Planta Med 2007; 73 - P_143
DOI: 10.1055/s-2007-986924

Chemical composition of volatile oils and evaluation of antioxidant and antimicrobial activities of ethnopharmacologically selected Thai medicinal plants

J Wungsintaweekul 1, W Putalun 2, W Sitthithaworn 3, HW Pfeifhofer 4, AH Brantner 5
  • 1Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla 90112, Thailand
  • 2Department of Pharmaceutical Botany and Pharmacognosy, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
  • 3Department of Pharmacognosy and Pharmaceutical Chemistry, Faculty of Pharmacy, Srinakharinwirot University, Ongkarak, Nakornayok 26120, Thailand
  • 4Institute of Plant Sciences, University of Graz, Holteigasse 6, A-8010, Graz, Austria
  • 5Institute of Pharmaceutical Sciences, Department of Pharmacognosy, University of Graz, Universitaetsplatz 4/I, A-8010 Graz, Austria

Thai medicinal plants belonging to the Lamiaceae, Rutaceae and Zingiberaceae were selected regarding their traditional medicinal use. Volatile oils and methanolic extracts were evaluated for their antimicrobial and antioxidant activities as well as for their chemical compositions using GC-MS and other chromatographic methods. The antimicrobial activity was tested against, 4 gram-positive and 5 gram-negative bacterial strains including Mycobacterium species and 3 fungi [1] by the disc diffusion method. The MIC was estimated by the microdilution broth method [2]. The result showed that the volatile oil of Ocimum americanum (major components (E)-citral and (Z)-citral) exhibited an activity against gram-positive bacteria (MIC 1.2–1.4mg/ml), gram-negative bacteria (MIC 1.8–2.0mg/ml) and fungi (MIC 0.2–0.3mg/ml). In addition, Ocimum sanctum volatile oil exhibited a considerable activity against Candida albicans, C. parapsilosis and C. tropicalis (MIC 0.8, 1.3 and 1.4mg/ml, resp.). The antioxidant activity of the volatile oils and the methanolic extracts were assessed using the DPPH and lipid peroxidation assays [3,4]. The results showed that the methanolic extracts of Citrus hystrix leaf (IC50 30µg/ml) and fruit peel (IC50 68µg/ml) as well as Kaempferia parviflora black rhizome ((IC50 68µg/ml) exhibited a remarkable scavenging activity by the DPPH method but showed less activity on lipid peroxide.

Acknowledgements: The authors thank the Ministry of Higher Education of Thailand for traveling grant support.

References: [1] Brantner, A.H., Grein, E. (1994) J. Ethnopharmacol. 44: 35–40. [2] Pharmacopoeia Europaea, ed. 5 (2005) [3] Hatano, T. et al. (1988) Chem. Pharm. Bull. 36(6): 2090–2097. [4] Houghton P.J et al. (1995). Planta Med. 61, 33–36.