Journal of
Medicinal Plants Research

  • Abbreviation: J. Med. Plants Res.
  • Language: English
  • ISSN: 1996-0875
  • DOI: 10.5897/JMPR
  • Start Year: 2007
  • Published Articles: 3636

Full Length Research Paper

Repellence effectiveness of essential oils from some Tanzanian Ocimum and Hyptis plant species against afro-tropical vectors of malaria and lymphatic filariasis

Hamisi M. Malebo1*, Calista Imeda1, Nteghenjwa A. Kitufe1, Shaaban J. Katani1, Richard Sunguruma1, Frank Magogo2, Patrick K. Tungu2, Vitus A. Nyigo1, Victor Wiketye1, George L. Mwaiko1, John W. Ogondiek1, Gloria P. Mbogo1, Paulo P. Mhame3, Daniel Z. Matata4, Robert Malima2, Stephen M. Magesa2,5, Julius J. Massaga1, Mwelecele N. Malecela1 and Andrew Y. Kitua1    
1Department of Traditional Medicine Research, National Institute for Medical Research, P. O. Box 9653, Dar es Salaam, Tanzania. 2Amani Medical Research Centre, National Institute for Medical Research, P. O. Box 81, Muheza, Tanzania. 3Ministry of Health and Social Welfare, P. O. Box 9083, Dar es Salaam, Tanzania. 4Government Chemist Laboratory Agency, P. O. Box 164, Dar es Salaam, Tanzania. 5RTI International, Centre for Strategic Malaria Solutions, Global Health Group, P. O. Box 1181-00621, Nairobi, Kenya.    
Email: [email protected], [email protected]

  •  Accepted: 06 November 2012
  •  Published: 17 March 2013

Abstract

Essential oils from three plant species growing in Dar es Salaam, Tanzania, Ocimum gratissimum (OG), Ocimum tenuiflorum (OT) and Hyptis suaveolens (HS) all from family Labiateae, were extracted by hydrodistillation and evaluated for laboratory and field based repellency against afro-tropical vectors of malaria and lymphatic filariasis. All oils were found to exhibit high mosquito repellency activity against Anopheles gambiae sensu stricto in the laboratory tests with RC50 values ranging from 2.0- to 15-×10−5 mg cm−2, whereas standard N,N-diethyl- 3-toluamide (DEET) was more repelling with RC50 value of 0.1×10−5mg cm−2. The formulation containing 10% of O. gratissimum provided protection against mosquito bites from Anopheles funestus of 70.5 to 95.7%, A. gambiae of 63.2 to 91.5% andCulex quinquefasciatus of 83.8 to 89.5%. The 30% O. gratissimum formulation was more effective with better protection against mosquito bites from A. funestus of 84.2 to 96.6%, A. gambiae of 73.7 to 91.5% and C. quinquefasciatus of 89.5 to 91.5%. The formulation containing 15% DEET showed slightly lower protection against mosquito bites from A. funestus of 70.5 to 78.9%, A. gambiae of 68.4 to  94.0%, C. quinquefasciatus of 85.5 to 89.5% (P<0.05). The individual components of the oils were identified by GC-MS. The implication of these results in the development and promotion of repellent plant extracts for commercialization is of priority in rural Tanzania where whole plants are currently used as repellents against mosquito vectors.

 

Key words: Repellent plants, Labiatae, Anopheles gambiaeCulex quinquefasciatus, essential oils..

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