Repellent activity of essential oils from Andean species of San Juan against Triatoma infestans

LÓPEZ SB, ZYGADLO JA, ARAGÓN LM, FERESIN GE1,TAPIA A, LÓPEZ ML

San Luis

Congreso; XXVII Congreso Anual de la Sociedad de Biología de Cuyo; 2009

Sociedad de Biología de Cuyo

Chagas disease is a major public health concern in Argentina with near three millions infected people. Essential oils from (EO) Azorella cryptantha and Gymnophyton polycephalum were assayed in vitro for their repellent activity against nymphs of T infestans, the vector of Chagas disease. Fresh aerial parts were hydrodistilled to obtain the EO in a Clevenger type apparatus. EO were evaluated at 1, 24 and 72 hours of treatment. Chemical composition was carried out by Gas Chromatography-Mass Spectrometry (GC-MS). The Percent Repellency (PR) was determined according to a standard method. Sixteen components were identified in the EO of G. polycephalum, representing 96.74 % of the oil and 31 components for A. cryptantha, representing 89.06 % of the oil. Main components in the EO from G. polycephalum were camphene, (E)-β-ocimene and α-phellandrene. The mean repellency was 100 % for A. cryptantha oil and 86.7% for G. polycephalum oil, both cases were classified into the highest repellent class (class V).  The results provide evidence that Andean species should be sheltered due to the bioactivity of the EO to alleviate local problems as Chagas´ disease. We are grateful to CICITCA UNSJ and to Servicio Nacional de Chagas, Córdoba for providing the insects.