Biomaterial-Based Therapeutic Strategies for Obesity and Its Comorbidities

Hawthorn carbon dots: a novel therapeutic agent for modulating body weight and hepatic lipid profiles in high-fat diet-fed mice

Obesity, a chronic metabolic disorder characterized by excessive body weight and adipose tissue accumulation, is intricately linked to a spectrum of health complications. It is driven by a confluence of factors, including gut microbiota dysbiosis, inflammation, and oxidative stress, which are pivotal in its pathogenesis. A multifaceted therapeutic strategy that targets these interrelated pathways is essential for effective obesity management. In this context, biomass-derived carbon dots have emerged as a promising avenue due to their diverse biological activities and potential in nanomedicine. Our study presents the synthesis of multi-modal hawthorn carbon dots (HCD), employing a green hydrothermal carbonization method that diverged from traditional stir-frying techniques. This eco-friendly approach facilitates the preparation of HCD, emphasizing the role of sugar compounds as the primary carbon source in their formation. In vitro assays demonstrate that HCD possess potent anti-inflammatory and antioxidant properties, which are crucial in combating the oxidative stress and inflammation associated with obesity. We further investigate the impact of HCD intervention in a high-fat diet (HFD)-induced obesity mouse model, employing both post-modeling and simultaneous modeling administration strategies. Our findings reveal that HCD treatment significantly reduces body weight and hepatic lipid accumulation in HFD mice, concurrently enhancing glucose tolerance and alleviating insulin resistance. Moreover, antibiotic perturbation experiments, complemented by bioinformatics analysis of colon microbiota, indicate that HCD substantially modulate gut microbiota composition. This modulation is associated with the amelioration of obesity-related conditions, suggesting that HCD may exert their beneficial effects through the regulation of gut microbiota, in addition to their anti-inflammatory and antioxidant activities. These multimodal mechanisms of action position HCD as a promising candidate for the prevention and treatment of obesity, offering a novel therapeutic strategy that targets the complex interplay of factors involved in this metabolic disorder.

Multi-Functional Polymer Nanoparticles with Enhanced Adipocyte Uptake and Adipocytolytic Efficacy

Multi-functional polymer nanoparticles have been widely utilized to improve cellular uptake and enhance therapeutic efficacy. In this study, it is hypothesized that the cellular uptake of poly(D,L-lactide-co-glycolide) (PLG) nanoparticles loaded with calcium carbonate minerals into adipocytes can be improved by covalent modification with nona-arginine (R9 ) peptide. It is further hypothesized that the internalization mechanism of R9 -modified PLG nanoparticles by adipocytes may be contingent on the concentration of R9 peptide present in the nanoparticles. R9 -modified PLG nanoparticles followed the direct penetration mechanism when the concentration of R9 peptide in the nanoparticles reached 38 µM. Notably, macropinocytosis is the major endocytic mechanism when the R9 peptide concentration is ≤ 26 µM. The endocytic uptake of the nanoparticles effectively generated carbon dioxide gas at an endosomal pH, resulting in significant adipocytolytic effects in vitro, which are further supported by the findings in an obese mouse model induced by high-fat diet. Gas-generating PLG nanoparticles, modified with R9 peptide, demonstrated localized reduction of adipose tissue (reduction of 13.1%) after subcutaneous injection without significant side effects. These findings highlight the potential of multi-functional polymer nanoparticles for the development of effective and targeted fat reduction techniques, addressing both health and cosmetic considerations.

Thymoquinone mitigates obesity and diabetic parameters through regulation of major adipokines, key lipid metabolizing enzymes and AMPK/p-AMPK in diet-induced obese rats

The present study was designed to evaluate the anti-obesity and anti-hyperglycemic activity of Thymoquinone (ThyQ) isolated from Nigella sativa seeds. Male Wistar rats were randomly divided into five groups and fed either normal pellet diet or high-fat diet (HFD) for 18 weeks and water ad-libitum. Group I: normal pellet diet (NPD)-fed, Group II: high-fat diet (HFD)-fed, Group III: HFD-fed-ThyQ (20 mg)-treated, Group IV: HFD-fed-ThyQ (40 mg)-treated and Group V: HFD-fed-Orlistat (5 mg)-treated group. Intervention with ThyQ started from 12th week onwards to HFD-fed rats of group III and IV. ThyQ administration significantly (p < 0.01) mitigated body weight gain, blood glucose, insulin level, serum and liver lipids (except HDL) and improved glucose tolerance and insulin sensitivity as evaluated by oral glucose tolerance test (OGTT), homeostasis model assessment-insulin resistance (HOMA-IR) and insulin tolerance test (ITT). Furthermore, ThyQ significantly (p < 0.01) diminished serum aspartate transaminase (AST), alanine transaminase (ALT), acetyl-CoA carboxylase (ACC), plasma leptin, resistin and visfatin levels but enhanced lipoprotein lipase (LPL) and adiponectin levels. RT-PCR analysis demonstrated down-regulated mRNA expression of sterol regulatory element-binding proteins-1c (SREBP-1c), CCAAT/enhancer-binding protein-α (C/EBP-α) and fatty acid synthase (FAS) but upregulation of Insulin receptor substrate-1 (IRS-1).Western blot analysis displayed phosphorylation of adenosine monophosphate activated protein kinase (AMPK) in ThyQ-treated rats. Liver microtome sections of HFD-fed rats showed degenerated hepatocytes with high lipid stores while that of adipose tissue sections displayed large, fat-laden adipocytes, however, these histological changes were considerably attenuated in ThyQ-treated groups. Together these findings demonstrate that ThyQ can be a valuable therapeutic compound to potentially alleviate diet-induced obesity, hyperglycemia and insulin resistance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03847-x.

