Search Results (153)

Ficus deltoidea Jack (Moraceae), locally known as Mas Cotek, is a medicinal plant traditionally used throughout Southeast Asia for the management of diabetes mellitus. This review summarises the available evidence on the antidiabetic properties of F. deltoidea based on eleven in vitro, nine in vivo and one clinical study identified through a structured literature search. In vitro investigations show that F. deltoidea inhibits α-glucosidase and α-amylase, stimulates insulin secretion in pancreatic β-cells via both K⁺-ATP channel-dependent and -independent pathways, enhances glucose uptake in hepatocytes and adipocytes, promotes adiponectin secretion and inhibits protein tyrosine phosphatase 1B (PTP1B). Vitexin and isovitexin, the predominant C-glycosyl flavonoids in F. deltoidea leaves, appear to be the main bioactive compounds responsible for these effects. Meanwhile, in vivo studies in streptozotocin-induced diabetic rodents report dose-dependent reductions in fasting blood glucose, improved glucose tolerance, restoration of pancreatic islet architecture, modulation of hepatic gluconeogenic and glucose-metabolic genes, and protection against diabetic nephropathy and bone loss. Inter-varietal differences in chemical composition and biological activity were observed, with var. trengganuensis and var. intermedia reported as the most active. The only available clinical trial in adults with prediabetes (1000 mg/day for 8 weeks) showed a reduction in LDL and total cholesterol but no significant change in fasting blood glucose or insulin. The discrepancy between preclinical and clinical findings highlights the need for standardised extracts, pharmacokinetic studies and adequately powered clinical trials in patients with established type 2 diabetes mellitus. Full article

The skipjack tuna (Katsuwonus pelamis) is one of the least commercially exploited tuna globally. The possible medicinal benefits of K. pelamis extract have not been explored. We investigated the 70% ethanol (EtOH) soluble fractions of skipjack tuna heart for the inhibition of protein-tyrosine phosphatase 1B (PTP1B) and α-glucosidase. The dichloromethane (CH₂Cl₂) fraction significantly inhibited the activities of PTP1B and α-glucosidase. Repeated column chromatography of the active CH₂Cl₂ fraction based on bioactivity-guided fractionation yielded cholesterol, cholesteryl myristate, and sn-1,3-dipalmitoyl-2-oleoylglycerol; the latter significantly inhibited PTP1B and α-glucosidase. Kinetic study revealed that sn-1,3-dipalmitoyl-2-oleoylglycerol showed mixed-type inhibition against PTP1B. Docking simulations showed that sn-1,3-dipalmitoyl-2-oleoylglycerol selectively inhibited PTP1B and α-glucosidase by targeting its active site and exhibited good binding affinity, with a docking score of −7.4 and −7.1 kcal/mol, respectively. Moreover, 70% EtOH, CH₂Cl₂ and EtOAc fractions, and sn-1,3-dipalmitoyl-2-oleoyl glycerol significantly inhibited ONOO−mediated albumin nitration. These results implicate tuna heart extract as a potential functional food ingredient for the prevention and treatment of diabetes and its associated complications. Full article

Diabetes mellitus, particularly type 2 diabetes mellitus (T2DM), represents a major global health challenge, driven by the increasing prevalence of obesity and sedentary lifestyles. T2DM is characterized by insulin resistance and progressive β-cell dysfunction, leading to chronic hyperglycemia and multiple complications. Among the molecular targets investigated for therapeutic intervention, protein tyrosine phosphatase 1B (PTP1B) has emerged as a key negative regulator of insulin signaling. By dephosphorylating the insulin receptor and its downstream substrates, PTP1B attenuates insulin action and contributes to metabolic dysfunction. In addition to its role in glucose homeostasis, PTP1B is implicated in obesity, diabetic complications, neurodegenerative disorders, and cancer, highlighting its relevance as a multifunctional therapeutic target. However, the development of PTP1B inhibitors remains challenging due to the highly conserved and polar nature of its catalytic site, which limits selectivity and cell permeability. Recent research has focused on alternative strategies, including allosteric modulation and multi-site inhibition, to overcome these limitations. This review provides a comprehensive overview of PTP1B inhibitors from both synthetic (2019–2025) and natural sources, with particular emphasis on natural products reported from 2022 onwards, while including selected earlier studies to provide historical context and illustrate representative structural classes and inhibition mechanisms. Although PTP1B remains an attractive therapeutic target, its clinical validation for diabetes treatment has yet to be achieved. Continued advances in medicinal chemistry and allosteric modulation may help overcome the current translational barriers. Full article

