Acute and sub-chronic toxicity of tetrandrine in intravenously exposed female BALB/c mice

In Vitro and In Vivo Evaluation of Lactoferrin-Modified Liposomal Etomidate with Enhanced Brain-Targeting Effect for General Anesthesia

Etomidate is a general anesthetic that has shown good hemodynamic stability without significant cardiovascular or respiratory depression. Despite several kinds of dosage forms having been reported for this drug, formulation types are very limited in clinical practice, and brain-targeted formulations for this central nervous system (CNS) drug have been rarely reported. Moreover, studies on the biocompatibility, toxicity, and anesthetic effects of the etomidate preparations in vivo were inadequate. The present study was to develop lactoferrin-modified liposomal etomidate (Eto-lip-LF) for enhanced drug distribution in the brain and improved anesthetic effects. Eto-lip-LF had good stability for storage and hemocompatibility for intravenous injection. Compared with the non-lactoferrin-containing liposomes, the lactoferrin-modified liposomes had notably enhanced brain-targeting ability in vivo, which was probably realized by the binding of transferrin with the transferrin and lactoferrin receptors highly distributed in the brain. Eto-lip-LF had a therapeutic index of about 25.3, higher than that of many other general anesthetics. Moreover, compared with the commercial etomidate emulsion, Eto-lip-LF could better achieve rapid onset of general anesthesia and rapid recovery from anesthesia, probably due to the enhanced drug delivery to the brain. The above results demonstrated the potential of this lactoferrin-modified liposomal etomidate to become an alternative preparation for clinical general anesthesia.

Tetrandrine promotes the survival of the random skin flap via the PI3K/AKT signaling pathway

Flaps are mainly used for wound repair. However, postoperative ischemic necrosis of the distal flap is a major problem, which needs to be addressed urgently. We evaluated whether tetrandrine, a compound found in traditional Chinese medicine, can prolong the survival rate of random skin flaps. Thirty-six rats were randomly divided into control, low-dose tetrandrine (25 mg/kg/day), and high-dose tetrandrine (60 mg/kg/day) groups. On postoperative Day 7, the flap survival and average survival area were determined. After the rats were sacrificed, the levels of angiogenesis, apoptosis, and inflammation in the flap tissue were detected with immunology and molecular biology analyses. Tetrandrine increased vascular endothelial growth factor and Bcl-2 expression, in turn promoting angiogenesis and anti-apoptotic processes, respectively. Additionally, tetrandrine decreased the expression of Bax, which is associated with the induction of apoptosis, and also decreased inflammation in the flap tissue. Tetrandrine improved the survival rate of random flaps by promoting angiogenesis, inhibiting apoptosis, and reducing inflammation in the flap tissue through the modulation of the PI3K/AKT signaling pathway.

Uncovering mechanisms of Baojin Chenfei formula treatment for silicosis by inhibiting inflammation and fibrosis based on serum pharmacochemistry and network analysis

BACKGROUND

Baojin Chenfei formula (BCF), a Chinese herbal formula, has significant effects on improving the clinical symptoms of patients with silicosis. However, its active compounds and the underlying mechanisms have not yet fully been elucidated.

PURPOSE

This study aimed to explore the underlying mechanisms of BCF in treating silicosis.

METHODS

The rat model of silicosis was developed via a single intratracheal instillation of SiO₂ suspension to examine the therapeutic impacts of BCF on silicosis. Subsequently, the active compounds, targets, and mechanisms of BCF were analyzed based on serum pharmacochemistry and network analysis. Finally, the underlying mechanisms of representative compounds of BCF were validated in vitro experiments.

RESULTS

BCF significantly alleviated SiO₂-induced silicosis in rats, evidenced by improved lung function, decreased pathological injury, and reduced inflammatory response and fibrosis. 19 active compounds were identified from the rat serum samples after BCF gavage. Subsequently, 299 targets for these 19 compounds in BCF and 257 genes related to silicosis were collected. 26 overlapping targets, including AKT1, TNF, IL6, MAPK3, EGFR, and others, were obtained from the intersection of the 299 BCF-related targets and 257 silicosis-associated genes. These overlapping targets mainly corresponded to glycyrrhetic acid and paeoniflorin and were mainly associated with positive regulation of smooth muscle cell proliferation, positive regulation of MAP kinase activity, and inflammatory response. In vitro experiments also demonstrated that the representative compounds of BCF (glycyrrhetic acid and paeoniflorin) could suppress inflammatory response by the MAPK pathway, and also inhibited fibroblast activation by the EGFR-PI3K-AKT pathway.

