Systematic Review on Herbal Preparations for Controlling Visceral Hypersensitivity in Functional Gastrointestinal Disorders

Background: Visceral hypersensitivity (VH) is an overreaction of the gastrointestinal (GI) tract to various stimuli and is characterized by hyperalgesia and/or allodynia. VH contributes to the etiology of many GI dysfunctions, particularly irritable bowel syndrome (IBS). Although the exact mechanisms underlying VH are yet to be found, inflammation and oxidative stress, psychosocial factors, and sensorimotor alterations may play significant roles in it. Objective: In this review, we provide an overview of VH and its pathophysiological function in GI disorders. Adverse effects of synthetic drugs may make herbal agents a good candidate for pain management. Therefore, in this review, we will discuss the efficacy of herbal agents in the management of VH with a focus on their anti-inflammatory and antioxidant potentials. Methods: Data were extracted from clinical and animal studies published in English between 2004 and June, 2020, which were collected from PubMed, Google Scholar, Scopus, and Cochrane Library. Results: Overall, Radix, Melissia, Glycyrrhizae, Mentha, and Liquorice were the most efficient herbals for VH management in IBS and dyspepsia, predominantly through modulation of the mRNA expression of transient receptor potential vanilloid type-1 (TRPV1) and suppression of 5- hydroxytryptamine 3 (5-HT3) or the serotonin receptors. Conclusion: Considering the positive effects of herbal formulations in VH management, further research on novel herbal and/or herbal/chemical preparations is warranted.