Phytol increases adipocyte number and glucose tolerance through activation of PI3K/Akt signaling pathway in mice fed high-fat and high-fructose diet

Conjugated linoleic acid (CLA) reduces intestinal fatty acid uptake and chylomicron formation in HFD-fed mice associated with the inhibition of DHHC7-mediated CD36 palmitoylation and the downstream ERK pathway

The anti-obesity effect of conjugated linoleic acid (CLA) has been well elucidated, but whether CLA affects fat deposition by regulating intestinal dietary fat absorption remains largely unknown. Thus, this study aimed to investigate the effects of CLA on intestinal fatty acid uptake and chylomicron formation and explore the possible underlying mechanisms. We found that CLA supplementation reduced the intestinal fat absorption in HFD (high fat diet)-fed mice accompanied by the decreased serum TG level, increased fecal lipids and decreased intestinal expression of ApoB48 and MTTP. Correspondingly, c9, t11-CLA, but not t10, c12-CLA induced the reduction of fatty acid uptake and TG content in PA (palmitic acid)-treated MODE-K cells. In the mechanism of fatty acid uptake, c9, t11-CLA inhibited the binding of CD36 with palmitoyltransferase DHHC7, thus leading to the decreases of CD36 palmitoylation level and localization on the cell membrane of the PA-treated MODE-K cells. In the mechanism of chylomicron formation, c9, t11-CLA inhibited the formation of the CD36/FYN/LYN complex and the activation of the ERK pathway in the PA-treated MODE-K cells. In in vivo verification, CLA supplementation reduced the DHHC7-mediated total and cell membrane CD36 palmitoylation and suppressed the formation of the CD36/FYN/LYN complex and the activation of the ERK pathway in the jejunum of HFD-fed mice. Altogether, these data showed that CLA reduced intestinal fatty acid uptake and chylomicron formation in HFD-fed mice associated with the inhibition of DHHC7-mediated CD36 palmitoylation and the downstream ERK pathway.

Flavonoid-Rich Trianthema decandra Ameliorates Cognitive Dysfunction in the Hyperglycemic Rats

The present study was aimed at the evaluation of neuroprotective ability of methanolic extract of Trianthema decandra (METD) against hyperglycemia-related cognitive impairment in rats. The extract of T. decandra was standardized by TLC and HPTLC methods. To verify the identity and purity of isolated compounds, they were segregated and characterized using various techniques, including UV-visible spectrophotometry, FT-IR, H-NMR, and Mass spectroscopy. α-Amylase and α-glucosidase inhibition property of the extracts were assessed in-vitro. The screening of the neuroprotective effects of METD in hyperglycemic rats was done utilizing Morri's water (MWM) and elevated plus maze (EPM) model, as well as acetylcholinesterase (AChE) activity. The extracts of Trianthema decandra and its chemical constituents, namely quercetin and phytol, demonstrated a significant protective effect on enzymes like α-amylase and α-glucosidase. Methanol and hydroalcoholic extracts have shown the strongest inhibitory activity followed by chloroform extract. Quercetin and phytol were associated with the methanolic and chloroform extracts which were identified using TLC and HPTLC techniques. During the thirty days of the study, the induction of diabetes in the rats exhibited persistent hyperglycemia, hyperlipidemia, higher escape latency during training trials and reduced time spent in target quadrant in probe trial in Morris water maze test, and increased escape latency in EPM task. Regimen of METD (200 and 400 mg/kg) in the diabetic rats reduced the glucose levels in blood, lipid, and liver profile and showed positive results on Morri's water and elevated plus maze tasks. During the investigation, it was determined that Trianthema decandra extracts and the chemical constituent's quercetin and phytol in it had anti-diabetic and neuroprotective activities.

Conjugated linoleic acid (CLA) reduces HFD-induced obesity by enhancing BAT thermogenesis and iWAT browning via the CD36-AMPK pathway

The antiobesity effect of conjugated linoleic acid (CLA) has been reported. However, the underlying mechanisms have not been fully clarified. Thus, this study aimed to investigate the effects of CLA on thermogenesis of interscapular brown adipose tissue (iBAT) and browning of inguinal subcutaneous white adipose tissue (iWAT) and explore the possible signaling pathway. The in vivo results showed that CLA enhanced the O2 consumption and heat production in HFD (high-fat diet)-fed female mice by roughly 38%. Meanwhile, CLA increased the average iBAT temperature by 2°C at the room temperature and cold exposure, respectively. Correspondingly, CLA caused 1.6- and 2.4-fold increases in the expression of UCP1 (uncoupling protein 1) of BAT and iWAT, respectively, suggesting the activated iBAT thermogenesis and iWAT browning in HFD-fed female mice. Meanwhile, CLA could promote the formation of brown and beige adipocytes in differentiated stromal vascular cells (SVCs) isolated from iBAT and iWAT (the expressions of UCP1 were promoted by about twofold changes). In possible mechanisms, CLA stimulated the expression of CD36 and the activation of the AMPK pathway in mice iBAT and iWAT as well as the differentiated SVCs. However, inhibition of CD36 and AMPK (adenosine 5'-monophosphate-activated protein kinase) abolished the promotive effects of CLA on brown and beige adipocytes formation. Hence, we showed that CLA reduced HFD-induced obesity through enhancing iBAT thermogenesis and iWAT browning via the  CD36-AMPK pathway.

