## 5 Therapeutic Implications of WA in AD
### Role of WA and Its Derivatives
#### 5.1.1 WA and Its Derivatives A\(\beta\) Plaque Formation Inhibitors  
Published research indicated that A\(\beta\) deposition in the brain is one of the main factors in neurodegeneration [145]. As a result, amyloid \(\beta\) is one of the therapeutic targets for the development of possible AD treatments [146]. By limiting the production of this peptide, compounds that may aid in their accumulation and aggregation are sought for both the prevention and advancement of AD. However, research findings showed that these strategies have failed to provide therapeutic benefits in large clinical trials for those with mild to severe AD. As a result, molecular species called A\(\beta\) oligomers are currently the primary focus, and numerous monoclonal antibodies have provided promising outcomes when directed against these species [147]. Because A\(\beta\) oligomers are in equilibrium with both monomeric and aggregated species, earlier medications that effectively eliminated monomeric A\(\beta\) or A\(\beta\) plaques should have shown therapeutic advantages as well.  
[PERSON] and coworkers conducted the first study, which showed that WA could protect the brain from the toxic effects of amyloid-beta plaques. These researchers demonstrated that amyloid-beta severely affects neuronal functions and structures, and WA decreased the secretion of amyloid \(\beta\) and induced neurotoxicity in SH-SYSY cells (SH-APP) in which the amyloid precursor protein (APP)-plasmid was transfected. When SH-APP cells were exposed to neurotoxic HIV-1 Tat and cocaine, the level of A\(\beta\)40 rose. Both neurotoxic protein HIV-1 Tat-induced and cocaine-induced A\(\beta\) aggregates in SH-APP were significantly reduced by employing WA with a concentration of 2 uM. Additionally, WA diminishes the amount of bending on the cell membrane and the occurrence of cytoplasmic vacuoles, two indices of neurotoxicity. However, further research is required to prove WA effectiveness in vivo [24]. A follow-up investigation examined the role of WA on A\(\beta\) formation by using congo red (CR) staining to highlight the cells. Results showed that WA treated SH-APP cell cultures display less staining with the toxic A\(\beta\) peptide than dimethyl sulfoxide (DMSO)-treated SH-APP cell cultures. DMSO-treated SH-APP cells expressed larger quantities of A\(\beta\), which is stained red after being CR tagged. As SH-APP cells treated with WA had lower amounts of A\(\beta\), there was less staining in these WA-treated cells [148].  
Published work demonstrated that derivatives such as withanolide A increases \(\alpha\)-secretase expression and decrease \(\beta\)-secretase expression in cultured normal rat cortical neurons. When APP is treated with ADAM10, production of A\(\beta\) is reduced due to alternative production of soluble and non-toxic APP\(\alpha\). As a result, withanolide A enhanced production of soluble APP\(\alpha\) in cultured neurons. It was also shown that withanolide A enhances the expression of a significant proteolytic insulin-degrading enzyme (IDE), which is associated with A\(\beta\) degradation [4; 146; 149; 150]. These findings indicate that withanolideA may decrease A\(\beta\) by enhancing the production of soluble APP\(\alpha\) and A\(\beta\). In light of these reports, withanolide A is a significant candidate for a multifunctional Alzheimer's disease drug [4; 146; 149; 150]. Furthermore, neuronal cell death caused by amyloid plaques was blocked by withuanamide. Molecular modeling studies have shown that withuanamide A and C attach uniquely to the active beta-amyloid pattern (A\(\beta\) 25-35) and block fibril formation [7; 151].