Brazil has the greatest plant diversity in the world. Many species exhibit a wide range of phytochemical compounds which can be exploited in food, agronomic, pharmacological and medicinal plant industries. Therefore, the chemical composition and in vitro bioactivities of volatile oil from Psidium firmum fresh leaves (PfVO) were investigated for the first time. GC-FID and GC-MS analyses revealed 28 compounds in PfVO. The major ones were α-selinene (20.8%), β-caryophyllene (16.5%) and nerolidol (10.4%). Results showed that PfVO affected the growth of Leishmania amazonensis promastigote forms in a dose-dependent manner; its IC50 value was 14.05 µg/mL. PfVO also exhibited antibacterial activity against Salmonella enteritidis, Yersinia enterocolitica, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes; MIC values ranged from 25 μg/mL to 250 μg/mL. Moreover, PfVO promoted normal cell growth inhibition at 61.02 ± 1.97 µg/mL. Antiproliferative activity was observed against human tumor cell lines; IC50 values of MCF-7 cells, HeLa cells and M059J cells were 47.91 µg/mL, 73.78 µg/mL and 41.94 µg/mL, respectively. Results provided strong evidence of the promising potential of PfVO as a nature-based antileishmanial, antibacterial and antiproliferative agent.

Abstract Brazil, the world’s largest citros producer, yields around 19 million tons per year and exports most part of its production as orange juice. Essential oils (EOs) extracted from leaves, fruit and flowers of many species of the genus Citrus have been widely used as the result of their promising bioactivities. The fungus Rhizopus stolonifer (Ehrenb.) Vuill., an agent which causes soft rot in fruit, has been considered one of the main factors that cause postharvest diseases, thus, leading to major economic losses in agribusiness. This research aimed at evaluating the chemical composition and in vitro antifungal effect of EOs from two varieties of fresh Citrus sinensis (lima orange and bahia navel orange) peel on mycelial growth of R. stolonifer. EOs were obtained by hydrodistillation, which was carried out by a Clevenger-type apparatus, while their chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Limonene was the major monoterpene identified in EOs from lima orange (95.2%) and bahia navel orange (93.2%) peel. EOs from lima orange and bahia navel orange inhibited 91.95% and 80.05% mycelial growth of R. stolonifer, respectively, at the highest dose under evaluation (100 µL). This study revealed the biotechnological potential of EOs extracted from fruit peel of two varieties of citros which may applied to biofilm preparation, so as to coat and preserve different types of fruit.

Abstract Propolis is a resinous substance collected and processed by Apis mellifera from parts of plants, buds and exudates. In Minas Gerais (MG) state, Brazil, green propolis is produced from the collection of resinous substance found in shoot apices of Baccharis dracunculifolia. This paper aims to investigate the chemical composition and in vitro antioxidant, anti-Helicobacter pylori, antimycobacterial and antiproliferative activities of essential oil (EO) from Brazilian green propolis (BGP-EO). The oil showed high antibacterial activity against H. pylori (MIC = 6.25 µg/mL), Mycobacterium avium (MIC = 62.5 µg/mL) and M. tuberculosis (MIC = 64 µg/mL). Its antioxidant activity was evaluated in vitro by both DPPH (IC50 = 23.48 µg/mL) and ABTS (IC50 = 32.18 µg/mL) methods. The antiproliferative activity in normal (GM07492A, lung fibroblasts) and tumor cell lines (MCF-7, HeLa and M059J) was analyzed by the XTT assay. BGP-EO showed inhibition of normal cell growth at 68.93 ± 2.56 µg/mL. Antiproliferative activity was observed against human tumor cell lines, whose IC50 values were 56.17, 66.43 and -65.83 µg/mL for MCF-7, HeLa and M059J cells, respectively. Its major constituents, which were determined by GC-FID and GC-MS, were carvacrol (20.7 %), acetophenone (13.5 %), spathulenol (11.0 %), (E)-nerolidol (9.7 %) and β-caryophyllene (6.2 %). These results showed the effectiveness of BGP-EO as a natural product which has promising biological activities.