Phytochemical composition, toxicological profiling and effect on pup birth weight of Corchorus olitorius leaf extract in rats: Implications for fetal macrosomia control

ETHNOPHARMACOLOGICAL RELEVANCE

Corchorus olitorius is used in ethnomedicine to arrest threatened miscarriage, ease labour, and promote smooth childbirth.

AIM OF THE STUDY

To evaluate the phytochemical composition, toxicity profile, and effect of Corchorus olitorius L. leaf extract (COLE) on fetal macrosomia control in rats.

MATERIALS AND METHODS

The chemical constituents of COLE were determined using gas chromatography-mass spectrometry (GC-MS). A single dose of up to 5000 mg/kg was administered in the acute toxicity test, and the rats were monitored for 14 days. In the sub-acute toxicity study, rats were treated with the extract for 28 days, and liver function, renal function, lipid profile, and serum antioxidant parameters, coupled with liver and kidney histology, were used to assess the toxicity potential of the extract. In the pup birth weight study, treatment of pregnant rats lasted until the birth of pups and continued for an extra 4 weeks. Rats in group 1 served as a control, whereas rats in groups 2, 3, and 4 received daily doses of 200, 400, and 800 mg/kg body weight of COLE, respectively, via oral gavage.

RESULTS

Bioactive compounds such as D-limonene, phytol, hexadecanoic acid, 9-octadecenoic acid (Z), dodecanoic acid, and ethyl 9,12,15-octadecatrienoate with well-known pharmacological activities were detected. LD50 of COLE was >5000 mg/kg. COLE decreased body weight and increased red blood cell, packed cell volume, and haemoglobin values when compared with the control (p < 0.05). COLE significantly decreased alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase but did not cause any significant (p > 0.05) changes in other biochemical (liver and kidney) parameters when compared to control. COLE decreased total cholesterol, triglycerides, low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol when compared with the control (p < 0.05). Birth weights of pups were significantly decreased in the COLE-treated groups when compared with the control (p < 0.05), but the observed difference terminated by the fourth week of weaning.

CONCLUSION

The results showed that COLE is not toxic but has several bioactive compounds with known pharmacological activities and therefore may be a safe oral agent for fetal macrosomia control.

Functional analysis of differentially expressed circular RNAs in sheep subcutaneous fat

BACKGROUND

Circular RNAs (circRNAs), as important non-coding RNAs (ncRNAs), are involved in many biological activities. However, the exact chemical mechanism behind fat accumulation is unknown. In this paper, we obtained the expression profiles of circRNAs using high-throughput sequencing and investigated their differential expression in subcutaneous fat tissue of Duolang and Small Tail Han sheep.

RESULTS

From the transcriptomic analysis, 141 differentially expressed circRNAs were identified, comprising 61 up-regulated circRNAs and 80 down-regulated circRNAs. These host genes were primarily enriched in the MAPK and AMPK signaling pathways which is closely associated with fat deposition regulation. We identified circRNA812, circRNA91, and circRNA388 as vital genes in fat deposition by miRNA-circRNA target gene prediction. The functional annotation results of target genes of key circRNAs showed that the signaling pathways mainly included PI3K-Akt and AMPK. We constructed the competing endogenous RNA (ceRNA) regulatory network to study the role of circRNAs in sheep lipid deposition, and circRNA812, circRNA91, and circRNA388 can adsorb more miRNAs. NC_040253.1_5757, as the source of miRNA response element (MRE) among the three, may play an important role during the process of sheep fat deposition.

CONCLUSIONS

Our study gives a systematic examination of the circRNA profiles expressed in sheep subcutaneous fat. These results from this study provide some new basis for understanding circRNA function and sheep fat metabolism.

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Oxidative stress and chronic low-grade inflammation play crucial roles in the pathophysiology of diabetes mellitus. There has been a growing interest in applying natural products to improve metabolic derangements without the side effects of anti-diabetic drugs. Microalgae biomass or extract and their bioactive compounds have been applied as nutraceuticals or additives in food products and health supplements. Several studies have demonstrated the therapeutic effects of microalgae and their bioactive compounds in improving insulin sensitivity attributed to their antioxidant, anti-inflammatory, and pancreatic β-cell protective properties. However, a review summarizing the progression in this topic is lacking despite the increasing number of studies reporting their anti-diabetic potential. In this review, we gathered the findings from in vitro, in vivo, and human studies to discuss the effects of microalgae and their bioactive compounds on diabetes mellitus and the mechanisms involved. Additionally, we discuss the limitations and future perspectives of developing microalgae-based compounds as a health supplement for diabetes mellitus. In conclusion, microalgae-based supplementation has the potential to improve diabetes mellitus and be applied in more clinical studies in the future.

