Copaiba oil: substance has antibiotic effect – 10/10/2023 – Science

Polyaltic acid, a substance present in copaiba oil, has antibacterial effects and can be used in the development of alternative medicines that can contribute to combating antibiotic resistance. The conclusion, published in the journal Antibiotics, is from a study conducted by researchers from Brazil and the United States.

According to the Centers for Disease Control and Prevention (CDC), a North American health agency, 2.8 million cases of antibiotic-resistant infections are recorded every year and more than 1 million people have died as a result of the problem. It is estimated that, by 2050, microbial resistance will become the leading cause of death in the world.

In addition to the inadequate prescription of antibiotics and their extensive use in agriculture, experts cite the low number of drugs of the type used as the cause of the crisis. This fact arises from the interruption of research into new therapeutic options by the main pharmaceutical companies, due to the high cost and low return on investment.

In this context, the use of plants in the production of new drugs has proven to be an important and promising alternative. To stimulate the production of knowledge in the area, researchers from the Department of Pharmaceutical Sciences of the Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP) and the São Carlos Institute of Physics (IFSC), both at the University of São Paulo (USP), and also from the University of Franca (Unifran) and the Faculty of Pharmacy at Western New England University (United States) investigated copaíba oil, a popular traditional medicine from the Amazon with healing, anti-inflammatory, leishmanicidal and antimicrobial properties, thanks to compounds known as sesquiterpenes and diterpenes – including polyaltic acid.

During the research, supported by Fapesp through five projects, compounds analogous to polyaltic acid were synthesized with structural modifications to increase their activity. Its antibacterial effects on biofilms of Staphylococcus epidermidiswhich causes skin and digestive infections, and in gram-positive bacteria (Enterococcus faecalis, Enterococcus faecium, S. epidermidis and Staphylococcus aureus).

The group also determined the minimum inhibitory concentration against planktonic bacterial cells (which live free in liquid media).

Activity and comparative tests with the original polyaltic acid and with the most clinically used drug today showed that the developed analogues were able to significantly eradicate the S. epidermidis biofilm, in addition to showing activity against all gram-positive bacteria tested. Although the observed activity was lower than that of the drug currently prescribed by doctors, the results reinforce the importance of additional in vitro and in vivo tests with the substance.

“The advantage of studying polyaltic acid is that there are already studies showing that some terpenes do not lose their activity and, therefore, its continuous use does not cause bacteria to develop resistance”, says Cássia Suemi Mizuno, professor at the Faculty of Pharmacy at Western New England University and corresponding author of the study.

A hemolysis (destruction of red blood cells) study also determined the safety of the analogs.

Next steps

“Our work is an important contribution against the crisis of antibiotic resistance and represents another step from which other groups can generate new knowledge”, believes Mizuno.

According to the researcher, the next step would be to produce more derivatives with other parts of the polyaltic acid molecule, improve its activity and, therefore, arouse the interest of the pharmaceutical industry in continuing the research.

To achieve this, it is also necessary to invest in the extraction of copaíba oil in the Amazon, a process that depends on professionals with knowledge of the forest capable of identifying the correct species of copaiferous tree that produces polyaltic acid (Copaifera reticulata Ducke).

“It is important to highlight that, to study the substance, we do not need to destroy trees – its extraction is similar to that of rubber and only requires scraping the bark from the trunk”, says Mizuno.

The article Synthesis and Antibacterial Activity of Polyalthic Acid Analogs can be read here.