Development of Synergy-Based Combination for Learning and Memory Using in vitro, in vivo and TLC-MS-Bioautographic Studies

Abstract

The present study is aimed at developing a synergistic combination to enhance learning and memory in Alzheimer’s patients with the help of eight common medicinal plants used in the AYUSH system. Aqueous and hydroalcoholic extracts of eight medicinal plants from the AYUSH system of medicine were prepared. These were subjected to in vitro anticholinesterase activity, to find out the combination index of synergistic combination. The synergistic combination and their individual extracts were subjected to total phenol, flavonoid and antioxidant activity estimation. Further, in vivo neurobehavioral studies in rats were carried out followed by TLC-MS-bioautographic identification of bioactive metabolites. Out of the sixteen extracts, aqueous extracts of Withania somnifera (L.) Dunal (WSA) and Myristica fragrans (L.) Dunal (MFA) were selected for the development of synergistic combination based on their IC50 value in vitro anticholinesterase assay. The synergistic combination inhibited the anticholinesterase activity significantly as compared to the individual extracts of WSA and MFA. The synergistic combination also showed more phenolic and flavonoid contents with potential antioxidant activity. The TLC-bioautography showed four white spots in WSA, signifying sitoindosides VII, VIII, quercetin, isopelletierine and Withanolide S as AChE inhibitory compounds while showing five white spots of anti-cholinesterase active metabolites identified as eugenol, methyl eugenol, myristic acid, galbacin and β-sitosterol in MFA. The observation of neurocognitive behavior in amnesia induced subjects manifested that both the synergistic combinations showed comparable results to that of standard piracetam, though the synergistic combination containing a higher concentration of WSA showed more appreciable results in ameliorating dementia in rats. The study suggests that the synergy based combination successfully enhanced memory and learning by abating free radical and acetylcholine levels, and increased learning and memory in rats, providing a strong rationale for its use in the treatment of dementia and Alzheimer’s disease.

In vitro antioxidant and acetylcholinesterase activities of catechin-loaded green fabricated zinc oxide nanoparticles

“…In a related investigation, Withania somnifera lowered AChE activity by 30% when used at a concentration of 12.50 µg/mL, and reached roughly 50% inhibition at 50 µg/mL [36]. A previous study in oral treatment of ZnONPS and ZnCAP for brain abnormalities caused by retinone RTNE has significantly higher inhibition activity of AChE [37].…”

Withania somnifera L.: Phenolic Compounds Composition and Biological Activity of Commercial Samples and Its Aqueous and Hydromethanolic Extracts

“…This finding is in agreement with the report of Maya and Sarada [ 87 ] who suggested important AChE inhibitory activity of methanolic extracts of roots, despite its low content of polyphenols. Apart from single-extract treatments, Khan et al [ 88 ] recently suggested the synergistic effects of the aqueous extracts of W. somnifera and Myristica fragrans which significantly increased the IC 50 values in in vitro anticholinesterase assays, compared to treatments with single extracts.…”

Molecular mechanism of Epimedium in the treatment of vascular dementia based on network pharmacology and molecular docking

“…Quercetin, as a component of Epimedium, has been shown to reduce oxidative stress, decrease NO levels, and inhibit NOS activity in brain tissue. It exerted a protective role on cognitive function in VaD by improving cerebral blood flow, regulating oxidative stress, cerebral energy metabolism and cholinergic function (Tota et al, 2010 ; Khan et al, 2021 ; Singh and Garabadu, 2021 ). Researches also have found that luteolin, another component of Epimedium, can inhibit cerebral ROS levels, and modulate inflammatory factors to achieve protective effects on neurons through anti-oxidative stress, anti-inflammatory and anti-apoptotic effects (Bastianetto et al, 2011 ; Wang and Gao, 2015 ).…”