Computational Analysis of Naturally Occurring Aristolochic Acid Analogues and Their Biological Sources.

Aristolochic acids are known for nephrotoxicity, and implicated in multiple cancer types such as hepatocellular carcinomas demonstrated by recent studies. Natural products that are analogues to aristolochic acids have been constantly isolated from organisms; a larger chemical space of these compounds and a wider coverage of biological sources should be determined in consideration of the potential hazard of aristolochic acid analogues and the wide distribution of their biological sources in the nature. Therefore, we carried out an in silico research of naturally occurring aristolochic acid analogues and their biological sources, as a supplement to existing studies. The result shows a chemical space of 238 naturally occurring aristolochic acid analogues that are present in 175 species of biological sources including 44 traditional medicines. With the computational estimation for toxicity and the implication in hazard assessment of a biological source with the presence of aristolochic acid analogues, we propose that additional awareness should be raised to the public for avoidance of toxic species, especially those that are used as herbal medicines and easily accessible.

A double-blinded, placebo-controlled randomized trial evaluating the efficacy and safety of Zhigancao Tang granules for treating HFpEF: study protocol for a randomized controlled trial.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome characterized by diastolic dysfunction. Despite the increasing incidence of HFpEF, there is no available therapy that reduces the mortality rate of HFpEF. Zhigancao Tang has been used traditionally for the treatment of cardiovascular diseases in China. The use of traditional Chinese medicine (TCM) is associated with improvements in clinical syndromes and quality of life of patients. A randomized clinical trial should be conducted to provide clear evidence regarding the efficacy and safety of Zhigancao Tang granules for the treatment of HFpEF. METHODS: A randomized, double-blinded, placebo-controlled clinical trial was proposed. A total of 122 patients with HFpEF will be randomly assigned to receive Zhigancao Tang granules or placebo for 12 weeks. The primary outcome measure is cardiac function. The secondary outcomes include measurement of the integral TCM syndrome score, echocardiography, 6-min walk test, N-terminal-pro hormone B-type natriuretic peptide level, atrial natriuretic peptide level, Minnesota Living with Heart Failure scale, and Lee's scale. The outcome measures will be evaluated at baseline, 4 weeks, and 12 weeks. Adverse events will be evaluated from baseline till the 12-week follow-up period. DISCUSSION: The results of this trial will demonstrate whether Zhigancao Tang granules are effective and safe for treating HFpEF. TRIAL REGISTRATION: ClinicalTrials.gov NCT04317339 . Registered on 23 March 2020.

Virtual Screening for Reactive Natural Products and Their Probable Artifacts of Solvolysis and Oxidation.

Chemically unstable natural products are prone to show their reactivity in the procedures of extraction, purification, or identification and turn into contaminants as so-called "artifacts". However, identification of artifacts requires considerable investments in technical equipment, time, and human resources. For revealing these reactive natural products and their artifacts by computational approaches, we set up a virtual screening system to seek cases in a biochemical database. The screening system is based on deep learning models of predicting the two main classifications of conversion reactions from natural products to artifacts, namely solvolysis and oxidation. A set of result data was reviewed for checking validity of the screening system, and we screened out a batch of reactive natural products and their probable artifacts. This work provides some insights into the formations of natural product artifacts, and the result data may act as warnings regarding the improper handling of biological matrixes in multicomponent extraction.

Curdione inhibits thrombin-induced platelet aggregation via regulating the AMP-activated protein kinase-vinculin/talin-integrin αIIbß3 sign pathway.

BACKGROUND: Curdione, a sesquiterpene compound isolated from the essential oil of Curcuma aromatica Salisb. inhibits platelet aggregation, suggesting its significant anticoagulant and antithrombotic effects. However, the mechanisms have not been fully elucidated. HYPOTHESIS: We hypothesized that curdione inhibits thrombin-induced platelet aggregation via regulating the AMP-activated protein kinase-vinculin/talin-integrin αIIbß3 signaling pathway. STUDY DESIGN: We performed in vitro assays to evaluate the effect of curdione on thrombin-induced expression levels of the AMPK signaling molecule and integrin αIIbß3 signaling pathway components. METHODS: Platelet proteins were extracted from washed human platelets, and the effects of curdione on thrombin-induced platelet aggregation were evaluated. The expression levels of the AMPK signaling molecule and integrin αIIbß3 signaling pathway-related proteins were examined using western blot and RT-PCR. The binding of vinculin and talin were studied using immunoprecipitation, double immunofluorescence staining and microscale thermophoresis. RESULTS: Platelet aggregation analysis showed that 0.02 U/ml thrombin significantly induces platelet aggregation. Western blot and RT-PCR analysis revealed that AMPK inhibits the vinculin/talin-mediated integrin αIIbß3 signaling pathway, and curdione downregulates the thrombin-induced expression of phosphorylated AMPK (P-AMPK) and P-integrin at both the protein and mRNA levels and downregulates vinculin and talin at the protein level. Furthermore, microscale thermophoresis experiments showed that curdione inhibits the binding of vinculin and talin. The results from the immunoprecipitation and double immunofluorescence staining were consistent with the results of the microscale thermophoresis experiments. CONCLUSION: Curdione inhibits thrombin-induced platelet aggregation via regulating the AMP-activated protein kinase-vinculin/talin-integrin αIIbß3 signaling pathway, which suggests its therapeutic potential in ethnomedicinal applications as an anti-platelet and anti-thrombotic compound to prevent thrombotic diseases.

Curdione attenuates thrombin-induced human platelet activation: ß1-tubulin as a potential therapeutic target.

Rhizoma Curcumae, the dry rhizomes derived from Curcuma aromatica Salisb., are a classical Chinese medicinal herb used to activate blood circulation, remove blood stasis and alleviate pain. Our previous study proved that curdione, a sesquiterpene compound isolated from the essential oil of Curcuma aromatica Salisb. can inhibit platelet activation suggesting its significant anticoagulant and antithrombotic effects. However, the underlying mechanism of curdione mediated anti-platelet effect has not been fully elucidated. Platelet proteins extracted from washed human platelets, including normal group (treated with normal saline), thrombin group and curdione group were digested and analysed by nano ESI-LC-MS/MS. UniProt database and SIEVE software were employed to identify and reveal the differentially expressed proteins. Furthermore, possible mechanisms involved were explored by Ingenuity Pathway Analysis (IPA) Software and validated by western blot experiments. Twenty-two differentially expressed proteins between the normal and thrombin group were identified. Compared with the thrombin group, the curdione treatment was significantly down-regulated only 2 proteins (Talin1 and ß1-tubulin). Bioinformatics analysis showed that Talin1 and ß1-tubulin could be involved in the integrin signal pathway. The results of western blot analysis were consistent with that of the proteomics data. Vinculin, identified in IPA database was involved in the formation of cell cytoskeletal. The down-regulation of ß1-tubulin facilitated the decrease in vinculin/Talin1. Curdione regulated the expression of vinculin and Talin1 by ß1-tubulin affecting the integrin signalling pathway and eventually inhibiting platelet activation. The ß1-tubulin may be a potential target of curdione, which attenuates thrombin-induced human platelet activation.