The Chinese plant, Artemisia annua, which is being grown in commercial quantities in Nigeria, has joined the league of plant validated for the treatment of TB and multi-drug resistant TB (MDR TB).
The drug-of-choice for malaria and the World Health Organization (WHO)-recommended drug, Artemisinin-based Combination Therapy (ACT), is derived from this plant. According to a new study published in the journal Nature Chemical Biology, the plant has been found to potentially aid in the treatment of tuberculosis and may slow the evolution of drug resistance.
In a promising study led by Robert Abramovitch, a Michigan State University, United States (U.S.), microbiologist and TB expert, the ancient remedy artemisinin stopped the ability of TB-causing bacteria, known as Mycobacterium tuberculosis, to become dormant. This stage of the disease often makes the use of antibiotics ineffective.
Abramovitch, an assistant professor in the College of Veterinary Medicine, said: “When TB bacteria are dormant, they become highly tolerant to antibiotics. Blocking dormancy makes the TB bacteria more sensitive to these drugs and could shorten treatment times.”
Mycobacterium tuberculosis, or Mtb, needs oxygen to thrive in the body. The immune system starves this bacterium of oxygen to control the infection. Abramovitch and his team found that artemisinin attacks a molecule called heme, which is found in the Mtb oxygen sensor. By disrupting this sensor and essentially turning it off, the artemisinin stopped the disease’s ability to sense how much oxygen it was getting.
Also, new research published in Respirology indicates that curcumin – a substance in turmeric that is best known as one of the main components of curry powder – may help fight drug-resistant tuberculosis.
Turmeric is a spice that comes from the root of Curcuma longa, a member of the ginger family, Zingaberaceae. In traditional medicine, turmeric has been used for its medicinal properties for various indications and through different routes of administration, including topically, orally, and by inhalation.
In Nigeria, it is called atale pupa in Yoruba; gangamau in Hausa; nwandumo in Ebonyi; ohu boboch in Enugu (Nkanu East); gigir in Tiv; magina in Kaduna; turi in Niger State; onjonigho in Cross River (Meo tribe).
Turmeric, also known as curcuma, produces a root that is used to produce the vibrant yellow spice used as a culinary spice so often used in curry dishes. Though native to India and parts of Asia, and is a relative of cardamom and ginger, turmeric has been domesticated in Nigeria. In Asia, turmeric is used to treat many health conditions and it has anti-inflammatory, antioxidant, and perhaps even anticancer properties.
Investigators found that by stimulating human immune cells called macrophages, curcumin was able to successfully remove Mycobacterium tuberculosis from experimentally infected cells in culture. The process relied on inhibiting the activation of a cellular molecule called nuclear factor-kappa B.
According to a study published in African Journal of Biotechnology, Adeleye and co-workers evaluated the ethanolic and aqueous extracts of 12 Nigerian medicinal plants for anti-mycobacterial activity. The study revealed that four of the plant extracts: Allium cepa (onions), Allium ascalonicum (shallots), Terminalia glaucescens and Securidaca longepedunculata) showed activity on both the culture isolate of M. tuberculosis and the control strain (M. tuberculosis) at 0.05 mg/mL. Mann et al. (2008) evaluated some Nigerian medicinal plants for anti-mycobacterial activity and found four plants giving anti-mycobacterial activity at ≤1250 μg/mL. These plants were Anogeissus leiocarpus, Terminalia avicennoides, Combretum spp. and Capparis brassii.
In another related study, eighty-six Nigerian plant based ethnomedicinal remedies were screened for anti-mycobacterial activity. Sixty nine percent of the extracts showed anti-tuberculosis activity in vitro, with 22 per cent revealing activity at < 500 μg/mL. Some of the plants, which showed promising activity, were Ficus sur, Pavetta crassipes, Combretum molle, Waltheria indica and Crotolaria lachnosema, Anogiessus leiocarpus, Calliandra portoricensis, Cassia sieberiana, Abrus precatorius and Cussonia arborea.
Source: The Tribune