Could a compound in neem help prevent the flu?
A new report from BioMed Central’s Complementary and Alternative Medicine, a peer-reviewed research journal, shows a compound in neem leaf could disable the virus from replicating and causing infections.
Influenza—commonly called the flu in the U.S.—continues to be a serious disease because of the number of deaths and hospitalizations it causes every year. From 2010 to 2014, for example, the flu killed from 12,000 to 56,000 people a year, depending on how severe the epidemic was. Several hundred thousand people end up in the hospital each year. Especially vulnerable are children under 2, adults over 65, pregnant women, and anyone with chronic health problems affecting their heart, liver, kidney, lung, among others. The annual flu vaccine reduces the chance of getting sick by an average of only 50%.
A compound from neem may hold exceptional promise for providing reliable and universal protection, and without the side effects that pharmaceutical drugs can cause. But before describing this research, it helps to understand why the flu virus has been so difficult to combat, and thus why this neem compound may be so valuable.
The flu virus infects people extremely easily, creating an epidemic every winter. The yearly vaccine injects inactivated virus to stimulate the body’s immune response. These immune cells stick around and protect against infection by the several flu virus strains used to make that year’s vaccine. But….developing truly effective protection has been elusive because this virus mutates with incredible ease from one year to the next. The next year’s vaccine has to be manufactured in advance to have enough on hand, so the vaccine specialists try to predict the versions of the virus we will encounter next year, and they develop a vaccine they hope will match the reality. Some years the match is better than others, but it’s never perfect. The worse the match, the less effective the vaccine. On top of this, some people respond better than others. Because vaccine protection is so unpredictable, and the vaccine causes a flu-like period of illness in some people, many never even bother getting vaccinated to begin with.
The ideal flu protection would target the flu virus directly by disabling a critical part of the virus—a part that does not change over time, and that the virus needs for its survival. And that is what the neem compound hyperoside, contained in neem leaves, has the potential to accomplish.
The viral protein called nucleoprotein—recently identified—fills this bill. It is unchanged in 89% of flu virus strains, and has a main role in the influenza virus life cycle. When it is damaged or inhibited, the virus cannot duplicate and create an infection. The study involved a search for existing drugs (some approved, some being developed). It was done in silico, meaning that it used a computer to visualize and manipulate molecules and structures in 3D, and determine how they would interact in real life. The goal was to see how effectively the anti-flu candidates can link up (or dock) with nucleoprotein. Effective linking enables the drug to deactivate nucleoprotein and stop the virus from replicating. The search narrowed down to 7 candidates—4 pharmaceuticals and 3 neem compounds. Of the 3 neem compounds—hyperoside, nimbaflavone, and rutin—hyperoside came out on top, and linked up more effectively than any of the pharmaceuticals.
The compound now has to be developed into a form that can be dosed consistently and used therapeutically. Then it has to be used against the virus in petri dishes, and if it kills the flu virus in that setting, the next step is testing its effectiveness in animals, and then in human subjects.