In Vivo and In Vitro Antidiabetic Efficacy of Aqueous and Methanolic Extracts of Orthosiphon Stamineus Benth

Orthosiphon stamineus is a popular folk herb used to treat diabetes and some other disorders. Previous studies have shown that O. stamineus extracts were able to balance blood glucose levels in diabetic rat animal models. However, the antidiabetic mechanism of O. stamineus is not fully known. This study was carried out to test the chemical composition, cytotoxicity, and antidiabetic activity of O. stamineus (aerial) methanol and water extracts. GC/MS phytochemical analysis of O. stamineus methanol and water extracts revealed 52 and 41 compounds, respectively. Ten active compounds are strong antidiabetic candidates. Oral treatment of diabetic mice with O. stamineus extracts for 3 weeks resulted significant reductions in blood glucose levels from 359 ± 7 mg/dL in diabetic non-treated mice to 164 ± 2 mg/dL and 174 ± 3 mg/dL in water- and methanol-based-extract-treated mice, respectively. The efficacy of O. stamineus extracts in augmenting glucose transporter-4 (GLUT4) translocation to the plasma membrane (PM) was tested in a rat muscle cell line stably expressing myc-tagged GLUT4 (L6-GLUT4myc) using enzyme-linked immunosorbent assay. The methanol extract was more efficient in enhancing GLUT4 translocation to the PM. It increased GLUT4 translocation at 250 µg/mL to 279 ± 15% and 351 ± 20% in the absence and presence of insulin, respectively. The same concentration of water extract enhanced GLUT4 translocation to 142 ± 2.5% and 165 ± 5% in the absence and presence of insulin, respectively. The methanol and water extracts were safe up to 250 µg/mL as measured with a Methylthiazol Tetrazolium (MTT) cytotoxic assay. The extracts exhibited antioxidant activity as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. O. stamineus methanol extract reached the maximal inhibition of 77 ± 10% at 500 µg/mL, and O. stamineus water extract led to 59 ± 3% inhibition at the same concentration. These findings indicate that O. stamineus possesses antidiabetic activity in part by scavenging the oxidants and enhancing GLUT4 translocation to the PM in skeletal muscle.

Rapid direct conversion of bovine non-adipogenic fibroblasts into adipocyte-like cells by a small-molecule cocktail

Introduction: The molecular regulation mechanism of fat deposition in bovine and its improvement on beef quality are important research directions in the livestock industry. The research of molecular mechanisms that govern the regulation and differentiation of adipocytes may conduct to understand the mechanism of obesity, lipid disorders, and fat deposition. In the recent decade, small-molecule compounds have been widely used in reprogramming and transdifferentiation fields, which can promote the induction efficiency, replace exogenous genes, or even induce cell fate conversion alone. Furthermore, small-molecule compound induction is expected to be a novel approach to generate new cell types from somatic cells in vitro and in vivo. Methods: In this study, we established rapid chemically induced platform for transdifferentiation of bovine ear fibroblasts into adipocyte-like cells using a small-molecule cocktail (Repsox, VPA, TTNPB). The chemically induced adipocytes (CiADCs) were characterized by lipid staining, qRT-PCR and WB. Bovine natural adipocytes were used as positive control, and the expression of adipocyte-related marker genes in CiADCs were analyzed. Moreover, RNA-Seq explore the mechanism of RVB in the regulation of Bovine adipocyte transdifferentiation. Results: In this study, the chemically induced adipocytes (CiADCs) could be identified as early as day 6. The CiADCs appeared to be circular and rich of lipid droplets. The adipocyte-specific genes of LPL, PPARγ, IGF1, GPD1, C/EBPδ, ADIPOQ, PCK2, FAS, C/EBPβ, PPARGC1A, C/EBPα, and CFD were detected to be significantly upregulated in both CiADCs and natural adipocytes. Western blot analysis also confirmed the increase C/EBPα and PPARγ protein level in induced adipocytes (CiADCs-6d) treated with RVB. In addition, we also found that the signaling pathways (PPAR signaling pathway, PI3K-Akt signaling pathway, p53 signaling pathway, MAPK signaling pathway, and ECM-receptor interaction) regulated by the DEGs played a vital role in adipogenesis. Discussion: In the present study, a combination of small-molecule compounds RVB was used to transdifferentiate bovine ear fibroblasts into the chemically-induced adipocyte cells (CiADCs) that have a large number of lipid droplets. Importantly, the small-molecule cocktail significantly shortened the reprogramming turnaround time. The morphology of CiADCs is close to the "ring type" of natural differentiated adipocytes on sixth day. And, the CiADCs showed similar adipocyte-specific gene expression patterns to natural adipocytes. Furthermore, RVB increased protein expression of PPARγ and C/EBPα in the chemically-induced adipocytes (CiADCs-6d). Our findings reveal that the signaling pathways of C/EBPα and PPARγ play pivotal roles in this transdifferentiation process. In addition, we also found that the signaling pathways (PPAR signaling pathway, PI3K-Akt signaling pathway, p53 signaling pathway, MAPK signaling pathway, and ECM-receptor interaction) regulated by the DEGs played a vital role in adipogenesis. In general, this study provides valuable evidence to deepen our understanding of the molecular mechanism of small molecule cocktails in regulating adipogenesis.

