Alstonia boonei (Nyamedua) bark – 150g

A small tree with smooth bark; opposite dark green, coriaceous and shiny leaves, obovate, with 3-5 basal nerves, up to 15 cm long and 10 cm broad; flowers unisexual, cream, in axillary and terminal panicles; fruit small drupe.

Studies have shown that the bark of the plant contains volatile oils, mucilage, calcium oxalate, tannins, and starch, all of which work synergistically to give the plant its appetizer, carminative, digestive and stomachic actions (Pamplona-Roger, 11998). C. zeylanicum promotes gastric and intestinal juice secretion and enhances gastric motility. The bark extracts have shown to be effective against fluconazole-resistant and -susceptible Candida isolates in vitro. A small scale clinical trial on AIDs patients showed the herb to be effective for treating oral candidiasis (Quale et al., 1996). Antibacterial actions have also been demonstrated in vitro (Azumi et al., 1997; Bruneton, 1995). C. zeylanicum‟s diterpenes have shown antiallergic activity (Nagai et., 1982). Aqueous extracts exhibited antiulcer effects (Akira et al., 1986). Cinnamon may have hypoglycaemic properties in vitro (Berrio et al., 1992). Its mild astringent action may be due to the tannins. The essential oils of C. zeylanicum, Ocimum gratissimum, Cymbopogon citratus, Eugenia uniflora, and Alpinia speciosa demonstrated inhibitory action against dermatophyte strains in vitro (Lima et al., 1993). The oil and leaf extracts have antiviral activity (Kato, 1975; Leung and Foster, 1996); the eugenol-containing leaf oil has demonstrated antiseptic and anaesthetic properties. Several studies have shown that cinnamaldehyde has hypotensive and spasmolytic effects. It also inhibits the enzymes cyclooxygenase and lipoxygenase and increases peripheral blood flow (Tahara et al., 1986; Harada and Yamazaki, 1981). Extracts have shown antioxidant activity in vitro and may be useful as food antioxidants (Mancini-Filho et al., 1998).