Tropical Health Matters

May 31st marks World No Tobacco Day. The Theme for 2017 is “Tobacco – a threat to development.” According to WHO, “Tobacco control has been enshrined in the Sustainable Development Agenda. It is seen as one of the most effective means to help achieve SDG target 3.4 of a one-third reduction globally, by 2030, of premature deaths from  noncommunicable diseases (NCDs).” Control is also associated with positive environmental and anti-poverty outcomes.

It is ironic then that the tobacco plant itself may be modified to produce life saving anti-malarial medicines. Nature reported that because Artemisia annua produces a precursor of the compound, artemisinic acid, only in low quantities, it is expensive to grow.  Consequently, “a team led by Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam-Golm, Germany, inserted genes for artemisinic acid synthesis into tobacco plants’ chloroplasts — abundant organelles that have their own DNA. By adding ‘accessory genes’ that make artemisinic acid production more efficient, they created a line that pumps out 120 milligrams of artemisinic acid per kilogram of biomass.”

Science magazine followed up to report that although “several years ago researchers transplanted the drugmaking genes into yeast, allowing them to collect the compound from a microbial brew, the fermentation process is still relatively expensive.” Tobacco, on the other hand, is an “inexpensive, high-volume crop.” Inserting the right genes into tobacco, they noted, would enable “harvesting artemisinic acid from a plot of land 200 square kilometers—less area than a city the size of Boston—would provide enough artemisinin to meet the entire worldwide demand.”

Malhotra et al. discovered another novel approach that found that, “Partially purified extracts from the leaves of transgenic tobacco plants inhibited in vitro growth progression of Plasmodium falciparum-infected red blood cells. Oral feeding of whole intact plant cells bioencapsulating the artemisinin reduced the parasitemia levels in challenged mice in comparison with commercial drug. Such novel synergistic approaches should facilitate low-cost production and delivery of artemisinin and other drugs through metabolic engineering of edible plants.”

Another approach looks at malaria vaccines. Beiss et al. note that malaria “transmission blocking vaccine (TBVs) need to be produced in large quantities at low cost.” They found a high level  transient expression in fresh leaves of Nicotiana benthamiana of an effective TBV candidate. Likewise Jones et al. demonstrated the potential of the new malaria vaccine candidate and also support feasibility of expressing Plasmodium antigens in Nicotiana benthamiana.

The American Cancer Society observed that most African Countries are in the early stages of the tobacco epidemic. This may be a good time to switch the production of tobacco on the continent from purveyor of cancer and NCDs to a ‘factory’ for producing malaria medicines. The sooner this can be done, the better since artemisinin  resistance is a growing threat.

Trackback This Post | Subscribe to the comments through RSS Feed