GDF11 inhibits adipogenesis of human adipose-derived stromal cells through ALK5/KLF15/β-catenin/PPARγ cascade

Obesity is a metabolic disease characterized by excessive fat storage, and the adipogenic differentiation of adipose-derived stromal cells (ADSCs) is closely linked to its occurrence. Growth differentiation factor 11 (GDF11), a well-known molecule in the field of anti-aging, also has great potential in regulating stem cell differentiation. In this study, we found that GDF11 inhibited adipogenic differentiation of human ADSCs in vitro by activating the WNT/β-catenin and SMAD2/3 pathways while inhibiting the AKT pathway. Moreover, the transcription factor Kruppel-like factor 15 (KLF15) was discovered to be an important downstream factor for GDF11 in inhibiting adipogenesis via the WNT/β-catenin pathway. Furthermore, AlphaFold2 structure prediction and inhibitor-blocking experiments revealed that ALK5 is a functional receptor of GDF11. Collectively, we demonstrated that GDF11 is a potential target for inhibiting adipogenic differentiation and combating obesity.

Acyclic Diterpene Phytol from Hemp Seed Oil (Cannabis sativa L.) Exerts Anti-Inflammatory Activity on Primary Human Monocytes-Macrophages

Seeds from non-drug varieties of hemp (Cannabis sativa L.) have been used for traditional medicine, food, and fiber production. Our study shows that phytol obtained from hemp seed oil (HSO) exerts anti-inflammatory activity in human monocyte-macrophages. Fresh human monocytes and human macrophages derived from circulating monocytes were used to evaluate both plasticity and anti-inflammatory effects of phytol from HSO at 10–100 mM using FACS analysis, ELISA, and RT-qPCR methods. The quantitative study of the acyclic alcohol fraction isolated from HSO shows that phytol is the most abundant component (167.59 ± 1.81 mg/Kg of HSO). Phytol was able to skew monocyte-macrophage plasticity toward the anti-inflammatory non-classical CD14⁺CD16⁺⁺ monocyte phenotype and toward macrophage M2 (CD200R^high and MRC-1^high), as well as to reduce the production of IL-1β, IL-6, and TNF-α, diminishing the inflammatory competence of mature human macrophages after lipopolysaccharide (LPS) treatment. These findings point out for the first time the reprogramming and anti-inflammatory activity of phytol in human monocyte-macrophages. In addition, our study may help to understand the mechanisms by which phytol from HSO contributes to the constant and progressive plasticity of the human monocyte-macrophage linage.

Kutkin, iridoid glycosides enriched fraction of Picrorrhiza kurroa promotes insulin sensitivity and enhances glucose uptake by activating PI3K/Akt signaling in 3T3-L1 adipocytes

BACKGROUND

Therapeutic failure and drug resistance are common sequelae to insulin resistance associated with type 2 diabetes mellitus (T2DM). Consequently, there is an unmet need of alternative strategies to overcome insulin resistance associated complications.

PURPOSE

To demonstrate whether Kutkin (KT), iridoid glycoside enriched fraction of Picrorhiza kurroa extract (PKE) has potential to increase the insulin sensitivity vis à vis glucose uptake in differentiated adipocytes.

METHODS

Molecular interaction of KT phytoconstituents, picroside-I (P-I) & picroside- II (P-II) with peroxisome proliferator-activated receptor gamma (PPARγ), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) were analyzed in silico. Cellular viability and adipogenesis were determined by following 3-(4, 5-Dimethylthiazol-2-Yl)-2, 5-Diphenyltetrazolium bromide (MTT) assay and Oil Red-O staining. Further, ELISA kit based triglycerides and diacylglycerol-O-Acyltransferase-1 (DGAT1) were assessed in differentiated adipocytes. ELISA based determination were performed to check the levels of adiponectin and tumor necrosis factor alpha (TNF-α). However, Flow cytometry and immunofluorescence based assays were employed to measure the glucose uptake and glucose transporter 4 (glut4) expression in differentiated adipocytes, respectively. Further to explore the targeted signaling axis, mRNA expression levels of PPARγ, CCAAT/enhancer binding protein α (CEBPα), and glut4 were determined using qRT-PCR and insulin receptor substrate-1 (IRS-1), Insulin receptor substrate-2 (IRS-2), PI3K/Akt, AS160, glut4 followed by protein validation using immunoblotting in differentiated adipocytes.

