Active anti-head lice component from custard apple seed

Seeds of custard apple (Annona squamosa Linn., Annonaceae) have been used for anti-head lice for a long time. In Thailand, the petroleum ether seed extract prepared as a cream preparation was reported to kill 93% of head lice within 3 hours [1]. Twenty grams of the 20% w/w freshly prepared cream can kill 94.5±9.1% of head lice within 3 hours when applied to school girls and the cream is biologically stable for at least 12 months [2, 3]. There have been no reports on chemically active anti-head lice component of this plant. The present study is focused on the separation and identification of the active compound from the hexane extract of the seeds of custard apple. Chromatographic and spectroscopic techniques revealed that a major component of the hexane seed extract was a triglyceride with one oleate ester (with 2 unknown acyl moieties). The separated pure triglyceride and the crude hexane extract which were separately diluted with coconut oil (1:1), contained 22.25 and 11.49mg of the triglyceride, respectively were tested in vitro for anti-head lice activity and found that they could kill all tested head lice within 11 and 30 minutes, respectively. The triglyceride with one oleate ester was the active compound against human head lice. It could be used as a marker for quality control and standardization of custard apple seeds, the extracts and anti-head lice preparations from the seeds of this plant.

References: 1. Areekul, M., Chaikledkaew, U. (1944), Antiparasitic cream from Annona squamosa Linn. A special project submitted in partial fulfillment of the requirement for the degree of Bachelor of Science in Pharmacy. Mahidol University. Bangkok. 2. Gritsanapan, W. et al. (1998), Studies of stability and effectiveness of intensive hair masks from Annona squamosa seed extract. 50^th IPC and 17^th FAPA Congress, Mumbai, India. 3. Tiangda, CH. et al. (2000), Southeast Asian J. Trop. Med. Public Health 31 (Suppl 1): 174–7.