Antibacterial And Antitumor Of Some Monomer Components From Natural Product

Part 1Backgrounds: Malignant tumors are one of the major diseases that seriously affect human health and threaten human life,and their treatment is difficult.Angiogenesis is a key process in tumor growth and metastasis.Therefore,inhibition of tumor growth by blocking tumor angiogenesis is a new therapeutic strategy.Rutaecarpine is one of the main components of Evodia,and is widely used in the treatment of various diseases in traditional medicine.Rutaecarpine can inhibit cell proliferation and induce apoptosis through various molecular mechanisms.However,the anti-angiogenic mechanism of rutaecarpine has not been reported.Therefore,studying the inhibition of angiogenesis by rutaecarpine is very valuable for the development of anti-tumor drugs.Objective: This study was designed to investigate the effects of rutaecarpine on angiogenesis and the potential regulatory mechanisms of related signal transduction.Methods: The effects of rutaecarpine on angiogenesis were studied by MTT assay,adhesion inhibition assay,migration inhibition assay and chicken chorioallantoic membrane(CAM)model.The potential targets of rutaecarpine were screened by computer simulation.The interaction of the compound with the target protein was detected by surface plasmon resonance(SPR),enzyme activity assay and Western blot.Results: The results confirmed that rutaecarpine showed moderate inhibitory activity against human umbilical vein endothelial cells(HUVECs),which also had a significant inhibitory effect on the migration and adhesion of HUVECs.And it exhibits significant anti-angiogenic activity in CAM experiments.Vascular endothelial growth factor receptor 2(VEGFR2)was identified as a possible target by computer simulation.The result was confirmed by SPR analysis.In addition,enzyme activity assays and Western blotting assays have shown that rutaecarpine inhibits VEGFR2 activity,which blocks the VEGFR2-mediated Akt/(mTOR)/p70s6 k signaling pathway.Rutaecarpine is a potential cancer prevention and treatment drug.Conclusion: Overall,the results clearly indicate that rutaecarpine,as an anticancer drug,blocks the VEGF signaling pathway in HUVECs that promotes new blood vessel growth.Rutaecarpine can inhibit angiogenesis by targeting the VEGFR2-mediated Akt/mTOR/p70S6 K signaling pathway.Therefore,rutaecarpine is a potential cancer prevention and treatment drug.Part 2Backgrounds: Bacterial infections are common in life,and the large-scale use of antibiotics in society has led to the emergence of resistant bacteria.This requires us to continuously develop new antibacterial drugs to solve the problem of drug resistance.Finding low-toxic and effective antibacterial drugs is the focus of medical research.At present,since many Chinese herbal medicine ingredients have low toxicity and effective antibacterial effect,and can also reverse the drug resistance of drug-resistant bacteria,it is a hot spot to find antibacterial drugs from Chinese herbal medicines.Cryptolepine is the main alkaloid in Cryptolepis,and has a wide range of biological activities.To date,natural compounds isolated from the Cryptolepis have mainly alkaloids and cardiac glycosides.Although it has been confirmed that cryptolepine has good pharmacological activity,most of its related research focuses on anti-tumor and anti-malarial directions.The antibacterial activity and antibacterial mechanism of cryptolepine have hardly been reported.Objective: The antibacterial activity of cryptolepine and its possible related antibacterial mechanism were discussed in this study.Methods: The antibacterial activity and minimum inhibitory concentration of cryptolepine were determined by drug sensitivity test and MIC test,respectively.Using the computer-aided simulation technique,the Discovery Studio software was used to reverse the target portion to try to find possible potential targets.Based on the reverse target-finding results,the antibacterial targets of the study were determined by genetic and amino acid sequence alignment and literature review,and Escherichia coli was used as a model for studying prokaryotic MetAP-1.Molecular dynamics simulations were used to dynamically describe the movement of cryptolepine after binding to the target.Then,the SPR experiment is used to directly detect the binding of the drug molecule to the target.Enzyme activity assay was performed in vitro to examine the effect of cryptolepine on the activity of target proteins.Results: Our experiments show that cryptolepine has a strong inhibitory effect on Gram-positive bacteria(e.g.Staphylococcus aureus,Bacillus subtilis).It has a strong inhibitory activity against Escherichia coli in Gram-negative bacteria and no inhibitory activity against Pseudomonas aeruginosa.The possible target MetAP1 was found by computer-aided simulation,gene and amino acid sequence alignment and literature review.The binding of the drug to the target was analyzed by computer molecular docking and dynamics simulation.The simulation results showed that the binding effect was good and the binding was stable.The results of enzyme activity assay showed that the activity of cryptolepine on MetAP1 showed a significant gradient with the concentration.Conclusion: Through experiments,they have shown that cryptolepine has a good antibacterial activity,and its inhibitory mechanism against bacteria can be produced by the MetAP1 target,which is a good potential antibacterial drug.