Biphasic effects of Morus alba leaves green tea extract on mice in chronic forced swimming model

Abstract

In this study, the effects of an aqueous extract of Morus alba leaves green tea (ME) on mouse behaviors (depression, anxiety, climbing activity and thermal response), muscle coordination and muscle strength were studied. Male IRC mice received a single intraperitoneal injection of either the ME, desipramine or diazepam. Thirty minutes after injection, the mice were tested in all experimental models. A significant antidepressant-like effect could be detected in the animals receiving either 100 or 200 mg/kg ME. The effect of 200 mg/kg ME in decreasing the immobility time was comparable to 10 mg/kg desipramine. With higher dose (1000 mg/kg), a significant increase in immobility time could be observed. In the elevated plus maze, no increase in time in the open arm could be observed in mice treated with ME at either 100 or 200 mg/kg. However, high doses of ME (500 or 1000 mg/kg) decreased both time in the open arm and the number of entries in the maze. No change in thermal response could be seen in mice treated with ME at doses up to 500 mg/kg, however, at 1000 mg/kg, the response time to heat was increased significantly. The ME at either 500 or 1000 mg/kg also decreased muscle coordination, strength and climbing activity significantly when compared with the control. This study suggests that ME possesses an antidepressant- without an anxiolytic-like effect, however, at high doses, the extract might show the sedative effect and alter other functions such as muscle strength, animal activity in the maze and pain response.

Effect of epigallocatechin gallate supplementation in schizophrenia and bipolar disorder: an 8-week, randomized, double-blind, placebo-controlled study

“…Preclinical studies suggest that green tea extract may possibly benefit patients with schizophrenia. For example, green tea extract: (1) enhances learning and memory in aged rats [Kaur et al 2008]; (2) causes antidepressant-like effects that are comparable to desipramine [Sattayasai et al 2008]; (3) ameliorates lipopolysaccharide (LPS)-induced sickness behavior [Singal et al 2006]; (4) induces anxiolytic effects [Vignes et al 2006]; and (5) reduces reserpine-induced oxidative hepatic damage [Al-Bloushi et al 2009]. As early as 2000 years ago, Chinese emperors made reference to the calming effects of green tea, but we are not aware of any clinical studies of EGCG's psychotropic properties.…”

“…For example, green tea extract: (1) enhances learning and memory in aged rats [Kaur et al . 2008]; (2) causes antidepressant-like effects that are comparable to desipramine [Sattayasai et al . 2008]; (3) ameliorates lipopolysaccharide (LPS)-induced sickness behavior [Singal et al .…”

Effect of green tea on reward learning in healthy individuals: a randomized, double-blind, placebo-controlled pilot study

“…A further research is needed to determine the regulatory effect of green tea on glucocorticoids receptors expression and the target genes involved in the reward learning process and the improvement of depressive symptoms. Furthermore, a significant antidepressant-like effect was detected in mice that received a single intraperitoneal injection of green tea in the forced swim test when compared with the control [28]. A cross-sectional study revealed that higher green tea and coffee consumption was associated with a lower prevalence of depressive symptoms, suggesting that higher consumption of green tea, coffee and caffeine may confer protection against depression [29].…”

Comparative study of hypoglycaemic activity of morus alba with oral hypoglycaemic drug (metformin) in alloxan induced diabetic rats

“…[6][7][8] Some studies have reported many different medicinal properties of mulberry leaves (Morus alba) like neuroprotective property, cardioprotective property, antidepressant property. [9][10][11] It is used as antiinflammatory, diuretic, expectorant and antidiabetic in traditional Chinese medicine. [12][13][14] So this study is undertaken to evaluate the hypoglycaemic effect of aqueous extract of leaves of Morus alba in Alloxan induced diabetic albino rats.…”