Eriocalyxin B Inhibits Adipogenesis in 3T3-L1 Adipocytes by Cell Cycle Arrest

The influence of IMPDH activity on ciliogenesis and adipogenesis of 3T3-L1 cells while undergoing differentiation

The functional roles of primary cilia and inosine 5'-monophosphate dehydrogenase (IMPDH) are among the hot topics in today's adipogenesis research. Considering the reported interaction between IMPDH and ADP Ribosylation Factor-Like GTPase 13B (ARL13B), as a key ciliary protein, our study focused on this interaction during the ciliogenesis process while 3T3-L1 pre-adipocytes undergoing differentiation to lipid-accumulating adipocytes. Our results indicated that, in the early days of differentiation, when cilium length is long, IMPDH expression is high and its interaction with ARL13B is low. Conversely, in the last days of differentiation, the cilia length and IMPDH expression reduced while, the IMPDH/ARL13B interaction remains high relative to the initial days. In either of these two situations, IMPDH was not documented within the cilia. The extent of the interaction between IMPDH and ARL13B might account for the lack of co-localization of IMPDH and ARL13B within cilia during the process of differentiation. Although, inhibiting IMPDH in the early days of differentiation did not have a significant effect on cilia length, it did reduce adipogenesis by limiting mitotic clonal expansion through arresting cells in the G1/G0 phase. These findings provide the ground for further research to investigate the relationship between the IMPDH/ARL13B interaction and cilia length, which decline in obesity.

Antidiabetic effects of two naphthoquinones from the branches and leaves of Tectona grandis and possible mechanism

Tectona grandis is a Dai medicine that plays an important role in traditional medicine in India, Myanmar, West Africa, and Yunnan Province in China. T. grandis was recorded as an anti-diabetic herb in the Ayurvedic Pharmacopoeia; however, its potential antidiabetic components and possible mechanisms of action have almostly not been described to far. To completely comprehend the pharmacological components and therapeutic potential of T. grandis, we isolated chemical components from the plant's leaves and branches, evaluated their antidiabetic activities, and explored the possible mechanisms of active compounds using molecular docking and network pharmacology. In this study, two new quinones (1-2) and eighteen known compounds (3-20) were isolated and identified from T. grandis. Except for the new quinones 1 and 2, compounds 4, 11-12, 14-15, 18-20 were separated from T. grandis for the first time. The naphthoquinones 1 and 3 showed significant antidiabetic activities in α-glucosidase inhibition assay (IC50: 92.52 ± 5.05 and 45.37 ± 1.50 μM, respectively), glucose uptake assay (Inhibition rate: 63.90 ± 1.04 % and 65.41 ± 1.96 %, respectively) and preadipocyte differentiation inhibition assay (Lipid droplet content decreased by 8.49 ± 0.71 % and 13.89 ± 0.29 %, respectively, compared to the model group). Our study also revealed that T. grandis might treat diabetes by targeting CASP3, ESR1, and PTGS2. This study provided important support for the traditional usage of T. grandis as an antidiabetic herb by identifying its antidiabetic components and possible mechanism.

Arthrocolin B Impairs Adipogenesis via Delaying Cell Cycle Progression During the Mitotic Clonal Expansion Period

Obesity and its related diseases severely threaten people's health, causing persistently high morbidity and mortality worldwide. The abnormal proliferation and hypertrophy of adipocytes mediate the expansion of adipose tissue, which is the main cause of obesity-related diseases. Inhibition of cell proliferation during the mitotic clonal expansion (MCE) period of adipogenesis may be a promising strategy for preventing and treating obesity. Arthrocolins are a series of fluorescent dye-like complex xanthenes from engineered Escherichia coli, with potential anti-tumor and antifungal activities. However, the role and underlying mechanisms of these compounds in adipocyte differentiation remain unclear. In this study, we discovered that arthrocolin B, a member of the arthrocolin family, significantly impeded adipogenesis by preventing the accumulation of lipid droplets and triglycerides, as well as by downregulating the expression of key factors involved in adipogenesis, such as SREBP1, C/EBPβ, C/EBPδ, C/EBPα, PPARγ, and FABP4. Moreover, we revealed that this inhibition might be a consequence of cell cycle arrest during the MCE of adipocyte differentiation, most likely by modulating the p53, AKT, and ERK pathways, upregulating the expression of p21 and p27, and repressing the expression of CDK1, CDK4, Cyclin A2, Cyclin D1, and p-Rb. Additionally, arthrocolin B could promote the expression of CPT1A during adipocyte differentiation, implying its potential role in fatty acid oxidation. Overall, our research concludes that arthrocolin B has the ability to suppress the early stages of adipocyte differentiation mainly by modulating the signaling proteins involved in cell cycle progression. This work broadens our understanding of the function and mechanisms of arthrocolins in regulation of adipogenesis and might provide a potential lead compound for treating the obesity.

