Alstonia scholaris (L.) R.Br. (Apocynaceae)

Abstract

A tall[aut]Alstonia scholarisevergreen tree widely cultivated throughout India and also found in China, Africa, southeast Asia, Latin America, and Australia. The bark is reputed in Hindu medicine for ages as tonic, alterative, useful in fever and skin diseases, a remedy in chronic diarrhea and advanced stages of dysentery, valued as a febrifuge, and used in the treatment of gout, rheumatism, in convalescence after exhausting diseases and fevers. In China, it is widely used to treat respiratory diseases, such as cough, asthma, phlegm, and COPD. On the island of Luzon, bark is esteemed by the natives as the most efficient tonic and febrifuge, and used as decoction since time immemorial for malignant, intermittent, and remittent fevers. In Nigeria, the bark is widely used as an antipyretic in malaria, and sometimes, together with leaves and roots, in external application for rheumatic pains. In GhanaGhana, bark decoction is given after childbirth to help expel placenta. Bark contains triterpenes: $β$-amyrine and lupeol; and indole alkaloids: echitamine or ditain as the main alkaloid, alstoscholarisines H-J, echitamidine and a lactone ditamine. Methanol bark extract produced adaptogenic effects in mice, increased cognitive and memory functions, and exhibited potent antioxidant activity. Petroleum ether and methanol bark extracts are devoid of antimalarial activity against P. falciparum (in vitro) and P. berghei (in vivo); methanol extract, though, delays mortality and improves physical conditions of treated mice. The spasmolytic activity in isolated preparations is proposed to be due to calcium channel blockade, and the bronchovasodilatory activity is presumed to be due to prostaglandins, calcium antagonism and release of NO.