Abstract The essential oils of Ocimum gratissimum Linn, Hyptis suaveolens (L) Poit and Vitex keniensis, which are used traditionally in Western Kenya for personal and space protection against mosquito bites, were screened for repellence against Anopheles gambiae Sensu Stricto. Essential oils were extracted from their leaves by hydrodistillation, characterised by gas chromatography linked with mass spectrophotometer and electroantennogram detectors. The repellency of the oils and their selected blends was studied by the reduction in probing and feeding on the human arm. The oils showed promising repellency for Anopheles gambiae, O. gratissimum (RD50 = 2.77 × 10-5 mg cm-2, 95% CI), Vitex keniensis (RD = 5.68 × 10-5 mg cm-2) and Hyptis suaveolens (6.27× 10-5 mg cm-2) as compared to that of DEET (control) RD = 1.25×10-5 mg cm-2). The bioactive constituents of each oil were identified by Gas chromatography-linked with Mass spectrometry and Electroantennography. Some compounds were confirmed by co-injections of the oil with available authentic standards. The results provide a scientific rationale for the traditional use of these plants in repelling disease vectors and other biting insects, and lay down some useful groundwork for downstream development of more effective products for personal and space protection.

中文翻译：

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在肯尼亚西部使用的精选民族植物精油对冈比亚按蚊 Sensu Stricto 叮咬的排斥性和成分

摘要 筛选 Ocimum gratissimum Linn、Hyptis suaveolens (L) Poit 和 Vitex keniensis 的精油，这些精油在肯尼亚西部传统上用于防止蚊虫叮咬的个人和空间保护，对冈比亚按蚊 Sensu Stricto 的驱避作用进行了筛选。通过水蒸馏从它们的叶子中提取精油，通过与质谱仪和触角电图检测器相连的气相色谱法进行表征。通过减少对人体手臂的探查和进食来研究油及其所选混合物的排斥性。这些油对冈比亚按蚊、O. gratissimum (RD50 = 2.77 × 10-5 mg cm-2, 95% CI)、Vitex keniensis (RD = 5.68 × 10-5 mg cm-2) 和 Hyptis suaveolens (6.27 × 10-5 mg cm-2）与避蚊胺（对照）相比，RD = 1.25 × 10-5 mg cm-2）。每种油的生物活性成分通过气相色谱联用质谱法和触角电图法进行鉴定。一些化合物通过油与可用的可靠标准的共同注射得到确认。结果为这些植物在驱除病媒和其他叮咬昆虫方面的传统用途提供了科学依据，并为下游开发更有效的个人和空间保护产品奠定了一些有用的基础。