Study on mosquito repellent activity of single and mixed extracts of eight plant essential oils

HUANG Yawen; ZHANG Naijiao; BAI Mingyu; CHEN Yanguo; WANG Xueyuan; YUAN Hongyu; LI Tianxiang

doi:10.19821/j.1671-2781.2025.05.002

Abstract：Objective To explore the mosquito repellent activity of Eupatorium fortunei Turcz.essential oil alone and in combination with essential oils from seven other medicinal plants,so as to provide new insights and data support for expanding the functional utility of E.fortunei and developing it as a botanical mosquito repellent.Methods Single essential oils were combined with each of the seven other plant essential oils in pairs,and the best proportioned oils were then mixed in four combinations.The baseline equal ratio increment method was used to prepare the mixtures.Following the indoor evaluation standards for repellents as stipulated by national standards,the mosquito repellent rate and effective protection time were recorded.A repellent rate of 80%and above was deemed qualified,and the duration for which the repellent rate met the criteria was recorded.Results The mosquito repellent activity of single essential oil was relatively low,with the four oils that had longer qualified repellent times being Artemisia annua oil,Eucalyptus globules oil,Cymbopogon citratus oil,and E.fortunei oil.Pairing two essential oils could effectively enhance the mosquito repellent effect.The optimal combination of the four oils significantly increased the synergistic effect and mosquito repellent activity.The optimal mixing ratio for A.annua oil,E.globules oil,E.fortunei oil,and C.citratus oilwas21∶49∶3∶27.Compared with single E.fortunei oil,the qualified time of the repellent rate increased by 2.7 times to 120 minutes,during which the repellent rate remained above 83%.Conclusions Single essential oils have poor mosquito repellent effects,while the combination of multiple essential oils shows better repellent effect.There is a strong synergistic effect between the oils.The repellents prepares by using the baseline equal ratio increment method has the best mosquito repellent effect.The rational formulation of mixed essential oils from medicinal plants has a broad market potential in the future development of mosquito repellents.