Pfaffia paniculata extract improves red blood cell deformability in sickle cell patients

The aim of the present study was to test the effects of Pfaffia paniculata (PP) extract on the red blood cell (RBC) rheological properties of patients with sickle cell disease (SCD) and healthy (AA) individuals. Blood from 7 SCD and 4 AA individuals were collected in EDTA tubes. Washed RBCs were incubated with various concentration of PP extract: 0.0, 0.2 or 0.5 mg/ml of PP solution for 5 hrs at 37°C. RBC deformability was measured by ektacytometry at 9 shear stresses ranging from 0.3 to 30 Pa, and RBC aggregation properties were determined by laser-backscattered techniques. Because RBCs from SCD patients are fragile, a stability test was also performed to test for the fragility of RBC exposed to a constant shear stress (70 Pa) for 10 min. While RBC deformability was not improved by the use of PP extract in AA, we noted an improvement of this parameter in patients with SCD between the 0.0 and 0.5 mg/ml conditions. In contrast to AA RBCs, the fragility of SCD RBCs was not affected by PP extract. In conclusion, this study demonstrates the beneficial effects, in-vitro, of PP extract on the RBC deformability of SCD patients, notably at high shear stress (a shear stress condition usually found in capillaries).