Direct reduction of blood serum cholesterol using Thymus vulgaris L.: Preliminary biosorption study

• Published in: Process biochemistry (1991) Vol. 67; pp. 155 - 164
• Main Authors: Salehi, Ehsan, Afshar, Saeedeh, Mehrizi, Majid Zarezadeh, Chehrei, Ali, Asadi, Marzieh
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.04.2018; Elsevier BV
• Subjects: Adsorbents; Adsorption; Ambient temperature; Biocompatibility; Biosorption; Blood; Blood serum; Cholesterol; Diffraction; Diffusion; Direct reduction; Fourier transforms; Infrared spectroscopy; Isotherm; Kinetics; Perfusion; Scanning electron microscopy; Sorption; Thyme; Thymus; Thymus vulgaris; X-ray diffraction; Isotherm; Biosorption; Kinetics; Blood serum; Cholesterol; Thymus
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2018.01.023

[Display omitted] •Thyme is an effective biosorbent to reduce the blood serum cholesterol.•The intraparticle diffusion model well fits the adsorption kinetic data.•The Langmuir isotherm model is in the best agreement with the equilibrium adsorption data.•Hydroxyl groups play an important role in cholesterol adsorption through H-bonding.•Coarse Thyme powder shows higher adsorption capacity compared to the milled powder. In-vitro batch adsorption of cholesterol from human blood serum was investigated using Thymus vulgaris L. (Thyme) as a biocompatible adsorbent. X-Ray Diffraction technique (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared spectroscopy (FTIR) were selected to characterize the biosorbent. The pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models were employed to study the adsorption kinetic with the intraparticle diffusion and pseudo-second order models providing superior fits. Kinetic results also showed that the time required for the equilibrium was around 2 h. The Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms were also applied to investigate the adsorption equilibria at ambient temperature. The Langmuir model provided superior agreement with the equilibrium data and the adsorption capacity was around 84.74 mg/g. The results showed that the cholesterol removal increased from 30% to 50% with increased adsorbent mass from 0.01 to 0.1 g; meanwhile, removal did not noticeably vary (∼7%) with further adsorbent dose increase from 0.1 to 0.2 g. The coarse Thyme powder indicated higher cholesterol removal (46%) compared to the milled (38%), due to aggregation of the latter in the serum environment. Based on the results, Thymus is an effective biosorbent for application in extracorporeal serum perfusion.