Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University, 90619-900 Porto Alegre, Rio Grande do Sul, Brazil.
Psychopharmacology (Berl). 2012 Feb;219(4):1133-40. doi: 10.1007/s00213-011-2449-3. Epub 2011 Aug 26.
Cannabidiol, the main nonpsychotropic constituent of Cannabis sativa, possesses a large number of pharmacological effects including anticonvulsive, sedative, hypnotic, anxiolytic, antipsychotic, anti-inflammatory, and neuroprotective, as demonstrated in clinical and preclinical studies. Many neurodegenerative disorders involve cognitive deficits, and this has led to interest in whether cannabidiol could be useful in the treatment of memory impairment associated to these diseases.
We used an animal model of cognitive impairment induced by iron overload in order to test the effects of cannabidiol in memory-impaired rats.
Rats received vehicle or iron at postnatal days 12-14. At the age of 2 months, they received an acute intraperitoneal injection of vehicle or cannabidiol (5.0 or 10.0 mg/kg) immediately after the training session of the novel object recognition task. In order to investigate the effects of chronic cannabidiol, iron-treated rats received daily intraperitoneal injections of cannabidiol for 14 days. Twenty-four hours after the last injection, they were submitted to object recognition training. Retention tests were performed 24 h after training.
A single acute injection of cannabidiol at the highest dose was able to recover memory in iron-treated rats. Chronic cannabidiol improved recognition memory in iron-treated rats. Acute or chronic cannabidiol does not affect memory in control rats.
The present findings provide evidence suggesting the potential use of cannabidiol for the treatment of cognitive decline associated with neurodegenerative disorders. Further studies, including clinical trials, are warranted to determine the usefulness of cannabidiol in humans suffering from neurodegenerative disorders.
大麻二酚是大麻的主要非精神活性成分，具有多种药理作用，包括抗惊厥、镇静、催眠、抗焦虑、抗精神病、抗炎和神经保护作用，这在临床和临床前研究中都有体现。许多神经退行性疾病都涉及认知障碍，这使得人们产生了这样的兴趣：大麻二酚是否可用于治疗与这些疾病相关的记忆障碍。
我们使用铁超负荷诱导的认知障碍动物模型来测试大麻二酚对记忆受损大鼠的作用。
大鼠在出生后 12-14 天接受载体或铁处理。在 2 个月大时，它们在新物体识别任务的训练后立即接受载体或大麻二酚（5.0 或 10.0 mg/kg）的单次腹腔内注射。为了研究慢性大麻二酚的作用，铁处理的大鼠接受每日腹腔内注射大麻二酚 14 天。最后一次注射后 24 小时，它们接受物体识别训练。在训练后 24 小时进行保留测试。
单次腹腔内注射最高剂量的大麻二酚能够恢复铁处理大鼠的记忆。慢性大麻二酚改善了铁处理大鼠的识别记忆。急性或慢性大麻二酚对对照大鼠的记忆没有影响。
本研究结果提供了大麻二酚可能用于治疗与神经退行性疾病相关的认知能力下降的证据。需要进一步的研究，包括临床试验，以确定大麻二酚在患有神经退行性疾病的人类中的有效性。