Marine rest raw materials are often undervalued or wasted despite their nutrient and bioactive composition. Calanus finmarchicus, harvested primarily for its omega-3-rich oil, yields a side-stream protein hydrolysate, C. finmarchicus hydrolysate (CFH), during commercial enzyme-assisted extraction. Although currently used as a feed ingredient, CFH contains low-molecular-weight peptides and free amino acids with potential for human health applications. This study evaluated the gastrointestinal stability of CFH and the impact of digestion on bioactivity using a static in vitro gastrointestinal digestion model. Fresh-frozen and freeze-dried C. finmarchicus were included to provide comparative data. Antioxidant capacity was measured by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays, and antidiabetic activity by dipeptidyl peptidase-IV (DPP-IV) and protein tyrosine phosphatase 1B (PTP1B) inhibition assays. The hydrolysate maintained its antioxidant capacity throughout digestion (at 165 min: FRAP: 27.5 ± 0.6 µmol TE/g dry weight (DW); ORAC: 411 ± 37 µmol TE/g DW). Digestion increased its DPP-IV inhibitory activity, with the inhibitory concentration (IC₅₀) decreased from 3.73 to 1.96 mg/mL (p ≥ 0.05). PTP1B inhibitors were nonselective and detected only at 0 and 30 min. These findings support our hypothesis that CFH may serve as a nutraceutical for humans and provide a rationale for subsequent in vivo studies. However, further identification of bioactive components and in vivo validation are warranted. Full article

Diabetes mellitus is a chronic and increasingly prevalent metabolic disorder characterized by persistent hyperglycemia, resulting from defects in insulin secretion, insulin action, or both. Despite the availability of pharmacological agents that effectively manage blood glucose levels, many are associated with adverse effects, limited efficacy over time, and high costs. Consequently, there is growing interest in alternative therapies, especially those derived from traditional medicinal plants, that have long been employed in various cultures for managing diabetes. Recent advances in phytochemistry have identified bioactive plant secondary metabolites with promising antidiabetic properties. This review aims to provide a comprehensive overview of plant-derived compounds that exhibit inhibitory activity against key diabetes-related enzymes, including α-glucosidase, α-amylase, protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl peptidase-4 (DPP-4). These enzymes play critical roles in glucose metabolism and insulin signaling pathways. The review highlights the structural diversity of these natural inhibitors, their mechanisms of action, and their effectiveness in preclinical models. Understanding the molecular interactions and pharmacological profiles of these metabolites may facilitate the development of safer and more effective antidiabetic agents. Full article

Alcoholic liver disease (ALD), secondary to chronic alcohol abuse, encompasses a spectrum of liver disorders that progress from steatosis and hepatitis to fibrosis, cirrhosis, and acute-on-chronic liver failure. It poses a considerable global health burden due to its elevated rates of associated morbidity and mortality. The rising prevalence of ALD, coupled with the lack of approved pharmacotherapies, presents considerable unmet clinical needs. In this study, long-chain acyl-CoA synthetase 4 (ACSL4) was identified as a pathogenic driver in the context of chronic alcohol consumption. Hepatocyte Acsl4 ablation mitigated key pathological manifestations in Gao-Binge model mice, as evidenced by reduced inflammatory cell infiltration and attenuated lipid accumulation. Mechanistically, ACSL4 inhibition augmented cellular antioxidant defence through elevating gamma-glutamylcysteine (γ-GC) levels. In addition, γ-GC bound to and suppressed the expression of protein tyrosine phosphatase type IVA member 1 (PTP4A1). Both genetic silencing and pharmacological inhibition of PTP4A1 attenuated the activation of the downstream MAPK-NF-κB inflammatory cascade. Dronedarone, identified as a novel compound targeting ACSL4, demonstrated efficacy in ameliorating the progression of ALD. Overall, these findings elucidate a novel mechanism wherein ACSL4 modulates antioxidant responses via a small bioactive peptide, highlighting ACSL4 as a potential therapeutic target for ALD. Full article

