PP  Vol.6 No.2 , February 2015
Study of in Vitro Interaction of Sildenafil Citrate with Bovine Serum Albumin by Fluorescence Spectroscopy
Abstract: In vitro interaction of sildenafil citrate (SC) with bovine serum albumin (BSA) was investigated at two excitation wavelengths of BSA (280 nm and 293 nm) at two different temperatures (298 K and 308 K) by fluorescence emission spectroscopy. The study showed that quenching of BSA fluores-cence by sildenafil citrate was the result of formation BSA-SC complex with probable involvement of both tryptophan and tyrosine residues of BSA. Fluorescence quenching constant was determined from Stern-Volmer equation, and both static quenching and dynamic quenching were showed for BSA by SC at the conditions. Van’t Hoff equation was used to measure the thermodynamic parameters ΔG, ΔH, and ΔS at the temperatures which indicated that the hydrogen bond and the hydrophobic forces played major roles for BSA-SC complexation. The binding number (n) was found to be ≈1 indicating that one mole BSA bound with one mole SC. The binding affinity of SC to BSA was calculated at different temperatures. The binding constant was decreased with increasing temperatures indicating that stability of BSA-SC complex decreased with increasing temperatures.
Cite this paper: Salam, M. , Rokonujjaman, M. , Rahman, A. , Nasrin Sultana, U. and Sultan, M. (2015) Study of in Vitro Interaction of Sildenafil Citrate with Bovine Serum Albumin by Fluorescence Spectroscopy. Pharmacology & Pharmacy, 6, 94-101. doi: 10.4236/pp.2015.62012.

[1]   Boolell, M., Allen, M.J., Ballard, S.A., Gepi-Attee, S., Muirhead, G.J., Naylor, A.M., Osterloh, I.H. and Gingell, C. (1996) Sildenafil: An Orally Active Type 5 Cyclic GMP-Specific Phosphodiesterase Inhibitor for the Treatment of Penile Erectile Dysfunction. International Journal of Impotence Research, 8, 47-52.

[2]   Tian, J.N., Liu, J.Q., He, W.Y., Hu, Z.O., Yao, X.J. and Chen, X.G. (2004) Probing the Binding of Scutellarin to Human Serum Albumin by Circular Dichroism, Fluorescence Spectroscopy, FTIR and Molecular Modeling Method. Biomacromolecules, 5, 1956-1961.

[3]   Malonga, H., Neault, J.F. and Tajmir-Riahi, H.A. (2006) Transfer RNA Binding to Human Serum Albumin: A Model for Protein-RNA Interaction. DNA Cell Biology, 25, 393-398.

[4]   Ahmad, B., Parveen, S. and Khan, R.H. (2006) Effect of Albumin Conformation on the Binding of Ciprofloxacinto Human Serum Albumin: A Novel Approach Directly Assigning Binding Site. Biomacromolecules, 7, 1350-1356.

[5]   Mallick, A., Haldar, B. and Chattopadhyay, N. (2005) Spectroscopic Investigation on the Interaction of ICT Probe 3-Acetyl-4-oxo-6,7-dihydro-12H Indolo-[2,3-a] Quinolizine with Serum Albumins. Journal of Physical Chemistry B, 109, 14683-14690.

[6]   Carter, D. and Ho, J.X. (1994) Structure of Serum Albumin. Advances in Protein Chemistry, 45, 153-203.

[7]   Lakowicz, J.R. (1999) Principles of Fluorescence Spectroscopy. 2nd Edition, Plenum Press, New York.

[8]   Peters Jr., T. (1985) Serum Albumin. Advances in Protein Chemistry, 37, 161-245.

[9]   Moriyama, Y., Ohta, D., Hachiya, K., Mitsui, Y. and Takeda, K. (1996) Fluorescence Behavior of Tryptophan Residues of Bovine and Human Serum Albumins in Ionic Surfactant Solutions: A Comparative Study of the Two and One Tryptophan(s) of Bovine and Human Albumins. Journal of Protein Chemistry, 15, 265-272.

[10]   Papadopoulou, A., Green, R.J. and Franzier, R.A. (2005) Interaction of Flavonoids with Bovine Serum Albumin: A Fluorescence Quenching Study. Journal of Agricultural and Food Chemistry, 53, 158-163.

[11]   Zhang, J., Yin, Z., Wu, W., Wang, Z., He, R. and Wu, Z. (2012) Characterization of Interaction between Raltitrexed and Bovine Serum Albumin by Optical Spectroscopic Techniques. Chemical Research in Chinese Universities, 28, 963-970.

