HPLC analysis of montanoa species for pharmacologically active constituents1

Mexican medicinal plants with anxiolytic or antidepressant activity: Focus on preclinical research

ETHNOPHARMACOLOGICAL RELEVANCE

Anxiety and depression are considered the most prevalent psychiatric disorders worldwide. In Mexico, the use of medicinal plants to alleviate the symptoms associated with these psychiatric disorders is increasing. However, there is little scientific evidence that validates the efficacy of these plants. This evidence needs to be critically revised, and further studied to provided scientific support for their use.

AIM OF THE STUDY

To identify the plants that are used in Mexico for the treatment of disorders related to anxiety and depression, and to review the current preclinical and when available, clinical information of these plants.

METHODS

We searched in scientific databases (Pubmed, Web of Science, Scopus and other web sources such as "Biblioteca digital de la medicina tradicional Mexicana" ) for Mexican plants used for the treatment of anxiety and depression that have been analyzed in preclinical studies. Additional information was obtained from published books. For this review, we also consider those plants used in Mexican traditional medicine for the treatment of "nervios," "susto" or "espanto;" common terms that describe symptoms related to anxiety and depression disorders.

RESULTS

The bibliographic search identified 49 plants used in Mexican traditional medicine for the treatment of disorders related to anxiety and depression. From all these plants, 59% were analyzed in preclinical research, and only 8% were tested in clinical studies; only a few of these studies tried to elucidate their mechanism of action. In general, it is proposed that the plant extracts interact with the GABAergic system. However, only part of these studies attempted to analyze other neurotransmitter systems. Finally, in some cases, drug-herbal interactions were reported.

CONCLUSIONS

There is a large number of Mexican medicinal plants used as a treatment for anxiety and depression disorders. Although some of these plants have been studied in preclinical research, in most cases these studies are preliminary, and the understanding of the mechanism of action is inconclusive. The need for systematic studies in preclinical and clinical research is evident, and efforts should be done to fulfill these research. Finally, it is important also to study possible drug-herbal interactions to establish specific recommendations for people that use these plants as anxiolytic or antidepressant treatments either alone or in combination with another type of medicine.

Capillary electrophoretic method for the determination of diterpenoid isomers in Acanthopanax species

Acanthoic, continentalic and kaurenoic acids are bioactive diterpenoids that are structural isomers isolated from Acanthopanax species. Due to the interest in their potent biological activity, an analytical method of diterpenoids was developed for the quality control and the classification of Acanthopanax species. Capillary electrophoresis was used to separate and quantify the isomers. The three compounds were successfully separated from each other and from the matrices in the extracts of leaves, stems and roots of Acanthopanax species. The contents of acanthoic, continentalic and kaurenoic acids showed taxonomical differences in Acanthopanax species. Relatively higher concentrations of diterpenoids were found from A. koreanum and A. trifoliatus, while only trace amounts were found from the four other species tested: A. senticosus, A. senticosus f. inermis, A. chiisanensis, and A. divaricatus var. albeofructus. The contents of diterpenoids in association with lignans and triterpenoids in the Acanthopanax species could provide a chemotaxonomical index able to be used in the classification and discrimination of the species.

Analytical aspects of drugs of natural origin

The current importance of drugs of natural origin and their different phytotherapeutical preparations are mentioned. Analytical aspects related to vegetable drugs and their extracts are discussed. An overview is given on procedures used for the isolation of reference compounds, sample preparation for high-performance liquid chromatographic analysis, identification of vegetable drugs and detection of adulterants. The different approaches currently employed for the standardization of extracts are presented. The various aspects are discussed with the aid of illustrative examples.