Current pharmaceutical treatments for depression have slow onset, limited efficacy, and many side effects. Interest in alternative therapeutic options is thus growing. One such area of research is plant extracts,which carry the benefit sof being suitable for long-term consumption and having fewer side effects.
Lycopene is a natural pigment found in plants, including tomatoes and watermelons. Research has shown that the extract has antioxidant and neuroprotective effects, with some research showing that it can alleviate depressive-like symptoms in mice. Compared to currently-used antidepressants, lycopene has low toxicity and high safety. Its mechanisms of action, however, remain unknown.
In the current study, researchers investigated how lycopene exerts its antidepressant effects. To do so, they treated mice with depressive-like behaviors with lycopene. To uncover potential mechanisms, they assessed synaptic plasticity via the expression of synaptic proteins in the hippocampus.
Ultimately, they found that lycopene treatment improved synaptic deficits caused by depression and reversed depressive-like behaviors in mice. It also upregulated the expression of brain-derived neurotrophic factor (BDNF) and reduced activity of the BDNF–TrkB/pTrkB pathway in the hippocampus. The researchers wrote that the findings suggest lycopene may enhance synaptic plasticity via the BDNF–TrkB/pTrkB signaling pathway.
"[Our] conclusions provide preclinical evidence for the potential clinical use of lycopene and introduce more possibilities for antidepressant treatment, such as serving as an adjunct therapy to SSRIs like fluoxetine. However, the efficacy of such combination therapy requires further investigation," wrote the researchers in their paper.
"In response to the limitations of this experiment, we plan to conduct further verification in future studies and include multiple brain regions in our research,” they continued.
Sources: EurekAlert, Food Science and Nutrition