Extracts of Sideritis scardica and Clinopodium vulgare Alleviate Cognitive Impairments in Scopolamine-Induced Rat Dementia

Sideritis scardica Griseb. and Clinopodium vulgare L., belonging to the Lamiaceae family, are rich in terpenoids and phenolics and exhibit various pharmacological effects, including antioxidant, anti-inflammatory and anti-cancer activities. While the memory-enhancing impacts of S. scardica are well documented, the cognitive benefits of C. vulgare remain unexplored. This study assessed the potential effect of C. vulgare on learning and memory in healthy and scopolamine (Sco)-induced memory-impaired male Wistar rats, comparing it with the effects of S. scardica. Over a 21-day period, rats orally received extracts of cultivated S. scardica (200 mg/kg) and C. vulgare (100 mg/kg), either individually or in combination, with administration starting 10 days before and continuing 11 days simultaneously with Sco injection at a dose of 2 mg/kg intraperitoneally. The results showed that both extracts effectively mitigated Sco-induced memory impairment. Their combination significantly improved recognition memory and maintained monoaminergic function. S. scardica excelled in preserving spatial working memory, while C. vulgare exhibited comparable retention of recognition memory, robust antioxidant activity and acetylcholinesterase inhibitory activity. The extracts alleviated Sco-induced downregulation of p-CREB/BDNF signaling, suggesting neuroprotective mechanisms. The extract combination positively affected most of the Sco-induced impairments, underscoring the potential for further investigation of these extracts for therapeutic development.