Comparative antimycobacterial activity of some Indonesian medicinal plants against multi-drug resistant Mycobacterium tuberculosis

2010 ◽  
Vol 59 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Fa Ge ◽  
Fanli Zeng ◽  
Siguo Liu ◽  
Na Guo ◽  
Haiqing Ye ◽  
...  

Reports have shown that oleanolic acid (OA), a triterpenoid, exists widely in food, medicinal herbs and other plants, and that it has antimycobacterial activity against the Mycobacterium tuberculosis strain H37Rv (ATCC 27294). In this study it was found that OA had antimycobacterial properties against eight clinical isolates of M. tuberculosis and that the MICs of OA against drug-sensitive and drug-resistant isolates were 50–100 and 100–200 μg ml−1, respectively. The combination of OA with isoniazid (INH), rifampicin (RMP) or ethambutol (EMB) showed favourable synergistic antimycobacterial effects against six drug-resistant strains, with fractional inhibitory concentration indices of 0.121–0.347, 0.113–0.168 and 0.093–0.266, respectively. The combination treatments of OA/INH, OA/RMP and OA/EMB displayed either a synergistic interaction or did not show any interaction against two drug-sensitive strains. No antagonism resulting from the OA/INH, OA/RMP or OA/EMB combination was observed for any of the strains tested. OA exhibited a relatively low cytotoxicity in Vero cells. These results indicate that OA may serve as a promising lead compound for future antimycobacterial drug development.


mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Qi Ouyang ◽  
Kehong Zhang ◽  
Dachuan Lin ◽  
Carl G. Feng ◽  
Yi Cai ◽  
...  

ABSTRACT Tuberculosis (TB) is still the leading killer caused by Mycobacterium tuberculosis infection. There is a clear need for new treatment strategy against TB. It has been reported that tamoxifen, known as a selective estrogen receptor modulator (SERM), exhibits antimycobacterial activity and inhibits M. tuberculosis growth in macrophages. However, it remains unknown whether such antimicrobial activity is a general property of all SERMs and how it works. In this study, we identified that bazedoxifene (BZA), a newer SERM, inhibits intracellular M. tuberculosis growth in macrophages. BZA treatment increases autophagosome formation and LC3B-II protein expression in M. tuberculosis-infected macrophages. We further demonstrated that the enhancement of autophagy by BZA is dependent on increased reactive oxygen species (ROS) production and associated with phosphorylation of Akt/mTOR signaling. In summary, our data reveal a previously unappreciated antimicrobial function of BZA and suggest that future investigation focusing on the mechanism of action of SERMs in macrophages may lead to new host-directed therapies against TB. IMPORTANCE Since current strategies for the treatment of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) have low efficacy and highly negative side effects, research on new treatments including novel drugs is essential for curing drug-resistant tuberculosis. Host-directed therapy (HDT) has become a promising idea to modulate host cell responses to enhance protective immunity against pathogens. Bazedoxifene (BZA), which belongs to a new generation of SERMs, shows the ability to inhibit the growth of M. tuberculosis in macrophages and is associated with autophagy. Our findings reveal a previously unrecognized antibacterial function of BZA. We propose that the mechanism of SERMs action in macrophages may provide a new potential measure for host-directed therapies against TB.


2002 ◽  
Vol 46 (2) ◽  
pp. 294-299 ◽  
Author(s):  
Rosanna Maccari ◽  
Rosaria Ottanà ◽  
Francesca Monforte ◽  
Maria Gabriella Vigorita

ABSTRACT As a result of our search for new isoniazid derivatives with extended spectra of activity, we evaluated the in vitro antimycobacterial activities of isonicotinohydrazides (compounds 2) and their cyanoborane adducts (compounds 3), both obtained by the reaction of isonicotinoylhydrazones (compounds 1) with sodium cyanoborohydride. Most of the tested compounds displayed moderate to high activity against Mycobacterium tuberculosis H37Rv, with MICs ranging from 0.2 to 12.5 μg/ml. In particular, some hydrazides showed activity similar to that of rifampin (MIC = 0.2 μg/ml) and rather low cytotoxicity, so that they were generally shown to possess high safety indices. In contrast, the coordination to a cyanoborane (BH2CN) group (compounds 3) in general brought about a decrease in antimycobacterial activity, while cytotoxicity increased. Interestingly, selected compounds 1 to 3, mostly hydrazides (compounds 2), were effective in killing M. tuberculosis growing within macrophages at concentrations in culture medium which were much lower than the corresponding MICs. These compounds also displayed good activity against drug-resistant M. tuberculosis strains.