Background/Objectives: This study aimed to evaluate the antidiabetic potential of five extracts/sub-extracts and five known cycloartane saponins [astragalosides (AST) I, II, III, IV, and cyclocanthoside E] from Astragalus noeanus (AN), using four specific diabetes-related molecular targets. Methods: Four diabetes-associated in vitro and in silico targets—protein tyrosine phosphatase 1B (PTP1B), dipeptidyl peptidase IV (DPP IV), α-amylase, and advanced glycation end-products (AGEs)—were employed to obtain comprehensive antidiabetic activity profiles. Additionally, the antioxidant and prebiotic capacities of the extracts/sub-extracts were assessed in vitro. A cycloartane saponin was isolated and structurally characterized. Quantitative analyses of total flavonoids, total saponins, and high-performance thin-layer chromatography (HPTLC) were performed to profile the chemical constituents of the plant material. Results: Among the extracts/sub-extracts, the aqueous extract (ANW) exhibited the highest inhibitory effects against all four diabetes-related targets, with inhibition percentages ranging from 83.70% to 93.49%. The methanol extract (ANM) demonstrated significant prebiotic activity comparable to standard controls on two Lactobacillus strains. The chloroform extract (ANC) showed the highest flavonoid content and exhibited the strongest antioxidant activity across all assays. ANM yielded the highest saponin content (3250 mg escin equivalent/g). HPTLC quantification revealed that AST IV was the predominant saponin in ANM (14.28 μg/mg) after cyclocanthoside E (117.27 ± 6.71 μg/mg). Among the saponins, AST IV displayed the most potent inhibition in diabetes-related enzyme assays, surpassing reference drugs acarbose and vildagliptin at equivalent concentrations. AST III also demonstrated considerable activity, ranking just below AST IV. Molecular docking studies identified AST II and AST III as the most promising ligands, exhibiting superior binding affinities and stronger hydrogen bonding and hydrophobic interactions with target proteins. Cyclocanthoside E was isolated from A. noeanus and evaluated for its antidiabetic effects for the first time, with its structure confirmed by NMR and LC-HRMS analyses. Conclusions: This study highlights Astragalus noeanus as a promising source for safe and effective antidiabetic agents. The potent activity of the aqueous extract, along with AST IV and AST III, warrants further investigation through clinical trials to validate their therapeutic potential in diabetes management. Full article

In the present study, seven previously undescribed resin glycosides, designated cusponins I-VII (1–7), together with one known analog (8), were isolated from the seeds of Cuscuta japonica, a traditional medicine used in China. Structural elucidation revealed them to be glycosidic acid methyl esters, generated through on-column methyl esterification of naturally occurring resin glycosides catalyzed by NH₂-functionalized silica gel. All isolates were characterized as either pentasaccharides or tetrasaccharides, incorporating D-glucose, L-rhamnose, or D-fucose units as the sugar residues. Notably, compounds 1 and 3–7 contained the uncommon aglycone, 11S-hydroxypentadecanoic acid. Bioactivity assessments demonstrated that compounds 1–4, 6 and 8 suppressed α-glucosidase activity, with IC₅₀ values between 8.02 and 71.39 μM. In addition, compounds 3 and 5 exhibited inhibitory effects on protein tyrosine phosphatase 1B (PTP1B), with IC₅₀ values of 14.19 ± 1.29 μM and 62.31 ± 8.61 μM, respectively, marking the first report of PTP1B inhibitory activity among resin glycosides. Enzyme kinetic analyses indicated that compound 2 acted as an uncompetitive α-glucosidase inhibitor (K_is = 3.02 μM), whereas compound 3 inhibited PTP1B via a mixed-type mechanism (Kᵢ = 24.82 μM; K_is = 64.24 μM). Molecular docking combined with molecular dynamics simulations suggested that compounds 2 and 3 interacted with α-glucosidase-pNPG and PTP1B, respectively, forming stable complexes with favorable binding free energies. Collectively, this study reported eight resin glycosides from C. japonica, seven of them newly identified, with compounds 2 and 3 highlighted as promising scaffolds for antidiabetic drug discovery. Full article

Lacking effective therapeutics, cholangiocarcinoma (CCA) remains a deadly malignancy of the biliary tract. The Hippo pathway effector protein Yes-associated protein (YAP) is implicated in CCA pathogenesis and chemotherapeutic resistance; however, the oncogenic mechanisms underlying YAP regulation remain incompletely understood. An enhanced understanding of YAP and its role in CCA may uncover novel therapeutic targets and better define resistance pathways. Human CCA cells and murine syngeneic CCA models were utilized to explore the molecular relationship of YAP and protein tyrosine phosphatase 1B (PTP1B). Previous work in CCA has demonstrated that YAP interacts with multiple protein tyrosine phosphatases, including SHP2 and PTP1B. We observed that PTP1B pharmacologic inhibition was associated with increased cell proliferation and YAP target gene expression, while genetically enforced overexpression of PTP1B was associated with a decrease in YAP activation. Treatment of CCA cells in vitro and syngeneic, orthotopically implanted CCA murine tumors in vivo with standard cytotoxic chemotherapy, gemcitabine/cisplatin, had enhanced efficacy in the setting of PTP1B overexpression. These findings demonstrate that pYAP^Y357 can be modulated through protein tyrosine 1B phosphatase activity, and reducing pYAP^Y357 through enhanced phosphatase levels can sensitize CCA to chemotherapy. Full article

