In Vitro Susceptibility of Brazilian Pythium insidiosum Isolates to Essential Oils of Some Lamiaceae Family Species

Abstract

The present study aimed to evaluate the in vitro antimicrobial action of Origanum vulgare, Origanum majorana, Mentha piperita and Rosmarinus officinalis on Pythium insidiosum oomycete zoospores. The antimicrobial activity evaluation was performed by the broth microdilution method according to CSLI M38-A2 documentation adapted to phytopharmaceuticals. Twenty-two P. insidiosum isolates were evaluated, and the minimum inhibitory concentration was determined at 100% growth inhibition. All P. insidiosum isolates evaluated showed a minimum inhibitory concentration ranging from 0.05 to 1.75 mg/mL when O. vulgare oil was used and from 0.11 to 3.5 mg/mL for O. majorana, M. piperita and R. officinalis oils. The results obtained indicate that the essential oils tested showed antimicrobial activity on P. insidiosum, with O. vulgare essential oil showing the best performance. These findings emphasize the potential use of plant essential oils as control agents in P. insidiosum infections; further research, however, is needed so as the in vivo activity of these oils can also be evaluated.

Treatment of experimental pythiosis with essential oils of Origanum vulgare and Mentha piperita singly, in association and in combination with immunotherapy

“…Therefore, both in vitro and in vivo studies using new antifungal and antimicrobial drugs groups have been evaluated as alternative treatments of pythiosis (Pereira et al, 2007;Argenta et al, 2012;Zanette et al, 2015,b;Jesus et al, 2014a,b). Additionally, in vitro research showed that essential oils (Fonseca et al, 2015;Jesus et al, 2014a,b), compounds extracted from root and fruits (Sriphana et al, 2013;Suthiwong et al, 2014), were capable of Fig. 2.…”

“…Ltda, respectively, together with a certificate of purity. Chromatography of the components was previously determined by Fonseca et al (2015).…”

“…Due to the need of effective therapeutic options for pythiosis, many investigations have sought alternative therapies with or without antifungal agents (Pereira et al, 2007;Argenta et al, 2012;Zanette et al, 2015;Jesus et al, 2014a,b). Among these investigations are in vitro studies that evaluate the antimicrobial activity of essential oils (Jesus et al, 2014a,b;Fonseca et al, 2015), as well as compounds extracted from plants, including root and fruits (Sriphana et al, 2013;Suthiwong et al, 2014). All of these studies show promising results for the treatment of P. insidiosum in vitro.…”

“…All of these studies show promising results for the treatment of P. insidiosum in vitro. Additionally, the use of essential oils in antimicrobial therapies can be an advantageous method as it presents a low toxicity to mammalian cells and a low environmental impact (Fonseca et al, 2015).…”

Essential Oils as a Sustainable Raw Material for the Preparation of Products with Higher Value-Added

“…O OE pode posteriormente, ser separado da fase aquosa por métodos físicos (filtração, decantação, centrifugação, entre outros) que não alterem significativamente sua composição. 15 Os OEs são considerados fontes de substâncias naturais, que possuem diversas atividades biológicas, como por exemplo, propriedade antioxidante, 13,[17][18][19] antibacteriana, 13,19,20 antifúngica, 13,19,21 antinociceptiva, 22 antinflamatória 23 e inseticida. 13,24 Além disso, um grande número de OEs e seus constituintes apresentam propriedades antimicrobianas contra vários microrganismos que afetam os alimentos.…”