Study On The Composition And Mechanism Of Anti-tuberculosis Bacilli In Dushan Melon

Tuberculosis(TB)is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis complex(MTBC),its mortality is ranking below AIDs,which seriously endangers human health and increases the family burden.Because of the emergence of drug resistance and the co-infection of Human immunodeficiency virus-Tuberculosis(HIV-TB),making the effective therapy of tuberculosis to face more serious challenges.So it is urgent to research the novel anti-tuberculosis drugs at present.Mycobacterium tuberculosis has the unique property of becoming persistent or dormant for very long periods,it is the major reason that leads a long course of treatment regimens,low efficiency,easy recurrence and difficult to cure.When the Mycobacterium tuberculosis stays dormancy,making Mycobacterium tuberculosis to first-line anti-TB drugs phenotypic resistance and latency for long time,but when the human body immunity drops,the dormant Mycobacterium tuberculosis will recover and the body become infection again.In this paper,the study is based on the previous research.Compound GF-01,with resuscitating activity on dormant Mycobacterium tuberculosis,was isolated from Fissistigma cavaleriei root by bioassay-guided method.It was identified as?-sitosterol-9,12-hexadecadienoate by physical and spectroscopic methods.Compound GF-01 showed activity to resuscitate dormant Mycobacterium tuberculosis into active state in a dose-dependent manner with minimum effective concentration of 16 ?g/mL.The dormant Mycobacterium tuberculosis was insensitive to isoniazid,ethambutol,rifampin,and pyrazinamide in single drug.At the concentration of 32 ?g/m L,compound GF-01 could help isoniazid to kill the dormant Mycobacterium tuberculosis after 14 and 21 days of exposure,and it can increase the killing activity of rifampin against dormant Mycobacterium tuberculosis.However,among two-drug combinations,compound GF-01-ethambutol and compound GF-01-pyrazinamide,exhibited antagonistic action on dormant Mycobacteriumtuberculosis.Compound GF-01 could activate the KatG activity of dormant Mycobacterium tuberculosis,which caused the content of O2 in dormant Mycobacterium tuberculosis cells at a high level to trigger the resuscitation of dormant Mycobacterium tuberculosis.Modified-Lowenstein-Jensen-Medium was used to evaluate the anti-Mycobacterium tuberculosis activity of the Fissistigma cavaleriei fraction.The active compound GF-02 were isolated from the active fraction of Fissistigma cavaleriei root by silica gel column chromatography.We found that the ethyl acetate fraction of Fissistigma cavaleriei root ethanol extracts showed activity to inhibit Mycobacterium tuberculosis,the minimum effective concentration less than 1mg/ml.And the compound GF-02,it was identified as 5-hydroxymethylfurfural(5-HMF).Through the activity test,the GF-02 showed activity to inhibit replicating Mycobacterium tuberculosis with minimum effective concentration of 80 ?g/ml,and also,the GF-02 showed asynergistic effect with isoniazid and rifampici,indicated that the GF-02 could reduce the degree of isoniazid and rifampicin resistance,so as to reduce the clinical dosage.GF-02 was isolated from the plant for the first time.Althoug the activity of GF-02 anti-Mycobacterium tuberculosis is not particularly strong,but its anti-Mycobacterium tuberculosis activity is the first discovery,and it is the new structure of anti-Mycobacterium tuberculosis molecular.In order to evaluate preliminary the structure-activity relationship of5-hydroxymethylfurfural,we carry out the anti-Mycobacterium tuberculosis activity test of four 5-hydroxymethylfurfural analogues,The results showed that2,5-dihydroxymethylfura and 5-hydroxymethyl-2-furancarboxylic acid had anti-Mycobacterium tuberculosis activity,so we can get conclusion that the active nucleus structure is furfuryl alcohol.It provides an opportunity to find new anti-TB drugs for the further.