Human head louse (Pediculus humanus capitis) : controlling with herbal shampoo and oil

Abstract

This study examined the effectiveness of various plant extracts in killing head lice (Pediculus humanus capitis) at different life stages. Extracts from Curcuma xanthorrhiza (nanwinga), Garcinia cowa (cowa), Passiflora laurifolia (passiflora fruit), Salacca wallichiana (salacca), Schleichera oleosa (ceylon oak), and Zingiber cassumunar (phlai) were tested. These plants were extracted with 95% ethyl alcohol and formulated into oil and shampoo. The results showed that combining oils was more effective than using single oils. After a 5-min immersion test with 5% C. xanthorrhiza oil + 5% Z. cassumunar oil (1:1 ratio), the formulation had a strong ovicidal activity, inhibiting 95.3% of lice eggs with an LT₅₀ of 3.5 days. Other oils had inhibition rates between 66.7% and 93.3%, with LT₅₀ values ranging from 4.5 to 11.4 days. Ten percent P. laurifolia shampoo was the most effective, killing 100% of both nymphs and adults within 30 min. The average time to kill half of the nymphs (LT₅₀) was 0.4 min, and for adults, it was 0.5 min. Other shampoos had mortality rates between 76.0% and 100%, with LT₅₀ values from 0.9 to 3.1 min. Carbaryl shampoo had a mortality rate of 73.3% to 96% for all stages of head lice. In conclusion, an effective lice treatment is to use C. xanthorrhiza oil + Z. cassumunar oil in combination with P. laurifolia shampoo. Not only that this combination very effective, it is also safe for humans and the environment.