Natural product Eriocalyxin B exerts anti-tumor effects by downregulating TCEA3 expression and sensitizes immune checkpoint blockade therapy in osteosarcoma

Osteosarcoma (OS) remains the most common bone tumor and the prognosis for many patients remains stagnant due to the unsatisfactory therapeutic effect of conventional treatment regimens. This research explored the effect and mechanism of a novel natural product, Eriocalyxin B (EB), in pathogenesis and immunotherapy in OS. Cell Count Kit 8 assay, colony formation assay, and wound healing assay were employed to detect the proliferative, colony-forming, and migratory abilities of human OS cells following EB treatment. Moreover, xenograft growth assay was performed to assess the effect of EB on OS in vivo. Subcutaneous OS models constructed in immunocompetent mice were employed to evaluate the effect of EB treatment in combination with immune checkpoint blockades (ICBs) PD1ab and CTLA4ab. Immunohistochemistry (IHC) staining was utilized to detect the level of CD8+ T cells infiltration and Ki67 expression. TARGET database, RNA interference technology, and qPCR assay were employed to explore the mechanism of EB on OS. EB inhibited the proliferative, colony-forming, and migratory abilities of the human OS cells MG63 and U2OS both in vitro and in vivo. TARGET data analysis demonstrated that up-regulation of TCEA3 was significantly negatively correlated with overall survival in OS patients. EB exerted anti-tumor activity via downregulation of TCEA3. EB, in conjunction with ICBs, synergistically optimized anti-tumorigenic activity against OS in immunocompetent mice. EB may promote infiltration of CD8+ T cells and down-regulate Ki67 expression. These results signaled that EB may have a role as a candidate therapeutic or preventive agent for the treatment of OS.

In vitro effects of phytochemicals on adipogenesis with a focus on molecular mechanisms: A systematic review

Adipogenesis, the process of proliferation of adipocyte progenitor cells and their differentiation into mature adipocytes, plays a critical role in the development of obesity. In this context, exploring the effects of phytochemicals on adipogenesis is very promising, as nowadays, they are widely used as food, drink, or supplement and can significantly impact general health and obesity control. This systematic review attempts to evaluate new findings regarding the molecular mechanisms of different phytochemicals on adipogenesis in in vitro models. Between 2010 and July 2023, a comprehensive systematic search of PubMed and Scopus databases was conducted. The following keywords were used: ("adipogenic") AND ("inhibit" OR "suppress" OR "reduce" OR "anti" OR "decrease") AND ("cell" OR "cell line" OR "adipocyte") AND ("phytochemical" OR "plant" OR "herb"). In this review, 109 studies were comprehensively analyzed, which provided important insights into the process of adipogenesis. Among the numerous transcription factors studied, PPARγ, C/EBPα, and SREBP1c were found to be the most important regulators actively involved in adipocyte differentiation. These results highlight the critical role of these factors in the control of adipogenesis and suggest that they represent promising targets for therapeutic interventions aimed at reducing the excessive lipid accumulation associated with obesity. This study provides a compelling rationale for further exploring phytochemicals as potential therapeutics for treating obesity. The potential benefits of using natural products to influence adipogenesis are evident, and future studies should focus on translating these findings into clinical applications.

Exploration of potential antidiabetic and antioxidant components from the branches of Mitragyna diversifolia and possible mechanism

In this study, sixteen compounds were isolated from the branches of Mitragyna diversifolia, including twelve triterpenes (1-12), a phenolic compound (13), and three flavonoids (14-16). Among them, compounds 1-7, and 10-16 were reported for the first time from this plant. Compounds 7, 14, and 15 exhibited significant inhibitory activities against α-glucosidase, with IC50 values of 18.48 ± 2.74, 12.14 ± 1.58 and 35.77 ± 4.52 µM, respectively. Furthermore, the inhibitory kinetics of α-glucosidase revealed that all fractions, active compounds 7, 14, and 15 belong to the mix inhibition type. In molecular docking, the analysis showed that compounds 13, 14, 15, and 16 possessed superior binding capacities with α-glucosidase (-8.3, -9.6, -9.9, and -9.2 kcal/mol, respectively). The results of the glucose uptake experiment indicated that only compound 14 showed a significant promotion effect on the glucose uptake rate of 3T3-L1 adipocytes (P < 0.05). Meanwhile, compounds 13, 14, 15, and 16 possessed potent antioxidant abilities with DPPH, ABTS, and FRAP. In DNA and protein oxidative damage assays, compound 15 had a stronger effect than the positive control Vc. The network-based pharmacological analysis platform was used to predict the diabetes-related target proteins of active compounds 7, 13, 14, 15, and 16, and two candidate targets (ALB and PPARG) related to their therapeutic effects on diabetes were identified.

