Ethnopharmacological relevance: Functional dyspepsia (FD), a chronic upper gastrointestinal syndrome, seriously affects the quality of life of patients and poses a significant economic burden. Since the pathological mechanisms of FD have not been fully elucidated, conventional therapies such as prokinetics, proton pump inhibitors, and antidepressants have some limitations. Siho-sogan-san (SHS) is commonly used as a therapeutic alternative in traditional medicine; however, scientific and clinical evidence supporting its application in FD remains insufficient.
Aim of the study: This review aimed to assess the safety and effectiveness of SHS and in combined with Western medicine (WM) for the treatment of FD.
Methods: Eleven databases, including EMBASE, Medline, and Cochrane Library, were searched for randomized controlled trials (RCTs) on FD published before December 31, 2022. After two independent reveiwers sceened and selected studies according to the inclusion and exclusion criteria, clinical data was pooled and synthesized via Review Manager software. The outcome parameters included total clinical effectiveness rate (TCE), time for symptom improvement, levels of motilin and corticotropin-releasing hormone (CRH), and adverse events. Cochrane's risk of bias tool was used for quality assessment.
Results: A total of 12 studies that included 867 participants comparing WM with SHS or combination therapy (SHS plus WM) were identified. Through a meta-analysis of five studies including 363 patients, SHS compared with WM showed a positive result in safely increasing TCE [risk ratio = 1.36, 95% confidence interval (CI) 1.22 to 1.51, P < 0.00001]. The time for symptom improvement, including abdominal pain, belching, nausea, vomiting, and abdominal distension, was significantly more shortened in the combination therapy than WM group. Furthermore, combination therapy resulted in greater secretion of motilin than WM alone [mean difference = 67.95, 95% CI 39.52 to 96.39, P < 0.00001]. No remarkable difference was observed in CRH levels between the combination therapy and WM groups. For a subgroup analysis, the administration of SHS based on the type of pattern identification (PI) showed larger effect size than in the group that do not consider PI.
Conclusions: These results suggest that SHS and combination therapy can be considered effective and safe options for the treatment of FD. However, owing to the low quality of the included studies, more well-designed investigational studies and RCTs with longer treatment and follow-up period are needed.
Keywords: Functional dyspepsia; Herbal medicine; Meta-analysis; Systematic review; Traditional Chinese medicine.
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