Isolation and pharmacological activities of the Tecoma stans alkaloids

Abstract

Tecoma stans is a plant traditionally used in Mexico for the control of diabetes. Amongst the alkaloids isolated from the plant harvested in Egypt, Tecomine was shown to be one of the compounds responsible for the hypoglycemic action. Given the interest in substances able to treat type II diabetes, we isolated the main alkaloids present in the plant growing in Egypt and Brazil and tested them in vivo on db/db mice. Contrary to previous literature reports on different animal models, Tecomine was unable to modify glycemia; the only effect seen being a decrease in plasma cholesterol levels. On the contrary, when tested in vitro on glucose uptake in white adipocytes, the compound showed a marked effect. The two other alkaloids isolated, namely 5b-Hydroxyskitanthine, early called Base C, and Boschniakine were inactive both in vivo and in vitro assays.

Antidiabetic activities of Tecoma stans (L.) Juss. ex Kunth

“…Tecoma stans is widely used by Mexicans as an alternative or complementary diabetes treatment (Shapiro and Gong, 2002); several groups have reported the following antidiabetic activities in extracts from its leaves: decrease in (a) fasting glycemia (Aguilar et al, 1993), (b) area under glucose tolerance test curve (Román-Ramos et al, 1991), (c) plasma cholesterol (Costantino et al, 2003b) and (d) prevention of weight loss in STZ-treated rats (Aguilar et al, 1993). Several compounds have been isolated from Tecoma stans and the pioneering work of Hammouda proposed the alkaloids tecomine and tecostanine as the active compounds (Hammouda et al, 1964).…”

Efecto hipoglicemiante coadyuvante del extracto etanólico de hojas de Annona muricata L (guanábana), en pacientes con diabetes tipo 2 bajo tratamiento de glibenclamida

“…Otros metabolitos secundarios que estarían coadyuvando con el efecto hipoglicemiante son los alcaloides, que inducen la secreción de insulina solo en concentraciones altas de glucosa, lo cual disminuye el riesgo de hipoglicemia (26)(27)(28) ; esto ha sido confirmado mediante estudios in vitro, al aislar los islotes pancreáticos y someterlos al alcaloide tipo quinolizidine, que determinó secreción de insulina, medida por radioimmunoensayo (29) .…”

Antioxidant and antibacterial activities of leaves and branches extracts of Tecoma stans (L.) Juss. ex Kunth against nine species of pathogenic bacteria

“…The primary applications of T. stans have been found in treating diabetes and digestive problems (Kirtikar and Basu, 2006). In the study of Costantino et al (2003), the flower infusion can be taken orally for diabetes and stomach pains. Amongst nine plants studied, T. stans was found to give the best of inhibition zones against the fungal activity (Gandhi and Ramesh, 2010).…”