ABSTRACT
The effect of water extract of Gynostemma pentaphyllum was evaluated on 6-month chronic toxicity in Wistar rats. Control group received orally 10 ml kg(-1) day(-1). The extract was orally given to the five treatment groups at the doses of 6, 30, 150, 750 and 750 mg kg(-1) day(-1) for 24 weeks. The last group served as the recovery group. The results showed that the extract did not produce any significant dose-related changes. Therefore, it is concluded that the extract of G. pentaphyllum at the given doses did not produce any significant toxic effect in rats during 6-month period of the treatment.
Subject(s)
Gynostemma , Phytotherapy , Plant Extracts/toxicity , Administration, Oral , Animals , Blood Chemical Analysis , Body Weight , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Male , Organ Size , Plant Components, Aerial , Plant Extracts/administration & dosage , Rats , Rats, WistarABSTRACT
Volatile oils extracted by steam distillation from four plant species (turmeric (Curcuma longa), kaffir lime (Citrus hystrix), citronella grass (Cymbopogon winterianus) and hairy basil (Ocimum americanum)), were evaluated in mosquito cages and in a large room for their repellency effects against three mosquito vectors, Aedes aegypti, Anopheles dirus and Culex quinquefasciatus. The oils from turmeric, citronella grass and hairy basil, especially with the addition of 5% vanillin, repelled the three species under cage conditions for up to eight hours. The oil from kaffir lime alone, as well as with 5% vanillin added, was effective for up to three hours. With regard to the standard repellent, deet alone provided protection for at least eight hours against Ae. aegypti and Cx. quinquefasciatus, but for six hours against An. dirus. However, deet with the addition of 5% vanillin gave protection against the three mosquito species for at least eight hours. The results of large room evaluations confirmed the responses for each repellent treatment obtained under cage conditions. This study demonstrates the potential of volatile oils extracted from turmeric, citronella grass and hairy basil as topical repellents against both day- and night-biting mosquitoes. The three volatile oils can be formulated with vanillin as mosquito repellents in various forms to replace deet (N,N-diethyl-3-methylbenzamide), the most common chemical repellent currently available.
