Summary: Researchers say Matcha, a traditional Japanese tea, can help improve mood and mental performance. Match tea powder activates dopaminergic neural networks and improves depressive symptoms in mice that have previously experienced stress due to social isolation.
Source: Kumamoto University
Matcha, a traditional Japanese tea, has been touted for its health benefits – it can boost mood and mental performance in humans and mice – but more mechanistic research is needed. Therefore, Japanese researchers evaluated the antidepressant effects of Matcha tea powder in mice.
The powder activates dopaminergic neural circuits and ameliorates depression in some mice, depending on the animal’s previous mental state. More studies like this could help develop better antidepressants.
Depression is currently the most common mental disorder in the world and the number of people affected by it continues to grow. Although the onset of depression varies among individuals, the condition is generally believed to stem from a reduction in dopamine in the brain.
Dopamine, a neurotransmitter and hormone, plays an important role in improving mood and making a person feel happy, fulfilled and motivated.
And although various antidepressants have been developed to counter the effect of low dopamine, these have many side effects. Additionally, people may develop resistance to antidepressants, requiring higher doses over time or a frequent change of medication. These problems have given impetus to the search for natural products with antidepressant effects.
One such product, Matcha, has recently gained popularity. Sourced from the leaves of Camellia sinensis, rich in mood-boosting compounds, matcha powder is traditionally used to make tea.
Consumption of this tea has been shown to improve anxiety behavior in mice by activating dopamine function via dopamine D1 receptor signaling. The resulting dopamine boost could also improve symptoms of depression. So Dr. Yuki Kurauchi from Kumamoto University led a team of researchers to study the effects of Matcha tea powder on socially isolated mice.
They detailed their findings in an article published in Nutrients.
The team used stress-tolerant BALB/c and stress-sensitive C57BL/6J mice subjected to social isolation stress for their experiments. However, oral administration of a Matcha tea suspension appeared to reduce levels of depression in stress-sensitive mice. This was indicated by their performance in the tail suspension test (TST), which is commonly used to assess depression in mice.
Dr. Kurauchi elaborates: “Matcha tea reduced immobility time only in stress-sensitive mice that experienced greater stress from social isolation and exhibited higher depression-like behavior, compared to stress-tolerant mice.
How did it happen? The team dug deeper. Immunohistochemical analysis of mouse brain revealed activation of prefrontal cortex (PFC) and nucleus accumbens (NAc) in stress-sensitive mice after consuming Matcha tea suspension. These regions form an important part of the dopaminergic circuit and are crucial for controlling dopamine levels in the brain.
Their activation, indicated by an increase in the number of cells expressing c-Fos, an important indicator of neuronal activity, would generally increase dopamine levels, thus improving mood.
Stress-sensitive mice with shorter immobility time also had more c-Fos-positive cells in the ventral tegmental area (VTA) of their brain (which initiates dopaminergic activity), as well as in the PFC and the NAc, indicating higher neuronal activity and dopamine production. In contrast, none of these effects were seen in stress-tolerant mice.
This was reinforced by another finding – administration of a dopamine D1 receptor blocker to stress-sensitive mice reversed the antidepressant effects of Matcha tea suspension. Dr. Kurauchi ties it all together.
“These results suggest that Matcha tea powder exerts an antidepressant effect by activating the brain’s dopaminergic system, and this is influenced by the mental state of the individual.”
Dr. Kurauchi is optimistic about the future implications of their research. When evaluating antidepressants in individuals, differences in their mental conditions must also be taken into account, given the sensitivity of stress-sensitive mice to the effect of Matcha tea suspension, but not stress-tolerant mice. stress.
“Additionally, incorporating Matcha into health promotion programs has the potential to improve its widespread utility,” he says.
About this depression research
Author: Press office
Source: Kumamoto University
Contact: Press Office – Kumamoto University
Picture: Image is in public domain
Original research: Free access.
“Antidepressant effect of Matcha tea powder via activation of dopaminergic system in mice is dependent on social isolation stress” by Yuki Kurauchi et al. Nutrients
Abstract
Antidepressant effect of matcha tea powder through activation of dopaminergic system in mice depends on social isolation stress
Matcha tea powder is believed to have various physiological benefits; however, its detailed mechanism of action has been poorly understood.
Here, we investigated whether the mental state of mice, due to social isolation stress, affects the antidepressant effect of Matcha tea powder using the tail suspension test.
Oral administration of Matcha tea powder reduced the duration of immobility in the stress-sensitive C57BL/6J strain, but not in the BALB/c strain. In C57BL/6J mice, SCH23390, a dopamine D1 receptor blocker, prevented Matcha tea powder from exerting its antidepressant effect.
Matcha tea powder also increased the number of c-Fos-positive cells in the prefrontal cortex (PFC) region and nucleus accumbens (NAc) region in C57BL/6J mice, but not in BALB/c mice. .
In contrast, Matcha tea powder did not alter the number of c-Fos-positive cells in the ventral tegmental area (VTA) region. Notably, C57BL/6J mice with shorter immobility time had higher numbers of c-Fos-positive cells in the PFC, NAc and VTA regions. However, no such correlation was observed in stress-tolerant BALB/c mice.
These results suggest that Matcha tea powder exerts an antidepressant effect via activation of the dopaminergic system, including the PFC-NAc-VTA circuit, and that mental states are important factors affecting the physiological benefits of Matcha tea powder. .