Authentication of the 31 species of toxic and potent Chinese Materia Medica by light microscopy, Part 3: two species of T/PCMM from flowers and their common adulterants.

Toxic and potent Chinese Materia Medica (T/PCMM) has become a hot and sensitive topic as more and more people around the world are interested in the safety of herbal medicines. T/PCMM is irreplaceable in treating some diseases; but it can easily cause serious problems if confused with other herbal medicines. Accurate identification is essential to ensure their safe use, but up to now, the literature on the authentication of T/PCMM is scant. Thus, we are undertaking a study of 31 T/PCMM originating from plants, animals, minerals, and secreta. Our previous study established microscopic observation as a simple, fast, accurate, and convenient method for identifying and authenticating animal and seed T/PCMM. This study focused on the authentication of flower T/PCMM as a part of the whole study. The flower T/PCMM studies were derived from two species, Datura metel L. (Flos Daturae) and Rhododendron molle G. Don (Flos Rhododendri Mollis). Other species easily confused with these two were also examined and characterized. Using the microscope camera, normal light and polarized light microscopy, we determined the macroscopic and microscopic features of the flowers; in addition, the oil immersion lens was used to study the pollen grain characteristics. The results demonstrated that flower T/PCMM can be identified and authenticated using a light microscope equipped with an oil immersion lens. This same equipment can be easily used to characterize other herbal flower medicines.

In vitro organogenesis and alkaloid accumulation in Datura innoxia.

The kinetics of tropane alkaloids accumulation in different organs such as roots, leaves, stems, flowers and seeds of Datura innoxia was investigated by GC-MS. Twenty-six tropane alkaloids were detected. The ester derivatives of tropine (3alpha-tigloyloxytropine and 3-tigloyloxy-6-hydroxytropine) are the major compounds. Undifferentiated callus were established from the stem explants of Datura innoxia using Murashige and Skoog (MS) medium supplied with 6-benzylaminopurine (BA, 1 mg l(-10) and indole-3-acetic acid (IAA, 0.5 mg l(-1)) in combination for 6 weeks. Callus differentiation was initiated by subculture onto solid MS medium, free from hormones, for more than 10 months. Initially, shoots were formed after four weeks from subculture. Further subculturing in basal MS medium without growth regulators initiated the rooting of a shooty callus after 6 weeks. Investigation of the alkaloid content of the unorganized and organized callus revealed that callus (either green or brown) yielded only trace amounts of alkaloids. On the other hand, re-differentiated shoots contained mainly scopolamine while re-differentiated roots biosynthesized hyoscyamine as the main alkaloid.