CONCLUSION

Active compounds of BCF, such as glycyrrhetic acid and paeoniflorin, could suppress inflammatory response by the MAPK pathway and suppress fibroblast activation by the EGFR-PI3K-AKT pathway. These might be the mechanisms of BCF in treating silicosis.

Phytocompounds as a source for the development of new drugs to treat respiratory viral infections

Respiratory viruses have an important history as a threat to global health. However, this problem has been aggravated due to the appearance of new outbreaks caused by a newly discovered virus or variant. Recently, the new coronavirus (SARS-CoV-2) has been a major concern for health authorities, and it was classified as a pandemic by the World Health Organization. Secondary metabolites obtained from plants represent an alternative to the discovery of new active molecules and have already shown potential to combat different viruses. In an effort to demonstrate the broad spectrum of antiviral action from these metabolites, this work describes the compounds that were effective against the major viruses that cause respiratory infections in humans. In addition, their mechanisms of action were highlighted as an approach to better understanding the virus-bioactive substance relationship. Finally, this study warns that, although phytocompounds have a broad antiviral action spectrum, the development of products and clinical trials based on these secondary metabolites is still scarce and therefore deserves greater attention from the scientific community.

Nephrotoxicity induced by natural compounds from herbal medicines - a challenge for clinical application

Herbal medicines (HMs) have long been considered safe and effective without serious toxic and side effects. With the continuous use of HMs, more and more attention has been paid to adverse reactions and toxic events, especially the nephrotoxicity caused by natural compounds in HMs. The composition of HMs is complex and various, especially the mechanism of toxic components has been a difficult and hot topic. This review comprehensively summarizes the kidney toxicity characterization and mechanism of nephrotoxic natural compounds (organic acids, alkaloids, glycosides, terpenoids, phenylpropanoids, flavonoids, anthraquinones, cytotoxic proteins, and minerals) from different sources. Recommendations for the prevention and treatment of HMs-induced kidney injury were provided. In vitro and in vivo models for evaluating nephrotoxicity and the latest biomarkers are also included in this investigation. More broadly, this review may provide theoretical basis for safety evaluation and further comprehensive development and utilization of HMs in the future.

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

Tetrandrine (Tet), derived from the traditional Chinese herb Fangji, is a class of natural alkaloids with the structure of bisbenzylisoquinoline, which has a wide range of physiological activities and significant pharmacfological effects. However, studies and clinical applications have revealed a series of drawbacks such as its poor water solubility, low bioavailability, and the fact that it can be toxic to humans. The results of many researchers have confirmed that chemical structural modifications and nanocarrier delivery can address the limited application of Tet and improve its efficacy. In this paper, we summarize the anti-tumor efficacy and mechanism of action, anti-inflammatory efficacy and mechanism of action, and clinical applications of Tet, and describe the progress of Tet based on chemical structure modification and nanocarrier delivery, aiming to explore more diverse structures to improve the pharmacological activity of Tet and provide ideas to meet clinical needs.

Targeting the two-pore channel 2 in cancer progression and metastasis

The importance of Ca²⁺ signaling, and particularly Ca²⁺ channels, in key events of cancer cell function such as proliferation, metastasis, autophagy and angiogenesis, has recently begun to be appreciated. Of particular note are two-pore channels (TPCs), a group of recently identified Ca²⁺-channels, located within the endolysosomal system. TPC2 has recently emerged as an intracellular ion channel of significant pathophysiological relevance, specifically in cancer, and interest in its role as an anti-cancer drug target has begun to be explored. Herein, an overview of the cancer-related functions of TPC2 and a discussion of its potential as a target for therapeutic intervention, including a summary of clinical trials examining the TPC2 inhibitors, naringenin, tetrandrine, and verapamil for the treatment of various cancers is provided.

