Evaluation of the effectiveness of Vernonia cinerea for the treatment of smoking cessation: a systematic review and meta-analysis

Abstract

Background: Smoking should be interpreted as a multidimensional and multicausal problem, for which different prevention and treatment strategies must be explored. Aims: To review the efficacy and safety of the plant, Vernonia cinerea (VC), for smoking cessation. Design: This systematic review complied with “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) Protocols. A comprehensive search was carried out, identifying randomized controlled trials (RCTs). Settings: health centers of any level. Participants: persons of any age or gender, smokers. Interventions: VC versus placebo with behavioral therapy and any other standard pharmacotherapy approved for smoking cessation. Findings: We identified 13 RCTs, all from Thailand. Ten RCTs compared VC to placebo covering 1878 patients, 943 of whom received VC, delivering an RR of 1.51 (95% CI 1.16 to 1.97; I2=10%; low-quality evidence). However, there is no certainty of this association when considering clinical trials with longer follow-ups and rated as having a low risk of bias (CAR for at least 24 weeks: RR of 0.98, 95% CI = 0.68 to 1.41; participants = 1489; I2= 0%; low-quality evidence). Thus, its efficacy in smoking cessation was only consistent in those trials where participants smoked less than 15 cigarettes per day (RR of 2.06, 95% CI= 1.25 to 3.41; participants= 246; moderate-quality evidence). There was not a clear benefit for VC in the CAR compared with NRT or nortriptyline. Non-serious AEs were tongue numbness, nausea, vomiting, drowsiness, and dizziness, found to be mild and transient Conclusions: Vernonia cinerea is a promising smoking cessation aid for those smoking fewer than 15 cigarettes daily, demonstrating efficacy only in trials with follow-ups of less than 12 weeks. It has a benign safety profile even in patients with non-communicable diseases. It underscores the need for further research, particularly outside Thailand, to fully explore its therapeutic potential