Seasonal changes and water stress effects on ambrosin and damsin of Ambrosia maritima plant

Ambrosia maritima is used for treatment of renal colic and calculi and for control of bilharzia [1]. A field experiment was conducted to determine ambrosin and damsin in different plant organs throughout the first two years of plant age. Seedlings were transplanted in the field in November, eight cuts were collected in a two month- interval from june to october of the first and second year of plant age. Another field experiment was conducted to study the effect of water stress. Plants were subjected to two water treatments, after 60 days from transplantation, normal plants irrigated every two weeks and water stressed plants irrigated every six weeks. Three cuts were taken after 4, 6, and 8 months from the beginning of water treatment. Five plant samples were taken from each cut and subjected to analysis by HPLC [2]. Amount of sesquiterpene lactone was calculated and analyzed using least significant differences (LSD). Ambrosin and damsin were present at high concentrations in leaves and flowers in all evaluated cuts, while stems and seeds contained only traces. These two organs accumulated more than 90% of sesquiterpene lactones produced by plant. Seasonal changes in ambrosin and damsin content in different plant organs nearly had the similar trend throughout two years of plant growth. It is increased reaching maximum values in August in the first year of plant age and in June in the second year and decreased by October. The highest yield of ambrosin (5.29mg/g dry matter and 2086mg/plant) and damsin (6.87mg/g dry matter and 2707mg/plant) occurred in June of the second year of plant age. Ambrosin concentration was slightly affected by water stress, but damsin decreased in leaves and increased in flowers. Water stress had a depressive effect on the amount of ambrosin and damsin accumulated per plant.

References: [1] El-Sawy, M. et al. (1984) Tropenmed. Parasitol.35: 100. [2] Geissman, T. et al. (1996) Phytochem. 8: 145.