Efficacy and safety of Carica papaya leaf extract in the dengue: A systematic review and meta-analysis

Background: Dengue is an infectious disease associated with high mortality and morbidity. Being a viral disease, there is no specific drug available for treatment. There are some reports that Carica papaya leaf extract may improve the clinical condition of dengue patients; however, to support this, at present, there is no systematically searched and synthesized evidence available.

Objectives: This systematic review and meta-analysis was designed to search the available evidence related to the efficacy and safety of C. papaya leaf extract in dengue and to synthesize the evidence in meaningful form through meta-analysis so that inference can be drawn.

Materials and methods: Randomized controlled trials related to the efficacy and safety of C. papaya leaf extract in dengue were searched from PubMed, Cochrane Clinical Trial Registry and Google Scholar. The primary endpoint was mortality, and secondary endpoints were increase in platelet count, hospitalization days, and Grade 3 and 4 adverse events. Data related to primary and secondary endpoints were pooled together and analyzed by review manager (Review Manager (RevMan) Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, Denmark) software. The random effect model was used. The bias was analyzed by the Cochrane risk of bias tool.

Results: Total four trials enrolling 439 subjects were included in the analysis. Of 439 subjects, data of 377 subjects were available for analysis. C. papaya leaf extract was found to be associated with increase in platelet count in the overall analysis (mean difference [MD] =20.27 [95% confidence interval (CI) 6.21-34.73; P = 0.005]) and analysis after 4^th day (MD = 28.25 [95% CI 14.14-42.37; P < 0.0001]). After 48 h, there was no significant difference between C. papaya and control group (MD = 13.38 [95% CI - 7.71-34.51; P = 0.21]). There was significant decrease in hospitalization days in the C. papaya group (MD = 1.90 [95% CI 1.62-2.18; P < 0.00001]). Because of nonavailability of data in published clinical trials, mortality, and adverse events cannot be pooled.

Conclusion: C. papaya leaf extract can be considered as a potential candidate for increase in platelet count in patients of dengue, however; there is need of high-quality evidence in the form of large clinical trials before a decision related to the use of such extract is made.