RESUMO
Cannabis indica and C. sativa have been used in homeopathy in extreme dilutions, called potencies, for therapeutic purposes since 1841. The purpose of the present study is to see whether Cannabis dilutions have specific levels of free water molecules which characterize other homeopathic potencies. The second objective is to see whether Cannabis mother tincture (MT) and potencies act on the binding sites of a protein. The three potencies 8, 14 and 32 cH were prepared from Cannabis mother tincture (MT) by successive dilution followed by succussion in 8, 14 and 32 steps, respectively. The 3 potencies of diluent medium 90% EtOH were similarly prepared. Each potency was analysed by differential scanning calorimetry (DSC) to determine the free water level in it. The drug potencies and unpotentised EtOH were tested for their binding reaction with a protein human serum albumin (HSA) by isothermal calorimetry (ITC). MTs and the potencies differ from each other and also from water control and EtOH with respect to free water content as revealed by DSC. MTs, their potencies and EtOH bind to HSA showing difference in thermodynamic parameters in terms of stoichiometry, binding constant, change in enthalpy, entropy and Gibbs free energy. Potencies may initiate their individual effect through binding with a protein thereby leading to subsequent biochemical events inside the cell.