A novel method to identify the Chinese herbal medicine Wuzhimaotao by quantification of laticifers.

Histology and the microscope have been used to identify Chinese herbal medicines for a long time. However, research on using the microscope for quantitative determination of identification characters is limited. A novel method which combines histological and microscopic analysis of laticifers by "blob" analysis is established to identify Wuzhimaotao, which is derived from species of Ficus (primarily F. hirta Vahl, but F. simplicissima Lour., F. hirta Vahl var. imberbis Gagnep., and F. esquiroliana Lévl. are also used). Results indicate that laticifers, which are stained orange-red by Sudan III, are mainly scattered in the phloem of Wuzhimaotao. The blob area of the laticifers is varied according to the species: F. hirta Vahl, F. simplicissima Lour., F. hirta Vahl var. imberbis Gagnep., and F. esquiroliana Lévl. showed 86,609 +/- 3,768 (mean +/- SD, n = 10), 48,582 +/- 2,603 (n = 10), 68,745 +/- 2,179 (n = 5), and 27,966 +/- 2,121 (n = 3) blob area, respectively. By directly measuring the blob area of laticifers in transverse sections, we could distinguish species of Wuzhimaotao in the same genus which were difficult to distinguish by microscopic examination of the dry roots, and we could provide objective data to describe and standardize the characters observed in microscopic images. This method is rapid, accurate, and inexpensive.