RESULTS

In silico analysis revealed the binding affinities of major constituents of KT (P-I& P-II) with PPARγ/PI3K/Akt. The enhanced intracellular accumulation of triglycerides with concomitant activation of PPARγ and C/EBPα in KT treated differentiated adipocytes indicates augmentation of adipogenesis in a concentration-dependent manner. Additionally, at cellular level, KT upregulated the expression of DAGT1, and decreases fatty acid synthase (FAS), and lipoprotein lipase (LPL), further affirmed improvement in lipid milieu. It was also observed that KT upregulated the levels of adiponectin and reduced TNFα expression, thus improving the secretory functions of adipocytes along with enhanced insulin sensitivity. Furthermore, KT significantly promoted insulin mediated glucose uptake by increasing glut4 translocation to the membrane via PI3/Akt signaling cascade. The results were further validated using PI3K specific inhibitor, wortmannin and findings revealed that KT treatment significantly enhanced the expression and activation of p-PI3K/PI3K and p-Akt/Akt even in case of treatment with PI3K inhibitor wortmannin alone and co-treatment with KT in differentiated adipocytes and affirmed that KT as activator of PI3K/Akt axis in the presence of inhibitor as well.

CONCLUSION

Collectively, KT fraction of PKE showed anti-diabetic effects by enhancing glucose uptake in differentiated adipocytes via activation of PI3K/Akt signaling cascade. Therefore, KT may be used as a promising novel natural therapeutic agent for managing T2DMand to the best of our knowledge, this is the first report, showing the efficacy and potential molecular mechanism of KT in enhancing insulin sensitivity and glucose uptake in differentiated adipocytes.

A Comprehensive Review of C. capsularis and C. olitorious: A Source of Nutrition, Essential Phytoconstituents and Pharmacological Activities

Plant bioactive compounds have gained global significance in terms of both medicinal and economic ramifications due to being easily accessible and are believed to be effective with fewer side effects. Growing relevant clinical and scientific evidence has become an important criterion for accepting traditional health claims of medicinal plants and also supports the traditional uses of Corchorus as folk medicine. C. capsularis and C. olitorius have broad applications ranging from textile to biocomposite, and young leaves and shoots are used as healthy vegetables and have long been used as traditional remedies for fever, ascites, algesia, liver disorders, piles, and tumors in many cultures. This review systematically summarized and emphasized the nutritional attributes, mostly available bioactive compounds, and biological and potential pharmaceutical properties of C. capsularis and C. olitorius, disclosed to users and non-users. Results suggest that various phytochemicals such as cardiac glycosides, phenols, flavonoids, sterols, lipids, and fatty acids were found or analytically identified in different plant parts (leaf, stem, seed, and root), and many of them are responsible for pharmacological properties and their antitumor, anticancer, antioxidant, antinociceptive, anti-inflammatory, analgesic, antipyretic, antiviral, antibacterial, anticonvulsant, antidiabetic and antiobesity, and cardiovascular properties help to prevent and cure many chronic diseases. In addition to their use in traditional food and medicine, their leaves have also been developed for skin care products, and some other possible uses are described. From this review, it is clear that the isolated compounds of both species have great potential to prevent and treat various diseases and be used as functional foods. In conclusion, this comprehensive review establishes a significant reference base for future research into various medical and functional food applications.

Phytochemistry and Biological Properties of Salvia verbenaca L.: A Comprehensive Review

The family Lamiaceae contains several plants used in traditional medicine to fight against different diseases. Salvia verbenaca L. (S. verbenaca) is one of the Lamiaceae species distributed around the Mediterranean regions. This plant exhibits different bioactive properties, including antibacterial, anticancer, antioxidant, antileishmanial, antidiabetic, immunomodulatory, and wound healing. This review was conducted to revise previous studies on S. verbenaca addressing its botanical description, geographical distribution, and phytochemical, pharmacological, and toxicological properties. Moreover, the main pharmacological actions of S. verbenaca major compounds were well investigated. Literature reports have revealed that S. verbenaca possesses a pivotal role in medicinal applications. The findings of this work noted that S. verbenaca was found to be rich in chemical compound classes such as terpenoids, phenolics, fatty acids, sterols, and flavonoids. Numerous studies have found that S. verbenaca essential oils and extracts have a wide range of biological effects. These results support the potential pharmacological properties of S. verbenaca and its traditional uses. This analysis can constitute a scientific basis for further refined studies on its pure secondary metabolites. Therefore, the outcome of the present work may support the perspective of identifying new therapeutical applications with detailed pharmacological mechanisms of S. verbenaca to prevent the development of some diseases such as neurodegenerative disorders. However, toxicological investigations into S. verbenaca are needed to assess any potential toxicity before it can be further used in clinical studies.

Phytochemistry, Toxicology, and Pharmacological Properties of Origanum elongatum

Origanum elongatum L. is an endemic aromatic and medicinal plant. This work reports previous studies on O. elongatum concerning its taxonomy, botanical description, geographical distribution, bioactive compounds, toxicology, and biological effects. Chemical analyses showed that O. elongatum contains different chemical compounds, in particular volatile compounds. Pharmacological investigations showed that volatile compounds and extracts from O. elongatum exhibit different pharmacological properties, such as antibacterial, antifungal, antiviral, antioxidant, vasodilator, corrosion inhibitor, and hepatoprotective effects. Moreover, toxicological reports revealed the safety of this species. The pharmacological effects of O. elongatum could be correlated with the main compounds, which exhibit different pharmacological properties with numerous mechanism insights.

