Gardenia jasminoides J. Ellis extract attenuates memory impairment in rats with Alzheimer's disease by suppressing NLRP3 inflammasome.

Alzheimer's disease (AD) is characterized by degeneration of the central nervous system. Recently, many studies have emphasized the beneficial role of Gardenia jasminoides J. Ellis extract (GJ-4) in neuroprotection, which is considered a potential drug for treating AD. However, the mechanism underlying its neuroprotective effects is obscure. This research intended to analyze the effectiveness of GJ-4 to induce neuronal protective role on a rat model of neurotoxicity and probe the potential mechanism. An AD model was established by intraperitoneal injection of aluminum chloride (AlCl). Then, AlCl-induced rats were administered 25 mg/kg and 50 mg/kg of GJ-4 orally. This study indicated that GJ-4 (25 and 50 mg/kg) mitigated AD-like behaviors, as evidenced by enhanced ambulation frequency, rearing frequency, and time spent in the target quadrant and decreased grooming frequency, defecation frequency, and escape latency in AlCl-challenged rats. Also, GJ-4 at 25 and 50 mg/kg exerted an anti-apoptosis effect in the hippocampus of AlCl-treated rats. Furthermore, GJ-4 (25 and 50 mg/kg) exhibited an anti-inflammatory effect in the hippocampus by repressing the activation of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome, further inhibiting the activation of Caspase 1, ASC, IL-1β, and IL-18 in AD hippocampus. Altogether, GJ-4 mitigated AlCl-triggered impairment of learning and memory in AD rats via repressing NLRP3 inflammasome.