2016 ◽  
Author(s):  
◽  
Alveera Singh

Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis (TB) has infected approximately one-third of the world population, with 9.6 million TB cases in 2014. The emergence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) strains of MTB has further complicated the problem of TB control. It is now imperative that novel antimycobacterial compounds are discovered in order to treat infections and reduce the duration of current TB therapy courses. For centuries, medicinal plants have been used globally worldwide for the treatment and prevention of various ailments. This occurs particularly in developing countries where infectious diseases are endemic and modern health facilities and services are inadequate. In recent years, the use and search for plant drug derivatives have been fast-tracked. Ethnopharmacologists, botanists, microbiologists, and natural product chemists are trying to discover phytochemicals which could be developed for the treatment of infectious diseases, especially TB. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimycobacterial activity. In the search for new lead compounds, nine medicinal plant species, Buddleja saligna, Capparis tomentosa, Carpobrotus dimidiatus, Dichrostachys cinerea, Ekerbergia capensis, Ficus Sur, Gunnera perpensa, Leonotis leonurus and Tetradenia riparia were collected in Kwa-Zulu Natal (KZN) following report of their therapeutic use in traditional medicine to treat symptoms and infections related to TB. They were tested in vitro for their activity against Mycobacterium smegmatis, Mycobacterium tuberculosis H37Rv (ATCC 25177) and three well-characterized clinical isolates of MDR-TB and XDR-TB using the agar incorporation method. The minimum inhibitory concentration of the active plant extracts was determined using the broth microdilution method. Our findings show that five of the nine plants screened have antimycobacterial activity with concentrations ranging from 125 µg/ml to 1000 µg/ml. The aqueous extracts of G. perpensa and T. riparia; and the methanolic extracts of B. saligna, C. tomentosa, and C. dimidiatus possessed significant activity against M. smegmatis, M. tuberculosis H37Rv (ATCC 25177) and the three well-characterized clinical isolates of MDR-TB and XDR-TB. The cytotoxic effect of the active plant extracts was evaluated against the mouse BALB/C monocyte-macrophage (J774.2) and peripheral blood mononuclear cells (PBMCs). The toxic effects of the active plant extracts were evaluated using the brine shrimp lethality assay. Except for a high concentration of G. perpensa none of the other plants which possessed antimycobacterial activity showed any toxic or cytotoxic activity. The active plant extracts were thereafter assessed to determine if they had any effect on the survival or death of mycobacterial species, M. smegmatis, bound within the macrophage (J774.2) cell line at a concentration of 100 µg/ml. B. saligna had inactivated most of the phagocytosed bacilli after 24 hours of treatment therefore, it has a bactericidal effect on the mycobacteria located within the mouse macrophage. A phytochemical investigation of the leaves of B. saligna led to the isolation of two isomeric pentacyclic triterpene compounds namely Oleanolic Acid (OA) and Ursolic Acid (UA) using thin layer chromatography followed by silica gel column chromatography. The structures of these compounds were fully characterized by detailed NMR investigations, which included 1H and 13C NMR. Ursolic acid was isolated from this plant for the first time. Two-dimensional (2D) and three-dimensional (3D) quantitative structure-activity relationship (QSAR) studies were carried out to provide insight on the interaction of the compounds with the enzyme. Molecular docking studies predicted the free binding energy of the triterpenes inside the steroid binding pocket of Mycobacterium tuberculosis fadA5 thiolase compared to a reported inhibitor. Thus, their ability to inhibit the growth of Mycobacterium tuberculosis was predicted and was confirmed to possess significant antimycobacterial activity when tested against M. smegmatis, M. tuberculosis H37Rv (ATCC 25177), clinical isolates of MDR-TB and XDR-TB using the Microplate Alamar Blue Plate (MABA) assay. The present study has scientifically validated the traditional use of medicinal plant B. saligna.


