Progress on structural modification of Tetrandrine with wide range of pharmacological activities

Insights on exploring the therapeutic potential and structural modification of Tetrandrine

Tetrandrine (Tet), a bisbenzylisoquinoline alkaloid from Stephania tetrandra, is noted for its diverse pharmacological effects but faces limitations in clinical use due to toxicity, poor solubility, and low bioavailability. Researchers are working to address these issues by developing Tet derivatives with greater therapeutic potential through structural modification. Generally, key modifications include: 1) introducing an aromatic heterocycle or a hydrophobic alkyne unit at the C-5 position can enhance its antitumor activity; 2) adding an amide, sulfonamide, or electron-withdrawing group at the C-14 position can enhance its antitumor activity; 3) changing its structure to a quaternary ammonium salt can alter its solubility and greatly boost its antibacterial activity; 4) structural modification of the C-12-methoxybenzyl motif can enhance its metabolic stability and thus change the activity of the analogs; 5) Tet structural simplification may result in the identification of anticancer lead compounds with novel mechanisms of action. This review systematically summarizes these modification strategies and evaluates the biological activities of Tet derivatives, aiming to guide further optimization and facilitate the discovery of lead analogs with improved efficacy. The future direction and possibility of Tet structural optimization are also considered.

Tetrandrine induces muscle atrophy involving ROS-mediated inhibition of Akt and FoxO3

Tetrandrine (Tet), a well-known drug of calcium channel blocker, has been broadly applied for anti-inflammatory and anti-fibrogenetic therapy. However, due to the functional diversity of ubiquitous calcium channels, potential side-effects may be expected. Our previous report revealed an inhibitory effect of Tet on myogenesis of skeletal muscle. Here, we found that Tet induced protein degradation resulting in the myofibril atrophy. Upon administration with a relative high dose (40 mg/kg) of Tet for 28 days, the mice displayed significantly reduced muscle mass, strength force, and myosin heavy chain (MyHC) protein levels. The MyHC reduction was further detected in C2C12 myotubes after treating with Tet. Interestingly, the expression of Atrogin-1 and Murf-1, the skeletal muscle specific E3 ligases of protein ubiquitin-proteasome system (UPS), was accordingly up-regulated, and the reduced MyHC was significantly mitigated by MG132, a 26S proteasome inhibitor, indicating a key role of UPS in the protein degradation of muscle cells. Further study showed that Tet induced autophagy also participated in the protein degradation. Mechanistically, Tet treatment caused ROS production in myotubes that in turn targeted on FoxO3/AKT signaling, resulting in the activation of UPS and autophagy processes that were involved in the protein degradation. Our study reveals a potential side-effect of Tet on skeletal muscle atrophy, particularly when the drug dose is relatively high.

Tetrandrine Alleviates Silica-induced Pulmonary Fibrosis Through PI3K/AKT Pathway: Network Pharmacology Investigation and Experimental Validation

Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid derived from Stephania tetrandra S. Moor, known for its potential use in attenuating the progression of silicosis. However, the precise effects and underlying mechanisms of TET remain controversial. In this study, we aimed to elucidate the pharmacological mechanism of TET using a network pharmacology approach, while also evaluating its effect on silica-induced lung fibrosis in mice and TGF-β1-stimulated pulmonary fibroblasts in vitro. We employed network pharmacology to unravel the biological mechanisms through which TET may exert its therapeutic effects on pulmonary fibrosis and silicosis. In a silica-induced mouse model of lung fibrosis, TET was administered orally either during the early or late stage of fibrotic progression. Additionally, we examined the effects of TET on fibroblasts stimulated by TGF-β1 in vitro. Through the analysis, we identified a total of 101 targets of TET, 7,851 genes associated with pulmonary fibrosis, and 80 overlapping genes. These genes were primarily associated with key pathways such as epidermal growth factor receptor tyrosine kinase inhibitor resistance, the vascular endothelial growth factor signaling pathway, and the phosphatidylinositol 3 kinase (PI3K)-protein kinase B (PKB or AKT) signaling pathway. Furthermore, molecular docking analysis revealed the binding of TET to AKT1, the catalytic subunit of phosphatidylinositol-3 kinase, and KDR. In vivo experiments demonstrated that TET significantly alleviated silica-induced pulmonary fibrosis and reduced the expression of fibrotic markers. Moreover, TET exhibited inhibitory effects on the migration, proliferation, and differentiation of TGF-β1-induced lung fibroblasts in vitro. Notably, TET mitigated silica-induced pulmonary fibrosis by suppressing the PI3K/AKT pathway. In conclusion, our findings suggest that TET possesses the ability to suppress silica-induced pulmonary fibrosis by targeting the PI3K/AKT signaling pathway. These results provide valuable insights into the therapeutic potential of TET in the treatment of pulmonary fibrosis and silicosis.

