaceae) (HD) has been used as a folk medicine to treat liver disease, detoxify alcoholism, and prevent and cure hangovers.

AIM OF THE STUDY

We investigated the pharmacology of HD on the kinetics of EtOH and on the enzymes related to alcohol metabolism to seek the scientific evidence of HD to prevent hangover, the effectiveness as a folk medicine.

MATERIALS AND METHODS

EtOH was orally administered 30 min after oral administration of HD boiling water extract in rats. Then, the profiles of blood EtOH concentrations were measured. Mice were reared with food containing powdered HD for 7 days, and the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in liver were measured. Hepa1c1c7 cells were cultured with the medium containing HD extract, and the activities of ADH and ALDH were measured.

RESULTS

HD extract reduced the blood EtOH concentrations in rats and induced the activities of ADH and ALDH and mRNA and protein expressions of ADH1B, ALDH1A1, and ALDH2 in the liver of mice and Hepa1c1c7 cells. Dihydromyricetin, one of the ingredients of HD, significantly induced the activities of ADH and ALDH in Hepa1c1c7 cells, however, the fractions containing hydrophilic organic compounds with small molecular weight contributed the most of the activities of HD extract.

CONCLUSIONS

We clarified the experimental pharmacological evidences of HD as a folk medicine to detoxify alcoholism and prevent hangovers.

White adipocyte-derived exosomal miR-23b inhibits thermogenesis by targeting Elf4 to regulate GLP-1R transcription

Promoting non-trembling thermogenesis of brown adipose tissue (BAT) and browning of white adipose tissue (WAT) helps prevent obesity. MiR-23b is highly expressed in adipose tissue-derived exosomes obtained from obese people, but the role of exosomal miR-23b in regulating thermogenesis and obesity progression remains to be further explored. Here, a mouse obesity model was established through high-fat diet (HFD), and inguinal WAT (iWAT)-derived exosomes and miR-23b antagomir were administered by intraperitoneal injection. The results showed that WAT-derived exosomal miR-23b upregulated body weight and adipocyte hypertrophy and enhanced insulin resistance. Moreover, exosomal miR-23b restrained mtDNA copy number and the expression of genes related to thermogenesis and mitochondrial biogenesis in BAT, and suppressed the expression of WAT browning-related genes under cold stimulation, indicating that exosomal miR-23b hindered non-trembling thermogenesis of BAT and WAT browning. Mechanism studies found that miR-23b targeted Elf4 to inhibit its expression. And Elf4 bound to the GLP-1R promoter region to promote GLP-1R transcription. In addition, silencing miR-23b effectively abolished the inhibitory effect of WAT-derived exosomes on thermogenic gene expression and mitochondrial respiration in adipocytes isolated from BAT and iWAT, which was reversed by GLP-1R knockdown. In conclusion, WAT-derived exosomal miR-23b suppressed thermogenesis by targeting Elf4 to regulate GLP-1R transcription, which contributed to the progression of obesity.

Hovenia dulcis Thunb. Fruit Extract Attenuates Psoriatic Skin Inflammation in Tumor Necrosis Factor-α-Stimulated Human Keratinocyte HaCaT Cells In Vitro

Hovenia dulcis Thunb. fruit (HDF) is traditionally used for treating liver diseases and alcohol poisoning. The purpose of this study was to explore the effects of HDF on hyperproliferation, levels of inflammatory cytokines, and signaling mechanisms in human psoriatic keratinocyte HaCaT cells. HDF showed a preventive effect on tumor necrosis factor-α (TNF-α)-induced abnormal proliferation of psoriatic keratinocytes. Furthermore, real-time reverse transcription-PCR analysis showed that HDF suppressed the expressions of inflammatory cytokines; interleukin (IL)-1α and IL-1β and chemokines; CCL-20 and CXCL-8 in TNF-α-induced HaCaT cells. Western blotting revealed that HDF suppressed the levels of phosphorylated IκB and STAT3 together with a decline in the levels of phosphorylated mitogen-activated protein kinases (MAPKs). These outcomes indicate that HDF prevents the abnormal proliferation of keratinocytes and modulates inflammatory responses by suppressing nuclear factor-κB (NF-κB) and STAT3 activation through downregulation of the MAPK signaling pathway in TNF-α-induced psoriatic keratinocytes. Our study demonstrates that HDF is prospective and beneficial for psoriatic skin inflammation.

Comparative analysis of the liver-protective effects of raw and stir-fried semen of Hovenia dulcis in rats via gas chromatography-mass spectrometry-based serum metabolomic profiling and chemometrics

In this study, we used a serum metabolomics methodology based on GC coupled with MS (GC-MS) to investigate the liver-protective effects of raw and stir-fried semen of Hovenia dulcis in rats models of carbon tetrachloride-induced liver injury. Multivariate statistical analysis, such as principal component analysis and orthogonal partial least squares discriminant analysis, were performed to examine changes in the metabolic state of rats with carbon tetrachloride-induced liver injury, as well as the recovery pattern of rats pretreated with the raw and stir-fried semen of H. dulcis. Liver tissues were subjected to histopathological examination. A total of 47 biomarkers were predicted to contribute to the dynamic pathological processes in the liver injury, such as phenylalanine, glutamic acid, glycine, arachidonic acid and linoleic acid. Further analysis revealed that pathways associated with phenylalanine, tyrosine and tryptophan biosynthesis, and linoleic acid metabolism were altered in the injured liver, and that pretreatment with raw and stir-fried semen of H. dulcis abolished the changes in the aforementioned metabolic pathways.

