DNA-Based Authentication of Botanicals and Plant-Derived Dietary Supplements: Where Have We Been and Where Are We Going?

Herbal medicines and botanicals have long been used as sole or additional medical aids worldwide. Currently, billions of dollars are spent on botanicals and related products, but minimal regulation exists regarding their purity, integrity, and efficacy. Cases of adulteration and contamination have led to severe illness and even death in some cases. Identifying the plant material in botanicals and phytomedicines using organoleptic means or through microscopic observation of plant parts is not trivial, and plants are often misidentified. Recently, DNA-based methods have been applied to these products because DNA is not changed by growth conditions unlike the chemical constituents of many active pharmaceutical agents. In recent years, DNA barcoding methods, which are used to identify species diversity in the Tree of Life, have been also applied to botanicals and plant-derived dietary supplements. In this review, we recount the history of DNA-based methods for identification of botanicals and discuss some of the difficulties in defining a specific bar code or codes to use. In addition, we describe how next generation sequencing technologies have enabled new techniques that can be applied to identifying these products with greater authority and resolution. Lastly, we present case histories where dietary supplements, decoctions, and other products have been shown to contain materials other than the main ingredient stipulated on the label. We conclude that there is a fundamental need for greater quality control in this industry, which if not self-imposed, that may result from legislation.

Plant species used in giardiasis treatment: ethnopharmacology and in vitro evaluation of anti-Giardia activity

The aim of this study was to compile the traditional knowledge about plants used for the treatment of giardiasis, and also to carry out experimental research to evaluate the anti-Giardia activity of five species.To reach this objective, 398 interviews were performed using a previously prepared questionnaire, followed by an in vitro evaluation of giardicidal potential of hydroalcoholic leaf extracts of Anacardium occidentale L., Chenopodium ambrosioides L., Passiflora edulis Sims, Psidium guajava L., and Stachytarpheta cayennensis (Rich.) Vahl. Among the interviewed people, 55.53% reported the use of plants to treat diarrhea, the most severe symptom of giardiasis. The results indicated 36 species used by this population for these problems. The use of leaves (72.50%) of a single plant (64.25%) collected from backyards and gardens (44.34%) and prepared by decoction were predominant. The majority of the interviewees (85.52%) attributed their cure to the use of plants. In the experimental tests, all extracts inhibited the growth of Giardia lamblia trophozoites in different intensities: A. occidentale and P. guajava extracts elicited a moderate activity (250 ≤ IC50 ≤ 500 μg/ml), C. ambrosioides and S. cayennensis extracts evoked a high activity (100 ≤ IC50 ≤ 250 μg/ml), and P. edulis extract showed very high activity (IC50 ≤ 100 μg/ml). This study shows that an ethnopharmacological approach is useful in the selection of plant materials with potential giardicidal activity.