Azidothymidine, the first
drug that was approved in the fight against AIDS in the
1980s, is still a main component in the medication mix commonly prescribed to
HIV patients today. But new research may have found a plant-derived
chemical compound that is much more effective than azidothymidine.
In the United States, the
Centers for Disease Control and Prevention (CDC) estimate that around
1.1 million people have HIV, and 1 in 7 of them are not aware that they
have it.
Due to awareness
campaigns and efforts to prevent HIV, the number of new infections dropped
by 19 percent between 2005 and 2014. The number of HIV-related deaths has also
been falling since the mid-1990s, largely due to advances in HIV
treatment.
Although there is yet no
cure for HIV, antiretroviral
therapy significantly slows down the progression of the virus. The first
drug to have been approved in the fight against AIDS is
azidothymidine (AZT).
Since 1987, however - the
year in which AZT was approved by the U.S. Food and Drug Administration (FDA) -
the virus has adapted to the drug. Today, HIV patients are given a combination
of various drugs, of which AZT
is often still the main component.
AZT works by inhibiting
an enzyme that the HIV
virus needs to replicate inside a host cell. This enzyme is called reverse
transcriptase.
New research, published
in the Journal of Natural Products, has found a plant compound that may be
more effective at inhibiting this enzyme than AZT.
The chemical compound is
called "patentiflorin A" and is derived from a medicinal plant found
in East Asia: Justicia gendarussa.
The discovery is the
result of a research effort extending over several years, carried out by an
international team of scientists from the University of Illinois at Chicago
(UIC), the Hong Kong Baptist University in Kowloon Tong, and the Vietnam
Academy of Science and Technology in Hanoi.
The team was led by Lijun
Rong, a professor of microbiology and immunology at the UIC College of
Medicine, who has special expertise in identifying antiviral agents.
Patentiflorin A inhibits
HIV 'much more effectively' than AZT
Prof. Rong and colleagues
selected Justicia from a pool of more than 4,500 plants.
After separating the
extracts of the stems and roots of this plant using bioassay-guided isolation -
which is the most common procedure for separating extracted compounds
based on their biological activity - the researchers found the "anti-HIV
arylnaphthalene lignan glycoside" that is patentiflorin A.
Then, Prof. Rong and team
assessed the effect of the compound against the M-tropic and T-tropic HIV
isolates. "Tropism" refers to the type of cells that the virus can
invade. M-tropism refers to the virus' ability to invade macrophages, while
T-tropism refers to its ability to invade T cells, which are both white
blood cells with key roles in immunity.
The tropism tests showed
that patentiflorin A had "a significantly higher inhibition effect than
the clinically used anti-HIV drug AZT."
"Patentiflorin A was
able to inhibit the action of reverse transcriptase much more effectively than
AZT and was able to do this both in the earliest stages of HIV
infection when the virus enters macrophage cells and alter infection when
it is present in T cells of the immune system," Prof. Rong explains.
He also notes that his
team managed to synthesize the compound de novo, or "from scratch."
He says:
"If we can make the
drug in the lab, we don't need to establish farms to grow and harvest the
plant, which requires significant financial investment, not to mention it has
an environmental impact."
He concludes,
"Patentiflorin A represents a novel anti-HIV
agent that can be added to the current anti-HIV drug cocktail regimens to
increase suppression of the virus and prevention of AIDS."
Source: https://www.medicalnewstoday.com/articles/317966.php
