Hexane Extract from Tradescantia pallida (Rose) D.R. Hunt (Commelinaceae): Its Volatile Constituents and in vitro Antifungal and Cytotoxic Activities

Abstract: Tradescantia pallida (Commelinaceae) has shown promising antibacterial, antioxidant and anticancer activities. This study aimed at extracting hexane from T. pallida (HE-TP) aerial parts to identify and quantify its volatile compounds by GC-MS and GC-FID and at evaluating its antifungal and antiproliferative activities. (E)-4-Methoxycynnamic acid (50.2%), 2,5-di-tert-butyl-1,4-benzoquinone (13.7%) and epijuvabione (10.4%) were the major components identified in HE-TP. HE-TP was incorporated into PDA medium, poured into Petri dishes and transferred to mycelial discs of pathogens. Percentages of inhibition of fungal growth were determined. HE-TP showed remarkable antifungal potential at the dose of 400 µL since it inhibited 100% of Penicillium digitatum and Sclerotinia sclerotiorum growth and 92.6% of Rhizopus stolonifer growth. Besides, HE-TP demonstrated cytotoxic activity against different human tumor cell lines with IC50 values between 231.43 and 428.76 µg/mL. Therefore, results showed that HE-TP has potential against fungi of agronomic interest and tumor cells.

Chemical composition and in vitro antibacterial activity of essential oils from Murraya paniculata (L. ) Jack (Rutaceae) ripe and unripe fruits against bacterial genera Mycobacterium and Streptococcus

This study aims to investigate chemical composition of essential oils from Murraya paniculata (L.) Jack (Rutaceae) ripe and unripe fruits and determine their in vitro antibacterial activity. Essential oils were extracted by hydrodistillation from Murraya paniculata (L.) Jack ripe and unripe fruits collected in the Cerrado, in Rio Verde, southwestern Goiás, Brazil. They were analyzed by gas chromatography with flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC-MS). Sesquiterpenes, which represent the most abundant class of compounds in oils, predominated in both ripe and unripe fruits. Major constituents of essential oils extracted from ripe fruits (RF-EO) were (-caryophyllene (21.3%), (-ylangene (13.3%), germacrene-D (10.9%) and (-zingiberene (9.7%) whereas the ones of unripe fruits (UF-EO) were sesquithujene (25.0%), (-zingiberene (18.2%), germacrene-D (13.1%) and (-copaene (12.7%). In vitro antibacterial activity of essential oils was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method in 96-well microplates. Both essential oils under investigation showed moderate anti-streptococcal activity against the following bacteria: Streptococcus mutans, S. mitis, S. sanguinis, S. sobrinus and S. salivarius. MIC values ranged between 100 and 400 µg/mL. Regarding the antimycobacterial activity, essential oils from M. paniculata (L.) Jack unripe and ripe fruits were active against Mycobacterium kansasii (MIC = 250 µg/mL), moderately active against M. tuberculosis (MIC = 500 µg/mL) and inactive against M. avium (MIC = 2000 µg/mL). This study was pioneer in revealing similar chemical profiles of both essential oils extracted from Murraya paniculata (L.) Jack unripe and ripe fruits, besides describing their in vitro anti-streptococcal and antimycobacterial activities.

Essential Oil from Psidium cattleianum Sabine (Myrtaceae) Fresh Leaves: Chemical Characterization and in vitro Antibacterial Activity Against Endodontic Pathogens

Abstract Endodontic infections result from oral pathogenic bacteria which reach and infect dental pulp, as well as surrounding tissues, through cracks, unrepaired caries and failed caries restorations. This study aims to determine the chemical composition of essential oil from Psidium cattleianum leaves (PC-EO) and to assess its antibacterial activity against endodontic bacteria. Antibacterial activity of PC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method on 96-well microplates. Bacteria Porphyromonas gingivalis (MIC = 20 µg/mL), Prevotella nigrescens (MIC = 62.5 µg/mL), Fusobacterium nucleatum (MIC = 12.5 µg/mL), Actinomyces naeslundii (MIC = 50 µg/mL), Bacteroides fragilis (MIC = 12.5 µg/mL), Aggregatibacter actinomycetemcomitans (MIC = 6.25 µg/mL) and Peptostreptococcus anaerobius (MIC = 62.5 µg/mL) were evaluated and compared to chlorhexidine dihydrochloride (CDH), the positive control. PC-EO was obtained by hydrodistillation with the use of a Clevenger-type apparatus whereas its chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Viridiflorol (17.9%), β-caryophyllene (11.8%), 1,8-cineole (10.8%) and β-selinene (8.6%) were the major constituents found in PC-EO, which exhibited high antibacterial activity against all endodontic pathogens under investigation. Therefore, PC-EO, a promising source of bioactive compounds, may provide therapeutic solutions for the field of endodontics.

