Ethnopharmacological Approaches for Dementia Therapy and Significance of Natural Products and Herbal Drugs

Abstract

Dementia is a clinical syndrome wherein gradual decline of mental and cognitive capabilities of an afflicted person takes place. Dementia is associated with various risk factors and conditions such as insufficient cerebral blood supply, toxin exposure, mitochondrial dysfunction, oxidative damage, and often coexisting with some neurodegenerative disorders such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD). Although there are well-established (semi-)synthetic drugs currently used for the management of AD and AD-associated dementia, most of them have several adverse effects. Thus, traditional medicine provides various plant-derived lead molecules that may be useful for further medical research. Herein we review the worldwide use of ethnomedicinal plants in dementia treatment. We have explored a number of recognized databases by using keywords and phrases such as “dementia”, “Alzheimer's,” “traditional medicine,” “ethnopharmacology,” “ethnobotany,” “herbs,” “medicinal plants” or other relevant terms, and summarized 90 medicinal plants that are traditionally used to treat dementia. Moreover, we highlight five medicinal plants or plant genera of prime importance and discuss the physiological effects, as well as the mechanism of action of their major bioactive compounds. Furthermore, the link between mitochondrial dysfunction and dementia is also discussed. We conclude that several drugs of plant origin may serve as promising therapeutics for the treatment of dementia, however, pivotal evidence for their therapeutic efficacy in advanced clinical studies is still lacking.

Acanthus ebracteatus leaf extract provides neuronal cell protection against oxidative stress injury induced by glutamate

“…At the present time, there is growing worldwide use of herbal medicines for preventive and therapeutic applications based on historical knowledge. In connection with the aforementioned mechanism of glutamate-induced oxidative toxicity, medicinal plants or naturally derived compounds with antioxidant and antiapoptotic effects are currently being researched as neuroprotective agents [ 15 – 19 ]. Acanthus ebracteatus Vahl.…”

Traditional Uses, Bioactive Chemical Constituents, and Pharmacological and Toxicological Activities of Glycyrrhiza glabra L. (Fabaceae)

“…This indicates that G. glabra extract is useful in improving the capacity for learning; however, its dose should be closely determined to inhibit the depressant effectiveness. Moreover, diammonium-glycyrrhizinate inhibited the cognitive and mitochondrial malfunctions caused by Aβ42 in vivo [101]. In conclusion, Glycyrrhiza extracts exhibit antioxidative and anti-inflammatory potential, and they regulate glutamate signaling and apoptosis.…”

“…They showed great learning and memory enhancement efficacy in mice; however, its mode of action is not clear yet [100]. The oral administration of another Glycyrrhiza species, G. glabra extract, was reported to enhance the learning ability of mice [101]. This indicates that G. glabra extract is useful in improving the capacity for learning; however, its dose should be closely determined to inhibit the depressant effectiveness.…”

Bioactive Compounds in Functional Meat Products

“…[ 104 , 105 ]. Numerous studies have reported a beneficial effect of polyphenols in the prevention of some diseases: ischemic heart diseases, Alzheimer’s disease, diabetes, liver disorders, allergies, bowel diseases and more [ 106 , 107 , 108 , 109 , 110 ]. Polyphenols have strong antioxidant properties related to free radical scavenging activity, chain-braking oxidation pathway activity and metal-chelating activity [ 111 , 112 , 113 , 114 ].…”