Investigations On The Effectiveness Of Three Natural Drugs Against Oxidative Stress Diseases

Oxidative stress is an imbalance of oxidative and antioxidative reactions in cells and organisms,which is stimulated by the overproduction of reactive oxygen species(ROS)and reactive nitrogen species(RNS),can damage important biomolecules and cells,and affect the entire organism.Therefore,oxidative stress is related to the pathogenesis of many chronic diseases,and it is also the main cause of human death.Nuclear factor erythroid 2-related factor 2(Nrf2)is a regulatory factor regulated the intracellular oxidative status and maintaining the redox homeostasis,which can regulate phase Ⅱ detoxifying enzymes and antioxidant enzymes to offset the damage caused by oxidative stress to organisms.Oxidative stress also activates the inflammatory response,which interacts and amplifies each other’s harm,causing more serious damage to the body.The nuclear factor kappa B(NF-κB)is a redox-sensitive transcription factor regulating genes in response to inflammatory stimuli.Inhibition of the NF-κB signaling pathway can inhibit the production of inflammatory cytokines and reduce the inflammatory response.Based on their biological functions,Nrf2 activators and/or NF-κB inhibitors are more likely to be developed as effective therapeutic or preventive agents.Natural medicine is an important part of medicine.Its source,including plants,animals,minerals,and microorganisms,is one of the broadest sources for discovering drugs or drug lead molecules.This paper focuses on natural drug molecules or extracts,bases on the Nrf2 and/or NF-κB pathway,aims at chronic obstructive pulmonary disease and diabetic nephropathy,completes the following three parts:Part1 Protective effect of flavonoid NOR as an Nrf2 activtor in human lung epithelial cellsThe isopentenyl-substituted flavonoid Norartocarpin(NOR)was isolated from the leaves of Artocarpus heterophyllus by our group,previously been demonstrated as a potential Nrf2 inducing molecule.Based on these,this research performed as followed:(1)NOR upregulated the protein levels of Nrf2 and its downstream genes,NAD(P)H quinone oxidoreductase 1(NQO1),and c-glutamyl cysteine synthetase(GCLM)through facilitating the nuclear translocation of Nrf2 and enhancing Nrf2 protein stability.(2)NOR-induced activation of Nrf2 pathway was associated with multiple upstream kinases,including mitogen-activated protein kinase(MAPK),phosphatidylinositol-4,5-bisphosphate 3-kinase(PI3K),protein kinase C(PKC),and protein kinase R-like endoplasmic reticulum kinase(PERK).(3)NOR protected human lung epithelial Beas-2B cells against sodium arsenite[As(III)]-induced cytotoxicity in an Nrf2-dependent manner.Collectively,NOR was firstly identified to be a potential preventive agent for oxidative damages and verified the preventive effects against oxidative stress-induced diseases in vitroPart2 4β-HWE as an Nrf2 activtor for the effectiveness evaluation of chronic obstructive pulmonary diseaseA bioactivity-guided purification of goldenberry led to the isolation of 4β-hydroxywithanolide E(4β-HWE)from whole furits of Physalis peruviana L(named as pichuberry or goldenberry).Further,our study indicated that(1)4P-HWE activated the Nrf2-mediated defensive response through interrupting Nrf2-Keap1 protein-protein interaction(PPI)via modification of Cys151 and Cys288 cysteine residues in Keapl and accordingly suppressing the ubiquitination of Nrf2.(2)4β-HWE enhanced intracellular antioxidant capacity and inhibited oxidative stress in normal human lung epithelial Beas-2B cells and wild-type AB zebrafish.(3)4β-HWE blocked LPS-stimulated inflammatory response and inhibited LPS-stimulated NF-κB activation in RAW 264.7 murine macrophages.(4)4β-HWE effectively suppressed oxidative stress and inflammatory response in a CS-induced mice model of pulmonary injury related Nrf2 and NF-κB signal pathway.Collectively,these results display the feasibility of using 4β-HWE to prevent or alleviate the pathological progression of COPD and suggest that 4p-HWE is a candidate or a leading molecule against COPD.Part3 Protective effect of Ligusticum chuanxiong rhizome against streptozotocin-induced diabetic nephropathy in miceRhizome of Ligusticum chuanxiong Hort.(Abbreviated as LC)is a frequently prescribed component in plenty of traditional Chinese medicine(TCM)formulas which are used to treat diabetic nephropathy(DN).Present study investigated that the ethanol extract of LC rhizome(EEL)demonstrated potential inhibitory effects against oxidative stress and inflammation in vitro.Using a STZ-induced DN mice model,it has been found that EEL treatment significantly prevented STZ-induced increases of urine production,urinary albumin excretion(UAE)and urine albumin-to-creatinine ratio(UACR),and markedly attenuated STZ-induced renal damages(e.g.glomerulosclerosis and fibrosis).Previous phytochemical investigation has verified that phthalides,phenolic acids,and alkaloids,are the predominant bioactive constituents in LC.The predominant bioactive constituents,Z-ligustilide(LGT),ferulic acid(FA),and tetramethylpyrazine(TMP),were inhibitors of oxidative stress and inflammation through acting with Nrf2 and NF-κB pathways.Our data support the traditional use of LC as an important anti-DN component in TCM,and the mechanism of strong active ingredients of different structural types in Chuanxiong was revealed.Collectively,in vitro,this paper systematically evaluates the ability of natural drug molecules NOR,4β-HWE,and Ligusticum chuanxiong ethanol extracts targeting the antioxidant or anti-inflammatory effects in cells.The discoveries and researches provide directions and ideas of antioxidant and anti-inflammatory active molecules in natural drugs.In vivo,this paper uses two animal models of chronic obstructive pulmonary disease(COPD)and diabetic nephropathy(DN)to evaluate the effectiveness of 4β-HWE and Ligusticum chuanxiong ethanol extract for disease treatment,laying a foundation for the development of drugs for chronic diseases caused by oxidative stress.