Safety and efficacy of Prunella vulgaris preparation in adjuvant treatment of thyroid nodules: A meta-analysis

BACKGROUND: Prunella vulgaris (PV), a traditional Chinese medical herb, is considered beneficial for some thyroid diseases. However, the effectiveness is not consistent in different studies. This review compiles the evidence from randomized controlled trials (RCTs) and quantifies the effects of PV preparation on thyroid nodules. METHODS: Eight databases were searched up to April 2021 to identify eligible studies. Only RCTs were included. Meta-analysis of homogeneous studies was performed by RevMan5.3 software. Cochrane risk of bias assessment tool version 2.0 was used to assess the risk of bias of each trial. The research screening, data extraction, and risk of bias assessment were employed by 2 reviewers independently, and disagreement will be decided by a third senior reviewer. The risk ratio (RR), mean difference (MD) and corresponding 95% confidence interval (CI) of each study are summarized. RESULTS: Thirteen RCTs with 1468 patients were included in this study. A meta-analysis showed that the RR of the clinical efficacy of PV combined with levothyroxine sodium tablets was 1.22 (95% CI [1.11, 1.33]). The MD of thyroid nodule diameter was −0.43 (95% CI [−0.63, −0.22]). The MD of free triiodothyronine and free tetraiodothyronine levels was −1.99 (95% CI [−3.14, −0.86]) and −3.20 (95% CI [−5.50, −0.89]), respectively. The RR of the adverse reaction rate was 0.67 (95% CI [0.36, 1.22]), and the RR of the clinical efficacy of PV preparation combined with thyroxin tablets was 1.29 (95% CI [1.03, 1.62]). CONCLUSIONS: PV combined with levothyroxine sodium tablets or thyroxin tablets has more benefits for thyroid nodules, further improving the clinical efficiency, reducing the diameter of nodules and reducing the occurrence of adverse reactions. However, the quality of these studies is uncertain, and higher quality and more RCTs are needed to provide comprehensive evidence-based medical evidence in the future.