Comparison of Efficacy of Fermented Garlic and Orlistat (Lipase Inhibitor) in Obesity Management Using an Experimental Rodent Model

BACKGROUND

Black garlic, also known as fermented garlic, is a useful food that may have therapeutic benefits. The aim of this study was to analyze the impact of fermented garlic and orlistat therapy on obese rats.

METHODS

A total of 40 male albino rats (245-250 g) were fed either an HFD (n = 32) or a normal diet (n = 8) for 6 weeks; therefore we randomly assigned the rats into: group I (normal diet), group II (HFD), groups III and IV (HFD with fermented garlic), and group V (orlistat for) 6 weeks. Two different dosages of fermented garlic (481.2 mg/kg and 963.3 mg/kg) were administered. Afterward, blood was collected, body weight was measured, and tissue was collected for further analysis.

RESULTS

Both the orlistat and black garlic groups showed a significant reduction in BMI, lipid profiles, and insulin levels compared with the baseline. The orlistat group showed significant elevation (p < 0.005) in body weight, organ weight, lipids, and liver parameters, with histopathological findings. The administration of black garlic improved the inflammatory markers with all other parameters.

CONCLUSION

The fermented garlic and orlistat reinstated all of the investigated parameters significantly (p < 0.05), especially body weight and lipid profiles, and induced histopathological changes compared to the drug orlistat. Additionally, it showed anti-obesity-related therapeutic impacts compared with the orlistat drug. Black garlic provides a reliable and effective treatment for obesity compared to orlistat.

Association between obesity, inflammation and insulin resistance: Insights into signaling pathways and therapeutic interventions

Obesity, a metabolic disorder, is becoming a worldwide epidemic that predominantly increases the risk for various diseases including metabolic inflammation, insulin resistance, and cardiovascular diseases. However, the mechanisms that link obesity with other metabolic diseases are not completely understood. In obesity, various inflammatory pathways that cause inflammation in adipose tissue of an obese individual become activated and exacerbate the disease. Obesity-induced low-grade metabolic inflammation perturbates the insulin signaling pathway and leads to insulin resistance. Researchers have identified several pathways that link the impairment of insulin resistance through obesity-induced inflammation like activation of Nuclear factor kappa B (NF-κB), suppressor of cytokine signaling (SOCS) proteins, cJun-N-terminal Kinase (JNK), Wingless-related integration site (Wnt), and Toll-like receptor (TLR) signaling pathways. In this review article, the published studies have been reviewed to identify the potential and influential role of different signaling pathways in the pathogenesis of obesity-induced metabolic inflammation and insulin resistance along with the discussion on potential therapeutic strategies. Therapies targeting these signaling pathways show improvements in metabolic diseases associated with obesity, but require further testing and confirmation through clinical trials.

Hydroxylated polymethoxyflavones reduce the activity of pancreatic lipase, inhibit adipogenesis and enhance lipolysis in 3T3-L1 mouse embryonic fibroblast cells

Hydroxylated polymethoxyflavones (HPMFs) have been shown to possess various anti-disease effects, including against obesity. This study investigates the anti-obesity effects of HPMFs in further detail, aiming to gain understanding of their mechanism of action in this context. The current study demonstrates that two HPMFs; 3'-hydroxy-5,7,4',5'-tetramethoxyflavone (3'OH-TetMF) and 4'-hydroxy-5,7,3',5'-tetramethoxyflavone (4'OH-TetMF) possess anti-obesity effects. They both significantly reduced pancreatic lipase activity in a competitive manner as demonstrated by molecular docking and kinetic studies. In cell studies, it was revealed that both of the HPMFs suppress differentiation of 3T3-L1 mouse embryonic fibroblast cells during the early stages of adipogenesis. They also reduced expression of key adipogenic and lipogenic marker genes, namely peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and β (C/EBP α and β), adipocyte binding protein 2 (aP2), fatty acid synthase (FASN), and sterol regulatory element-binding protein 1 (SREBF 1). They also enhanced the expression of cell cycle genes, i.e., cyclin D1 (CCND1) and C-Myc, and reduced cyclin A2 expression. When further investigated, it was also observed that these HPMFs accelerate lipid breakdown (lipolysis) and enhance lipolytic gene expression. Moreover, they also reduced the secretion of proteins (adipokines), including pro-inflammatory cytokines, from mature adipocytes. Taken together, this study concludes that these HPMFs have anti-obesity effects, which are worthy of further investigation.

Pharmacological Treatments and Natural Biocompounds in Weight Management

The obesity pandemic is one of society’s most urgent public health concerns. One-third of the global adult population may fall under obese or overweight by 2025, suggesting a rising demand for medical care and an exorbitant cost of healthcare expenditure in the coming years. Generally, the treatment strategy for obese patients is largely patient-centric and needs dietary, behavioral, pharmacological, and sometimes even surgical interventions. Given that obesity cases are rising in adults and children and lifestyle modifications have failed to produce the desired results, the need for medical therapy adjunct to lifestyle modifications is vital for better managing obesity. Most existing or past drugs for obesity treatment target satiety or monoamine pathways and induce a feeling of fullness in patients, while drugs such as orlistat are targeted against intestinal lipases. However, many medications targeted against neurotransmitters showed adverse events in patients, thus being withdrawn from the market. Alternatively, the combination of some drugs has been successfully tested in obesity management. However, the demand for novel, safer, and more efficacious pharmaceutical medicines for weight management does exist. The present review elucidates the current understanding of the available anti-obesity medicines of synthetic and natural origin, their main mechanisms of action, and the shortcomings associated with current weight management drugs.