Rosmarinic Acid Derivatives’ Inhibition of Glycogen Synthase Kinase-3β Is the Pharmacological Basis of Kangen-Karyu in Alzheimer’s Disease

Abstract

Inhibition of glycogen synthase kinase 3β (GSK-3β) is considered to be the central therapeutic approach against Alzheimer’s disease (AD). In the present study, boiled water extracts of the Kangen-karyu (KK) herbal mixture and its constituents were screened for GSK-3β inhibitory activity. KK is used in traditional Kampo and Chinese medicines for improving cognitive function. The GSK-3β inhibition potential was evaluated by using the Kinase-Glo luminescent kinase assay platform. Furthermore, enzyme kinetics and in silico modeling were performed by using AutoDockTools to demonstrate the mechanism of enzyme inhibition. KK extract significantly inhibited GSK-3β in a concentration-dependent manner (IC50: 17.05 ± 1.14 μg/mL) when compared with the reference drug luteolin (IC50: 2.18 ± 0.13 μM). Among the six components of KK, extracts of Cyperi Rhizoma and Salviae Miltiorrhizae Radix significantly inhibited GSK-3β with IC50 values of 20.68 ± 2.50 and 7.77 ± 1.38 μg/mL, respectively. Among the constituents of the roots of S. miltiorrhiza water extract, rosmarinic acid, magnesium lithospermate B, salvianolic acid A, salvianolic acid B, and salvianolic acid C inhibited GSK-3β with IC50 values ranging from 6.97 to 135.5 μM. Salvianolic acid B was found to be an ATP-competitive inhibitor of GSK-3β and showed the lowest IC50 value (6.97 ± 0.96 µM). In silico modeling suggested a mechanism of action by which the hydrophobic, π–cation, and hydrophilic interactions of salvianolic acid B at ATP and substrate sites are critical for the observed GSK-3β inhibition. Therefore, one of the mechanisms of action of KK against AD may be the inhibition of GSK-3β and one of the active components of KK is the root of S. miltiorrhiza and its constituents: rosmarinic acid, magnesium lithospermate B, and salvianolic acids A, B, and C. Our results demonstrate the pharmacological basis for the use of KK against AD.

Ras-AKT signaling represses the phosphorylation of histone H1.5 at threonine 10 via GSK3 to promote the progression of glioma

“…not only involved in the regulation of glycogen metabolism, but also play central roles in a variety of signaling pathways which are closely associated with cell mobility, proliferation, and survival [31]. More interestingly, a previous study strongly suggested that GSK3 was responsible for phosphorylating H1.5 at threonine 10 [17].…”

Overview of Salvia miltiorrhiza as a Potential Therapeutic Agent for Various Diseases: An Update on Efficacy and Mechanisms of Action

“…For instance, Yu et al demonstrated that treatment with S. miltiorrhiza extract at doses of 0.01, 0.1, 0.2 mg/mL for 2 h inhibited ROS generation in SH-SY5Y cells [ 92 ]. In addition, Paudel et al reported on the inhibitory effect of S. miltiorrhiza extract on GSK-3β [ 93 ], while Ozarowski et al examined the inhibitory effect of S. miltiorrhiza extract administration at a dose of 200 mg/kg for 28 days on AChE as well as BuChE and BACE1 in the rat brain cortex [ 94 ]. These multi-functional properties of S. miltiorrhiza extract suggest that it could act on multiple targets for the treatment of cognitive impairment and neurodegeneration.…”

“…S. miltiorrhiza extract decreased the intracellular reactive oxygen species (ROS) levels, cleaved caspase-3 and cytosolic cytochrome c expression, and Bax/Bcl-2 ratio. Paudel et al reported that S. miltiorrhiza extract significantly inhibited the expression of glycogen synthase kinase-3β (GSK-3β) with IC 50 values of 7.77±1.38 [ 93 ]. According to Ozarowski et al, subchronic (28-fold) oral administration of 200 mg/kg S. miltiorrhiza extract for 28 days led to an improvement in long-term memory of rats as assessed by passive avoidance test, partially through inhibition of acetylcholinesterase (AChE) activity [ 94 ].…”

A systematic review on anti-Alzheimer's disease activity of prescription Kangen-karyu

“…In our previous study conducted to evaluate anti-AD activity in vitro via the GSK3 enzyme, boiled water extract of Kangen-karyu demonstrated potent inhibition of GSK3β with an IC 50 value of 17.05 ± 1.14 μg/mL, as shown in Table 4 (39). Also, water extracts of all individual components showed good inhibition with IC 50 values ranging from 7.77 to 93.61 μg/mL.…”