Tetrandrine Inhibits Titanium Particle-Induced Inflammatory Osteolysis through the Nuclear Factor-κB Pathway

Peri-implant osteolysis (PIO) and the subsequent aseptic loosening are the main reasons for artificial joint implant failure. Existing methods for treating aseptic loosening are far from satisfactory, necessitating advanced drug exploration. This study is aimed at investigating the effect and underlying mechanism of tetrandrine (Tet) on inflammatory osteolysis. We established a Ti particle-induced inflammatory osteolysis mouse model and administered Tet or an equal volume of phosphate-buffered saline (PBS). Two weeks later, specimens were collected. Histological staining showed that Tet administration inhibited Ti-stimulated osteolysis. Tartrate-resistant acid phosphate (TRAP) staining and transmission electron microscopy (TEM) demonstrated that osteoclast formation was remarkably inhibited in the groups treated with Tet in a dose-dependent manner. In addition, relevant inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) were also significantly reduced in the calvaria of the Tet-treated groups. Exposure of receptor activator for nuclear factor-κB ligand- (RANKL-) induced bone marrow-derived macrophages (BMMs) and RAW264.7 cells to Tet significantly reduced osteoclast formation, F-actin ring formation, bone resorption, and the expression of relevant genes (matrix metallopeptidase 9 (MMP-9), TRAP, and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1)) during osteoclastogenesis in vitro. Mechanistic studies using Western blotting demonstrated that Tet inhibited the nuclear factor (NF)-κB signaling pathway by decreasing the phosphorylation of inhibitor of NF-κB α (IκBα) and p65, which play important roles in osteoclast formation. Collectively, our data indicate that Tet suppressed Ti-induced inflammatory osteolysis and osteoclast formation in mice, suggesting that Tet has the potential to be developed to treat and prevent wear particle-induced inflammatory osteolysis.

History of uses, phytochemistry, pharmacological activities, quality control and toxicity of the root of Stephania tetrandra S. Moore: A review

ETHNOPHARMACOLOGICAL RELEVANCE

the root of Stephania tetrandra S. Moore, known as Fangji in China (Chinese: ), is a traditional Chinese medicine (TCM) with a long history of use. Fangji is a type of medicine used to treat various diseases, including rheumatism, arthralgia, edema and beriberi, unfavorable urination, and eczema.

AIM OF THIS REVIEW

There are many newly published reports on the history of uses, phytochemistry, pharmacological activity, quality control and toxicity of Fangji; however, no comprehensive systematic review exists. Therefore, the purpose of this review is to compile the latest and most comprehensive information on Fangji and provide a scientific basis for future research.

MATERIALS AND METHODS

A systematic literature search was conducted using multiple electronic databases, including SciFinder, Web of Science, PubMed, Science Direct, ACS Publications, J-stage, SpringerLink, Thieme, Wiley, and CNKI. Information was also collected from journals and Chinese Pharmacopoeia.

RESULT

Thus far, there were uses of Fangji against 20 different diseases/disorders, such as relieving edema and rheumatism pain, treating cough and asthma, treating enuresis, astringent urine and beriberi edema, purging blood and damp heat, and dispelling wind evil and dampness, etc. 48 compounds have been isolated from Fangji, belonging to alkaloids, flavonoids, and steroids, other compounds. The crude extracts and isolated compound of Fangji have shown a wide range of pharmacological activities, such as anti-tumor, anti-inflammatory, and neuroprotective activities, as well as role in reoxygenation, and antimicrobial effect, etc. Moreover, qualitative and quantitative analyses of quality control are reviewed, including qualitative analyses for the identification of compounds, as well as fingerprint and quantitative analyses by high performance liquid chromatography (HPLC) and capillary electrochromatography (CE). In the toxicity study, the hepatotoxicity, hepatorenal toxicity, nephrotoxicity, subacute and acute toxicities of the alcohol extract and water extract of Fangji, and tetrandrine were studied in-vitro and in-vivo experiments.

CONCLUSION

In the history of uses, Fangji can be used to treat a variety of diseases, most of which are manifested in removing wind and dampness. In recent years, the phytochemistry of Fangji has rarely been reported. The pharmacological activities of Fangji mainly focus on the compounds, tetrandrine and fangchinoline, and there are a few reports on the pharmacological studies of other compounds in Fangji. Moreover, the quality control of Fangji lacks a standard fingerprint to distinguish Fangji from other easily-confused medicinal materials. In the toxicity study, there is no report on the mechanism of toxicity research. Therefore, further studies on such mechanisms are needed.

