TLR4 and major depressive disorder: They further found that OBB or OBB‐NC administration can reduce long‐term neuropsychiatric complications such as anxiety, depression, and cognitive impairment, as well as inhibit the HMGB1‐mediated TLR4/NF‐κB pathway in microglia by downregulating the levels of TLR4, HMGB1, NF‐κB, TNF‐α and IL‐6 [66].