Ocotea glomerata (Nees) Mez Extract and Fractions: Chemical Characterization, Anti-Candida Activity and Related Mechanism of Action.

BACKGROUND: Opportunistic fungal infections are increasingly common, with Candida albicans being the most common etiological agent; however, in recent years, episodes of candidiasis caused by non-albicans Candida species have emerged. Plants belonging to the Lauraceae family have shown remarkable antifungal effects. This study assessed the anti-Candida activity of Ocotea glomerata extracts and fractions, time of death and the synergistic effects with conventional antifungals. The possible mechanism of action was also addressed. METHODS: Minimal inhibitory concentrations (MIC) were determined by broth microdilution technique, and the mechanism of action was assessed by ergosterol, sorbitol, cell viability, reactive oxygen species (ROS) generation and phosphatidylserine externalization tests. RESULTS: All the tested extracts evidenced antifungal activity, but the methanol extract was revealed to be the most effective (MIC = 3.12 µg/mL) on C. krusei. The combination of methanol extract with ketoconazole and fluconazole revealed a synergistic effect for C. krusei and C. albicans, respectively. Fractions 1 and 5 obtained from the methanol extract had fungicidal activity, mainly against C. krusei. Methanol extract did not reveal effects by ergosterol and sorbitol assays; however, it led to an increase in intracellular ROS levels, decreased cell viability, and consequently, cell death. CONCLUSION: O. glomerata methanol extract may be viewed as a rich source of biomolecules with antifungal activity against Candida spp.

Crude extract and fractions from Eugenia uniflora Linn leaves showed anti-inflammatory, antioxidant, and antibacterial activities.

BACKGROUND: This study showed phytochemical composition and evaluates the anti-inflammatory, and analgesic activities of crude extract (CE) and fractions from E. uniflora Linn leaves. METHODS: Polyphenols present in crude extract (CE), in aqueous fraction (AqF), and ethyl acetate (EAF) treated fractions from E. uniflora Linn leaves were shown by chromatographic analysis in order to conduct a phytochemical characterization. Antibacterial activity was evaluated based on minimum inhibitory concentrations (MICs) determined using the agar dilution method. Doses of 50, 100, and 200 mg/kg of the CE and fractions were applied for conducting in vivo models (male Swiss mice, 8-10 weeks old). The peritonitis experimental model was induced by carrageenan following of Myeloperoxidase activity (MPO), Total glutathione and malondialdehyde (MDA), IL-1ß and TNF-α levels by spectroscopic UV/VIS analysis. Antinociceptive activity was evaluated based on an abdominal writhing model and hot plate test. The results were statistically evaluated using one-way analysis of variance (ANOVA), followed by Bonferroni's post-hoc test. The level of statistical significance was p < 0.05. RESULTS: High-performance liquid chromatography with photodiode array detection (HPLC-DAD) detected varying concentrations of gallic acid, ellagic acid, and myricitrin in the CE and fractions obtained from E. uniflora Linn leaves (0.05-0.87%w/w, 0.20-0.32%w/w, and 1.71-6.56%w/w, respectively). In general, the CE had lower MIC values than the fractions, including the lowest MIC against the MRSA strain. The CE and AqF also significantly reduced leukocyte migration and MPO activity (p < 0.05). In addition, AqF significantly reduced IL-1ß and TNF-α levels (p < 0.05). Furthermore, the CE and fractions exhibited an antioxidant effect (p < 0.05) and peripheral analgesic activity (p < 0.05). CONCLUSIONS: The CE and fractions from the studied E. uniflora Linn leaves exhibited antibacterial, anti-inflammatory, antioxidant, and analgesic activity in the performed assays.

Evaluation of the Folin-Ciocalteu Method and Quantification of Total Tannins in Stem Barks and Pods from Libidibia ferrea (Mart. ex Tul) L. P. Queiroz

ABSTRACT The stem bark and pods of "jucá" are widely used in Brazilian folk medicine and, despite their therapeutic relevancies, there are insufficient reports about their quality control. Both herbal drugs from the species are rich in tannins, which showed a lot of biological and economic interest. Thus, the purpose of this study was to evaluate the method for quantification of tannins in the stem bark and pods from L. ferrea. The performance of the method was tested against the influence of the most relevant parameters (reaction time; amount of drug; type and amount of precipitationagents; and, concentration of the reagents). The procedure was validated according to the literature. After optimization, the experimental conditions were established as: 30 min of reaction; λ of 760 nm; 1.0 mL of Folin-Ciocalteu; 29% of Na2CO3 (w/v); and, skin powder as complexion agent. The method validation showed that the instrumental response was linear and sensitive to the investigated analyte. The method presented the necessary precision (RSD < 2.19%) and accuracy (96.84%-109.13%), as recommended by the official codex. Moreover, the deliberate introduction of experimental variations showed the stability of the procedure error against external sources (RSD < 2.42%). In conclusion, the data demonstrated the suitability of the method and can be used as anappropriate analytical tool for quality control of herbal drugs from L. ferrea.