Evaluation of the Coagulating Potential of the Crude Extract from the Barbatimão Bark for the Treatment of Dairy Effluents

The coagulating potential of the crude extract from the barbatimao bark for the treatment of dairy effluent was assessed and compared with industrial coagulants such as aluminum sulfate (inorganic coagulant), the crude extract of black wattle bark (used in the manufacture of natural organic coagulants), and gallic acid (the main constituent of condensed tannins). The aqueous extract of barbatimao was obtained by refluxing for 12 h, and the black wattle was provided by a producer of natural coagulants. The determinations of total phenolic compounds and tannins in the extracts were performed by the Folin-Ciocalteu method and precipitation with casein, respectively. The treatment of the effluent with coagulant was performed by the Jar-Test. After testing, the effluent was evaluated for turbidity, total solids, and biochemical oxygen demand (BOD). A higher content of phenolic compounds (19.81% mg of gallic acid/g extract) was observed in the barbatimao extract than in the black wattle extract (14.24% mg of gallic acid/g extract). However, the extracts contained the same amount of tannins, 13.95% for the barbatimao extract and 12.89% for the black wattle extract. A 63%, reduction in BOD was observed for the effluent treated with barbatimao extract, 35% for the black wattle extract, 58% for gallic acid and 60.59% for the treatment with aluminum sulfate. Treatment with gallic acid caused a 98% reduction in the turbidity of the effluent;with aluminum sulfate, a 97% reduction was obtained;with barbatimao extract, 96%, and with black wattle extract, 93%. The barbatimao extract was shown to be a potential coagulant for dairy effluents.

Essential Oils from Mentha piperita,Cymbopogon citratus,Rosmarinus officinalis,Peumus boldus and Foeniculum vulgare:Inhibition of Phospholipase A_(2) and Cytotoxicity to Human Erythrocytes

The essential oils from Mentha piperita, Cymbopogon citratus, Rosmarinus officinalis, Peumus boldus and Foeniculum vulgare were extracted by hydrodistillation and characterized and quantified by GC-MS and GC-DIC. The oils induced hemolysis with all the doses evaluated (0.6 to 1.8 μL), and the diameters of the halos varied between 9 and 15 mm. Pre-incubation of P. boldus oil with Bothrops jararacussu venom resulted in potentiation of venom-induced hemolysis (30%) (proteases and phospholipases A2). The essential oil from M. piperita (0.6 μL) inhibited venom-induced hemolysis by 45%, whereas 0.6 μL of R. officinalis oil increased the hemolysis by 20%. For the essential oil from F. vulgare, 100% inhibition of activity (0.6 and 1.2 μL) was observed. The application of C. citratus oil induced hemolysis with all the volumes evaluated. Phospholipase activity induced by the venom was only inhibited (10%) with the 0.6 μL volume of R. officinalis oil. The oils from M. piperita and F. vulgare (1.8 μL) and C. citratus oil (0.6 μL) potentiated the phospholipase activity. The results highlight the need for a broad characterization and regulation of the use of natural products, because they can have therapeutic or toxic actions.

Characterization of the Biological Potential of the Essential Oils from Five Species of Medicinal Plants

Essential oils from Mentha piperita, Cymbopogon citratus, Rosmarinus officinalis, Peumus boldus and Foeniculum vulgare were extracted by hydrodistillation, chemically characterized and quantified by GC/MS and GC/FID. The principal componentes in the essential oil of M. piperita (carvone and limonene), C. citratus (geranial, neral and myrcene), R. officinalis (1,8-cineole, camphor and α-pinene), P. boldus (α-terpinyl formate, p-cymene and 1,8-cineole) and F. vulgare (methyl chavicol, limonene and fenchone) were identified. The oils were tested for antioxidant activity employing the DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical-capture method, the oxidation of the β-carotene/linoleic acid system, and the ABTS radical-capture method. The essential oils were not effective. The antioxidant activities of the oils were determined by the hydroxyl method, and the highest activity (62.80%) was observed with the essential oil from M. piperita. Activities of 1.54 and 1.82 μg μg-1, respectively, were observed for the essential oils from C. citratus and P. Boldus using the phosphomolybdenum method. No activity was observed with respect to reducing power. The essential oil from C. citratus was effective in inhibiting the growth of L. monocytogenes (15.63 mg·L-1), S. choleraesuis (15.63 mg·L-1) and E. coli (31.25 mg·L-1), and the essential oil from P. boldus inhibited the growth of S. aureus (62.5 mg·L-1). No essential oil inhibited the growth of P. aeruginosa. A low antioxidant activity and a promising antibacterial activity were observed for these essential oils.

Essential Oils from Mentha viridis(L).L.and Mentha pulegium L.:Cytogenotoxic Effects on Human Cells

The essential oils from Mentha viridis (L). L. and Mentha pulegium L. were studied to assess their inhibitory potential on phospholipase from snake venoms and to determine their cytogenotoxic action on human cells. These essential oils were able to inhibit the breakdown of phospholipids induced by venoms of snakes of the Bothrops genus. Both oils presented hemolytic activity, although the Mentha viridis (L). L. oil induced hemolysis only at the highest concentrations (14.6 and 29 μL&#183mL-1). The essential oil from M. viridis induced 3.9;8.6 and 16.2 times greater damage to human leukocyte DNA than that observed with the positive control (100 μg&#183μL-1 doxorubicin) at concentrations of 0.25;0.5 and 1.0 μL&#183mL-1, respectively. A similar effect was observed for the oil from M. pulegium (2.1, 2.5 and 15.8 times greater damage). The results extend the characterization of these essential oils and demonstrate their potential use in industries.

Essential Oils from the Leaves and Flowers of Callistemon viminalis:Chemical Characterization and Evaluation of the Insecticide and Antifungal Activities

The chemical compositions of the essential oils from the leaves and flowers of Callistemon viminalis and their insecticide and fungitoxic activities were determined. The essential oil was extracted by the hydrodistillation method using a modified Clevenger apparatus. The chemical characterization was performed by GC-MS and GC-FID. The evaluation of the insecticidal activity was performed with the Myzus persicae aphid, and the antifungal potential was determined via the inhibition of the mycelial growth of Alternaria alternata, Fusarium oxysorum and Botrytis cinérea phytopathogenic fungi. The principal components of the essential oils from the leaves and flowers were eucalyptol (84.60% and 61.47%), α-pinene (10.28% and 21.48%) and α-terpineol (2.59% and 2.79%), respectively. The use of a 0.5% concentration of the essential oil from the flowers influenced the preference of aphids and their reproduction. The number of adult aphids decreased within a period of 48 hours in the presence of the essential oil from the leaves. In the test with no chance of choice, the mean number of adults decreased with both oils within 48 hours. No inhibition of the mycelial growth of the A. alternate microorganism was observed in any of the treatments with the two essential oils. However, the growth of F. oxysporum and B. cinerea fungi was inhibited. The mycelial growth of F. oxysporum was inhibited with the concentration of 100 μL·Lˉ1 of the oil from the flowers and 250 μL·Lˉ1 of the oil from the leaves. The inhibition of the growth of B. cinerea was observed at concentrations of 500 and 100 μL·Lˉ1 for the oils from the flowers and leaves, respectively. The essential oils presented insecticidal and antifungal potentials. However, further studies are needed for these oils to be used in integrated pest management.