In vitro Anti-mycobacterial activity of selected medicinal plants against Mycobacterium tuberculosis and Mycobacterium bovis Strains

Abstract

BackgroundTuberculosis (TB) is a global burden with one –third of the world’s population infected with the pathogen Mycobacterium tuberculosis complex and annually 1.4 million deaths occur due to the disease. This high incidence of infection and the increased rate of multi-drug resistant and extensively-drug resistant strains of the organism further complicated the problem of TB control and have called for an urgent need to develop new anti-TB drugs from plants. In this study, the in vitro activity of root of Calpurnia aurea, seeds of Ocimum basilicum, leaves of Artemisia abyssinica, Croton macrostachyus, and Eucalyptus camaldulensis were evaluated against M. tuberculosis and M. bovis strains.MethodsFive Ethiopian medicinal plants, root of Calpurnia aurea, seeds of Ocimum basilicum, leaves of Artemisia abyssinica, Croton macrostachyus, and Eucalyptus camaldulensis used locally for the management of TB. They were investigated for in vitro antimycobacterial activity against M. tuberculosis and M. bovis strains. 80% methanolic extracts of the plant materials were obtained by maceration. The antimycobacterial activity was determined using 96 wells of microplate with the help of visual Resazurin Microtiter Assay.ResultsThe crude 80% methanolic extracts of the root of C. aurea, seeds of O. basilicum, and leaves of A. abyssinica, C. macrostachyus, and E. camaldulensis had anti-mycobacterial activity with minimum inhibitory concentration (MIC) ranging from 6.25–100 μg/mL. The MIC of 80% methanol extracts in the order mentioned above ranged 25-100 μg/ml and 12.5-75 μg/mL, 25–100 μg/mL and 25–50 μg/mL, 6.25-50 μg/mL and 12.5-50 μg/mL, 12.5-100 μg/mL and 18.25-50 μg/mL and 6.25-50 μg/mL and 12.5-50 μg/mL, respectively for M. tuberculosis and M. bovis strains.ConclusionsThe results support the local use of these plants in the treatment of TB and it is suggested that these plants may have therapeutic value in the treatment of TB. However, further investigations are needed on isolating chemical constituents responsible for eliciting the observed activity in these plants.

Antibacterial activity of Lamiaceae plant extracts in clinical isolates of multidrug-resistant bacteria

“…Gemechu et al (2013) tested the methanol extract of Ocimum basilicum against Mycobacterium tuberculosis and M. bovis.…”

Antimycobacterial activity of medicinal plants used by the Mayo people of Sonora, Mexico

“…Bañuelos (1999) Salinas et al, 2007), Convolvulus arvensis L. (Gautam et al, 2007;Grange and Davey, 1990;Tosun et al, 2005), Eucalyptus camaldulensis Dehnh. (Gemechu et al, 2013;Lawal et al, 2011;Lawal et al, 2012;Leite et al, 1998;Moreira et al, 1997;Newton et al, 2000), Ficus carica (Tosun et al, 2005), Karwinskia humboldtiana (Schult.) Zucc.…”

Metabolites from endophytic Aspergillus fumigatus and their in vitro effect against the causal agent of tuberculosis

“…The high level of mortality is mainly due to the emergence of multidrugresistant strains, coupled with inadequate use of antibiotics, such as inappropriate choices, inadequate dosing, poor adherence to treatment guidelines and self-medication, which makes this disease a major concern of the World Health Organization (WHO) (Petrini and Hoffner 1999;Prestinaci et al 2015). With the emergence of drug-resistant strains of M. tuberculosis, and the necessarylong-term treatment that is detrimental to a patient's health due to the high levels of drug toxicity and various adverse effects, it has become of critical importance to search for new effective anti-M. tuberculosis agents (Gemechu et al 2013). Antimicrobial resistance (AMR) is a major public health problem that undermines the effective prevention and treatment of an ever-increasing range of infections caused by pathogens, such as bacteria, which are no longer susceptible to common antibiotics (Prestinaci et al 2015).…”