No abstract

Camellia euphlebia (family, Theaceae) is a Chinese folk medicine, known for its multiple pharmacological properties. The present study aimed to provide further insights into the therapeutic basis of C. euphlebia using several animal behavioral tests and physiological indexes. Tail suspension test, forced swimming test, open-field test, chronic unpredictable mild stress (CUMS), reversal of reserpine-induced hypothermia and palpebral ptosis, and 5-hydroxytryptophane-induced head-twitch response were used to evaluate the antidepressant effect of aqueous extract of Camellia euphlebia (AEC) on mice. The possible underlying mechanism was explored by investigating the changes associated with several parameters of animal behavior, as well as the changes in monoamine neurotransmitter and stress hormone levels in these animals during the tests. Mice administered AEC at 100 and 200 mg/kg/day doses for 7 days showed significantly reduced immobility duration in forced swimming test and tail suspension test, whilst exhibiting no apparent changes in locomotor activity. Additionally, administration of AEC also effectively antagonized reserpine-induced palpebral ptosis and hypothermia and enhanced 5-hydroxytryptophane-induced head-twitch response. AEC significantly elevated the levels of serotonin, noradrenaline and dopamine in the blood and brain compared to non-treated mice. After 28 days of administration, the maximum AEC dose (100 mg/kg/day) significantly reversed CUMS-induced inhibition of weight gain and sucrose intake, while decreasing the levels of plasma adrenocorticotropic hormone and serum corticosterone. The antidepressant effect of AEC appeared to involve the alteration of hypothalamic-pituitary-adrenal axis and monoaminergic systems.

Camellia euphlebia Merr. ex Sealy is a traditional Chinese medicine that has been widely used for improvement of human emotions in the Guangxi Province of southern China. However, there are no studies about the anxiolytic and antidepressant activities of Camellia euphlebia. This study evaluated the anxiolytic and antidepressant activities of the aqueous extract from Camellia euphlebia (CEE) in mice. We found that administration of 400 mg/kg CEE or 20 mg/kg fluoxetine for 7 days significantly reduced the immobility time in both TST and FST. Oral administration of 100 mg/kg extract or 4 mg/kg diazepam for 7 days significantly increased the percentage of time spent and the number of entries into the open arms of the EPMT. In addition, the time spent by mice in the illuminated side of the LDBT was increased. Furthermore, pretreatment with 400 mg/kg CEE for 7 days significantly elevated the level of 5-HT and DA in the whole brain of mice. These results provide support for the potential anxiolytic and antidepressant activity of Camellia euphlebia and contribute towards validation of the traditional use of Camellia euphlebia in the treatment of emotional disorders.