May papaya help treat dengue

Do the leaves of the papaya plant help increase blood platelets in dengue fever?

With some digging, I found some articles / presentations showing that fresh papaya leaf extract increases platelet counts. The first link tested this in a rodent model and found that in the test group treated with the leaf extract, the platelet count and red blood cells (RBCs) from the control group increased significantly. Here is the summary of their earnings trend from the paper:

In addition, I found a multicenter, double-blind, placebo-controlled, randomized, prospective study and meta-analysis that supports the observation that papaya leaf extract actually shows a statistically significant increase in platelet counts than that of the control groups. (Dengue fever causes the platelet count to drop). [# 2-3] Below is the picture of the platelet count from the multicenter, double-blind, placebo-controlled, randomized, prospective study (2):

Fig. 1: Comparison of the platelet count between two groups at different times

A good criticism of the papaya leaf extract meta-analyzes is that something that is statistically significant does not equate to clinically significant. However, the placebo-controlled, double-blind prospective clinical study provides some evidence that it is indeed clinically significant in this case.

However, the mechanism by which this happens is not well understood. According to the 4th article, "the secondary metabolite of plant origin forms a huge repository of compounds with a wide range of biological activities". The presentation (5) names some possible mechanisms by which the extract can inhibit the dengue virus / vector.

  1. Does Carica Papaya Leaf Extract Increase Platelet Count? An Experimental Study in a Mouse Model

  2. Efficacy and Safety of Carica Papaya Leaf Extract in Dengue Fever: A Systematic Review and Meta-Analysis

  3. A multicenter, double-blind, placebo-controlled, randomized, prospective study to evaluate the efficacy and safety of Carica papaya leaf extract as an empirical therapy for thrombocytopenia associated with dengue fever.

  4. Dengue fever treatment with Carica papaya leaf extracts

  5. The role of papaya in dengue fever, an evidence-based answer