Celastrol: An Update on Its Hepatoprotective Properties and the Linked Molecular Mechanisms

Enzymatic Glycosylation of Ganoderma Terpenoid via Bacterial Glycosyltransferases and Glycoside Hydrolases

Glycosylation is a critical enzymatic modification that involves the attachment of sugar moieties to target compounds, considerably influencing their physicochemical and biological characteristics. This review explored the role of two primary enzyme classes-glycosyltransferases (GTs) and glycoside hydrolases (GHs, glycosidases)-in catalyzing the glycosylation of natural products, with a specific focus on Ganoderma triterpenoids. While GTs typically use activated sugar donors, such as uridine diphosphate glucose, certain GHs can leverage more economical sugar sources, such as sucrose and starch, through transglycosylation. This paper also reviewed strategies for producing novel terpenoid glycosides, particularly recently isolated bacterial GTs and GHs capable of glycosylating terpenoids and flavonoids. It summarized the newly synthesized glycosides' structures and biotransformation mechanisms, enhanced aqueous solubility, and potential applications. The regioselectivity and substrate specificity of GTs and GHs in catalyzing O-glycosylation (glucosylation) at distinct hydroxyl and carboxyl groups were compared. Furthermore, a special case in which the novel glycosylation reactions were mediated by GHs, including the formation of unique glycoside anomers, was included. The advantages and specific capabilities of GT/GH enzymes were evaluated for their potential in biotechnological applications and future research directions. Novel fungal triterpenoid glycosides produced through various glycosidases and sugars is expected to expand their potential applications in the future.

Baicalein: unveiling the multifaceted marvel of hepatoprotection and beyond

Flavonoids are bioactive compounds derived from plants that play a crucial role in human health. Baicalein is a prominent phytoconstituent with multifaceted therapeutic potential against various diseases. This review explores recent advancements in understanding baicalein's hepatoprotective action against different toxicity models (acetaminophen, cisplatin, doxorubicin, CCL4, monocrotaline, & d-galactosamine). Furthermore, we report the key pharmacological activities of baicalein against neurotoxicity (6-OHDA, rotenone, d-galactose, stroke, alzheimer, & sclerosis), inflammation (arthritis, pulmonary fibrosis, & LPS-induced sepsis), cancer (breast, prostate, gall bladder, gastric, & pancreatic), & diabetes. Overall, baicalein has potential to influence diverse biological networks, making it a promising candidate for both dietary supplementation and therapeutic development.

Effects of celastrol on the heart and liver galaninergic system expression in a mouse model of Western-type diet-induced obesity and metabolic dysfunction-associated steatotic liver disease and steatohepatitis

Background

The complexity of the galaninergic system is still not fully understood, especially under specific pre-existing comorbidities related to metabolic dysfunction. A plant-derived triterpenoid celastrol was demonstrated to exert a complex effect on the galaninergic system and to have hepatoprotective and anti-obesity properties. However, the exact molecular mechanisms responsible for these effects remain unclear. Specifically, there are no data on the impact of celastrol on the heart and liver galaninergic system. Therefore, this study aimed to investigate the effects of celastrol on the galaninergic system expression in the heart and liver of mice suffering from diet-induced obesity and metabolic dysfunction-associated steatotic liver disease and steatohepatitis (MASLD/MASH).

Methods

The male mice C57BL/6J were fed a Western-type high-fat diet for 16 and 20 weeks to induce obesity and MASLD/MASH. Celastrol was administered along with a specific diet for the last 4 weeks to evaluate its impact on the progression of these conditions. Moreover, the inhibitor of sterol regulatory element-binding protein 1/2 (SREBP1/2), fatostatin, was also tested to compare its influence on the galaninergic system with celastrol.

Results

The study demonstrates that celastrol treatment was safe and led to a reduction in food and energy intake, body fat and liver weights, and MASLD-to-MASH progression and improved glucose tolerance, serum biochemistry markers, and hepatic lipid peroxidation in mice. Quantitative gene expression originally showed significant regulation of galanin and all three of its receptors (GalR1/2/3) in the heart ventricles and only GalR2 in the liver of obese mice. Celastrol influenced the gene expression of galanin receptors: it downregulated Galr1 in the heart and upregulated Galr2 in the liver and Galr3 in the heart ventricles, potentially affecting energy metabolism, oxidative stress, and inflammation. Fatostatin suppressed gene expression of all the detected members of the galaninergic system in the heart ventricles, depicting the role of SREBP in this process.

Conclusion

These findings suggest that celastrol may beneficially modulate the galaninergic system under obesity and MASLD-to-MASH progression, indicating its potential as a therapeutic agent for disorders associated with metabolic dysfunction.

