A Research on HIV Protease Inhibitors

HIV Protease Inhibitors

INTRODUCTION.

Basically, HIV is a type of virus that attack the most importance part in the human body which is the immune system and eventually HIV virus will be converted to AIDS. 

HIV LIFE CYCLE.

We deal with HIV virus as a malicious type of viruses. The secret of their effect is how they hide their own DNA inside our body's DNA, because this action will indirectly make our cells work as a large factory of producing more HIV cells and allowing more copies to be formed.

The clearest steps of HIV life cycle are six main stages:

1. Binding (the attachment that occur between HIV proteins and CD4+ on the T4 cells) .
2. Reverse transcription (by enzyme called reverse transcription that work on making DNA copy of the RNA that present in HIV cells) .
3. Integration (the dissimulation of DNA that are related to HIV into the DNA in the human normal cells by an enzyme called integrase).
4. Transcription (Formation of newly genetic material known as mRNA).
5. Translation (making new viral proteins).
6. Maturation (creating new HIV cells).

WHATE IS HIV PROTEASE ENZYME?!

It's a special type of enzymes that consist of 2 symmetrical subunits. The cleavage between a poly-alanine and tyrosine or protein is the unique function of this enzyme.

The main action of protease is the inducement of human immune system as well. They can degenerate of any kind of pathogens that possibly enter the body. Also the can produce a defense effect by activation Toll-like receptors. Such researches shows that proteases are the aim and the primary target in a broad spectrum therapeutic sittings.

After several researches, scantiest discover that Anti-retroviral drugs can improve the condition on HIV patients. In a very simple way we can define this type of drugs by saying that they are mainly exert there effect by preventing the virus from breakthrough body cells and start producing more copies.

PROTEASE ENZYME STRUCTURE\ pep-statin.

Pep-statin is the major and general inhibitor for all protease, and starting from pep-statin we discovered the most of protease enzyme inhibitor drugs. So the structure of pep-statin:

PROTEASE INHIBITOR DRUGS STRUCTURE.

Drugs that are approved from FDA are over 11 and more, but we will mention only two drugs with their structure:

• Ritonavir\ Norvir Structure:
• Indinavir\ crixivan Structure:

MECHANISM OF ACTION FOR PROTEASE INHIBITOR.

There mechanism of action is complicated, but the very main point in their effect mechanism that all protease inhibitor apply is about the binding to protease via an extensive network of hydrogen bonds, resulting in the drug become attach to the active site and this will prevent HIV reproduction. Unfortunately; mutations in HIV proteases occur frequently in a very short period so it limit the use of protease inhibitors drugs.

A brief change in few Amino Acids can prevent the binding of drug to protease leading to broad drug resistance. The more strong binding of protease into drugs can be achieved by direct hydrogen bond with the backbone atoms of the iso-aminoacids at position 50 of the protease chain.

PHARMACOKINETICS.

Pharmacokinetics is all about absorption, distribution, and elimination.

The protease-inhibitor drugs are absorbed in the gastrointestinal tract and they are PH-dependence drugs in their nature. The most of protease inhibitor drugs whatever classes they are; have high bioavailability that exceed 65%. There protein binding property is approximately 60% (as in indinavir drug). The metabolism action is locally occur in hepatic via CYP3A4, and related to the elimination half-life rate is detected clinically =1.8 hours.

ADVERSE EFFECT OF PROTEASE INHIBITOR.

As these drugs are dealing with one of the most serious type of viruses, there side effects are generally as following:

1. Kidney stones.
2. Alopecia (heavy hair loss, known also as baldness).
3. Ingrown nails.
4. Increase bilirubin level
5. Extreme fatigue
6. Distinctive oral ulceration
7. Abnormal increase in cholesterol levels

CLINICAL USE OF PROTEASE INHIBITOR DRUGS.

Protease enzyme inhibitors drugs are used mainly for HIV treatment. Also for treating specific types of cancer as their strong ability on killing tumors cells in cutler. And by combination of protease inhibitor drugs with anti-protozoal may treat Malaria or some gastric infection.

METABOLISM OF TWO DRUGS.

About ritonavir metabolism, as we mentioned before in explanation, it's mainly metabolism done by the action of CYP450. And its importance thing to mention that ritonavir drug is contraindication when patients are dealing also with rifalutin and trimethoprim drugs as these drugs are highly present in a concentered amount in the plasma body that is happened because of badly inhibition of oxidative metabolism.

When talking about the metabolism action of Indinavir drug so it's a little bit different story because of the glucuronide conjugation that occur in a very wide manner. The metabolism of this type of drugs are detected accurately by urine and feces samples collected from patients when doctors found that over 21% percent of the drug is excreted in the urine ( the amount of drug that shows an effect on the patient). This drug doesn't last for a long time in the human body when it's taken, the half-life of it is approximately around 1.8 H. We should also mention that this drug will make a drug-interaction with ketoconazole drug and eventually lead to increase in indinavir concentration in the blood plasma.

REFRENCES.

1. https://www.ncbi.nlm.nih.gov/pubmed/12422251
2. https://www.researchgate.net/figure/Mechanism-of-action-of-protease-inhibitors_fig2_266592083
3. https://accesspharmacy.mhmedical.com/content.aspx?bookid=2189?§ionid=172486528
4. https://www.bocsci.com/pepstatin-a-cas-26305-03-3-item-84-88872.html?gclid=Cj0KCQiAw5_fBRCSARIsAGodhk_l4o__ElOzrbP5eR
5. https://www.hiv.va.gov/patient/basics/what-is-HIV.asp
6. https://www.cellsalive.com/hiv4.htm

Cite this page