[12]   Mostafa, S., EL-Sadek, M. and Alla, E.A. (2002) Spectrophotometric Determination of Ciprofloxacin, Enrofloxacin and Pefloxacin through Charge Transfer Complex Formation. Journal of Pharmaceutical and Biomedical Analysis, 27, 133-142.

[13]   Ni, Y., Liu, G.L. and Kokot, S. (2011) Competitive Binding of Small Molecules with Biopolymers: A Fluorescence Spectroscopy and Chemometrics Study of the Interaction of Aspirin and Ibuprofen with BSA. Analyst, 136, 4794-4801.

[14]   Gentili, P.L., Ortica, F. and Favaro, G. (2008) Static and Dynamic Interaction of a Naturally Occurring Photochromic Molecule with Bovine Serum Albumin Studied by UV-Visible Absorption and Fluorescence Spectroscopy. Journal of Physical Chemistry B, 112, 16793-16801.

[15]   Kwon, S. and Carson, J.H. (1998) Fluorescence Quenching and Dequenching Analysis of RNA Interactions in Vitro and in Vivo. Analytical Biochemistry, 264, 133-140.

[16]   Steinhardt, J., Krijn, J. and Leidy, J.G. (1971) Differences between Bovine and Human Serum Albumins: Binding Isotherms, Optical Rotatory Dispersion, Viscosity, Hydrogen Ion Titration, and Fluorescence Effects. Biochemistry, 10, 4005-4015.

[17]   Bhattacharyya, M., Chaudhuri, U. and Poddar, R.K. (1990) Evidence for Cooperative Binding of Chlorpromazine with Hemoglobin: Equilibrium Dialysis, Fluorescence Quenching and Oxygen Release Study. Biochemical and Biophysical Research Communications, 167, 1146-1153.

[18]   Rasoulzadeh, F., Asgari, D., Naseri, A. and Rashidi, M.R. (2010) Spectroscopic Studies on the Interaction between Erlotinib Hydrochloride and Bovine Serum Albumin. DARU Journal of Pharmaceutical Sciences, 18, 179-184.

[19]   Kaushelendra, M., Himesh, S., Govind, N., Sita, S.P. and Singhai, A.K. (2011) Method Development and Validation of Metformin Hydrochloride in Tablet Dosage Form. E-Journal of Chemistry, 8, 1309-1313.

[20]   Kandagal, P.B., Seetharamappa, J., Shaikh, S.M.T. and Manjunatha, D.H. (2007) Binding of Trazodone Hydrochloride with Human Serum Albumin: A Spectroscopic Study. Journal of Photochemistry and Photobiology A: Chemistry, 185, 239-244.

[21]   Sun, S-F., Zhou, B., Hou, H-N., Liu, Y. and Xiang, G-Y. (2006) Studies on the Interaction between Oxaprozin-E and Bovine Serum Albumin by Spectroscopic Methods. International Journal of Biological Macromolecules, 39, 197-200.

[22]   Ross, P.D. and Subramanian, S. (1981) Thermodynamics of Protein Association Reactions: Forces Contributing to Stability. Biochemistry, 20, 3096-3102.

[23]   Li, D., Zhu, J., Jin, J. and Yao, X. (2007) Studies on the Binding of Nevadensin to Human Serum Albumin by Molecular Spectroscopy and Modeling. Journal of Molecular Structure, 846, 34-41.

[24]   Sultana, S., Bin Sayeed, M.S., Ahamed, M.U., Islam, M.S., Bahar, A., Sultan, M.Z. and Hasnat, A. (2013) Interaction of Nalbuphine Hydrochloride with Deoxyribonucleic Acid Measured by Fluorescence Quenching. Drug Research, 63, 224-227.

[25]   Rahman, M.A., Salam, M.A., Sultan, M.Z., Hossain, K., Rahman, A. and Rashid, M.A. (2014) DSC and HPLC Studies of Some Common Antidiabetic and Antihypertensive Drugs. Bangladesh Pharmaceutical Journal, 17, 123-127.

[26]   Ahsan, M.R., Sultan, M.Z., Amjad, F.M., Sultana, S., Baki, M.A., Hossain, M.A., Hossain, M.A. and Amran, M.S. (2012) The Study of in Vitro Interaction of Ciprofloxacin with Paracetamol and Zinc in Aqueous Medium. Journal of Scientific Research, 4, 701-708.

[27]   Rokonujjaman, M., Salam, M.A. and Sultan, M.Z. (2015) In Vitro Study of Interactions of Sildenafil Citrate with Bovine Serum Albumin in Presence of Bisoprolol Fumarate and Metformin Hydrochloride by Fluorescence Spectrophotometry. British Journal of Medicine & Medical Research, 5, 362-375.