Brazilian Green Propolis: Chemical Composition of Essential Oil and Their In Vitro Antioxidant, Antibacterial and Antiproliferative Activities

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.

Chemical variability between different organs of the medicinal plant Casearia sylvestris

The phytochemical profile of essential oils and extracts from Casearia sylvestris leaves, flowers and fruits have been investigated here. Leaf and flower extracts were prepared by sonication and analyzed by thin-layer chromatography and high-performance liquid chromatography. The phenolic content was determined by ultraviolet spectrophotometry. Leaves, flowers, and fruits essential oils were extracted by hydrodistillation. The highest extracts yields were 20.3 % (leaves) and 23.4 % (flowers) with ethanol 70 %. Essential oil extraction yields were 0.3 % (leaves) and 0.1 % (flowers and fruits). Bicyclogermacrene was the major component in all essential oil. Thin-layer chromatography suggests a chemical profile similar for leaves and flowers. The leaves and flowers phenolic content were similar (14.0 and 15.0 %, respectively). Chromatography analyses indicated the predominance of casearin clerodane diterpenes in leaves (λmax 232-235), whereas in flowers, diterpenes with a different standard diene in side-chain C13(16) and C14 (λmax 223-229). The different phytochemical profile of C. sylvestris flowers as compared to the leaves could be explored by the search for new bioactive components. This is the first report on the fruit and flower C. sylvestris essential oil composition. These data could be used as quality control of herbal medicine derived from C. sylvestris leaves.(AU)

Antimicrobial activity of the essential oil of Tetradenia riparia (Hochst.) Codd. (Lamiaceae) against cariogenic bacteria

In Brazilian folk medicine, Tetradenia riparia (Hochst.) Codd. (Lamiaceae) is used to treat toothaches and dental abscesses and diseases induced by worms, bacteria, or fungi. This paper aims to investigate the chemical composition and the antibacterial effects of the essential oil obtained from Tetradenia riparia leaves (TR-EO) grown in Southeastern Brazil against a representative panel of oral pathogens. We evaluated the antibacterial activity of TR-EO in terms of the minimal inhibitory concentration (MIC). We identified aromadendrene oxide (14.0%), (E,E)-farnesol (13.6%), dronabinol (12.5%), and fenchone (6.2%) as the major constituents of TR-EO. TR-EO displayed MIC values between 31.2 and 500 μg/mL, with the lowest MIC value being obtained against Streptococcus mitis (31.2 μg/mL), S. mutans (62.5 μg/mL), S. sobrinus (31.2 μg/mL), and Lactobacillus casei (62.5 μg/mL). In time-kill experiments, TR-EO demonstrated bactericidal activity against S. mutans within the first 12 h, resulting in a curve profile similar to that of chlorhexidine. These results revealed that the essential oil of Tetradenia riparia displays promising activity against most of the selected cariogenic bacteria, including Streptococcus mutans.

Antifeedant and allelopathic activities of the hydroalcoholic extract obtained from Neem (Azadirachta indica) leaves

Azadirachta indica, the so-called Neem or Nim, is well-known for its biological activities in many countries. The present study aimed at investigating the antifeedant properties of the hydroalcoholic extract obtained from the leaves of Neem on Zabrotes fasciatus (Coleoptera: Bruchidae), an insect pest that commonly feeds on common bean (Phaseolus vulgaris) during seed storage. We observed that the hydroalcoholic extract obtained from Neem leaves displayed significant antifeedant activity when it was added to the insect diet via Phaseolus vulgaris seeds. Additionally, the inhibitory effects of this extract on Phaseolus vulgaris germination and growth were also evaluated, indicating that both seed germination and radicle growth were affected in a concentration-dependent manner.

A espécie vegetal Azadirachta indica, popularmente chamada de Nim, é conhecida em muitos países devido a suas inúmeras propriedades biológicas. O presente estudo teve como objetivo investigar a propriedade antialimentar do extrato hidroalcoólico das folhas de Nim sobre Zabrotes fasciatus (Coleoptera: Bruchidae), um inseto conhecido como carucho-do-feijão e que atua como praga durante o processo de estocagem do feijão comum (Phaseolus vulgaris). Este inseto provoca danos tais como perda de peso, redução do valor nutritivo e do grau de higiene do feijão. Quando adicionado a sua dieta, usando sementes de Phaseolus vulgaris, o extrato hidroalcoólico das folhas de Nim demonstrou efeito antialimentar, ocasionando assim, uma significativa redução nos danos. Os efeitos inibitórios deste extrato sobre a germinação e o crescimento de Phaseolus vulgaris também foram avaliados. O extrato de Nim afetou a germinação das sementes e o crescimento das radículas de Phaseolus vulgaris de uma maneira dose-dependente.