Therapeutic effects of tetrandrine in inflammatory diseases: a comprehensive review

Inflammation can be triggered by any factor. The primary pathological manifestations can be summarized as the deterioration, exudation, and proliferation of local tissues, which can cause systemic damage in severe cases. Inflammatory lesions are primarily localized but may interact with body systems to cause provocative storms, parenchymal organ lesions, vascular and central nervous system necrosis, and other pathologic responses. Tetrandrine (TET) is a bisbenzylquinoline alkaloid extracted from the traditional Chinese herbal medicine Stephania tetrandra, which has been shown to have significant efficacy in inflammatory conditions such as rheumatoid arthritis, hepatitis, nephritis, etc., through NF-κB, MAPK, ERK, and STAT3 signaling pathways. TET can regulate the body's imbalanced metabolic pathways, reverse the inflammatory process, reduce other pathological damage caused by inflammation, and prevent the vicious cycle. More importantly, TET does not disrupt body's normal immune function while clearing the body's inflammatory state. Therefore, it is necessary to pay attention to its dosage and duration during treatment to avoid unexpected side effects caused by a long half-life. In summary, TET has a promising future in treating inflammatory diseases. The author reviews current therapeutic studies of TET in inflammatory conditions to provide some ideas for subsequent anti-inflammatory studies of TET.

Identification of propranolol and derivatives that are chemical inhibitors of phosphatidate phosphatase as potential broad-spectrum fungicides

Plant diseases cause enormous economic losses in agriculture and threaten global food security, and application of agrochemicals is an important method of crop disease control. Exploration of disease-resistance mechanisms and synthesis of highly bioactive agrochemicals are thus important research objectives. Here, we show that propranolol, a phosphatidate phosphatase (Pah) inhibitor, effectively suppresses fungal growth, sporulation, sexual reproduction, and infection of diverse plants. The MoPah1 enzyme activity of the rice blast fungus Magnaporthe oryzae is inhibited by propranolol. Alterations in lipid metabolism are associated with inhibited hyphal growth and appressorium formation caused by propranolol in M. oryzae. Propranolol inhibits a broad spectrum of 12 plant pathogens, effectively inhibiting infection of barley, wheat, maize, tomato, and pear. To improve antifungal capacity, we synthesized a series of propranolol derivatives, one of which shows a 16-fold increase in antifungal ability and binds directly to MoPah1. Propranolol and its derivatives can also reduce the severity of rice blast and Fusarium head blight of wheat in the field. Taken together, our results demonstrate that propranolol suppresses fungal development and infection through mechanisms involved in lipid metabolism. Propranolol and its derivatives may therefore be promising candidates for fungicide development.

Tetrandrine for Targeting Therapy Resistance in Cancer

During the last five decades, there has been tremendous development in our understanding of cancer biology and the development of new and novel therapeutics to target cancer. However, despite these advances, cancer remains the second leading cause of death across the globe. Most cancer deaths are attributed to the development of resistance to current therapies. There is an urgent and unmet need to address cancer therapy resistance. Tetrandrine, a bis-benzyl iso-quinoline, has shown a promising role as an anti-cancer agent. Recent work from our laboratory and others suggests that tetrandrine and its derivatives could be an excellent adjuvant to the current arsenal of anti-cancer drugs. Herein, we provide an overview of resistance mechanisms to current therapeutics and review the existing literature on the anti-cancer effects of tetrandrine and its potential use for overcoming therapy resistance in cancer.

Mechanism of ferroptosis in breast cancer and research progress of natural compounds regulating ferroptosis

Breast cancer is the most prevalent cancer worldwide and its incidence increases with age, posing a significant threat to women's health globally. Due to the clinical heterogeneity of breast cancer, the majority of patients develop drug resistance and metastasis following treatment. Ferroptosis, a form of programmed cell death dependent on iron, is characterized by the accumulation of lipid peroxides, elevated levels of iron ions and lipid peroxidation. The underlying mechanisms and signalling pathways associated with ferroptosis are intricate and interconnected, involving various proteins and enzymes such as the cystine/glutamate antiporter, glutathione peroxidase 4, ferroptosis inhibitor 1 and dihydroorotate dehydrogenase. Consequently, emerging research suggests that ferroptosis may offer a novel target for breast cancer treatment; however, the mechanisms of ferroptosis in breast cancer urgently require resolution. Additionally, certain natural compounds have been reported to induce ferroptosis, thereby interfering with breast cancer. Therefore, this review not only discusses the molecular mechanisms of multiple signalling pathways that mediate ferroptosis in breast cancer (including metastasis, invasion and proliferation) but also elaborates on the mechanisms by which natural compounds induce ferroptosis in breast cancer. Furthermore, this review summarizes potential compound types that may serve as ferroptosis inducers in future tumour cells, providing lead compounds for the development of ferroptosis-inducing agents. Last, this review proposes the potential synergy of combining natural compounds with traditional breast cancer drugs in the treatment of breast cancer, thereby suggesting future directions and offering new insights.

Anti-Neuroinflammatory Potential of Natural Products in the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is an age-related chronic progressive neurodegenerative disease, which is the main cause of dementia in the elderly. Much evidence shows that the onset and late symptoms of AD are caused by multiple factors. Among them, aging is the main factor in the pathogenesis of AD, and the most important risk factor for AD is neuroinflammation. So far, there is no cure for AD, but the relationship between neuroinflammation and AD may provide a new strategy for the treatment of AD. We herein discussed the main etiology hypothesis of AD and the role of neuroinflammation in AD, as well as anti-inflammatory natural products with the potential to prevent and alleviate AD symptoms, including alkaloids, steroids, terpenoids, flavonoids and polyphenols, which are available with great potential for the development of anti-AD drugs.