Use of compounds from neotropical plants to control disease-causing bacteria, viruses and insects

Abstract

With the increase in deaths caused by microorganisms, whether due to antibiotic resistance, the emergence of new diseases, and the high transmission by insect vectors of diseases, there is a need to develop alternative treatments. In this sense, the use of plants from neotropical regions has emerged as a promising form of bioprospecting for new molecules due to the high biodiversity of this region. Plants such as Siparuna guianensis and Chiococca alba have been studied for their chemical composition compounds that act against these targets. The essential oil of S. guianensis has the molecules Germacrene B and D in its composition, which showed excellent results in the molecular docking tests performed and in the control of pathogenic bacteria (i.e., Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pyogenes). In sílico analysis indicated high affinity between some main components of the essential oil (e.g., Germacrene B) and active sites of bacterial DNA and RNA polymerases, which indicates possible damage to the replication processes of pathogenic bacterial cells. At the same time, with high volatility in the control of vector insects such as Aedes aegypti and Culex quinquefasciatus, the use of encapsulation techniques is necessary to increase their larvicidal potential. There was a continuous release of essential oil during the period of contact with the larvae, and particle OS1:3, at a concentration of 1.667 mg/cm³, presented mortality of 50% over 16 days, thus increasing the larvicidal capacity concerning the essential oil in nature, in front of the 3rd instar larvae of A. aegypti and C. quinquefasciatus. Bioassays with microparticles still proved safe for nontarget zebrafish. Another potential target of neotropical plants is the control of the Sars-CoV-2 virus. The methanol extract of C. alba showed promise in laboratory tests, showing a high selectivity index for controlling infection of Vero E6 cells against Sars-CoV-2. In silico studies have shown that naringin and vitexin bind to ACE2 x Spike receptors with better energy affinity values. Clinical trials with humans showed that the sachet and tea prepared from the roots of C. alba, at the end of the treatment, showed a significant number of patients with negative RT-PCR tests and a reduction in clinical symptoms. These products had no adverse reactions to humans, with promising results against Sars-Cov-2. Therefore, we can say that the results found are promising in the bioprospecting of new molecules, thus demonstrating the importance of studying new applications for plants from the neotropical region.