Multi-Target Neuroprotective Activity of the Traditional Thai Polyherbal Formula Sangvichai against Amyloid-β42-Induced Cellular Stress: An in vitro Study

Background

Sangvichai is a traditional Thai polyherbal formula composed of 40 botanical ingredients and has been used for neurological complaints and age-related cognitive decline. However, scientific evidence supporting its neuroprotective effects and underlying mechanisms remains limited.

Objectives

This study aimed to investigate the biological activity of Sangvichai against amyloid-β42 (Aβ42)-induced neuronal cytotoxicity and to evaluate its multi-target effects in cellular models relevant to Alzheimer’s Disease (AD).

Materials and Methods

Sangvichai extract was evaluated using a panel of in vitro assays. Antioxidant activity was assessed by DPPH radical scavenging and intracellular reactive oxygen species (ROS) assays. Anti-inflammatory effects were examined via nitric oxide production in lipopolysaccharide-stimulated macrophages. Cholinergic modulation was determined by acetylcholinesterase inhibition, while melatonin MT2 receptor-mediated cAMP signaling was analyzed. Neuroprotective effects were assessed in SH-SY5Y neuronal cells exposed to aggregated Aβ42.

Results

Sangvichai showed moderate DPPH radical scavenging activity (IC₅₀ = 737.80 ± 3.03 μg/mL) but demonstrated stronger cellular antioxidant effects, significantly reducing intracellular ROS under inflammatory conditions (IC₅₀ = 503.20 ± 37.40 μg/mL). The extract suppressed nitric oxide production by 31.48% and inhibited acetylcholinesterase activity in a concentration-dependent manner (IC₅₀ = 1.21 ± 0.20 mg/mL). In addition, Sangvichai reduced MT2 receptor-mediated cAMP signaling by 43.73% and significantly attenuated Aβ42-induced neuronal cytotoxicity.

Conclusion

Sangvichai exerts coordinated antioxidant, anti-inflammatory, neuromodulatory, and neuroprotective effects in vitro, supporting a multi-target mode of action relevant to AD-associated cellular pathology and providing a foundation for further preclinical investigation.