Evaluation of hepatoprotective and nephroprotective activities of Castanopsis costata extract in rats

The liver and kidneys are important organs for body homeostasis but susceptible to damage or injury caused by different factors. A number of medicinal plants, such as Castanopsis costata have been proven effective in protecting the liver and kidneys from damage. Therefore, the present study aimed to examine the effect of C. costata extract (CcE) on paracetamol-induced hepatotoxicity and gentamicin-induced nephrotoxicity in rat model. Each treatment group was given CcE at doses of 100, 200 and 400 mg/kg for 21 and 8 days for hepatoprotective tests and nephroprotective tests, respectively. To induce liver and kidney damage, rats were given paracetamol 1,000 mg/kg orally for 7 (15-21) and gentamicin 80 mg/kg intraperitoneally for 5 (4-8) days. To assess liver function, the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin (TB), total cholesterol (TC), total albumin (TA) and total protein (TP) were measured, as well as liver antioxidant enzymes. Meanwhile, to assess kidney function, the levels of serum creatinine (SCr), serum urea (SU) and uric acid (UA) were measured. TNF-α and IFN-γ were also measured with histopathology testing to assess the effects of liver and kidney organ damage in each experiment. The results showed that CcE reduced the levels of AST, ALT, ALP, TB and TC, increased TA, TP and liver antioxidant enzymes, as well as reducing SCr, SU and UA when compared with the pathological group. Additionally, CcE reduced the levels of TNF-α and IFN-γ, as well as improving the structure of liver and kidney tissue as confirmed by histopathology. CcE had hepatoprotective and nephroprotective effects on paracetamol-induced and gentamicin-induced rats, respectively.

The role of celastrol in inflammation and diseases

Celastrol is one of the main active ingredients extracted from the plant Tripterygium wilfordii Hook F. A growing number of studies have shown that celastrol has various pharmacological effects, including anti-inflammation, anti-rheumatism, treatment of neurodegenerative diseases, and anti-tumor. This article systematically summarized the mechanism and role of celastrol in lipid metabolism and obesity, rheumatoid arthritis (RA), osteoarthritis (OA), gouty arthritis, inflammatory bowel disease, neurodegenerative diseases, and cancer and other diseases (such as diabetes, respiratory-related diseases, atherosclerosis, psoriasis, hearing loss, etc.). The celastrol played roles in inflammation response, cell apoptosis, autophagy, ferroptosis, and lipid metabolism mainly by acting on chondrocytes, macrophages, mitochondria, and endoplasmic reticulum (ER) through NF-κB, STAT, MAPK, TLR, PI3K-AKT-mTOR, and other signal pathways. This review could provide a reference for the clinical application and further development and utilization of celastrol.

Hepatoma-Targeting and ROS-Responsive Polymeric Micelle-Based Chemotherapy Combined with Photodynamic Therapy for Hepatoma Treatment

Background

The combination of nanoplatform-based chemotherapy and photodynamic therapy (PDT) is a promising way to treat cancer. Celastrol (Cela) exhibits highly effective anti-hepatoma activity with low water solubility, poor bioavailability, non-tumor targeting, and toxic side effects. The combination of Cela-based chemotherapy and PDT via hepatoma-targeting and reactive oxygen species (ROS)-responsive polymeric micelles (PMs) could solve the application problem of Cela and further enhance antitumor efficacy.

Methods

In this study, Cela and photosensitizer chlorin e6 (Ce6) co-loaded glycyrrhetinic acid-modified carboxymethyl chitosan-thioketal-rhein (GCTR) PMs (Cela/Ce6/GCTR PMs) were prepared and characterized. The safety, ROS-sensitive drug release, and intracellular ROS production were evaluated. Furthermore, the in vitro anti-hepatoma effect and cellular uptaken in HepG2 and BEL-7402 cells, and in vivo pharmacokinetic, tissue distribution, and antitumor efficacy of Cela/Ce6/GCTR PMs in H22 tumor-bearing mice were then investigated.

Results

Cela/Ce6/GCTR PMs were successfully prepared with nanometer-scale particle size, favorable drug loading capacity, and encapsulation efficiency. Cela/Ce6/GCTR PMs exhibited a strong safety profile and better hemocompatibility, exhibiting less damage to normal tissues. Compared with Cela-loaded GCTR PMs, the ROS-responsiveness of Cela/Ce6/GCTR PMs was increased, and the release of Cela was accelerated after combination with PDT. Cela/Ce6/GCTR PMs can efficiently target liver tumor cells by uptake and have a high cell-killing effect in response to ROS. The combination of GCTR PM-based chemotherapy and PDT resulted in increased bioavailability of Cela and Ce6, improved liver tumor targeting, and better anti-hepatoma effects in vivo.

