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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #193477
Title: Pyrrolizidine alkaloids in Senecio madagascariensis from Australia and Hawaii and assessment of possible livestock poisoning

Author
item Gardner, Dale
item THORNE, MARK - U OF HAWAII
item Molyneux, Russell
item Pfister, James
item SEAWRIGHT, ALAN - U OF QUEENSLAND

Submitted to: Biochemical Systematics and Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/27/2006
Publication Date: 8/1/2006
Citation: Gardner, D.R., Thorne, M.S., Molyneux, R.J., Pfister, J.A., Seawright, A.A. 2006. Pyrrolizidine alkaloids in Senecio madagascariensis from Australia and Hawaii and assessment of possible livestock poisoning. Biochemical Systematics and Ecology.

Interpretive Summary: A relative recent infestation of a plant commonly called “fireweed” (Senecio madagascariensis Poir.) among the Hawaii Islands has become a serious weed problem and heightened the concern for possible poisoning of grazing livestock in the area. Many of the Senecio spp. contain hepatotoxic pyrrolizidine alkaloids and if grazed over a period of time may induce irreversible liver damage. Senecio madagascariensis is native to Madagascar and southern Africa and was first observed in Australia in 1918, although the means of introduction is unknown. It is a major economic concern because of poisoning of cattle and horses. S. madagascariensis was first discovered in the early 1980s at the northernmost tip of the island of Hawaii and introduction is suspected to have been through contaminated groundcover seed from Australia. The plant is now very widespread in the area around Waimea (Kamuela) the primary cattle-ranching area of Hawaii. The potential for poisoning of livestock in this area is therefore extremely high. Samples of Senecio madagascariensis were collected from Australia, and from Hawaii, and the pyrrolizidine alkaloid content examined. Samples collected from the Hawaiian Islands were found to be identical in pyrrolizidine alkaloid content to those from Queensland, Australia. Alkaloid levels from individual plants on the island of Hawaii and from the island of Maui were also measured. Overall, no appreciable difference in alkaloid content was found between locations, whereas variation among individual plants was evident. The average total pyrrolizidine alkaloid content varied from 0.02 % to 0.20% (dry weight basis) among the locations. Based on comparable alkaloid content and documented pyrrolizidine alkaloidosis cases from Australia, S. madagascariensis may pose a significant risk to livestock grazing heavily infested ranges on the Hawaii islands.

Technical Abstract: The alkaloid content of Senecio madagascariensis collected from Australia, and from Hawaii, was examined. Alkaloids were identified by GC-MS analysis and included: senecivernine, senecionine, integerrimine, senkirkine, mucronatinine, retrorsine, usaramine, otosenine, acetylsenkirkine, desacetyldoronine, florosenine, doronine. Plant material collected from the Hawaiian Islands were found to be identical in pyrrolizidine alkaloid content to those from a single composite collection made from Queensland, Australia. The quantitative alkaloid levels from individual plants on the island of Hawaii and from the island of Maui were measured. Overall, no appreciable differences in alkaloid content was found between locations, whereas variation among individual plants was evident. The average total pyrrolizidine alkaloid content varied from 0.02 % to 0.20% (dry weight basis) among the locations. Based on comparable alkaloid content and documented pyrrolizidine alkaloidosis cases from Australia, S. madagascariensis may pose a significant risk to livestock grazing heavily infested ranges on the Hawaii islands.