Effects of antiretroviral treatment on paraoxonase 1 (PON1) activity in rats

Zidovudine and Lamivudine as Potential Agents to Combat HIV-Associated Neurocognitive Disorder

The central nervous system has been identified as an anatomical reservoir for HIV due the difficulties in delivering therapeutic agents into the brain and this complication results in HIV-associated neurocognitive disorder that persists in infected patients. The brain regions that are potentially exposed to tissue deficits due to HIV have been reported in previous reports; therefore, it is important to determine the drugs that can enter and localize in brain regions that are known to be susceptible to HIV neurodegeneration. Sprague-Dawley rats received intraperitoneal doses of zidovudine and lamivudine (50 mg kg^-1). Mass spectrometry methods were used to determine the pharmacokinetics, of zidovudine and lamivudine, in the brain using liquid chromatography tandem mass spectrometry and mass spectrometry imaging (MSI), respectively. Zidovudine and lamivudine displayed complementary pharmacokinetic curves indicating a rapid absorption and blood-brain barrier penetration of both drugs reaching C_max at 0.5 h after single dose. MSI of coronal brain sections showed that zidovudine and lamivudine are mostly distributed in corpus callosum, globus pallidus, striatum, and the neocortex region. Mass spectrometry techniques were used to demonstrate that zidovudine and lamivudine drugs are able to reach and localize in brain regions that are targets of HIV neurodegeneration in the brain.

A potential risk factor for paraoxonase 1: in silico and in-vitro analysis of the biological activity of proton-pump inhibitors†

Objectives

Proton-pump inhibitors (PPIs) are drugs commonly utilized by about 7% of adults in the world. Recent researches have shown that there are countless and severe side effects of these drugs. This situation has raised concern among clinicians and patients alike. The purpose of this study is to contribute the novel drug discovery and development technology and toxicology field by researching interactions of PPIs on paraoxonase 1.

Methods

In this study, the paraoxonase 1 enzyme was purified from human serum by using rapid and straightforward chromatographic techniques. Subsequently, the inhibition effects of pantoprazole, omeprazole, and esomeprazole, PPIs, were investigated on paraoxonase 1. Besides, molecular docking studies were performed to unravel the binding mechanism between the enzyme and drugs.

Key findings

All drugs showed potent inhibitory activities. IC50 of the drugs values were 54.780 ± 0.524, 86.470 ± 0.818 and 93.390 ± 0.885 mm and Ki constants were found as 39.895 ± 0.005 mm, 70.112 ± 0.010 mm and 78.868 ± 0.008 mm, respectively. The binding scores observed in silico studies were found to agree with the obtained from in-vitro experimental results.

Conclusions

We observed that the drugs decreased PON1 activity at low concentrations. The results show that adjusting the dosages of these medications is a crucial case for each patient. The physicians should more carefully interpret whether there is an essential indication before prescribing PPIs and, if there is, to approve the proper dosing for the situation.