Reply to: Applications and limitations of Centers for Disease Control and Prevention miniature light traps for measuring biting densities of African malaria vector populations: a pooled-analysis of 13 comparisons with human landing catches
With great respect, we found that out nearly 30 years ago see Jonathan Davis paper of 1995 Davis et al Med Vet Emtomol.9 249-255. Nice to know the work was validated!
Reply to: Malaria, anaemia and nutritional status among schoolchildren in relation to ecosystems, livelihoods and health systems in Kilosa District in central Tanzania
This is a valuable analysis of the increased malaria risk in areas with rice irrigation. It should suggest to the folks who plan malaria suppression in RBM and the US PMI that they ought to pay special attention to areas with irrigation. And they might also investigate improved irrigation (and drainage) as a supplement to their usual drugs and biocides.
Reply to: Cost & feasibility of mosquito control with larviciding and environmental engineering in an urban area
Besides the wealth of data you refer to Rune on larviciding in urban areas all over the world, there has also been a recent demonstration of the efficacy and low cost of community-based larviciding in East Africa against malaria (Maheu-Giroux M, Castro MC. Malaria J. 2014 Dec 4:13:477. doi: 10.1186/1475-2875-13-477.)
Of course successful larviciding has been used in the semi-tropics against malaria for over 60 years (TVA 1947 Malaria control in impounded waters, USGPO). as well as Soper's famous campaign against An gambiae in Brazil.
Reply to: Is Moringa bad for malaria ?
The blog of Dr Mutaz Akkawi and Dr Pierre Lutgen opens the door for more questions.
Considering the avalanche of claims posted on internet, the support of severals associations (UNICEF, Anamed, Church World Service, Peace Corps…) and the huge market developing around creams and powders based on Moringa oleifera, several research groups have launched in-depth studies on these claims. The result is often frustrating, sometimes frightening. Except for a few peer-reviewed studies confirming the water purification properties of grinded Moringa oleifera seeds no scientific proof has been established for the numerous auto-proclaimed health benefits of this plant.
Moringa oleifera leaves contain important phytochemicals, such as gallic tannins, catechol tannins, steroids and triterponoids, flavonoids, saponins, anthraquinones, alkaloids and reducing sugars. It also contains proteins, vitamins, beta-carotene and amino acids. When taken in large quantities they can cause adverse effects in rats. Many families worldwide consume the leaves over varying periods of time, without knowing the possibility of causing organ toxicity.
Assays made in Uganda showed that Moringa oleifera leaves aqueous extract given to rats orally in a single dose of LD50 for 30 days was associated with mild organ toxicity (JN Kasolo et al., Int J Plant Res., 2012, 1-6, 75-81). A study from Nigeria showed that albino rats had observable lesions in several organs (AA Ambi et al., Int J Pharmaceut Res and Innovat. 2011,4, 22-24). The authors conclude that indiscriminate consumption of the leaves of Moringa oleifera as both food and medicine is not safe for a long period of time. The aqueous seed extract after water purification affects the bile canaculi around the portal vein of the liver and this leads to a significant increase of the enzymes ALT, AST ALP and ACP in serum (A Oludoro et al., Afr J Microb Res. 2009, 3, 537-540). High dose treatment increases bilirubin increase which suggests that the extract which may predispose to jaundice (O Akwari et al., Inter J Of Pharma sciences and Research, 2015, 6 777-82). Another study showed that leaves and seeds contained toxic substances extractable with organic solvents. But a significant depletion in ATP and GSH only occurred at high concentrations (N Mekonnen et al., Phytother Res. 2005, 19-10, 870-75). Moringa oleifera contains glucosinolates which have shown toxicity at high consumption in animal feed. (M.K.Tripathi, A.S.Mishra, Animal Feed Science and Technology, vol. 132, 2007, p. 1-27). Moringa oleifera is genotoxic at supra-supplementation levels (GA Asare et al. J Ethopharmacol 2012 139 265-272).
