Turmeric Component Studied in Discomfort and Mood

According to a new study, curcumin modifies behavioral changes associated with temporary physical discomfort and sadness in rats. Discomfort and sadness often occur simultaneously. Previous research suggests that this may be mediated by nitrogen-containing compounds and may involve the production of nervous system inflammation caused by nitrodative stress.

Curcumin is the principal curcuminoid in turmeric (Curcuma longa). It is an effective antioxidant and scavenger of reactive oxygen and nitrogen species.

Rats were initially treated with reserpine daily for 3 days to induce pain and sadness. Some of the rats were treated with various dosages of curcumin. The rats were evaluated for biogenic nitrogen-containing compounds including the neurotransmitters dopamine, norepinephrine and serotonin. The rats were also assessed in the areas of the brain known as the cortex and hippocampus for levels of substance P, a neuropeptide involved in pain perception; nitrodative stress; inflammatory cytokines; nuclear factor kappa beta, which is a protein complex that plays a role in the cellular response to stressors; and caspase-3, an enzyme involved in apoptosis, or programmed cell death.

The researchers showed that reserpine significantly reduced the pain threshold in the rats and increased immobility time in the forced swim test, which is used as a test for sadness in animal models. The changes in rat behavior with reserpine were associated with reduced levels of dopamine, norepinephrine and serotonin and increased levels of substance P, nitrodative stress, inflammatory cytokines, nuclear factor kappa beta and caspase-3. Treatment of the rats with curcumin ameliorated these changes, with increasing dosages resulting in a more pronounced effect.

The study authors concluded that curcumin ameliorated the behavioral deficits associated with physical discomfort and sadness in rats induced by reserpine by restoring behavioral, biochemical, neurochemical and molecular alterations.

Reference:

Arora V, Kuhad A, Tiwari V, Chopra K. Curcumin ameliorates reserpine-induced pain-depression dyad: Behavioural, biochemical, neurochemical and molecular evidences. Psychoneuroendocrinology. 2011 May 23. Published Online Ahead of Print.