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It is small, 0.6 mm to 2 cm in size, but can cause considerable damage. Every year, the brown spider (Loxosceles sp) denounces about 7,000 people in Brazil – 7,441 in 2016, latest data available from Sinan, the Ministry of Health's information system.
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To reduce these problems, scientists from the Butantan Institute (IB) have developed an ointment whose curative effects have already been demonstrated in tests carried out. in cell culture and in animals
According to the IB researcher, Denise Tambourgi, main responsible for the work, the developed ointment is based on tetracycline, a substance known and already used as an antibiotic. "We used it at a concentration lower than that which would be microbicidal, however," he explains
that is, smaller than that required to be considered an antibiotic, but used in a dose capable of interfering with the activity of sphingomyelinase D, is the main component of spider venom and is involved in the process of inflammation and destruction of tissues ( necrosis) and other effects. "
In addition to a skin lesion – which occurs in 80% of cases and may take months to heal itself – the bite of Loxosceles can also cause systemic effects in 20% of patients, such as l & # 39; 39, hemolysis (alteration, dissolution or destruction of red blood cells), platelet aggregation (which causes the formation of blood clots in the blood vessels that hinder or prevent circulation), inflammation and l \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ kidney failure, which can lead to death.
Origin of the ointment
The history of Denise's research that led to the creation of the ointment is long A. She began to decipher the components
As each Loxosceles produces very little venom – only about 30 micrograms – it would be very difficult to obtain the amount required for the studies.The researchers then inserted a gene into the Esch bacterium erichia coli, thereby creating a biopharmaceutical product based on sphingomyelinase D, and then produced it with sufficient volume for research.
Throughout the work, Denise and her team discovered that the brown spider can cause, in addition to the known effects, side reactions, which are primarily triggered by the sphingomyelinase D protein. ” clbad=”img img-responsive image-large”/>
Modified cells, "he explains." Then there is a deregulation of the body, which leads to the production of proteases – enzymes that function to break the chemical bonds of other proteins which, in turn, causes cell death and necrosis. should be inhibited by the ointment. "
In summary, the study coordinated by Denise deciphered the mechanism of action of venom triggered by the brown spider and the systemic and cutaneous form of the disease
Testing the antidote on the skin [19659008] The first tests on human skin cells in culture, specifically keratinocytes and fibroblasts, and on animals began to be performed in 2005 and were extended until August 2018.
"We have performed several experiments by applying brown spider venom in the cultures, "says Denise." As we expected, the cells died, and then we exposed them to toxin and tetracycline at different doses in same time. "We then found that the venom was no longer able to kill the cells."
then at the next stage of labor, which was the test in animals. "The rabbits were chosen because they are a good model for the study of cutaneous necrosis caused by Loxosceles toxin," says Denise. "The wound of this animal is similar to that which is formed in the man." We inject the poison into the skin and after a few hours, we start treating them with an ointment containing tetracycline and lanolin. take the medicine in the deep layers of the skin. "
The results were encouraging.In tetracycline-treated rabbits, the lesion quickly regressed." The ointment reduced the lesion size by about 80%, "says Denise." Given these results, we embarked on human clinical trials. "
Since tetracycline is a drug already tested for various infections and therefore used in commerce, it is not not necessary to treat it.the different stages of the tests required by the research protocols for the release of drugs.It can be tested directly on the human. "In fact, we are only making a new application for this substance ", explains the researcher.
This phase began in October, a total of 240 patients will be treated, including 120 with an ointment and 120 with a placebo, in 61 hospitals in Santa C Atarina, the state in which occur the greatest number of bites and in which Denise maintains several partnerships, including the Federal University of UFSC, as well as doctors, nurses and professionals of the pharmacy and health sector. To date, 20 patients are already treated.
Placebo patients will not be left behind. They will receive what is used today for the bite, namely the specific antivenomous serum of the brown spider or a nonspecific, anti-arachnid toxin in general. The bites can also be treated with medications called corticosteroids, better known as corticosteroids.
If the results of clinical tests are as expected, ointment can reach pharmacies. But there is no time limit for that. Once approved during testing, it still has to be published for use in humans and marketed by the National Health Surveillance Agency (Anvisa).
In addition to the accidents with Loxosceles that have occurred in recent years in South America, Central America and North America, cases of bites have also been reported in Europe. Have you ever watched our new videos on YouTube ? Subscribe to our channel!
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