Limonoids isolated from Chisocheton ceramicus Miq. and the antiadipogenic mechanism of action of ceramicine B

Different types of limonoids have been isolated from plants of the Chisocheton genus, notably from the species Chisocheton ceramicus Miq. which is largely distributed in the Indonesian archipelago and Malaysia region. A variety of natural products have been found in the bark of the tree and characterized as antimicrobial and/or antiproliferative agents. The isolated limonoids include chisomicines A-E, proceranolide, and a few other compounds. A focus is made on a large series of limonoids designated ceramicines A to Z including derivatives with antiparasitic activities, antioxidant, antimelanogenic, and antiproliferative effects and/or acting as regulators of lipogenesis. The lead compound in the series is ceramicine B functioning as a potent inhibitor of lipid droplet accumulation (LDA). Extracts from Chisocheton ceramicus and ceramicines have shown anti-LDA effects, with little or no cytotoxic effects. Ceramicine B is the most active compound functioning as a regulator of lipid storage in cells and tissues. Ceramicine B is a transcriptional repressor of peroxisome proliferator-activated receptor γ (PPARγ) and an inhibitor of phosphorylation of the transcription factor FoxO1, acting via an upstream molecular target. Targeting of glycogen synthase kinase-3β is proposed, based on the analogy with structurally related limonoids known to target this enzyme, and supported by a molecular docking analysis. The target and pathway implicated in ceramicine B activity are discussed. The analysis shed light on ceramicine B as a natural product precursor for the design of novel compounds capable of reducing LDA in cells and of potential interest for the treatment of obesity, liver diseases, and other pathologies.

Nutraceuticals and the Network of Obesity Modulators

Obesity is considered an increasingly widespread disease in the world population, regardless of age and gender. Genetic but also lifestyle-dependent causes have been identified. Nutrition and physical exercise play an important role, especially in non-genetic obesity. In a three-compartment model, the body is divided into fat mass, fat-free mass and water, and obesity can be considered a condition in which the percentage of total fat mass is in excess. People with a high BMI index or overweight use self-medications, such as food supplements or teas, with the aim to prevent or treat their problem. Unfortunately, there are several obesity modulators that act both on the pathways that promote adipogenesis and those that inhibit lipolysis. Moreover, these pathways involve different tissues and organs, so it is very difficult to identify anti-obesity substances. A network of factors and cells contributes to the accumulation of fat in completely different body districts. The identification of natural anti-obesity agents should consider this network, which we would like to call "obesosome". The nutrigenomic, nutrigenetic and epigenetic contribute to making the identification of active compounds very difficult. This narrative review aims to highlight nutraceuticals that, in vitro or in vivo, showed an anti-obesity activity or were found to be useful in the control of dysfunctions which are secondary to obesity. The results suggest that it is not possible to use a single compound to treat obesity, but that the studies have to be addressed towards the identification of mixtures of nutraceuticals.

Antidiabetic potential of Catechu via assays for α-glucosidase, α-amylase, and glucose uptake in adipocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Catechu is the dry water extract of barked branches or stems from Senegalia catechu(L. F.)P. J. H. Hurter & Mabb, which is used as a hypoglycemic regulator in recent researches. Potential anti-hyperglycemic components and the putative mechanisms were evaluated in this investigation.

AIM OF THE STUDY

Evaluated the hypoglycemic activity of Catechu via α-glucosidase, α-amylase inhibition assays, and glucose uptake in 3T3-L1 adipocytes.

MATERIALS AND METHODS

The effects of Catechu on α-glucosidase, α-amylase inhibition assays and glucose uptake experiment were tested after the ethanol extract of Catechu (EE) was sequentially partitioned with petroleum ether (PEE), ethyl acetate (EAE), and n-butanol fractions (NBE). Next, HPLC-MS and traditional Chinese medicine (TCM) database were used to detect and analyze the primary active ingredients presented in hypoglycemic fraction. In addition, in silico molecular docking study was used to evaluate the candidates' inhibitory activity against α-glucosidase and α-amylase.

RESULTS

The results of α-glucosidase and α-amylase inhibition assays indicated that all fractions, with the exception of PEE, presented significant inhibitory effects on α-glucosidase and α-amylase. The inhibitory effect of NBE on α-glucosidase was similar to the positive control (NBE IC₅₀ = 0.3353 ± 0.1215 μg/mL; Acarbose IC₅₀ = 0.1123 ± 0.0023 μg/mL). Furthermore, the inhibitory kinetics of α-glucosidase revealed that all fractions except for PEE belong to uncompetitive type. In silico molecular docking analysis showed that the main compositions of NBE ((-)-epicatechin, cyanidin, and delphinidin) possessed superior binding capacities with α-glucosidase (3WY1 AutoDock score: 4.82 kcal/mol; -5.59 kcal/mol; -5.63 kcal/mol) and α-amylase (4GQR AutoDock score: 4.80 kcal/mol; -5.89 kcal/mol; -4.26 kcal/mol), respectively. The results of glucose uptake experiment indicated that EE, PEE, EAE, and NBE without significant promotion effect on glucose uptake rate of 3T3-L1 adipocytes (P > 0.05).

