EFAVIRENZ: SCIENCE & TECHNOLOGYY
NEWS: Treating chikungunya using HIV/AIDS drug efavirenz
WHAT’S IN THE NEWS?
A recent study suggests that efavirenz, a drug used to treat HIV/AIDS, could be repurposed to combat chikungunya, an infectious disease caused by the chikungunya virus (CHIKV).Chikungunya currently lacks an approved antiviral treatment, and only a few compounds have been tested in animal models. This discovery is significant because it opens the possibility of utilizing an existing drug to treat a viral disease without a dedicated antiviral.
1. Key Findings of the Study
• Chikungunya Outbreak History:
• In 2006, about 14 million people were clinically suspected to have chikungunya, with 2,001 confirmed cases.
• After a decline in cases post-2014, chikungunya has resurged since 2018, leading to renewed interest in finding effective treatments.
• Efavirenz's Effectiveness:
• Researchers from IIT Roorkee’s Department of Biosciences and Bioengineering tested efavirenz in cell cultures and animal models for its potential to combat the chikungunya virus.
• The study found that efavirenz significantly reduced the viral load by inhibiting chikungunya virus replication in lab conditions.
• In laboratory experiments using Vero cells (a type of cell line), efavirenz inhibited 99% of chikungunya virus replication, even at low concentrations.
• Similar inhibitory effects were observed when efavirenz was tested on human hepatic (liver) cell lines, as chikungunya also affects liver cells.
• Additionally, efavirenz was also found to inhibit replication of Sindbis virus (SINV), which is evolutionarily similar to chikungunya virus.
2. Efavirenz: Overview
• Drug Type: Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) used primarily in the treatment of HIV-1 infection.
• Mechanism: It works by binding to the reverse transcriptase enzyme of HIV-1, causing conformational changes that inhibit HIV replication, thus preventing the virus from multiplying.
3. Vero Cells:
• Origin: Vero cells are derived from kidney epithelial cells of the African green monkey (Cercopithecus aethiops).
• Uses in Research: These cells are widely used in virology research, vaccine production, and cytotoxicity testing due to their ability to support the replication of many viruses, including the chikungunya virus.
4. Hepatic Cells (Hepatocytes):
• Function: Hepatocytes are the main functional cells of the liver and are involved in key functions like metabolism, detoxification, protein synthesis, and bile production.
• Role in Chikungunya: Since chikungunya can infect liver cells, testing efavirenz on hepatic cells helps understand how the drug affects virus replication in a system more relevant to human infection.
5. Sindbis Virus (SINV):
• Virus Type: Sindbis virus is a positive-sense, single-stranded RNA virus belonging to the Togaviridae family and considered the prototype alphavirus.
• Transmission and Symptoms: Like chikungunya, SINV is transmitted primarily by mosquitoes and causes fever, rash, and arthritis in humans.
• Similarity to Chikungunya: SINV is closely related to chikungunya virus, and the study’s finding that efavirenz inhibits SINV replication suggests its potential efficacy against chikungunya.
6. Chikungunya Virus (CHIKV):
• Transmission: Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus, which is transmitted through the bites of infected female mosquitoes, primarily Aedes aegypti and Aedes albopictus.
• Symptoms: The infection is characterized by fever, severe joint pain (arthralgia), and swelling in the joints, which can sometimes last for weeks to months.
• History: The disease was first recognized in 1952 during an outbreak in southern Tanzania.
• Origin of Name: The word "chikungunya" comes from a term in the Kimakonde language of southern Tanzania, meaning "to become contorted," describing the stooped appearance of sufferers due to joint pain.
7. What is HIV?
• Definition: HIV (Human Immunodeficiency Virus) is a virus that attacks the immune system, specifically the CD4 cells (T cells), which are crucial for the body’s defense against infections. Over time, if left untreated, HIV can lead to AIDS (Acquired Immunodeficiency Syndrome).
• Transmission: HIV is transmitted through contact with certain bodily fluids, including blood, semen, vaginal fluids, and breast milk. It is most commonly spread through unprotected sex or sharing injection drug equipment.
• Treatment: Although there is no cure for HIV, antiretroviral therapy (ART) can manage the infection, reducing the viral load to undetectable levels and preventing the progression to AIDS.
8. Conclusion
• The repurposing of efavirenz for chikungunya treatment represents an important step forward in addressing a disease that currently lacks effective antiviral options.
• Since chikungunya continues to resurge in various regions, particularly in India, this research is timely and could provide an existing treatment that is both safe and effective, paving the way for more treatment options for patients with chikungunya.
Source: https://www.thehindu.com/sci-tech/treating-chikungunya-using-hivaids-drug-efavirenz/article69330638.ece