Conclusion

Hepatoma-targeting and ROS-responsive GCTR PMs co-loaded with Cela and Ce6 combined with PDT exhibited improved primary hepatic carcinoma therapeutic effects with lower toxicity to normal tissues, overcoming the limitations of monotherapy and providing new strategies for tumor treatment.

Insulin Resistance in Pediatric Obesity: From Mechanisms to Treatment Strategies

Insulin resistance, an increasingly prevalent characteristic among children and adolescents with obesity, is now recognized as a significant contributor to the development of type 2 diabetes mellitus (T2DM) and other metabolic diseases in individuals with obesity. Insulin resistance refers to a decrease in the sensitivity of peripheral tissues (primarily skeletal muscle, adipose tissue, and liver) to insulin, which is mainly characterized by impaired glucose uptake and utilization. Although the mechanisms underlying insulin resistance in children with obesity remain incompletely elucidated, several risk factors including lipid metabolism disorders, oxidative stress (OS), mitochondrial dysfunction, inflammation, and genetic factors have been identified as pivotal contributors to the pathogenesis of obesity-related insulin resistance. In this review, we comprehensively analyze relevant literature and studies to elucidate the underlying mechanisms of insulin resistance in childhood obesity. Additionally, we discuss treatment strategies for pediatric obesity from a perspective centered on improving insulin sensitivity, aiming to provide valuable insights for the prevention and management of pediatric obesity.

Celastrol attenuates streptozotocin-induced diabetic cardiomyopathy in mice by inhibiting the ACE / Ang II / AGTR1 signaling pathway

BACKGROUND

Heart failure is closely correlated with diabetic cardiomyopathy (DCM) and can lead to mortality. Celastrol has long been utilized for the treatment of immune and inflammatory disorders. However, whether celastrol would exert protective effects on DCM has not been determined. This work aimed to explore the protective actions of celastrol on DCM and unravel the underlying mechanisms involved.

METHODS

A DCM model was constructed in mice by intraperitoneal administration of streptozotocin. ELISA and echocardiography were performed to examine myocardial injury markers and cardiac function, respectively. Morphological changes and fibrosis were assessed using H&E staining and Masson's staining. Inflammatory cytokines and fibrotic markers were detected by ELISA and RT-PCR. Endothelial nitric oxide synthase, apoptosis, and reactive oxygen species were detected by microscopic staining. Network pharmacology approaches, molecular docking analysis, ELISA, and Western blot were used for mechanism studies.

RESULTS

Celastrol alleviated diabetes-induced cardiac injury and remodeling. Celastrol also suppressed diabetes-induced production of inflammatory cytokines and reactive oxygen species, as well as cardiomyocyte apoptosis. The cardioprotective effects of celastrol were associated with its inhibition on the angiotensin-converting enzyme / angiotensin II / angiotensin II receptor type 1 signaling pathway.

CONCLUSION

Celastrol exhibits significant potential as an effective cardioprotective drug for DCM treatment. The underlying mechanisms can be attributed to the blockage of celastrol on the angiotensin-converting enzyme signaling pathway.

Liver Cell Type-Specific Targeting by Nanoformulations for Therapeutic Applications

Hepatocytes exert pivotal roles in metabolism, protein synthesis and detoxification. Non-parenchymal liver cells (NPCs), largely comprising macrophages, dendritic cells, hepatic stellate cells and liver sinusoidal cells (LSECs), serve to induce immunological tolerance. Therefore, the liver is an important target for therapeutic approaches, in case of both (inflammatory) metabolic diseases and immunological disorders. This review aims to summarize current preclinical nanodrug-based approaches for the treatment of liver disorders. So far, nano-vaccines that aim to induce hepatitis virus-specific immune responses and nanoformulated adjuvants to overcome the default tolerogenic state of liver NPCs for the treatment of chronic hepatitis have been tested. Moreover, liver cancer may be treated using nanodrugs which specifically target and kill tumor cells. Alternatively, nanodrugs may target and reprogram or deplete immunosuppressive cells of the tumor microenvironment, such as tumor-associated macrophages. Here, combination therapies have been demonstrated to yield synergistic effects. In the case of autoimmune hepatitis and other inflammatory liver diseases, anti-inflammatory agents can be encapsulated into nanoparticles to dampen inflammatory processes specifically in the liver. Finally, the tolerance-promoting activity especially of LSECs has been exploited to induce antigen-specific tolerance for the treatment of allergic and autoimmune diseases.