Resveratrol (RSV), a polyphenol found in a variety of berries and wines, is known for its anti-inflammatory, anticancer, and antioxidant properties. It has been suggested that RSV may play a role in the regulation of metabolic disorders, including diabetes and insulin resistance. However, in recent years, it has been reported to completely inhibit Akt kinase function in liver cells. Akt is a central protein involved in the metabolic function of insulin and is regulated by the phosphatidylinositol-3-kinase (PI3K) pathway. In this study, we examined the effect of RSV on insulin-induced insulin receptor (IR) phosphorylation and proteins involved in the PI3K/Akt pathway in a hepatic cell model, clone 9 (C9), and in hepatoma cells, Hepa 1-6 (H1-6). In both cell lines, RSV inhibited tyrosine phosphorylation of IR and insulin-induced activation of Akt. We also evaluated the effect of RSV on the activation of protein tyrosine phosphatase 1B (PTP1B), which is associated with IR dephosphorylation, and found that RSV increased PTP1B-Tyr¹⁵² phosphorylation in a time- and concentration-dependent manner. Furthermore, we found that the protein kinase C (PKC) inhibitors BIM and Gö6976 prevented the inhibition of Akt phosphorylation by RSV and increased the phosphorylation of Ser/Thr residues in IR, suggesting that PKC is involved in the inhibition of the insulin pathway by RSV. Thus, classical PKC isoforms impair the PI3K/Akt pathway at the IR and GSK3 and GS downstream levels; however, IRS-Tyr⁶³² phosphorylation remains unaffected. These results suggest that RSV can lead to insulin resistance by activating PTP1B and PKC, consequently affecting glucose homeostasis in hepatic cells. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory loss and limited therapeutic options. Metal-based drugs have emerged as promising alternatives in the search for effective treatments, and vanadium coordination complexes have shown significant potential due to their neuroprotective and anti-aggregant properties. This review explores the advances in the development of vanadium-based metallodrugs for AD, focusing on their ability to modulate amyloid-beta (Aβ) aggregation, oxidative stress, and neuroinflammation. Recent in vitro and in vivo studies highlight the efficacy of oxovanadium (IV) and peroxovanadium (V) complexes in inhibiting Aβ fibril formation and reducing neuronal toxicity. Additionally, the interaction of vanadium complexes with key biological targets, such as peroxisome proliferator-activated receptor gamma (PPARγ) and protein-tyrosine phosphatase 1B (PTP1B), suggests a multifaceted therapeutic approach. While these findings underscore the potential of vanadium compounds as innovative treatments for AD, further research is needed to optimize their bioavailability, selectivity, and safety for clinical applications. Full article

Mycobacterium indicus pranii (MIP), an atypical mycobacterium originally developed as an anti-leprosy vaccine, has emerged as a potent immunomodulator with diverse therapeutic applications. Despite its clinical significance, molecular mechanisms underlying MIP’s immunomodulatory properties remain largely unexplored. Bacterial phosphatases are recognized as crucial virulence factors that enable pathogens to evade host defenses by modulating host immune signaling pathways, including phosphoinositide metabolism. MIP_07528 was identified as a putative protein tyrosine phosphatase B (PtpB) ortholog through in silico analysis, with significant sequence conservation observed within catalytic domains of pathogenic mycobacterial PtpB proteins. Phosphatase activity was detected in both cell lysate and culture filtrate fractions, revealing differential expression patterns between MIP and M. tuberculosis. Upregulation of MIP_07528 was demonstrated under oxidative stress, suggesting involvement in stress adaptation. The recombinant protein exhibited distinctive kinetic properties, characterized by higher substrate affinity yet increased susceptibility to oxidative inactivation compared to its M. tuberculosis counterpart. In macrophages, MIP_07528 suppressed pro-inflammatory cytokines while enhancing anti-inflammatory IL-10 production. These findings establish MIP_07528 as a functional phosphatase that may contribute to MIP’s immunomodulatory properties. This work advances understanding of phosphatase function in non-pathogenic mycobacteria while providing insights into virulence factor evolution and establishing a foundation for novel antimicrobial strategies. Full article

