Progress 08/01/05 to 07/31/08
Outputs
OUTPUTS: Completed the planting of 22 kava varieties in the germplasm collection at Waimanalo Research Station, Honolulu that includes 13 Hawaii varieties (Papa 'eleele pu'upu'u, Hiwa, Papa'eleele, Hanakapi'ai, Moi, Opihikao, Pana'ewa, Kumakua, Nene, Mapulehu, Papa kea, Honokane iki, Mahakea) 3 Samoan (Red Samoan, Ava laau, Samoa waimea 96p99), 2 Papua New Guinea (Isa, Iwi), 1 Tongan (Hina Tonga), 1 Fijian (Kaojarau) and 2 Micronesian (Rahmwahger, Rahmedel) varieties. Collection provides a source of known varieties for future research. Kavalactones (6) and pipermethystine (PM) were characterized for dried samples of 5 varieties (commercial Fijian (Ratoma), Micronesian (Kosrae), Papua New Guinea 'Isa', and 2 Vanuatu 'Borogu' and 'Palisi'. Palisi, a not-for-drinking variety also known as tudey (two days of negative kava effects), is believed to have been harvested and used in the manufacture of kava products in Germany prior to the alleged liver problems in Europe. For each variety roots, stump, and basal 20 cm of stem were analyzed separately, virtually no PM was detected except in Isa stems. Beverage was prepared from the 3 plant parts of the 5 varieties (15 samples) and the kavalactones and PM content determined. No PM was recovered in the beverage. PARTICIPANTS: Drs. Wei-yue Qu and Jun Wang, analytical chemists and Visiting Scientists from China with Dr. Qing Li, MBBE, CTAHR, UHM. TARGET AUDIENCES: Target audiences are peer scientists around the world, kava beverage retailers, and nutraceutical manufacturers. PROJECT MODIFICATIONS: Project was modified for several reasons. We had proposed to further investigate the role of the kava alkaloid, pipermethystine (PM), found in the above ground organs of several kava cultivars by C.S. Tang (University of Hawaii) and students on alleged liver adverse reactions on users of commercial kava extract products. It was demonstrated that PM was much more toxic to human and rat liver cell cultures in vitro than any combination of kavalactones. However subsequent research by Nerurkar with PM feed to rats found no impact on liver function. This was corroborated by several other published reports. This finding plus the retirement of CS Tang and the departure of the main technical resource for the project junior researcher Rachel Li to accept a professorship in Australia forced a modification of the research plan. Subsequently several graduate research assistants were unable to achieve accurate and repeatable chemical analysis of kavalactone content of a wide selection of kava cultivars and organs. Dr. Qing Li agreed to provide analytical support. Our thrust changed to clarifying the impact of different solvents commonly used for kavalactone extract on the measured kavalactone content of the six major kavalactone. In addition we pursued new techniques for rapid kavalactone analysis using Fourier Transform Infrared Spectroscopy. We further refined an improved aqueous extraction method for preparing kava beverage at home or businesses.
Impacts
Because the alkaloid pipermethystine (PM) was undetected in dry kava which is the form used for extraction and because other researchers have failed to show that PM had activity in vivo these aspects of the project were discontinued. We focused our remaining efforts on a paper on the impact of different solvents on extraction of the 6 major kavalatones for gas chromatography is in draft form. A paper entitled Rapid Determination of Six Kavalactones in Kava Root and Stem Samples Using Fourier Transform Infrared Spectroscopy and Multivariate Analysis and Comparison with Gas Chromatography is in draft form. Our UH warm water extraction method has been widely accepted by the kava preparation community. Use warm 45-50 C water, take one third water of the needed to prepare the beverage and using an electric blender or food mixer mix the water and kava for one minute, pour the mixture into a nylon net bag and squeeze out liquid (the beverage). Extract the press cake in the bag with a second third of the water, mic for one minute, squeeze the liquid out, and repeat one more time. This reduced the kavalactone content of the press cake which is a waste product from 90% of kavalactones in the origin sample to 45-50% remaining. A major increase in yield in beverage yield which is then diluted to the consistency that the business or user desires.
Publications
- No publications reported this period
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Progress 08/01/06 to 07/31/07
Outputs
Progress 2007 Objective 1: Collect dried and live plant material of Hawaiian and other Pacific kava varieties and grow kava for chemical analysis and bioassay. Thirteen Hawaii, 2 Papua New Guinea, 2 Pohnpei, 3 Samoa and 2 Tongan varieties have been planted at the Waimanalo Research Farm on Oahu. Live kava plants or parts may not be exported from Fiji or Vanuatu. Therefore dried root, stump (rhizome) and stem parts of Borogu and Palisi varieties were imported from Dr. Vincent Lebot, CIRAD (France) Vanuatu. Rotuman a popular Fijian variety was obtained as dried root, stump, and stems from a single tree from a known kava grower in Fiji. Objective 2: Chemically characterize the beverage preparations of these kava varieties prepared from dried, fresh, and fresh frozen kava with or without the inclusion of 20 cm of the basal stem. We have invited Dr. Qing Li to join our project as a chemist to replace CS Tang who is retired. His lab is characterizing 5 varieties - Isa (PNG),
Rotuman (Fiji), Borogu and Palisi (Vanuatu) , and Rahmedel (Micronesian) initially for kavalactone in the stem, rhizome and root. Objective 3: Evaluate the hepatotoxicity of these preparations, including combinations of PM and kavalactones. No progress this year. Objective 4: Clarify the fate and the toxicity of breakdown products of PM and kavalactones during storage of kava raw materials and preparations. No progress this year.
Impacts
We have established the largest kava collection in terms of varieties and plants per variety in Hawaii. Being on university property and with 15 plants per variety the survival of Hawaiian varieties is more assure than single plants in a private nursery.
Publications
- No publications reported this period
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Progress 08/01/05 to 07/31/06
Outputs
Funding was received on August 1, 2005. No progress at this time.
Impacts
Expected Outcome: Collection of kava varieties will be ready for harvest in January 2008 and can be stored as growing plants for years. Dried and possibly frozen Vanuatu and Fiji varieties will be stored in our freezers by January 2006. The chemical characteristics of the popular kava beverage varieties (e.g., Moi) and the kava with a poor reputation (e.g., Tu-Dei) established. In conjunction with the toxicity data, chemical evaluation of kava beverage becomes a reality. In conjunction with the chemical analysis, the quality (toxicity) of beverage prepared from various kava varieties using various methods will be evaluated. Impact on the toxicity of PM and its decomposition product in different kavalactone ratios will be clarified. Provide valuable information on safe storage, shipping and handling of kava and kava beverage.
Publications
- No publications reported this period
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