Genome-Wide DNA Methylation Changes of Perirenal Adipose Tissue in Rabbits Fed a High-Fat Diet

DNA methylation is an epigenetic mechanism that plays an important role in gene regulation without an altered DNA sequence. Previous studies have demonstrated that diet affects obesity by partially mediating DNA methylation. Our study investigated the genome-wide DNA methylation of perirenal adipose tissue in rabbits to identify the epigenetic changes of high-fat diet-mediated obesity. Two libraries were constructed pooling DNA of rabbits fed a standard normal diet (SND) and DNA of rabbits fed a high-fat diet (HFD). Differentially methylated regions (DMRs) were identified using the option of the sliding window method, and online software DAVID Bioinformatics Resources 6.7 was used to perform Gene Ontology (GO) terms and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis of DMRs-associated genes. A total of 12,230 DMRs were obtained, of which 2305 (1207 up-regulated, 1098 down-regulated) and 601 (368 up-regulated, 233 down-regulated) of identified DMRs were observed in the gene body and promoter regions, respectively. GO analysis revealed that the DMRs-associated genes were involved in developmental process (GO:0032502), cell differentiation (GO:0030154), and lipid binding (GO:0008289), and KEGG pathway enrichment analysis revealed the DMRs-associated genes were enriched in linoleic acid metabolism (KO00591), DNA replication (KO03030), and MAPK signaling pathway (KO04010). Our study further elucidates the possible functions of DMRs-associated genes in rabbit adipogenesis, contributing to the understanding of HFD-mediated obesity.

Dietary Supplementation of Lauric Acid Alleviates the Irregular Estrous Cycle and the Impaired Metabolism and Thermogenesis in Female Mice Fed with High-Fat Diet (HFD)

Lauric acid (LA) has been implicated in the prevention/treatment of obesity. However, the role of LA in modulating an obesity-related female reproductive disorder remains largely unknown. Here, female mice were fed a control diet, high-fat diet (HFD), or HFD supplemented with 1% LA. The results demonstrated that the HFD-induced estrous cycle irregularity and the reduction of serum follicle-stimulating hormone (FSH) were alleviated by LA supplementation. In possible mechanisms, LA supplementation led to significant increase in serum lipid metabolites such as sphingomyelin and lysophosphatidylcholine containing LA (C12:0) and the improvement of glucose metabolism in mice fed HFD. Moreover, impaired body energy metabolism and weakened brown adipose tissue (BAT) thermogenesis of HFD-fed mice were improved by LA supplementation. Together, these findings showed that LA supplementation alleviated HFD-induced estrous cycle irregularity, possibly associated with altered serum lipid metabolites, improved glucose metabolism, body energy metabolism, and BAT thermogenesis. These findings suggested the potential application of LA in alleviating obesity and its related reproductive disorders.

Nrf2 contributes to the weight gain of mice during space travel

Space flight produces an extreme environment with unique stressors, but little is known about how our body responds to these stresses. While there are many intractable limitations for in-flight space research, some can be overcome by utilizing gene knockout-disease model mice. Here, we report how deletion of Nrf2, a master regulator of stress defense pathways, affects the health of mice transported for a stay in the International Space Station (ISS). After 31 days in the ISS, all flight mice returned safely to Earth. Transcriptome and metabolome analyses revealed that the stresses of space travel evoked ageing-like changes of plasma metabolites and activated the Nrf2 signaling pathway. Especially, Nrf2 was found to be important for maintaining homeostasis of white adipose tissues. This study opens approaches for future space research utilizing murine gene knockout-disease models, and provides insights into mitigating space-induced stresses that limit the further exploration of space by humans.

Using Nrf2 knockout mice, Suzuki, Uruno, Yumoto et al. show that space travel activates Nrf2 signaling, which contributes to the weight gain of mice by regulating fat metabolism of white adipose tissues. This study provides insights into potential interventions to mitigate stresses that accompany space travels.

Effects of dietary phytol on tissue accumulation of phytanic acid and pristanic acid and on the tissue lipid profiles in mice

Recent in vitro evidence suggests that the phytol-derived fatty acids, phytanic acid (PA) and pristanic acid (PrA), are components of animal products with the potential to cause both beneficial and harmful effects on human health. In this study, we investigated the in vivo tissue accumulation of PA and PrA and the changes in tissue lipid profiles, using mice fed a phytol-containing diet. After 4 weeks of treatment with a diet containing 1.0% phytol, plasma, adipose tissue, liver, and brain were collected and their lipid profiles were biochemically and gas-chromatographically determined. Dietary phytol caused PA and PrA accumulation in the adipose tissue and liver but not in the brain, and reduced plasma and liver triacylglycerol levels. Phytol intake also decreased the fatty acid concentrations in the adipose tissue, especially polyunsaturated fatty acids such as linoleic acid, but increased the concentrations of these fatty acids in the liver. However, dietary phytol had a low impact on the brain lipid profile. This study suggests that dietary phytol intake caused accumulation of PA and PrA and modified lipid profiles in the adipose tissue and liver, but that the brain is an insusceptible tissue to dietary phytol-induced changes.

