Combating depression with rosemary (Rosmarinus officinalis L.)-derived polyphenols: Major phytochemicals, functional properties, and potential.

Depression is a common mental condition with high prevalence and recurrence rates worldwide. The active polyphenols in Rosmarinus officinalis L. contain several pharmacological activities, including anti-inflammatory, antibacterial, and neuroprotective characteristics. However, the effects of rosemary polyphenols on depression have not been thoroughly studied. The anti-inflammatory activity and regulatory effects on gut microbiota of key rosemary polyphenols, as well as their impacts on depression, are the main emphasis of this research. We conclude that the anti-depressive effects of rosemary polyphenols are due to anti-inflammatory properties and bidirectional relationship with gut microbiota, including inhibiting inflammatory pathways and cytokines (reducing pro-inflammation cytokines, suppressing NF-κB and NLRP3 inflammasomes, and upregulating Nrf2/HO-1 pathway), altering intestinal microbiota structure and metabolites (polyphenols-related microbial metabolites and biotransformation of polyphenols by microbiota). This paper provides a better understanding of the anti-depressive effects of polyphenols in Rosmarinus officinalis L.