Establishing Natural Nootropics: Recent Molecular Enhancement Influenced by Natural Nootropic

Abstract

Nootropics or smart drugs are well-known compounds or supplements that enhance the cognitive performance. They work by increasing the mental function such as memory, creativity, motivation, and attention. Recent researches were focused on establishing a new potential nootropic derived from synthetic and natural products. The influence of nootropic in the brain has been studied widely. The nootropic affects the brain performances through number of mechanisms or pathways, for example, dopaminergic pathway. Previous researches have reported the influence of nootropics on treating memory disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Those disorders are observed to impair the same pathways of the nootropics. Thus, recent established nootropics are designed sensitively and effectively towards the pathways. Natural nootropics such as Ginkgo biloba have been widely studied to support the beneficial effects of the compounds. Present review is concentrated on the main pathways, namely, dopaminergic and cholinergic system, and the involvement of amyloid precursor protein and secondary messenger in improving the cognitive performance.

Figure 1

Bacopa monnieri. The plant has purple flowers with oblong leaves found throughout the Indian subcontinent. This plant is classified under the family of Scrophulariaceae. On the right is the chemical structure for bacosides [107].

Figure 2

Nicotiana mutabilis. The plant is classified under the family of Solanaceae and contains nicotine as psychoactive compound (a). Compound A, syn-5-isobutoxy-2-phenyl-3-(3-pyridyl)-isoxazolidine (b), and compound B, syn-2,5-diphenyl-3-(3-pyridyl)-isoxazolidine (c), are example of synthesised nootropics derived from nicotine for learning and memory purposes [122].

Figure 3

Ginkgo biloba. The plant is classified under the family of Ginkgoaceae, the only species in the division of Ginkgophyta. With 40 m in height, this tree is characterised by the fan-shaped leaves composed of more than two distinct lobes (a). Ginkgolide A, R¹=H; R²=H; R³=OH, Ginkgolide B, R¹=OH; R²=H; R³=OH, Ginkgolide C, R¹=OH; R²=OH; R³=OH, Ginkgolide J, R¹=H; R²=OH; R³=OH, Ginkgolide M, R¹=OH; R²=OH; R³=H (b) [129].

Figure 4

Panax ginseng. Ginseng belongs to the genus Panax of the family Araliaceae, found in the cooler climates. The name of the plant is derived from the Chinese term meaning “person” and “plant root” due to the feature of the root that resembles the legs of a person (a). Ginsenosides, the principal bioactive compounds of P. ginseng. A, Panaxadiol; B, Panaxatriol; C, oleanolic acid (b) [137].

Figure 5

Rhodiola rosea. It belongs to the family of Crassulaceae. R. rosea is growing on the sea cliffs and on the mountains. The plant is dioecious, with yellow to greenish yellow flowers (a). Salidroside is claimed as an active constituent responsible for neuroprotective and antioxidant properties (b) [140].