Ye Ying Pi

This database holds a separate record, Ying Pi, for cherry bark from Cerasus serrulata (Lindl.) G. Don ex Loudon, synonym Prunus serrulata, classified under clearing heat, whereas Ye Ying Pi is assigned to Prunus pseudocerasus Lindl. and classified under transforming phlegm. They are different species in the same genus and are not the same drug, though the pinyin names differ only by the word ye, wild. Two further problems attach to this record's own identity. First, Prunus pseudocerasus is the cultivated Chinese cherry, Ying Tao, not a wild cherry, so the vernacular Ye Ying Pi and the assigned binomial pull in opposite directions. Second, the Latin name combines Pericarpium, a fruit pericarp, with Cortex, a bark, which cannot both describe one drug; the traditional functions given, descending Lung qi and stopping cough, belong to a bark. Note also that the authority string on the existing Ying Pi record reads G. Don ex London, a corruption of G. Don ex Loudon.

Cyanogenic glycosides, chiefly prunasin and amygdalin, are a characteristic feature of bark, leaf and kernel tissue across the genus Prunus, and gut beta-glucosidases liberate hydrogen cyanide from them after oral dosing. The Cochrane review of laetrile found no reliable evidence of anticancer benefit and identified cyanide poisoning as the principal harm of orally administered cyanogenic preparations. No assay of prunasin or amygdalin in Prunus pseudocerasus bark was located in the searched literature, so the cyanogenic content of this specific drug is unknown in both directions; absence of an assay is not evidence of absence. The only toxicological study located for the species examined seed oil, a different part with a different composition, and cannot be read across to the bark.