Author(s):  
Nandan Sarkar ◽  
Yadu Nandan Dey ◽  
Dharmendra Kumar ◽  
Mogana R

: Effective treatment of tuberculosis has been hindered by the emergence of drug-resistant strains of Mycobacterium therapeutic facilities tuberculosis. With the global resurgence of tuberculosis with the development of multidrug-resistant cases, there is a call for the development of new drugs to combat these diseases. Throughout history, natural products have afforded a rich source of compounds that have found many applications in the fields of medicine, pharmacy and biology, and continued to play a significant role in the drug discovery and development process. This review article depicts the various potential plant extracts as well as plant-derived phytoconstituents against the H37rv, the most persistent strains of Mycobacterium tuberculosis and its multidrug strains.


2019 ◽  
Vol 63 (3) ◽  
Author(s):  
Zeinab G. Khalil ◽  
Timothy A. Hill ◽  
Luis M. De Leon Rodriguez ◽  
Rink-Jan Lohman ◽  
Huy N. Hoang ◽  
...  

ABSTRACT Wollamides are cyclic hexapeptides, recently isolated from an Australian soil Streptomyces isolate, that exhibit promising in vitro antimycobacterial activity against Mycobacterium bovis Bacille Calmette Guérin without displaying cytotoxicity against a panel of mammalian cells. Here, we report the synthesis and antimycobacterial activity of 36 new synthetic wollamides, collated with all known synthetic and natural wollamides, to reveal structure characteristics responsible for in vitro growth-inhibitory activity against Mycobacterium tuberculosis (H37Rv, H37Ra, CDC1551, HN878, and HN353). The most potent antimycobacterial wollamides were those where residue VI d-Orn (wollamide B) was replaced by d-Arg (wollamide B1) or d-Lys (wollamide B2), with all activity being lost when residue VI was replaced by Gly, l-Arg, or l-Lys (wollamide B3). Substitution of other amino acid residues mainly reduced or ablated antimycobacterial activity. Significantly, whereas wollamide B2 was the most potent in restricting M. tuberculosis in vitro, wollamide B1 restricted M. tuberculosis intracellular burden in infected macrophages. Wollamide B1 synergized with pretomanid (PA-824) in inhibiting M. tuberculosis in vitro growth but did not antagonize prominent first- and second-line tuberculosis antibiotics. Furthermore, wollamide B1 exerted bactericidal activity against nonreplicating M. tuberculosis and impaired growth of multidrug- and extensively drug-resistant clinical isolates. In vivo pharmacokinetic profiles for wollamide B1 in rats and mice encourage further optimization of the wollamide pharmacophore for in vivo bioavailability. Collectively, these observations highlight the potential of the wollamide antimycobacterial pharmacophore.


Author(s):  
Kpatcha E. Poro Yao Hoekou ◽  
Passimna Pissang Iwaba Kpabi ◽  
Kosi M. Novidzro Anoumou Y. Dagnra ◽  
Tchadjobo Tchacondo Komlan Batawila

2021 ◽  
Author(s):  
Balaji Muralikrishnan ◽  
Lekshmi K Edison ◽  
Azger Dusthackeer ◽  
Jijimole Gopi Reji ◽  
Ranjit Ramachandran ◽  
...  

Novel anti-tuberculosis drugs are essential to manage drug resistant tuberculosis, caused by the notorious pathogen Mycobacterium tuberculosis. We recently reported the antimycobacterial activity of chrysomycin A in vitro and in infected macrophages. In this study, we report that the molecule inhibits the growth of drug resistant clinical strains of Mycobacterium tuberculosis and acts in synergy with anti-TB drugs such as ethambutol, ciprofloxacin and novobiocin. In pursuit of its mechanism of action, it was found that chrysomycin A renders bactericidal activity by interacting with DNA at specific sequences and by inhibiting topoisomerase I activity of Mycobacterium tuberculosis. It also exhibits weak inhibition of gyrase enzyme of the pathogen.


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