Background: Dengue fever is a re-emerging threat that can lead to thrombocytopenia (low platelet count) and severe plasma leakage, sometimes fatal. Supportive care is needed in severe cases, as no specific treatment is yet available. In Burkina Faso, the population commonly uses Carica papaya and Vernonia colorata. This study aimed to compare the effectiveness of Vernonia colorata to Carica papaya in reducing the major symptoms of Dengue fever. Methods: Lyophilized aqueous ethanolic macerations of fresh leaves of the two plants were prepared, and flavonoid contents were visualized by a fingerprint approach. Platelet and lymphocyte count and the amount of dye leaked from the vascular duct
were monitored in pharmacologically induced mouse models. The plant extracts were tested at 100
mg/kg bw on carrageenan (100 mg/kg bw) depressed platelet count on day 2 and at 30 and 100 mg/kg
bw on acetic acid-induced dye leakage from the vascular duct. Results: The plant extracts at 100 mg/kg
bw significantly prevented thrombocytopenia (p˂0.05) with an increased platelet count on day 2. The
acetic acid-increased vascular permeability was inhibited by over 85% (p˂0.001) in animals treated with
30 and 100 mg/kg bw of each lyophilized plant extract. The effect of Vernonia colorata and Carica papaya leaf extracts did not differ statistically on thrombocyte count or in preventing increased vascular permeability. A phytochemical fingerprint allowed the characterization of flavonoids in the two plant extracts. Conclusion: The leaf extract of Vernonia colorata can prevent provoked thrombocytopenia and increased vascular permeability, similar to Carica papaya. Further phytochemical content-based molecular mechanisms are expected.
Carica papaya, Dengue, Thrombocytopenia, Vascular permeability, Vernonia colorata.

Carica papaya, Dengue, Thrombocytopenia, Vascular permeability