Anti-obesity effect of plant diterpenes and their derivatives: A review

Obesity is a medical condition in which excess body fat is accumulated by a combination of excessive food intake, lack of physical activity, and genetic susceptibility. Obesity increases the risk of various diseases and conditions, including cardiovascular diseases, diabetes, cancer, and depression. This review focuses on most recent reports pertaining to the antiobesity activity of plant-derived diterpenes in different databases. For this, a search (until August 2019) was conducted in the PubMed and Science Direct databases with the following keywords: "plant diterpenes" or "plant diterpenoids" paired with "obesity" or "antiobesity effects." Overall, 729 references that used the aforementioned keywords were selected, among which 34 articles have been included in this review. Results from this search suggest that a number of diterpenes and their derivatives have been found to exert antiobesity effects through various mechanisms, such as overweight reduction or modification of body mass index, protein-tyrosine phosphatase 1B inhibition, lipase activity inhibition, antiadipogenesis effect, among others. Carnosic acid, carnosol and the derivatives of abietic acid, steviol, and andrographolide are examples of important antiobesity diterpenes and their derivatives. Of note, plant-derived diterpenes may be potential candidates for managing obesity and obesity-related diseases and disorders in human and other animals.

Effect of He Qi San on DNA Methylation in Type 2 Diabetes Mellitus Patients with Phlegm-blood Stasis Syndrome

This study was performed to elucidate the potential influence of He Qi San (HQS) on glucose and lipid metabolism in type 2 diabetes mellitus (T2DM) patients with phlegm-blood stasis syndrome (PBSS), and to determine DNA methylation changes. Sixty T2DM patients with PBSS were randomly divided into control and HQS groups. The control group received conventional treatments, and the HQS group received conventional treatments plus HQS. Glucose metabolism (FPG, 2hPG, FINS, and HbA1c) and lipid metabolism indexes (TG, TC and LDL-C) were determined. Genes with differential DNA methylation were subjected to GO and KEGG analyses. Glucose and lipid metabolism indexes in both groups were reduced, but were much more pronounced in the HQS group. Differential promoter CpG methylation regions were identified in 682 genes, including 426 genes with high-CpG promoters, 150 genes with intermediate CpG promoters, and 106 genes with low CpG promoters. Genes with differential DNA methylation were mainly enriched in the AMPK and insulin signaling pathways, terpenoid backbone biosynthesis, and renin secretion. We concluded that HQS remarkably improved indexes of glucose and lipid metabolism in T2DM patients with PBSS through regulating the DNA methylation of genes in the AMPK and insulin signaling pathways and terpenoid backbone biosynthesis.

Phytol and its metabolites phytanic and pristanic acids for risk of cancer: current evidence and future directions

This review summarizes the current evidence on the potential role of phytol, a microbial metabolite of chlorophyl A, and its metabolites, phytanic and pristanic acids, in carcinogenesis. Primary food sources in Western diets are the nut skin for phytol and lipids in dairy, beef and fish for its metabolites. Phytol and its metabolites gained interest as dietary compounds for cancer prevention because, as natural ligands of peroxisome proliferator-activated receptor-α and -γ and retinoid X receptor, phytol and its metabolites have provided some evidence in cell culture studies and limited evidence in animal models of anti-carcinogenic, anti-inflammatory and anti-metabolic-syndrome properties at physiological concentrations. However, there may be a narrow range of efficacy, because phytol and its metabolites at supra-physiological concentrations can cause in vitro cytotoxicity in non-cancer cells and can cause morbidity and mortality in animal models. In human studies, evidence for a role of phytol and its metabolites in cancer prevention is currently limited and inconclusive. In short, phytol and its metabolites are potential dietary compounds for cancer prevention, assuming the challenges in preventing cytotoxicity in non-cancer cells and animal models and understanding phytol metabolism can be mitigated.

Lipidomic Profiling Reveals Disruption of Lipid Metabolism in Valproic Acid-Induced Hepatotoxicity

Valproic acid (VPA) is one of the most widely prescribed antiepileptic drugs, as VPA-induced hepatotoxicity is one of the most severe adverse reaction that can lead to death. The objective of this study was to gain an understanding of dysregulated lipid metabolism in mechanism of hepatotoxicity. Nontargeted lipidomics analysis with liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF/MS) was performed to explore differential lipids from the patient serum and L02 cells. Lipidomics data interpretation was augmented by gene expression analyses for the key enzymes in lipid metabolism pathways. From patient serum lipidomics, pronouncedly changed lipid species between abnormal liver function (ALF) patients and normal liver function (NLF) patients were identified. Among these lipid species, LPCs, Cers, and SMs were markedly reduced in the ALF group and showed negative relationships with liver injury severity [alanine aminotransferase (ALT) levels], while significantly increased triacylglycerols (TAG) with higher summed carbon numbers demonstrated a positive relationship with ALT levels. Regarding lipidomics in hepatic L02 cells, TAG was markedly elevated after VPA exposure, especially in TAGs with more than 53 summed carbons. Besides, gene expression analysis revealed dysregulated lipid metabolism in VPA-treated L02 cells. Peroxime proliferators-activated receptor (PPARγ) pathway played an important role in VPA-induced lipid disruption through inducing long-chain fatty acid uptake and TAG synthesis, which was also regulated by Akt pathway. Our findings present that VPA-induced lipid metabolism disruption might lead to lipotoxicity in the liver. This approach is expected to be applicable for other drug-induced toxicity assessments.

