Protective effects of Lactobacillus acidophilus LM1060 on LPS/H2O2-induced cytotoxicity in SK-N-SH cells and scopolamine-induced memory impairment in mice.

Abstract

Background/objectives: This study examined the neuroprotective effects of Lactobacillus acidophilus LM1060 against scopolamine-induced memory impairment to elucidate its underlying mechanisms.

Materials/methods: LM1060 (1 × 10⁹ CFU/day) or donepezil (DO, 2 mg/kg) was administered to Institute of Cancer Research mice by oral gavage for 14 days (days 1-14). Memory impairment was induced by scopolamine (1 mg/kg, intraperitoneal injection) for 6 days (days 9-14). Behavioral tests, including the Y-maze and novel object recognition tests, were performed to evaluate the cognitive function. The effects of LM1060 on the acetylcholine (ACh), acetylcholinesterase (AChE), and choline acetyltransferase (ChAT) levels in the hippocampus were examined. The β-secretase activity, β-amyloid levels, and DNA damage in brain tissue were also assessed. In vitro studies were conducted using SK-N-SH neuroblastoma cells to evaluate the cell viability, antioxidant capacity, lactate dehydrogenase (LDH) release, AChE activity, and inflammatory cytokine gene expression.

Results: LM1060 showed a protective effect against scopolamine-induced cognitive dysfunction, as confirmed by behavioral tests including the Y-maze and novel object recognition tests. Oral administration of LM1060 restored the ACh and ChAT activity reduced by scopolamine. The β-secretase activity and β-amyloid levels decreased after the LM1060 and DO treatment. The LM1060 administration group exhibited a higher protective effect against scopolamine-induced DNA damage in brain tissue than the scopolamine-treated group. In vitro studies showed that LM1060 significantly enhanced the cell viability and antioxidant capacity, reduced LDH release and AChE activity, and modulated inflammatory cytokine gene expression by downregulating interleukin (IL)-1β and IL-6 and upregulating IL-10.

Conclusion: L. acidophilus LM1060 exerts potent neuroprotective effects through anti-inflammatory, antioxidant, and cholinergic mechanisms, highlighting its potential as a functional ingredient for cognitive health.