piperine and Malaria

Insecticide resistance carries the potential to undermine the efficacy of insecticide based malaria vector control strategies. Therefore, there is an urgent need for new insecticidal compounds. Black pepper (dried fruit from the vine, Piper nigrum), used as a food additive and spice, and its principal alkaloid piperine, have previously been shown to have larvicidal properties. The aim of this study was to investigate the larvicidal effects of ground black pepper and piperine against third and fourth instar Anopheles larvae drawn from several laboratory-reared insecticide resistant and susceptible strains of Anopheles arabiensis, An. coluzzii, An. gambiae, An. quadriannulatus and An. funestus.. Larvae were fed with mixtures of standard larval food and either ground black pepper or piperine in different proportions. Mortality was recorded 24 h after black pepper and 48 h after piperine were applied to the larval bowls.. Black pepper and piperine mixtures caused high mortality in the An. gambiae complex strains, with black pepper proving significantly more toxic than piperine. The An. funestus strains were substantially less sensitive to black pepper and piperine which may reflect a marked difference in the feeding habits of this species compared to that of the Gambiae complex or a difference in food metabolism as a consequence of differences in breeding habitat between species.. Insecticide resistant and susceptible strains by species proved equally susceptible to black pepper and piperine. It is concluded that black pepper shows potential as a larvicide for the control of certain malaria vector species.

Topics: Alkaloids; Animals; Anopheles; Benzodioxoles; Insecticide Resistance; Insecticides; Larva; Malaria; Piper nigrum; Piperidines; Polyunsaturated Alkamides

Recent studies have proposed curcumin as a potential partner for artemisinin in artemisinin combination therapies to treat malaria infections. The efficacy of curcumin alone and in combination with artemisinin was evaluated on a clone of Plasmodium chabaudi selected for artemisinin resistance in vivo. The addition of piperine as an enhancer of curcumin activity was also tested. Results indicated that curcumin, both alone and in combination with piperine had only a modest antimalarial effect and was not able to reverse the artemisinin-resistant phenotype or significantly affect growth of the tested clone when used in combination with artemisinin. This is in contrast with previous in vivo work and calls for further experimental evaluation of the antimalarial potential of curcumin.

Topics: Administration, Oral; Alkaloids; Animals; Anti-Infective Agents; Artemisinins; Benzodioxoles; Biological Availability; Curcumin; Drug Resistance; Drug Therapy, Combination; Malaria; Male; Mice; Parasitemia; Piperidines; Plasmodium chabaudi; Polyunsaturated Alkamides

Human red cells infected in vitro with Plasmodium falciparum showed a significant increase in the rate of both ouabain-sensitive and ouabain-insensitive 86Rb+ influx. The increase in ouabain-insensitive 86Rb+ influx was due, in part, to increased transport via a bumetanide-sensitive system and, in part to transport via a pathway that was absent (or at least inactive) in uninfected cells. The parasite-induced pathway was inhibited by piperine and had a dose response very similar to that of the Gardos channel of uninfected cells but was less sensitive than the Gardos channel to inhibition by quinine.

Topics: Alkaloids; Animals; Benzodioxoles; Biological Transport; Bumetanide; Dose-Response Relationship, Drug; Erythrocytes; Humans; In Vitro Techniques; Malaria; Ouabain; Piperidines; Polyunsaturated Alkamides; Potassium; Quinine; Rubidium Radioisotopes