Investigation of Lovastatin interaction with human serum albumin in physiologic pH: Study of cation effect on interaction

Lovastatine is a statin drug, used for the treatment of dyslipidemia. Serum albumins have important role in drug delivery. The drug binding mode of serum albumin influences drug solubility, efficacy, and biological distribution. Interaction of drugs with HSA can be affected by the presence of cations. The effect of different cations on lovastatin interaction with human serum albumin (HSA) was studied using fluorescence quenching titration method. [1-3]. HSA solution (Phosphate buffer pH 7.4) emission were recorded in 342 nm after excitation in 278 nm in pure form and in complex with lovastatin. Different mono and divalent cations (e.g. sodium nitrate. Zinc nitrate, copper nitrate, iron nitrate and magnesium nitrate solutions were prepared and were added to the lovastatin-HSA. The emission intensities were correlated with lovastatin concentration using stern–volmer equation.Complex formation between lovastatin and HSA leads to the HSA emission quenching. Increased lovastatin concentration lead to the enhanced quenching. Ksv was 3.3×104 and the intercept was about 1. Binding affinity of about 10-3 M showed loose binding between lovastatin and HSA. Binding constant of lovastation to HSA in the presence of cations altered significantly in which some cations (e.g.) leads to an enhanced affinity that could be a result of ion bridge binding. The results confirmed the previous reports of total plasma protein binding of lovastatin. Variation of binding constant of lovastatin in the presence of cations could be a result of cation binding to the HSA rather than their interaction with lovastatin. Reduced binding of lovastatin can lead to its quick release from blood and the necessity of drug dosage revision.