The researchers said that their finding is a major step toward creating a vaginal gel that can prevent HIV spread. HIV is the virus that causes AIDS.
Joshua L. Hood, MD, PhD, a research instructor in medicine, said:
"Our hope is that in places where HIV is running rampant, people could
use this gel as a preventive measure to stop the initial infection."
Melittin destroys some viruses and malignant tumor cells
Melittin is a powerful toxin found in bee venom. It can poke holes in
the protective viral envelope that surrounds the human immunodeficiency
virus, as well as other viruses. Free melittin in large-enough
quantities can cause considerable damage.
Senior author, Samuel A. Wickline, MD, the J. Russell Hornsby Professor
of Biomedical Sciences, has demonstrated that nanoparticles loaded with
melittin have anti-cancer properties and have the capacity to kill tumor cells. Linking bee venom with anticancer therapies is not new, in 2004 Croatian scientists reported in the
Journal of the Science of Food and Agriculture that honey-bee products, including venom, could well have applications in cancer treatment and prevention.
Normal cells remain intact - the scientists showed that
nanoparticles loaded with melittin do not harm normal, healthy cells.
Protective bumpers were added to the nanoparticles surface, so that when
they come into contact with normal cells (which tend to be much
larger), the nanoparticles bounce off rather than attach themselves.
HIV is much smaller than the nanoparticles and fits in between the
bumpers. When HIV comes across a nanoparticle it goes in between the
bumpers and comes into direct contact with its surface, which is coated
with the bee toxin, which destroys it.
Hood explained "Melittin on the nanoparticles fuses with the viral
envelope. The melittin forms little pore-like attack complexes and
ruptures the envelope, stripping it off the virus."
While most anti-HIV medications work on inhibiting the virus' ability to
replicate, this one attacks a vital part of its structure. The problem
with attacking a pathogen's ability to replicate is that it does not
stop it from starting an infection. Some HIV strains have found ways to
circumvent replication-inhibiting drugs, and reproduce regardless.
Hood said:
"We are attacking an inherent physical property of HIV. Theoretically,
there isn't any way for the virus to adapt to that. The virus has to
have a protective coat, a double-layered membrane that covers the
virus."
Melittin nanoparticles may prevent and treat existing HIV infections
Hood believes that the melittin-loaded nanoparticles have the potential for two types of therapies:
- A vaginal gel to prevent the spread of HIV infection
- Therapy for existing HIV infections, particularly drug-resistant ones
In theory, if the nanoparticles were injected into the patient's bloodstream, they should be able to clear the blood of HIV.
Hood said "The basic particle that we are using in these experiments was
developed many years ago as an artificial blood product. It didn't work
very well for delivering oxygen, but it circulates safely in the body
and gives us a nice platform that we can adapt to fight different kinds
of infections."
Melittin attacks double-layered membranes indiscriminately, making it a potential for drug therapies beyond HIV infections.
The
hepatitis B and C viruses, among several others, rely on the same type
of protective envelope and could be targeted and destroyed by
administering melittin-loaded nanoparticles.
The gel also has the potential to target sperm, the researchers
explained, making it a possible contraceptive medication. The study,
however, did not look at contraception.
Hood said "We also are looking at this for couples where only one of
the partners has HIV, and they want to have a baby. These particles by
themselves are actually very safe for sperm, for the same reason they
are safe for vaginal cells."
This study was carried out in cells in a laboratory environment.
However, the nanoparticles are easy to produce - enough of them could
easily be supplied for future human studies.
Recent research on HIV
Over the last few years, scientists have made strides in improving HIV/AIDS treatments and prevention strategies.
Baby "functionally cured" of HIV infection - researchers from
Johns Hopkins Children's Center, the University of Mississippi Medical
Center and the University of Massachusetts Medical School reported that a baby who was administered antiretroviral therapy thirty hours after being born was "functionally cured"
1. Opt for wholegrains
3. Binge on blueberries
5. Add vitality with vitamins
6. Get a blackcurrant boost
7. Pick up pumpkin seeds
8. Bet on broccoli
9. Sprinkle on sage