Celastrol pretreatment attenuates concanavalin A-induced hepatitis in mice by suppressing interleukin-6/STAT3-interleukin-17 signaling

BACKGROUND AND AIM

Celastrol is extracted from Tripterygium wilfordii Hook F. It has been reported to have protective effects against various liver diseases and immune regulation of autoimmune diseases. However, little is known about whether celastrol protects against immune-mediated hepatitis. This study aimed to investigate the effect of celastrol on liver injury induced by concanavalin A (ConA) and the potential mechanisms.

METHODS

Intravenous administration of ConA was applied to induce acute liver injury in mice with or without pretreatment of celastrol. The effects of celastrol on ConA-induced liver injury were further demonstrated by biochemical and histopathological assessments, immunoblotting, and flow cytometry analysis.

RESULTS

Both biochemical and histopathological observations showed that pretreatment of celastrol significantly ameliorated liver injury induced by ConA. Moreover, the hepatocyte apoptosis and inflammatory responses induced by ConA were also improved in celastrol-pretreated mice. Further studies revealed that these improvements were characterized as the celastrol-mediated suppression of total interleukin (IL)-17 from liver mononuclear cells in ConA-treated mice. Flow cytometry analysis suggested that celastrol specifically decreased IL-17 production by CD4+ T cells but not by CD8+ T cells. Fundamentally, pretreatment with celastrol inhibited both the IL-6 produced by F4/80+ macrophages and the IL-6 receptor on Th17 cells in the liver, which further led to the downregulated activation of STAT3, thus accounting for blocked Th17 signaling.

CONCLUSIONS

Celastrol may exhibit immune regulatory effects by regulating IL-6/STAT3-IL-17 signaling in ConA-induced hepatitis, which suggested new potentials for celastrol to be applied in treating immune-mediated liver diseases.

Hepatoprotective Effect of Kaempferol: A Review of the Dietary Sources, Bioavailability, Mechanisms of Action, and Safety

The liver is the body's most critical organ that performs vital functions. Hepatic disorders can affect the physiological and biochemical functions of the body. Hepatic disorder is a condition that describes the damage to cells, tissues, structures, and functions of the liver, which can cause fibrosis and ultimately result in cirrhosis. These diseases include hepatitis, ALD, NAFLD, liver fibrosis, liver cirrhosis, hepatic failure, and HCC. Hepatic diseases are caused by cell membrane rupture, immune response, altered drug metabolism, accumulation of reactive oxygen species, lipid peroxidation, and cell death. Despite the breakthrough in modern medicine, there is no drug that is effective in stimulating the liver function, offering complete protection, and aiding liver cell regeneration. Furthermore, some drugs can create adverse side effects, and natural medicines are carefully selected as new therapeutic strategies for managing liver disease. Kaempferol is a polyphenol contained in many vegetables, fruits, and herbal remedies. We use it to manage various diseases such as diabetes, cardiovascular disorders, and cancers. Kaempferol is a potent antioxidant and has anti-inflammatory effects, which therefore possesses hepatoprotective properties. The previous research has studied the hepatoprotective effect of kaempferol in various hepatotoxicity protocols, including acetaminophen (APAP)-induced hepatotoxicity, ALD, NAFLD, CCl₄, HCC, and lipopolysaccharide (LPS)-induced acute liver injury. Therefore, this report aims to provide a recent brief overview of the literature concerning the hepatoprotective effect of kaempferol and its possible molecular mechanism of action. It also provides the most recent literature on kaempferol's chemical structure, natural source, bioavailability, and safety.

Targeting Oxidative Stress and Inflammation in Intervertebral Disc Degeneration: Therapeutic Perspectives of Phytochemicals

Low back pain is a major cause of disability worldwide that declines the quality of life; it poses a substantial economic burden for the patient and society. Intervertebral disc (IVD) degeneration (IDD) is the main cause of low back pain, and it is also the pathological basis of several spinal degenerative diseases, such as intervertebral disc herniation and spinal stenosis. The current clinical drug treatment of IDD focuses on the symptoms and not their pathogenesis, which results in frequent recurrence and gradual aggravation. Moreover, the side effects associated with the long-term use of these drugs further limit their use. The pathological mechanism of IDD is complex, and oxidative stress and inflammation play an important role in promoting IDD. They induce the destruction of the extracellular matrix in IVD and reduce the number of living cells and functional cells, thereby destroying the function of IVD and promoting the occurrence and development of IDD. Phytochemicals from fruits, vegetables, grains, and other herbs play a protective role in the treatment of IDD as they have anti-inflammatory and antioxidant properties. This article reviews the protective effects of phytochemicals on IDD and their regulatory effects on different molecular pathways related to the pathogenesis of IDD. Moreover, the therapeutic limitations and future prospects of IDD treatment have also been reviewed. Phytochemicals are promising candidates for further development and research on IDD treatment.