**Author details**

concern is that some infusions or extracts used as household remedies lose their antidepressant or anxiolytic effects when fractioned [96]. These findings indicate that in some cases it may be necessary to keep the metabolites together at the concentrations present in the original infusion or extract that has a proven therapeutic effect. As explained herein, some metabolites share pharmacological targets, which explains why they lose their effect when separated and emphasizes the importance of using standardized extracts with demonstrated therapeutic effects in animal and human studies [97, 98]. Unfortunately, very few clinical studies have evaluated the potential antidepressant or anxiolytic effects of isolated metabolites,

Several observations suggest that active metabolites share the mechanism of action of antidepressant and anxiolytic drugs like SSRIs, SNRIs, MAOIs, DDNRI, and BZDs, but we should emphasize that some metabolites—at least in preclinical studies—produced better effects than conventional drugs, even at lower doses, while others presented a pharmacological synergism between both types at suboptimal doses that improved the effects exerted separately at higher doses. A second shared characteristic is that they contain active stereoisomers and probably, some metabolites, once metabolized, could become more active. This encourages us to consider a significant number of substances with anxiolytic and/or antidepressant pharmacological profiles and invites us to take on the challenge of evaluating

In conclusion, terpenes, flavonoids, alkaloids, and sterols share mechanisms of action that include activation of the critical enzyme for catecholamine synthesis (e.g., tyrosine hydroxylase) or the inhibition of their limiting enzymes, MAO-A and MAO-B, and transporters, thus stimulating the vesicular storage monoamine and the release of neurotransmitters toward the synaptic cleft. Finally, they can prevent the production of ROS and inhibit NO synthesis and, further downstream, interact with the 5-HT1A, 5-HT2A, D1, D2, GABAA receptors, and α1, α2, β-adrenoceptors that contribute to stimulating PKA. One consequence is that CREB increases BDNF levels, which foster the appearance of dendritic contacts that improve cerebral

This chapter discusses the efficacy of some plant metabolites in treating anxiety and depression disorders, as demonstrated in preclinical studies. In the future, this option for treating such disorders will allow us to reduce treatment costs and moderate the side effects produced by drugs currently in use. However, our review also points out that few clinical studies have focused on the pharmacokinetic and pharmacodynamic processes involving metabolites that would permit the safe use of these extracts. Despite this, research has shown that traditional medicine, especially forms that use medicinal plants that have been passed down through several

generations, constitutes an important alternative for health care.

The third author received (Ramos-Molina Ana Raquel) fellowships from Consejo Nacional de Ciencia y Tecnología (CONACyT) for postgraduate studies in

so a great deal of work remains to be done.

*Behavioral Pharmacology - From Basic to Clinical Research*

their pharmacokinetics, pharmacodynamics, and safety.

neurotransmission and modulate the emotions.

**10. Perspective**

**Acknowledgements**

**114**

Science and Technology (Reg. 631048).

Rosa Isela García-Ríos<sup>1</sup> \*, Armando Mora-Pérez<sup>1</sup> , Ana Raquel Ramos-Molina<sup>2</sup> and Cesar Soria-Fregozo<sup>1</sup>

1 Laboratory of Psychobiology, University Center of Los Lagos, University of Guadalajara, Lagos de Moreno, Jalisco, Mexico

2 University Center of Los Lagos, University of Guadalajara, Lagos de Moreno, Jalisco, Mexico

\*Address all correspondence to: rosai\_garios@yahoo.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
