Although resistance is increasing at an exponential rate, synthetic pyrethroids remain the only recommended insecticides for mosquito nets. One may wonder what the reasons behind this monopoly are : incompetence or business ?
Pierre Lutgen's blog
After some important research work had been done some 30 years ago on amino acids, the impact these molecules might have on a vast array of diseases has been neglected. But there is increasing evidence that the amino acid proline plays an important role in the virulence mechanism of human and mammalian pathogens.
As most of the people suffering from malaria are living in French speaking countries we post also a French version
Les plantes de la grande famille des armoises sont utilisées comme herbes médicinales depuis des millénaires dans toutes les régions du monde.
L’Artemisia annua est venue sous les feux de la rampe lors de la guerre du Vietnam.
The large family of Artemisia plants have been used as herbal medicine for millenniums in all regions of the world.
Amino-acids in Artemisia annua have barely been studied. The analytical data published by EA Brisibe and J Ferreira date back to 2009 (Food Chemistry, 2009, 115, 1240-1246). Their role in malaria infections has been ignored, except for a study published in Japan (DT Uyen et al., Biol Pharm Bull. 2008, 31, 1483-1488). To gain insight into the mechanism of malarial haemozoin formation, they examined the effects of amino acids on beta hematin formation in vitro. Surprisingly some of these amino acids like arginine, histidine, lysine showed a significant inhibition.
Luteolin (3′,4′,5′,7′-tetrahydroxyflavone) is a widespread flavonoid aglycon structurally related to quercetin. The ethnobotanical use of this flavone includes applications in the treatment of cough, diarrhea, dysentery, diabetes, cancer and malaria.
Moringa oleifera is called the „miracle tree“, and has a strong reputation for curing many diseases, but it is impossible to find any peer reviewed paper on PubMed which describes antimarial properties for this plant. This probably does not exclude the presence in the plant of a few molecules which could demonstrate antiplasmodial properties in vitro.
Dry leaves of the plant do not inhibit beta-hematin (G Mergeai, personal communication) in the assay which is often used to screen for antimalarials.
On October 23 , 2014 WHO issued a recommandation (www.who.int/elena/titles/zinc_diarrhoea) stating that mothers, other caregivers and health workers should provide children with 20 mg per day of zinc supplementation for 10-14 days (10 mg per day for infants under the age of six months).
Mosquitoes are progressively becoming resistant to industrial repellents and insecticides. This is the case for pyrethroids used on bednets.
Most of these products are expensive and African households cannot afford their purchase.
Plants, their extracts and their essential oils have been used during centuries to fight aggressive mosquitoes responsible for malaria, dengue, sleeping sickness but also insects acting as vectors for many other diseases.
Most research work on Artemisia annua has ignored saponins and polysaccharides because these are only soluble in water and in the search of the golden fleece or the exceptional antimalarial molecule most extracts are obtained with organic solvents.
Saponins are found in many plants, often in desert plants and are also present in some marine organisms. Most medicinal plants are rich in saponins, which to a large extent are responsible for their bitterness. In fact saponins protect plants from phytopathogenic microorganisms, phytophagous mammalian and insects.