Nanoemulsion-based piperine to enhance bioavailability for the treatment of LPS-induced depression-like behaviour in mice.

In the present study, the objective was to encapsulate piperine in nanoform by solvent evaporation method and to investigate the antidepressant-like activity of nanopiperine in lipopolysaccharide (LPS) induced depression in mice. LPS-induced depression in mice was reversed by repeated treatment of nanopiperine at dosages of 5 and 10 mg/kg body weight for 14 days. After 24 h of LPS injection, the animals were exposed to a (TST) tail suspension test and (FST) forced swim test. A sequence of behaviours was measured on days 0, 7, and 14. On day 14, the animals were euthanized, and the blood was collected; biochemical analysis was performed for the measurement of inflammatory and oxidative stress markers. Within the same period, nanopiperine improved hippocampal progenitor cell proliferation and increased brain-derived neurotrophic factor (BDNF) levels in the hippocampus of mice subjected to LPS-induced stress. In addition, the neurotransmitter estimation by the HPLC method showed that nanopiperine increased the levels of neurotransmitters. In summary, the nanopiperine showed potent neuroprotective and antidepressant activity, and stability relating to the elevated level of hippocampal BDNF level and as compared to pure piperine, the nanopiperine showed better oral bioavailability and stability.