Adaptogenic and Neuroprotective Effects of the Thai Herbal Formula AYW-KK-04 Against Chronic Stress-Induced Cognitive Impairment

Background/Objectives: Unpredictable chronic mild stress exposure is a primary driver of cognitive decline, largely mediated by hypothalamic–pituitary–adrenal (HPA) axis dysregulation and subsequent oxidative neurotoxicity. In traditional Thai medicine, the AYW-KK-04 formulation—a complex polyherbal remedy—has long been utilized as a “Ya Aayu-Wattana” to restore vitality and elemental balance, yet its neurobiological mechanisms remain poorly understood. This study aimed to evaluate the adaptogenic and neuroprotective potential of AYW-KK-04 against cognitive impairment. Methods: Unpredictable Chronic Mild Stress (UCMS)-induced cognitive impairment in a ICR mouse model. Total phenolic and flavonoid contents and antioxidant capacity (ABTS assay) of AYW-KK-04 were determined. Behavioral assessments using Y-maze test, novel object recognition test (NORT), and Morris Water Maze (MWM) test. BDNF, CREB, Nrf and Keap1 mRNA gene expression, SOD and CAT enzymatic activity and lipid peroxidation assay were investigated to clarify the mechanisms of action. Moreover, HPLC chromatography was studied to quantify the active compounds of the AYW-KK-04 formulation. Results: It demonstrated that oral administration of AYW-KK-04 significantly reversed UCMS-induced memory deficits. At the molecular level, AYW-KK-04 effectively upregulated BDNF and CREB mRNA expression in the frontal cortex and hippocampus, suggesting a restoration of synaptic plasticity. Simultaneously, the formulation activated the Nrf2/Keap1 signaling pathway, leading to enhanced SOD and CAT enzymatic activities and a marked reduction in MDA-mediated lipid peroxidation. HPLC analysis confirmed the presence and consistency of key bioactive constituents. Conclusions: These findings suggest that the adaptogenic properties of AYW-KK-04 arise from its dual capacity to reinforce neurotrophic support and bolster the endogenous antioxidant shield, providing a mechanistic support for the traditional use of AYW-KK-04 as an adaptogenic formulation and highlighting its potential as a multi-target intervention for stress-related cognitive dysfunction.