Pharmacological hypothesis: TPC2 antagonist tetrandrine as a potential therapeutic agent for COVID-19

More than ten million patients worldwide have been diagnosed with coronavirus disease 19 (COVID-19) to date (WHO situation report, 1st July 2020). There is no vaccine to prevent infection with the causative organism, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), nor a cure. In the struggle to devise potentially useful therapeutics in record time, the repurposing of existing compounds is a key route of action. In this hypothesis paper, we argue that the bisbenzylisoquinoline and calcium channel blocker tetrandrine, originally extracted from the plant Stephania tetrandra and utilized in traditional Chinese medicine, may have potential in the treatment of COVID-19 and should be further investigated. We collate and review evidence for tetrandrine's putative mechanism of action in viral infection, specifically its recently discovered antagonism of the two-pore channel 2 (TPC2). While tetrandrine's particular history of use provides a very limited pharmacological dataset, there is a suggestion from the available evidence that it could be effective at doses used in clinical practice. We suggest that further research to investigate this possibility should be conducted.

Synthesis, biological evaluation and toxicity of novel tetrandrine analogues

In this work, we present the design and synthesis of novel fully synthetic analogues of the bisbenzylisoquinoline tetrandrine, a molecule with numerous pharmacological properties and the potential to treat life-threatening diseases, such as viral infections and cancer. Its toxicity to liver and lungs and the underlying mechanisms, however, are controversially discussed. Along this line, novel tetrandrine analogues were synthesized and biologically evaluated for their hepatotoxicity, as well as their antiproliferative and chemoresistance reversing activity on cancer cells. Previous studies suggesting CYP-mediated toxification of tetrandrine prompted us to amend/replace the suspected metabolically instable 12-methoxy group. Of note, employing several in vitro models showed that the proposed CYP3A4-driven metabolism of tetrandrine and analogues is not the major cause of hepatotoxicity. Biological characterization revealed that some of the novel tetrandrine analogues sensitized drug-resistant leukemia cells by inhibition of the P-glycoprotein. Interestingly, direct anticancer effects improved in comparison to tetrandrine, as several compounds displayed a markedly enhanced ability to reduce proliferation of drug-resistant leukemia cells and to induce cell death of liver cancer cells. Those enhanced anticancer properties were linked to influences on activation of the kinase Akt and mitochondrial events. In sum, our study clarifies the role of CYP3A4-mediated toxicity of the bisbenzylisoquinoline alkaloid tetrandrine and provides the basis for the exploitation of novel synthetic analogues for their antitumoral potential.

Therapeutic potential of alkaloids in autoimmune diseases: Promising candidates for clinical trials

Clinical investigations have characterized numerous disorders like autoimmune diseases, affecting the population at a rate of approximately 8-10%. These disorders are characterized by T-cell and auto-antibodies responses to self-molecules by immune system reactivity. Several therapeutic options have been adopted in clinics to combat such diseases, however, most of them are recurring. Thus, the discovery of new effective agents for the treatment of autoimmune diseases is paramount. In this context, natural products might be a useful alternative to the current therapies. Plant alkaloids with their substantial therapeutic history can be particularly interesting candidates for the alleviation of autoimmune ailments. This review encompasses various alkaloids with significant effects against autoimmune diseases in preclinical trials. These results suggest further clinical assessment with respect to autoimmune illnesses. Furthermore, the application of modern technologies such as nanoformulation could be also helpful in the design of more effective therapies and thus further studies are needed to decipher their therapeutic efficacy as well as potential limitations.

A critical review: traditional uses, phytochemistry, pharmacology and toxicology of Stephania tetrandra S. Moore (Fen Fang Ji)

ABSTRACT

Stephania tetrandra S. Moore (S. tetrandra) is distributed widely in tropical and subtropical regions of Asia and Africa. The root of this plant is known in Chinese as "Fen Fang Ji". It is commonly used in traditional Chinese medicine to treat arthralgia caused by rheumatism, wet beriberi, dysuria, eczema and inflamed sores. Although promising reports have been published on the various chemical constituents and activities of S. tetrandra, no review comprehensively summarizes its traditional uses, phytochemistry, pharmacology and toxicology. Therefore, the review aims to provide a critical and comprehensive evaluation of the traditional use, phytochemistry, pharmacological properties, pharmacokinetics and toxicology of S. tetrandra in China, and meaningful guidelines for future investigations.

