Identification of Extracts Responsible for the Effect of Tick Reppeling Activity of Turmeric

Turmeric (Curcuma longa L.) is one of the essential condiments all over the world. Turmeric is an important medicine in the eastern medical systems and its therapeutic properties have been well recorded. Curcumin, commonly called diferuloyl methane (hydrophobic polyphenol), was studied extensively for its biological properties. Sri Lankan turmeric records relatively higher percentage (up to 9%) of curcumin. The bioactive compounds with insecticidal or pesticidal activity were studied from the Sri Lankan turmeric as there is an increasing demand for natural products to control ticks and fleas in dogs against the chemicals that induce some secondary effects. Fifty grams (50 g) of dried coarsely ground turmeric (Curcuma longa L.) was subjected to sequential extractions with four different solvents in ascending order of polarity using Soxhlet apparatus. The treatments consisted of solvent-fractionated turmeric extracts from hexane, dichloromethane (CH2Cl2), ethyl acetate (EtOAc) and Methanol (CH3OH) dissolved in the water to 100 ppm. The test carried out using a modified olfactometer and the degree of repellency of common tick species Rhipicephalus sanguineus was recorded. The hexane extract from dried turmeric powder showed the highest repellence of 80% whereas other fractions showed lesser repellence. Further studies in the direction of purification, dose dependent repellency and persistency.