Calcium Supplementation Alleviates High-Fat Diet-Induced Estrous Cycle Irregularity and Subfertility Associated with Concomitantly Enhanced Thermogenesis of Brown Adipose Tissue and Browning of White Adipose Tissue

Obesity has been demonstrated as a disruptor of female fertility. Our previous study showed the antiobesity effects of calcium on HFD-fed male mice. However, the role of calcium in alleviating reproductive dysfunction of HFD-fed female mice remains unclear. Here, we found that HFD led to estrus cycle irregularity (longer cycle duration and shorter estrus period) and subfertility (longer conception time, lower fertility index, and less implantations) in mice. However, the HFD-induced reproductive abnormality was alleviated by calcium supplementation. Additionally, calcium supplementation enhanced activation/thermogenesis of BAT and browning of WAT in HFD-fed mice. Consequently, the abnormality of energy metabolism and glucose homeostasis induced by HFD were improved by calcium supplementation, with elevated metabolic rates and core temperature. In conclusion, these data showed that calcium supplementation alleviated HFD-induced estrous cycle irregularity and subfertility associated with concomitantly enhanced BAT thermogenesis and WAT browning, suggesting the potential application of calcium in improving obesity-related reproductive disorders.

Amelioration of experimental metabolic syndrome induced in rats by orlistat and Corchorus olitorius leaf extract; role of adipo/cytokines

OBJECTIVES

To determine the efficacy of Corchorus olitorius (C. olitorius) leaf extract in the prevention of metabolic syndrome induced in rats by high-fat diet (HFD) and compare it with that of orlistat.

METHODS

Phytochemical analysis was performed. Effect of orlistat and C. olitorius extract on lipase activity and acute food intake were investigated. Body weight, biochemical parameters and histopathological examination were demonstrated.

KEY FINDINGS

Corchorus olitorius extract inhibited the pancreatic lipase activity, but orlistat was more potent. Cumulative food intake has not changed by the tested agents. In obese rats, C. olitorius or orlistat significantly decreased weight gain and visceral white adipose tissue. They exhibited a significant reduction in serum glucose, total cholesterol, triglycerides, low density lipoprotein cholesterol, free fatty acids, IL-1β, tumour necrosis factor-α (TNF-α), insulin and leptin levels of obese rat groups while high density lipoprotein cholesterol and adiponectin levels were significantly increased by them. Histopathological examination of the liver revealed that C. olitorius was more effective than orlistat in the alleviating of steatosis and adipocyte hypertrophy shown in obese control rats.

CONCLUSIONS

Corchorus olitorius is effective as orlistat in preventing obesity, hyperlipidaemia, steatosis and insulin resistance. These actions may be mediated by inhibiting of lipase activity, TNF-α, IL-1β and leptin resistance along with increasing of adiponectin.

Milk Fat Globule Membrane Attenuates High-Fat Diet-Induced Obesity by Inhibiting Adipogenesis and Increasing Uncoupling Protein 1 Expression in White Adipose Tissue of Mice

Milk fat globule membrane (MFGM), a protein-lipid complex surrounding the fat globules in milk, has many health benefits. The aim of the current study was to investigate whether MFGM could prevent obesity through inhibiting adipogenesis and promoting brown remodeling of white adipose tissue (WAT) in mice fed with high-fat diet. C57BL/6 mice were fed a normal diet (ND), high-fat diet (HFD), HFD plus MFGM at 100 mg/kg BW, 200 mg/kg BW or 400 mg/kg BW for 8 weeks. Results showed that MFGM suppressed body weight gain induced by HFD, reduced white adipose tissue (WAT) mass accompanied with the decrease in adipocyte sizes. MFGM was found to have partially improved serum lipid profiles, as well as to have suppressed HFD-induced adipogenesis as shown by reduced expression of peroxisome proliferators-activator receptor-γ (PPARγ), CCAAT/enhancer-binding protein-α (C/EBPα) and sterol regulatory element-binding protein-1c (SREBP-1c). MFGM also markedly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), showing activation of AMPK pathway. Moreover, MFGM promoted browning of inguinal WAT by upregulation the protein expression of uncoupling protein 1 (UCP1) in HFD mice. Taken together, these findings provide evidence that MFGM may protect against diet-induced adiposity by suppressing adipogenesis and promoting brown-like transformation in WAT.

Phytol stimulates the browning of white adipocytes through the activation of AMP-activated protein kinase (AMPK) α in mice fed high-fat diet

In vivo and in vitro studies show that phytol stimulates the browning of mice iWAT and formation of brown-like adipocytes in the differentiated 3T3-L1 through the activation of the AMPKα signaling pathway.