شناسایی ترکیبات شیمیایی و ارزیابی اثر دورکنندگی اسانس گیاه Juniperus Virginiana علیه آنوفل استفنسی (دوبالان: کولیسیده)

With approximately 200 million new cases and 500000 deaths annually and despite many efforts to control, eliminate and eventually eradicate, malaria yet remains one of the most serious diseases in the world. There are different methods for malaria control such as the prevention by drugs, insecticides and repellents. But, the emergence of parasite resistance to anti-malarial medicines and mosquito resistance to insecticides was caused to failure control programs. Personal protective measures, like the use of insect repellents reduce the contact between humans and vectors and consequently prevent vector-borne diseases. Due to resistant to old repellents and their toxic and environmental problems, natural repellents as novel, safe and innovative vector-control tools can be replaced them, especially with botanical origin. The purpose of this study is the achievement to a natural repellent. Based on search in the books of Iranian traditional medicine and other scientific resources, Juniperus Virginiana (Cupressaceae family) from Alborz province was selected and evaluated its repellent activity against Anopheles stephensi. The fresh aerial parts were collected, the essential oil was obtained by hydrodistillation in a Clevenger-type apparatus and the chemical compositions were detected by gas chromatography - mass spectrometry. Then, a new device for mosquito behavior surveillance was used to evaluate the repellent effect of essential oil under laboratory condition. For test, a restrained guinea pig was covered with essential oil (J. virginiana) treated net and placed into the device. Then, twenty 4-7- day old non-blood fed females An. stephensi were release into the device. Blood fed, live and dead mosquitoes were collected and counted 45 minutes after post treatment and % protection was reported. The pure essential oil presented complete protection (%100) for the host, compared to the control group. Meanwhile, 45% of mosquitoes were killed and remaining 55% did not eat the blood. When, voracious mosquitoes were connected to the impressed net, they were killed, which prove high insecticide activity of J. virginiana essential oil in addition to its repellent activity. The most important identified compounds in the essential oil were pinene, cedrol and Terpineol, which the essential oil activity can be attributed to these. According to the results, J. virginiana essential oil showed the remarkable repellent and insecticide effects on Anopheles stephensi, which can be introduced as a low-cost and friendly natural product for the mosquito control.