Study: Plant Sugars Could Influence Malaria Transmission

A new study revealed that sugar sources of the plant-based part of female Anopheles mosquitoes' diet may affect the transmission of malaria by influencing the host-pathogen interaction between the mosquito and the Plasmodium parasites.

The study, published in the journal PLOS Pathogens, suggests that natural sources of plant sugar could influence the lifespan and blood-feeding rate of female Anopheles, resulting to potential decrease of malaria transmission.

"Our findings add a more direct effect of epidemiological importance by showing that plant-derived sugars can modulate mosquito- Plasmodium interactions," the researchers wrote in a press release.

For the study, the researchers raised groups of Anopheles mosquito in cages and fed them with different kind of sugars. Researchers used plant sugars derived from ornamental flowering plants B. lupilina and T. neriifolia, as well as mangoes and the grape-like fruit from the Lannea microcarpa tree. They also provided one group with 5 percent glucose solution as baseline.

The mosquitoes were then starved for 24 hours before being provided with a diluted Plasmodium-infected blood meal from healthy parasite-infected local human volunteers.

The researchers took about 30 mosquitoes from each group to study under a microscope seven or fourteen days after their blood-meal. They then discovered that the plant sugar source influenced the proportion of the mosquitoes harboring sporozoites and the sporozoites release. Furthermore, different sugar sources had different effects on the infection and survival rates of mosquitoes and survival rates of the parasites seven days after the blood-meal.

The malaria transmission of mosquitoes fed with L. microcarpa and B. lupilina has increased by an estimated 30 and 40 percent respectively, compared to the baseline scenario of 5 percent glucose solution. However, mosquitoes exposed to T. neriifolia were predicted to decrease malaria transmission by 30 percent compared with sugar water, due to its negative effects on infection rate and decreased longevity.

With their findings, researchers recommend planting of anti-Plasmodium plant sugar sources as an alternative strategy to contribute to the control of malaria.