Lychnopholide, a substance isolated from a Brazilian plant, and formulated as part of “nanocapsules” cured more than half of a group of mice that had been infected experimentally with Chagas disease parasites.
“Chagas disease affects millions of people, mainly in poor rural areas of 21 Latin American countries,” said Marta de Lana, PhD. The research is published in online ahead of print June 20 in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.
The new nanocapsules that constitute the delivery system for the lychnopholide in this study are a clever advance over the previous version. The previous–conventional–nanocapsules are recognized as foreign and attacked by host immune cells as they travel through the blood, before entering host cells, where the parasites lodge, said de Lana, who is Professor of Clinical Parasitology, in the School of Pharmacy, the Federal University of Ouro Preto, Minas Gerais, Brazil.
The new “stealth” nanocapsules are designed to go unrecognized by immune cells that patrol the blood. Once they enter host cells, they release the lychnopholide, killing the parasites,Trypanosome cruzi.
Another advantage of the stealth nanocapsules is that they can be taken orally, rather than intravenously, as they are impervious to the acidity and enzymes of the stomach. This is far more practical, especially in less developed countries.
Not surprisingly, the stealth nanocapsules are considerably more effective than the conventional nanocapsules. In the study, in the acute (early) phase of the disease, the stealth nanocapsules cured 62.5 percent of the mice, compared to 57.0 percent for the conventional nanocapsules. During the later chronic phase, the stealth and the conventional nanocapsules cured 55.6 percent and 30.0 percent of the mice, respectively.
“Both nanoencapsulated formulations are so simple that they may be produced in a simple laboratory,” said de Lana. Additionally, scale-up for commercial production would be simple, she said.
Using tracer viruses, researchers found that contamination of just a single doorknob or table top results in the spread of viruses throughout office buildings, hotels, and health care facilities.
Within 2 to 4 hours, the virus could be detected on 40 to 60 percent of workers and visitors in the facilities and commonly touched objects, according to research presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), an infectious disease meeting of the American Society for Microbiology.
There is a simple solution, though, says Charles Gerba of the University of Arizona, Tucson, who presented the study.
“Using disinfecting wipes containing quaternary ammonium compounds (QUATS) registered by EPA as effective against viruses like norovirus and flu, along with hand hygiene, reduced virus spread by 80 to 99 percent,” he says.
Norovirus is the most common cause of acute gastroenteritis in the United States, according to the Centers for Disease Control and Prevention (CDC). Each year, it causes an estimated 19-21 million illnesses and contributes to 56,000-71,000 hospitalizations and 570-800 deaths. Touching surfaces or objects contaminated with norovirus then putting your fingers in your mouth is a common source of infection.
In the study, Gerba and his colleagues used bacteriophage MS-2 as a surrogate for the human norovirus, as it is similar in shape, size and resistance to disinfectants. The phage was placed on 1 to 2 commonly touched surfaces (door knob or table top) at the beginning of the day in office buildings, conference room and a health care facility. After various periods of time (2 to 8 hours) they sampled 60 to 100 fomites, surfaces capable of carrying infectious organisms (light switches, bed rails, table tops, countertops, push buttons, coffee pots handles, sink tap handles, door knobs, phones and computer equipment), for the phages.
“Within 2 to 4 hours between 40 to 60% of the fomites sampled were contaminated with virus,” says Gerba.