Plant-Derived Alkaloids: The Promising Disease-Modifying Agents for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) represents a group of intestinal disorders with self-destructive and chronic inflammation in the digestive tract, requiring long-term medications. However, as many side effects and drug resistance are frequently encountered, safer and more effective agents for IBD treatment are urgently needed. Over the past few decades, a variety of natural alkaloids made of plants or medicinal herbs have attracted considerable interest because of the excellent antioxidant and anti-inflammatory properties; additionally, these alkaloids have been reported to reduce the colonic inflammation and damage in a range of colitic models. In this review paper, we summarize the recent findings regarding the anti-colitis activity of plant-derived alkaloids and emphasize their therapeutic potential for the treatment of IBD; obvious improvement of the colonic oxidative and pro-inflammatory status, significant preservation of the epithelial barrier function and positive modulation of the gut microbiota are the underlying mechanisms for the plant-derived alkaloids to treat IBD. Further clinical trials and preclinical studies to unravel the molecular mechanism are essential to promote the clinical translation of plant-derived alkaloids for IBD.

Quantitative MALDI Imaging of Spatial Distributions and Dynamic Changes of Tetrandrine in Multiple Organs of Rats

Detailed spatio-temporal information on drug distribution in organs is of paramount importance to assess drug clinically-relevant properties and potential side-effects. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) as a label-free and sensitive imaging modality provides an additional means of accurately visualizing drug and its metabolites distributions in tissue sections. However, technical limitations, complex physiochemical environment of surface and low abundance of target drugs make quantitative MALDI imaging of drug and its metabolites quite challenging.

Methods: In this study, an internal standard correction strategy was applied for quantitative MALDI imaging of tetrandrine in multiple organs of rats including lung, liver, kidney, spleen, and heart. The feasibility and reliability of the developed quantitative MSI method were validated by conventional liquid chromatography-tandem MS (LC-MS/MS) analysis, and the two methods showed a significant correlation.

Results: The quantitative MALDI imaging method met the requirements of specificity, sensitivity and linearity. Tissue-specific spatio-temporal distribution patterns of tetrandrine in different organs were revealed after intravenous administration in the rat. Moreover, demethylated metabolite was detected in liver tissues.

Conclusions: The current work illustrates that quantitative MALDI imaging provides an alternative means of accurately addressing the problem of drug and its metabolites distribution in tissues, complementary to traditional LC-MS/MS of tissue homogenates and whole-body autoradiography (WBA). Quantitative spatio-chemical information obtained here can improve our understanding of pharmacokinetics (PK), pharmacodynamics (PD), and potential transient toxicities of tetrandrine in organs, and possibly direct further optimization of drug properties to reduce drug-induced organ toxicity.

Research Progress on Reversing Multidrug Resistance in Tumors by Using Chinese Medicine

Multidrug resistance (MDR) is a major cause of cancer chemotherapy failure, and it is important to develop suitable reversal agents to overcome MDR. A majority of chemical reversal agents have acceptable reversal effects. However, the toxicity and adverse reactions associated with these agents restricts their clinical use. Chinese medicines (CMs) have lower toxicities and adverse reactions and are associated with multiple components, multiple targets and reduced toxicity. CMs have several advantages and could reverse MDR, decrease drug dosage, enhance patient compliance and increase efficacy. This review summarizes the current progress of CM reversal agents..

Tetrandrine and cancer - An overview on the molecular approach

Tetrandrine has been known in the treatment of tuberculosis, hyperglycemia, negative ionotropic and chronotropic effects on myocardium, malaria, cancer and fever since years together. It has been known that, tetrandrine could modulate multiple signaling molecules such as kinases of cell cycle and rat sarcoma (RAS) pathway along with proteins of tumor suppressor genes, autophagy related, β-catenins, caspases, and death receptors. Moreover, tetrandrine exhibited reversal of drug resistance by modulating P-glyco protein (P-gp) expression levels in different cancers which is an added advantage of this compound compared to other chemotherapy drugs. Though, bioavailability of tetrandrine is a limiting factor, the anticancer activity was observed in animal models without changing any pharmacokinetic parameters. In the present review, role of tetrandrine as kinase inhibitor, inducer of autophagy and caspase pathways and suppressor of RAS mediated cell proliferation were discussed along with inhibition of angiogenesis. It has also been discussed that how tetrandrine potentiate anticancer effect in different types of cancers by modulating multidrug resistance under in vitro and in vivo trials including the available literature on the clinical trials.