Biological activities of four essential oils against Anopheles gambiae in Burkina Faso and their in vitro inhibition of acetylcholinesterase

The control of malaria is still a challenge partly due to mosquito’s resistance to current available insecticides. The aim of this work was to evaluate the ovicidal, larvicidal and repellent activities of Lantana camara, Hyptis suaveolens, Hyptis spicigera and Ocimum canum essential oils against  Anopheles gambiae s.l.  according to the World Health Organization standard method. The in vitro acetylcholinesterase inhibition activity of these oils was also evaluated. The repellent effect using the method of “separated arms” was evaluated. Lantana camara oil was more effective on both eggs and larvae. The LD50 and LD90 values observed in this oil solution were respectively 53.59 and 170.89 ppm on eggs whereas LD50 and LD90 were 61 and 125 ppm respectively on larvae. All oils exhibited repellent activities against adult mosquitoes. The most effective repellent was the oil of Hyptis suaveolens with a 50% efficacy dose value of 67 ppm. The highest  cetylcholinesterase inhibitory activity was observed with O. canum and H. suaveolens essential oils which IC50 was 0.21 and 0.55 μg/ml respectively. Results suggest that these essential oils have a potential for vector control and can be considered as a source of natural and ecofriendly substances for malaria vector control.Keywords: Anopheles gambiae s.l., malaria, essential oil, acetylcholinesterase, insecticidal activity

Antimalarial agents from medicinal plant and fungal sources

Malaria is the fourth major parasitic infectious disease for humans, causing severe symptoms and life-threatening complications, which, if untreated within 24–48 h may evolve in the fatality. In the past five decades, major initiatives in the treatment and prevention of this devastating disease have been implemented in endemic areas, leading to significant progress and declining trends. The majority of the reports presented here are focused on the activity of the extracts and fractions of plant or fungal origin: this approach has its rationale in the observation that crude materials are often more active than isolated compounds, due to the manifestation of beneficial synergistic and additional effects and/or pharmacokinetic/pharmacodynamic interactions. Consideration has been given to the antiplasmodial activities in relation to the different herbal part and nature of extracting solvents and to safety studies; whenever available, phytochemical fingerprint has been reported, disclosing a variety of unique molecular scaffolds with a potential as new pharmacophores. Despite the general lack of mechanistic information for the curative effects of the reported plants and fungi, these studies may undoubtedly pave the way to a new generation of antimalarial agents