The potential of three different PCR-related approaches for the authentication of mixtures of herbal substances and finished herbal medicinal products.

BACKGROUND: Herbal substances and preparations thereof play an important role in healthcare systems worldwide. Due to the variety of these products regarding origin, composition and processing procedures, appropriate methodologies for quality assessment need to be considered. A majority of herbal substances is administered as multicomponent mixtures, especially in the field of Traditional Chinese Medicine and ayurvedic medicine, but also in finished medicinal products. Quality assessment of complex mixtures of herbal substances with conventional methods is challenging. Thus, emphasis of the present work was directed on the development of complementary methods to elucidate the composition of mixtures of herbal substances and finished herbal medicinal products. HYPOTHESIS/PURPOSE: An indispensable prerequisite for the safe and effective use of herbal medicines is the unequivocal authentication of the medicinal plants used therein. In this context, we investigated the potential of three different PCR-related methods in the characterization and authentication of herbal substances. METHODS: A multiplex PCR assay and a quantitative PCR (qPCR) assay were established to analyze defined mixtures of the herbal substances Quercus cortex, Juglandis folium, Aristolochiae herba, Matricariae flos and Salviae miltiorrhizae radix et rhizoma and a finished herbal medicinal product. Furthermore, a standard cloning approach using universal primers targeting the ITS region was established in order to allow the investigation of herbal mixtures with unknown content. RESULTS: The cloning approach had some limitations regarding the detection/recovery of the components in defined mixtures of herbal substances, but the complementary use of two sets of universal primer pairs increased the detection of components out of the mixture. While the multiplex PCR did not retrace all components in the defined mixtures of herbal substances, the established qPCR resulted in simultaneous and specific detection of the five target sequences in all defined mixtures. CONCLUSION: These data indicate that for authentication purposes, complementary PCR-related methods are highly recommendable for the analysis of herbal mixtures in parallel.

Enhanced production of undecylprodigiosin in Streptomyces coelicolor by co-cultivation with the corallopyronin A-producing myxobacterium, Corallococcus coralloides.

Prolific producers of natural products like streptomycetes and myxobacteria live in complex natural frameworks consisting of many microorganisms. Presumably intricate physiological and metabolic regulatory networks have evolved to enable the organisms to respond to intra- and interspecies interactions, e.g. biosynthesis of specific natural products is up-regulated due to competitors in the surrounding area. The soil-dwelling bacterium, Streptomyces coelicolor, produces the biologically-active compound, undecylprodigiosin (Red). Co-incubation with the corallopyronin A-producer, Corallococcus coralloides, was performed to explore the hypothesis that Red production can be enhanced by a myxobacterial competitor. Co-cultivation resulted in earlier onset and increased production of Red (60-fold increase of the intra-cellular concentration). Using different Corallococcus-derived extracts for elicitation, revealed that water-soluble factors triggered the enhanced production of Red which shows antimicrobial, immunosuppressive and anticancer properties.