Bioactivity guided isolation of mosquito larvicide from Piper longum

Objective:To isolate the larvicidal component from the fruits of Piper longum（P.longum） against the filariasis vector,Culex quinquefasciatus（C.quinquefasciatus）.Methods:Pulverized fruits of P.longum were subjected to soxhlet extraction using series of organic solvents of increasing polarity.All the solvent extracts were verified for their larvicidal efficacy against 4th instar larvae of C.quinquefasciatus employing standard WHO procedure.Bioassayguided fractionation through column chromatography lead to the isolation of a bioactive amide, pipyahyine from the petroleum ether extract.Results:Petroleum ether extract was found to be the most active fraction among all the extracts tested with LC50 and LC90 being 1.03 and 2.04 ppm respectively.Whereas,pipyahyine,an isolated component of the same fraction was found to be even more effective than the parent extract in terms of LC50 being 0.58 and 1.88 ppm respectively. Conclusions:From the results,it is evident that P.longum can be considered as a powerful arsenal for the control of mosquito population.

Molecular detection of Leishmania species in human and animals from cutaneous leishmaniasis endemic areas of Waziristan, Khyber Pakhtunkhwa, Pakistan

Objectives: To detect Leishmania species in human patients, animal reservoirs and Phlebotomus sandflies in Waziristan, Pakistan. Methods: Tissue smears and aspirates from 448 cutaneous leishmaniasis(CL) suspected patients were analyzed. To sort out role of the reservoir hosts, skin scrapings, spleen and liver samples from 104 rodents were collected. Furthermore, buffy coat samples were obtained from 60 domestic animals. Sandflies were also trapped. All human, animals and sandfly samples were tested by microscopy, kinetoplastic PCR and internal transcribed spacer 1(ITS1) PCR followed by restriction fragment length polymorphism for detection of Leishmania species. Results: An overall prevalence of 3.83% and 5.21% through microscopy and ITS1 PCR respectively was found. However, the statistically non-significant correlation was found between area, gender, and number of lesions. The presence of rodents, sandflies, domestic animals and internally displaced people increased the risk of CL. Using ITS1-PCR-RFLP, Leishmania tropica(L. tropica) was confirmed in 106 samples while 25 of the isolates were diagnosed as Leishmania major(L. major). Similarly, 3/104 rodents were positive for L. major and 14 pools of DNA samples containing Phlebotomus sergenti sandflies were positive for L. tropica. None of samples from domestic animals were positive for leishmaniasis. Conclusions: In the present study, L. tropica and L. major are found to be the main causative agents of CL in study area. Movement of internally displaced people from CL endemic areas presents a risk for nearby CL free areas. To the best of our knowledge, we report for the first time L. major infection in rodents(Rattus rattus) and L. tropica in Phlebotomus sergenti sandflies trapped in Waziristan, Pakistan.