Exploring the Anti-Infective Value of Inuloxin A Isolated from Inula viscosa against the Brain-Eating Amoeba (Naegleria fowleri) by Activation of Programmed Cell Death.

Primary amoebic meningoencephalitis (PAM), caused by the pathogenic free-living amoeba Naegleria fowleri, is a rare but fatal disease. Nowadays, no fully effective therapy is available to erradicate or prevent this disease. Natural products could constitute a promising source of useful bioactive compounds in drug discovery. The present study is a characterization of main active compounds from the ethanolic extract of Inula viscosa (Asteraceae) leaves against N. fowleri trophozoites. Four compounds (1-4) were successfully identified by spectroscopic techniques, but only inuloxin A displayed a potential antiamoebic activity with an IC50 of 21.27 µM. The specificity of this compound toward the studied strain leads us to analyze the insight into its mechanism of action by performing in vitro assays of programmed cell death markers and to discuss the structure-activity relationship (SAR). The obtained results demonstrated that inuloxin A interferes with various processes leading to membrane damage, mitochondria alteration, chromatin condensation, and ROS accumulation, which highlight features specific to apoptosis. The current findings could be a promising step for developing new effective drugs against PAM.

Essential oil composition and anti Acanthamoeba studies of Teucrium ramosissimum.

The aim of the present study was to evaluate the chemical composition of the essential oil obtained from the aerial parts of T. ramosissimum by hydrodistillation and to investigate their anti-Acanthamoeba activity. Identification and quantification were realized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection by (GC-FID). Sixty-eight compounds representing 97.78% of the essential oil were identified, of which δ-cadinene (18.63%), δ-cadinol (18.70%), ß-eudesmol (12.13%), γ-gurjunene (4.34%) and 8-cedrene (3.99%) were the main compounds. This essential oil contained a complex mixture consisting mainly on sesquiterpenes (80.62%) and monoterpene fractions (14.34%). The findings of the anti-Acanthamoeba assay indicate that T. ramosissimum essential oil have a good activity with an IC50 = 25.73 ± 0.75 µg/mL.