Herbal Extracts and Phytochemicals: Plant Secondary Metabolites and the Enhancement of Human Brain function

Abstract

Humans consume a wide range of foods, drugs, and dietary supplements that are derived from plants and which modify the functioning of the central nervous sytem (CNS). The psychoactive properties of these substances are attributable to the presence of plant secondary metabolites, chemicals that are not required for the immediate survival of the plant but which are synthesized to increase the fitness of the plant to survive by allowing it to interact with its environment, including pathogens and herbivorous and symbiotic insects. In many cases, the effects of these phytochemicals on the human CNS might be linked either to their ecological roles in the life of the plant or to molecular and biochemical similarities in the biology of plants and higher animals. This review assesses the current evidence for the efficacy of a range of readily available plant-based extracts and chemicals that may improve brain function and which have attracted sufficient research in this regard to reach a conclusion as to their potential effectiveness as nootropics. Many of these candidate phytochemicals/extracts can be grouped by the chemical nature of their potentially active secondary metabolite constituents into alkaloids (caffeine, nicotine), terpenes (ginkgo, ginseng, valerian, Melissa officinalis, sage), and phenolic compounds (curcumin, resveratrol, epigallocatechin-3-gallate, Hypericum perforatum, soy isoflavones). They are discussed in terms of how an increased understanding of the relationship between their ecological roles and CNS effects might further the field of natural, phytochemical drug discovery.

Phytochemical Screening and Antibacterial Activity of Genista Microcephala and Rosmarinus Officinalis Extracts From Libyan’s Regions

“…In concisely the results of agar disc diffusion method are presented as in Table 1 several phytochemicals have been known to possess antibacterial properties. Such as tannins, alkaloids, saponins, flavonoids and sterols have found to own growth inhibitory impact on Salmonella 26 . Tannins form irreversible complexes with proline-rich protein resulting in inhibition of cell synthesis of bacteria 27 .…”

Safety assessment and behavioral effects of Solanum guaraniticum leaf extract in rats

“…Although this study does not present microscopic evaluation of brain tissues, these results should be further investigated prior to indication of this plant as a phytotherapeutic agent. Further, it is quite possible that the extract´s compounds are related to this activity, since it is known that a wide range of phenolic compounds interact directly with neurotransmitter systems and exert depressant effects (Kennedy, Wightman, 2011).…”

Does the Plant Matrix Type Have Impact on Rutin Transformation During Its Extraction?

“…(Bourgaud et al 2001;Crozier et al 2006;Kennedy and Wightman 2011;Pandey and Rizvi 2009). Rutin, being a secondary plant metabolite, is one of the highly valued compounds.…”