Several authors studied the impact on blood parameters and found that Moringa oleifera only raised the white blood cell count (AL Asomugha et al., Int J Biomed and Adv Res., 2015, 6, 98-102). Contrary to the hypothesis of the book “Moringa oleifera: the miracle tree”, daily consumption of Moringa oleifera dried leaf powder did not improve iron status and ferritin level in lactating women (N Idohou-Dossou et al. Afr J Food, Agric, Nutrition and Debvelpment, 2011, 11, 4985-90).
The main claim is that this is the plant on our planet with the highest concentration of nutrients of all kinds. So it would be ideal against malnutrition. Some trials had already been run in 1969 on the interaction between, methionine, choline and fat in young rats in respect to weight gain. There are strong interactions, leading in some cases to weight losses (GS Percival et al., 1969, J Nutrition 100, 664-670). A more recent study on broiler chicken confirms these results, including Moringa oleifera leaf powder in a cassava based diet. It was found that above 5% Moringa oleifera powder decreased the weight gain. It is thus not strange to find on the American markets Moringa extracts claiming that choline burns fat and reduces weight. In South Africa it is sold with the claim to cause weight loss as it’s been found to slow the rate at which sugar is released into the bloodstream.
Fresh Moringa oleifera leaves are very rich in Vitamin C, 7 times more than orange juice. The malaria belt of the world (tropical regions) with rich sources of vitamin C constitutes malaria endemic zones, where vitamin C rich food such as citrus fruits and green vegetables abound, a mutual relationship between the two appears to exist.
Ascorbic acid affects malaria in several pathways. Ascorbic acid is probably the most effective absorption enhancer of non-haem iron. This may be beneficial against anemia but is detrimental for malaria. Ascorbic acid may increase parasitemia. The uptake of ascorbic acid into erythrocytes is increased as a result of malaria infection (R Stocker et al., Biochim Phyys Acta 1986, 881, 391-7). Vitamin C particularly enhances the development of young parasites (E Marva et al., Trop J Med Parasitol 1992, 43 , 17-23). It appears that the Plasmodium parasite needs vitamin C.
The most disturbing issue is that several papers find an impact of Moringa oleifera on cancer. The plant is rich in amino-acids known as the building blocks of life, some amino acids may also be important for the spread of cancer.
Methionine for example is an essential amino acid with many key roles in mammalian metabolism such as protein synthesis, methylation of DNA and polyamine synthesis. Restriction of methionine may be an important strategy in cancer growth control particularly in cancers that exhibit dependence on methionine for survival and proliferation (P Cavuoto et al., Cancer Treat Rev. 2012, 38, 726-36). It was found that leucine supplementation differentially enhances pancreatic cancer growth in lean and overweight mice (Kristyn A Liu,#1 et al Cancer Metab 2014, 2 :6 doi: 10.1186/2049-3002-2-6). Another study targeted arginine metabolism pathway to treat arginine-dependent cancers. (Qiu F, Huang J, Cancer Lett. 2015 Aug 1;364(1):1-7. doi: 10.1016). Arginine is a semi-essential amino acid because normal cells can not only synthesize arginine de novo but also take up extracellular arginine. Several types of tumors have abnormalities in arginine metabolism enzymes and completely rely on extracellular arginine to support necessary biological processes. Arginine deprivation demonstrated promising efficacy against arginine-auxotrophic tumors. AICR researcher Gary Meadows, Ph.D., is investigating how restriction of two essential amino acids, tyrosine and phenylalanine, might help prevent cancer metastasis.
More information, caution and research is needed !
Reply to: In order to progress to global eradication, what's most important?
You are right on Tony, but we know the problem was caused by a certain rich man, who we all admire but who doesn't know beans about malaria, and has too many admirers who are afraid to tell him the truth. And the idea of vaccines and eradication fits into the current fascination with Modern Science and gleaming laboratories, but shows an abysmal lack of understanding of history. Let us pray that before the whole effort comes crashing down, someone will become aware - as Mark Hoppe says - that malaria is an ecological disease, and to suppress it we need to take a holistic and ecological approach. Someday.