Diabetes mellitus has emerged as a global public health crisis, with Type 2 diabetes (T2D) constituting over 90% of cases. Current treatments are palliative, primarily focusing on blood glucose modulation. This review systematically evaluates 181 bioactive compounds isolated from 66 marine fungal strains for their inhibitory activities against key diabetes-related enzymes, including α-glucosidase, protein tyrosine phosphatase 1B (PTP1B), dipeptidyl peptidase-4 (DPP-4), glycogen synthase kinase-3β (GSK-3β), and fatty acid-binding protein 4 (FABP4). These compounds, categorized into polyketides, alkaloids, terpenoids, and lignans, exhibit multitarget engagement and nanomolar-to-micromolar potency. The review highlights the potential of marine fungal metabolites as novel antidiabetic agents, emphasizing their structural novelty and diverse mechanisms of action. Future research should focus on overcoming challenges related to yield and extraction, leveraging advanced technologies such as genetic engineering and synthetic biology to enhance drug development. Full article

As a part of our ongoing search for bioactive constituents of Artemisia capillaris, we isolated 4-O-caffeoyl-2-C-methyl-d-threonic acid (PPT-14). This is a rare caffeic acid ester derivative that is reported here for the first time in the Artemisia species, which is the third occurrence in any plant species worldwide. In this study, we evaluated the anti-diabetic potential of PPT-14 using in vitro and in silico approaches. PPT-14 demonstrated significant inhibitory activity against two crucial enzymes linked to diabetes progression and complications: protein tyrosine phosphatase 1B (PTP1B) and aldose reductase (AR). These had IC₅₀ values of 64.92 and 19.50 µM, respectively. Additionally, PPT-14 exhibited free radical scavenging activity with 2,2-diphenyl-2-picrylhydrazyl (IC₅₀ 14.46 µM). Molecular docking and 200 ns molecular dynamics simulations confirmed that there were stable binding interactions with the key residues of PTP1B and AR, highlighting strong affinity and dynamic stability. Pharmacokinetic analyses revealed favorable water solubility, adherence to Lipinski’s Rule of Five, and minimal interactions with cytochrome P450 enzymes, indicating the drug-like potential of PPT-14. Toxicity studies confirmed its safety profile, showing no genotoxicity, hepatotoxicity, or significant toxicity risks, with an acceptable oral LD₅₀ value of 2.984 mol/kg. These findings suggest that PPT-14 could be a promising multitarget lead compound for ameliorating diabetes and its associated complications. Full article

Background/Objectives: Tuberculosis (TB) is one of the leading infectious causes of death worldwide, highlighting the importance of identifying new anti-TB agents. In previous research, our team identified antimycobacterial activity in Kielmeyera membranacea leaf extract; therefore, this study aims to conduct further exploration of its potential. Methods: Classical chromatography was applied for fractionation and spectrometric techniques were utilized for chemical characterization. For in vitro tests, samples were assessed against Mycobacterium tuberculosis and Mycobacterium marinum. The toxicity and efficacy of active samples were evaluated in vivo using different zebrafish models. Chemogenomics studies were applied to predict the isolated active compound’s potential mode of action. Results: We performed fractionation of K. membranacea ethanolic extract (EE) and then its dichloromethane fraction (DCM), and the biflavonoid podocarpusflavone A (PCFA) was isolated and identified as a promising active compound. The EE and PCFA were found to be non-toxic to zebrafish larvae and were able to inhibit M. tuberculosis growth extracellularly. Additionally, PCFA demonstrated antimycobacterial activity within infected macrophages, especially when combined with isoniazid. In addition, the EE, DCM, and PCFA have shown the ability to inhibit M. marinum’s growth during in vivo zebrafish larvae yolk infection. Notably, PCFA also effectively countered systemic infection established through the caudal vein, showing a similar inhibitory activity profile to rifampicin, both at 32 µM. A reduction in the transcriptional levels of pro-inflammatory cytokines confirmed the infection resolution. The protein tyrosine phosphatase B (PtpB) of M. tuberculosis, which inhibits the macrophage immune response, was predicted as a theoretical target of PCFA. This finding is in agreement with the higher activity observed for PCFA intracellularly and in vivo on zebrafish, compared with the direct action in M. tuberculosis. Conclusions: Here, we describe the discovery of PCFA as an intracellular inhibitor of M. tuberculosis and provide evidence of its in vivo efficacy and safety, encouraging its further development as a combination drug in novel therapeutic regimens for TB. Full article