Anti-depressant-like effect of peony: a mini-review

Context: Depression is a common psychiatric disorder, yet the clinical efficacy of antidepression therapies is unsatisfactory. Thus, the search for new anti-depressants continues, and natural products remain a promising source of new therapeutic agents. The root part of Paeonia lactiflora Pall. (Ranunculaceae), known as peony, is often used in Chinese herbal prescriptions for the treatment of depression-like disorders. Objectives: The objective of this review is to provide scientific evidence to support further research on peony as a potential anti-depressant drug. Methods: This review summarizes the results obtained in our laboratory, together with other literature data obtained through a comprehensive search in databases including PubMed, ScienceDirect, Scirus, and Web of Science. Results: The peony extract is active in the mouse forced swim test and tail suspension test, and it produces anti-depressant effects in chronic unpredictable mild stress-induced depression model in mice and rats. The anti-depressant mechanisms of peony are likely mediated by the inhibition of monoamine oxidase activity, neuroprotection, modulation of the function of hypothalamic-pituitary-adrenal axis, inhibition of oxidative stress, and the up-regulation of neurotrophins. Conclusions: Peony is used clinically to treat depression-like symptoms in Chinese medicine, and it has been shown to possess anti-depressant property in a battery of test models using laboratory animals. Its effect is likely mediated by multiple targets. Further studies are warranted to delineate the molecular mechanisms of action, determine the pharmacokinetics, establish the toxicological profile, and assess the potentials of peony in clinical applications. Identification of the clinically active ingredient(s) is also warranted.