BackgroundDengue fever is a mosquito-borne virus belonging to the family Flaviviridae. It is an old virus that has re-emerged globally over the past 20 years and now causes a global burden of 50 million infections per year across approximately 100 countries. Despite this, there is no safe vaccine available, and therapy is largely supportive. Its pathogenesis is multifaceted and currently still poorly understood, leading to a lack of disease-specific therapy. Propolis is a natural antiviral and anti-inflammatory product derived from the saps of plants and mixed with the saliva of honeybees. Propoelix™ is a uniquely potent and water-soluble extract of propolis containing high concentrations of anti-inflammatory compounds like caffeic acid phenethyl ester.ObjectiveThe primary objective is to determine the effectiveness of a unique propolis extract (Propoelix™) on the clinical course of patients with dengue hemorrhagic fever (DHF). The secondary objective is to examine the effect of Propoelix™ on tumor necrosis factor-α (TNF-α) levels in patients with DHF.MethodsA double-blind, randomized, placebo-controlled trial was conducted at the Department of Internal Medicine, Gatot Soebroto Central Army Hospital in Jakarta, Indonesia, from May 2012 to July 2013. Sixty-three patients who met the inclusion criteria were enrolled in the trial. Patients were randomized to receive either two capsules of Propoelix™ 200 mg three times a day or placebo daily for 7 days. Clinical and laboratory variables of both groups, including the anti-inflammatory marker TNF-α, were investigated. Patients were deemed technically fit for discharge if their platelet counts had recovered and exceeded 100,000/μL but were all observed as inpatients for 7 days.ResultsThere were 31 patients in the Propoelix™ treatment group and 32 patients in the placebo group. Platelet counts in the Propoelix™-treated group showed a trend toward a faster recovery by day 3 of admission and became statistically significant by day 6 (101.42±48.79 vs 80.78±43.35 [103/mL], P=0.042) and day 7 (146.67±64.68 vs 107.84±57.22 [103/mL], P=0.006). Patients treated with Propoelix™ had a significantly greater decline in TNF-α levels on day 7 of therapy compared with patients in the placebo group (P=0.018). They also had a significantly shorter length of hospitalization compared with those in the placebo group (4.69±0.78 days vs 5.46±1.16 days, P=0.012).ConclusionPropoelix™ appears to hasten the improvement in platelet counts and TNF-α levels and shortens the duration of hospitalization in patients with DHF.