Antioxidant activity and blood alcohol concentration lowering effect of fermented Hovenia dulcis fruit vinegar

In this study, Hovenia dulcis fruit fermented vinegar (HFV) was produced by the two-step fermentation of the H. dulcis fruit. The bioactivities before and after fermentation were compared. During the two-stage fermentation, the highest total acidity (4.99%) in the H. dulcis fruit extract juice was determined to be 16°Bx. During fermentation, the acetic acid content increased from 54.45 to 5404.30 mg%, and the fructose level in the HFV decreased from 130.68 to 54.91 mg%. The levels of DPPH and ABTS·+ free radicals scavenging activities, reducing power, hydrogen peroxide scavenging and β-carotene bleaching activities were found to be increased in HFV as compared to before fermentation. Furthermore, the serum alcohol and acetaldehyde levels were reduced significantly in HFV compared to before fermentation. This study shows that HFV enhances the antioxidant and alcohol degradation activities and can potentially be used as a functional drink to prevent hangovers.

Potato protease inhibitor II prevents obesity by inducing browning of white adipose tissue in mice via β3 adrenergic receptor signaling pathway

There are currently few effective and safe pharmacologic means for inducing beige adipogenesis in humans. This study highlights the role of potato protease inhibitor II (PPI II) in regulating the browning of adipose tissue. The in vitro results showed that PPI II increased the expression of the uncoupling protein 1 (UCP1) protein and gene and beige-specific genes, including Cd137, Cited1, Tbx1, and Tmem26 in vitro. PPI II treatment for three months in diet-induced obesity mice increased the levels of the UCP1 protein in white adipose tissue, causing elevated energy expenditure, thus preventing obesity and improving glucose tolerance. Mechanistic studies further revealed that PPI II regulated the abundance and activity of β₃ adrenergic receptor (β₃ -AR) in white adipocytes. Chemical-inhibition experiments revealed the crucial role of β₃ -AR-dependent protein kinase A (PKA)-p38 kinase (p38)/extracellular signal-related kinase1/2 (ERK1/2) signaling in PPI II-mediated browning program of white adipose tissues. In summary, our findings highlight the role of PPI II in beige adipocyte differentiation and thermogenesis and provide new insights into its use in preventing obesity.

Fruit of Gardenia jasminoides Induces Mitochondrial Activation and Non-Shivering Thermogenesis through Regulation of PPARγ

The extract of the Gardenia jasminoides fruit (GJFE) can been consumed as an herbal tea or used as a yellow dye. Recently, studies report that GFJE exerts inhibitory effects on lipid accumulation and adipogenesis in white adipocytes. We evaluated the thermogenic actions of GJFE by focusing on mitochondrial activation and studying the underlying mechanisms. To investigate the role of GJFE on thermogenesis in mice, we used an acute cold exposure model. After 2 weeks of feeding, the cold tolerance of GJFE-fed mice was notably increased compared to PBS-fed mice. This was due to an increase in thermogenic proteins in the inguinal white adipose tissue of the cold-exposed mice. Moreover, GJFE significantly increased thermogenic factors such as peroxisome proliferator-activated receptor gamma (PPARγ), uncoupling protein 1 (UCP1), and PPARγ coactivator 1 alpha (PGC1α) in vitro as well. Factors related to mitochondrial abundance and functions were also induced by GJFE in white and beige adipocytes. However, the treatment of PPARγ inhibitor abolished the GJFE-induced changes, indicating that activation of PPARγ is critical for the thermogenic effect of GJFE. In conclusion, GJFE induces thermogenic action by activating mitochondrial function via PPARγ activation. Through these findings, we suggest GJFE as a potential anti-obesity agent with a novel mechanism involving thermogenic action in white adipocytes.

Gomisin A Alleviates Obesity by Regulating the Phenotypic Switch between White and Brown Adipocytes

Although gomisin A (GA) alleviates cancer and inflammation, its anti-obesity effect and the underlying mechanism have not yet been elucidated. Therefore, in this study, we aimed to elucidate the anti-obesity effects of GA by investigating the phenotypic changes involved in the browning and whitening of adipocytes. Here, obesity was induced to C57BL/6J mice using a high-fat diet (HFD). We administrated GA and checked weight changes for 12 weeks. We found that GA decreased the weight of weight gain, epididymal white adipose tissue (eWAT), and liver in the mice. In addition, the administration of GA elevated the levels of high-density lipoprotein (HDL)-cholesterol in the mice serum. Moreover, even after 12 weeks of treatment with GA, it did not cause any hepatic and renal toxicity. However, we found that GA induced the browning of eWAT and inhibited the whitening of brown adipose tissue. We further confirmed the anti-obesity mechanism of GA using 3T3-L1 cells, the human adipose mesenchymal stem cells (hAMSCs), and primary brown adipocytes (BAs) in vitroexperiments. We found that GA suppressed adipogenesis via the activation of AMP-activated protein kinase (AMPK). Furthermore, GA-induced browning by increasing the expression levels of uncoupling protein 1 (UCP1) in hAMSCs. The results of our study indicate that GA can inhibit weight gain by regulating the phenotypic changes involved in the browning and whitening of adipose tissues, which makes it a potential therapeutic agent for the treatment of obesity.