Bee Venom Melittin Modulates In Vivo Water Permeability of Red Blood Cells: Microscopic and ¹H-NMR Data

Bee venom (BV) molecules, including melittin (Mlt), are known to modify the permeability of membranes. This paper assessed red blood cell (RBC) shape (by phase contrast microscopy) in relation to some of the parameters (haematology data) and calculated the RBC membranes' water diffusional permeability (P_d) with ¹H-NMR spectroscopy. Rats were injected for 30 days with either small daily doses of BV (VST) or Mlt (MST) or with high single doses of BV (VSLT) or Mlt (MSLT). The RBCs displayed aberrant shapes, all of the analysed parameters significantly changed, and the values of P_d were higher (and increased with temperature) in all of the treated groups compared to the control group. The RBCs in the venom-treated groups had the highest mean values (expressed in cm × s^-1 × 10³) of P_d at 37 °C-8.95 in the VSLT group and 8.69 in the VST group-which were followed by the MST and MSLT groups and the control group. Our results demonstrated the ability of Mlt to retain the ability to interact with the RBC membrane in vivo and proved that Mlt is the most important BV molecule involved in this process.