CONCLUSION

This study revealed that the hypoglycemic effect of Catechu might be related to the inhibitory effects of phenols on digestive enzymes (α-glucosidase and α-amylase), and the possible active phenols were (-)-epicatechin, cyanidin, delphinidin and their derivatives, which provided scientific evidences for Catechu's traditional use to treat T2DM.

Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba

Our research focused on the hypoglycemic capability and the possible mechanisms of extract and fractions from Polygoni Avicularis Herba (PAH) based on α-glucosidase, α-amylase inhibition assays, glucose uptake experiment, HPLC-MS analysis, and molecular docking experiment. In addition, DPPH, ABTS, and FRAP assays were used for determining the antioxidant capability. The results of total flavonoids and phenolics contents showed that ethyl acetate fraction (EAF) possessed the highest flavonoids and phenolics with values of 159.7 ± 2.5 mg rutin equivalents/g and 107.6 ± 2.0 mg galic acid equivalents/g, respectively. The results of in vitro hypoglycemic activity showed that all samples had effective α-glucosidase inhibition capacities, and EAF possessed the best inhibitory effect with IC50 value of 1.58 ± 0.24 μg/mL. In addition, n-butanol fraction (NBF) significantly promoted the glucose uptake rate of 3T3-L1 adipocytes. HPLC-MS analysis and molecular docking results proved the interactions between candidates and α-glucosidase. The results of antioxidation capacities showed that EAF possessed the best antioxidation abilities with DPPH, ABTS, and FRAP. In summary, the hypoglycemic activity of PAH might be related to the inhibition of α-glucosidase (EAF > PEF > NBF) and the promotion of glucose uptake in 3T3-L1 adipocytes (NBF). Simultaneously, the antioxidation capacity of PAH might be related to the abundant contents of flavonoids and other phenolics (EAF > PEF > NBF).

Genome-wide identification of cyclin-dependent kinase (CDK) genes affecting adipocyte differentiation in cattle

BACKGROUND

Cyclin-dependent kinases (CDKs) are protein kinases regulating important cellular processes such as cell cycle and transcription. Many CDK genes also play a critical role during adipogenic differentiation, but the role of CDK gene family in regulating bovine adipocyte differentiation has not been studied. Therefore, the present study aims to characterize the CDK gene family in bovine and study their expression pattern during adipocyte differentiation.

RESULTS

We performed a genome-wide analysis and identified a number of CDK genes in several bovine species. The CDK genes were classified into 8 subfamilies through phylogenetic analysis. We found that 25 bovine CDK genes were distributed in 16 different chromosomes. Collinearity analysis revealed that the CDK gene family in Bos taurus is homologous with Bos indicus, Hybrid-Bos taurus, Hybrid Bos indicus, Bos grunniens and Bubalus bubalis. Several CDK genes had higher expression levels in preadipocytes than in differentiated adipocytes, as shown by RNA-seq analysis and qPCR, suggesting a role in the growth of emerging lipid droplets.

CONCLUSION

In this research, 185 CDK genes were identified and grouped into eight distinct clades in Bovidae, showing extensively homology. Global expression analysis of different bovine tissues and specific expression analysis during adipocytes differentiation revealed CDK4, CDK7, CDK8, CDK9 and CDK14 may be involved in bovine adipocyte differentiation. The results provide a basis for further study to determine the roles of CDK gene family in regulating adipocyte differentiation, which is beneficial for beef quality improvement.

ent-Kaurane-Based Diterpenoids, Dimers, and Meroditerpenoids from Isodon xerophilus

Eight new diterpenoids (1-8) with varied structures were isolated from the aerial parts of Isodon xerophilus. Among them, xerophilsin A (1) was found to be an unusual meroditerpenoid representing a hybrid of an ent-kauranoid and a long-chain aliphatic ester, xerophilsins B-D (2-4) are dimeric ent-kauranoids, while xerophilsins E-H (5-8) are new ent-kauranoids. The structures of 1-8 were elucidated mainly through the analyses of their spectroscopic data. The absolute configurations of 2, 6, and 8 were confirmed by single-crystal X-ray diffraction, and the configuration of C-16 in 7 was established through quantum chemical calculation of NMR chemical shifts, as well as modeling of key interproton distances. Bioactivity evaluation of all isolated compounds revealed that 2, 3, and 5 inhibited NO production in LPS-stimulated RAW264.7 cells.