Fabrício Souza Silva

Biological Oxidations and Antioxidant Activity of Natural Products

Oxygen is the most prevalent element in the earth’s crust. It exists in air as a diatomic molecule, O2. Except for a small number of anaerobic bacteria, all living organisms use O2 for energy production and it is essential for life as we know it. Energy production by organisms from food material requires “oxidation”, which implies the loss of electrons. However the potential of O2 to oxidize also makes it toxic. Oxidation can inactivate important enzymes, and anaerobes that do not have antioxidant mechanisms do not survive in an O2 environment (Magder, 2006).

Avaliação toxicológica pré-clínica do chá das folhas de Morus nigra L. (Moraceae)

O objetivo desse estudo foi realizar um ensaio toxicologico pre-clinico para analisar a toxicidade do cha das folhas de Morus nigra L. (Moraceae). A toxicidade subcronica do cha (CF-Mn) foi avaliada durante 30 dias por via oral em ratos. Ao grupo controle foi administrado agua, para comparacao. Durante o periodo experimental foi avaliada a presenca de sinais de toxicidade, variacao do peso corporal, e o consumo de liquido e alimento. Ao final do experimento o sangue dos animais foi retirado para analise de parâmetros hematologicos e bioquimicos. Nao foram observados mortalidade e sinais de toxicidade indicando baixa toxicidade da planta. Nao houve alteracoes nos parâmetros hematologicos e bioquimicos. Nas condicoes do estudo, o CF-Mn pode ser considerado de baixa toxicidade, pois nao produziu efeitos toxicos nos animais tratados.

Medicinal Plants and Natural Compounds from the Genus Morus (Moraceae) with Hypoglycemic Activity: A Review

© 2012 da Silva Almeidaet al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Medicinal Plants and Natural Compounds from the Genus Morus (Moraceae) with Hypoglycemic Activity: A Review

Chemical composition and pharmacological properties of the essential oils obtained seasonally from Lippia thymoides.

Abstract Context: Lippia thymoides Mart. & Schauer (Verbenaceae) is used in folk medicine to treat wounds, fever, bronchitis, rheumatism, headaches, and weakness. Objective: This study determinates the chemical composition of essential oils from L. thymoides, obtained at during each of the four seasons and correlates with pharmacological properties. Materials and methods: Essential oils were obtained by hydrodistillation and analyzed by gas chromatography coupled to mass spectroscopy (GC-MS). Antioxidant activity was determined by DPPH free radical scavenging and β-carotene bleaching methods. The antimicrobial assays were performed by minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) methods. Isolated rat aorta and uterus, and guinea-pig trachea were utilized to evaluate relaxant potential in pre-contracted smooth muscle. Results and discussion: Essential oils from leaves of L. thymoides had the sesquiterpene β-caryophyllene (17.22–26.27%) as the major constituent followed by borneol (4.45–7.36%), camphor (3.22–8.61%), camphene (2.64–5.66%), and germacrene D (4.72–6.18%). In vitro assays showed that these essential oils do not have antioxidant activity, have antimicrobial selectivity to Gram-positive bacteria Staphylococcus aureus (MICu2009=u20090.004u2009mg/mL and MMCu2009=u20090.26–10.19u2009mg/mL) and Micrococcus luteus (MICu2009=u20090.03u2009mg/mL and MMCu2009=u20098.43u2009mg/mL), relax isolated rat aorta (EC50u2009=u2009305–544u2009μg/mL, with endothelium; and EC50u2009=u2009150–283u2009μg/mL, without endothelium), and uterus (EC50u2009=u200974–257u2009μg/mL), and minor potency, isolated guinea-pig trachea. Conclusions: Lippia thymoides is a source of natural products of pharmaceutical interest, being necessary additional studies to determine the substances involved in the biological activities.

Pharmacological Basis for Traditional Use of the Lippia thymoides

The aim of this study was to evaluate crude extracts and fractions from leaves and stems of Lippia thymoides and to validate their use in folk medicine. In vitro antioxidant and antimicrobial activities and in vivo wound healing in rats, baker yeast-induced fever in young rats, and acute oral toxicity in mice assays were realized. The crude extracts and their dichloromethane and ethyl acetate fractions had potent radical-scavenging activity against the DPPH but were not effective in the β-carotene bleaching method. The dichloromethane fraction from the leaves extract showed the broadest spectrum of activity against S. aureus, B. cereus, and C. parapsilosis. The animals treated with crude extracts showed no difference in wound healing when compared with the negative control group. The crude extract from leaves (1200u2009mg/kg) has equal efficacy in reducing temperature in rats with hyperpyrexia compared to dipyrone (240u2009mg/kg) and is better than paracetamol (150u2009mg/kg). In acute toxicity test, crude extract of leaves from Lippia thymoides exhibited no mortality and behavioral changes and no adverse effects in male and female mice. This work validates the popular use of Lippia thymoides for treating the wound and fever, providing a source for biologically active substances.

Spasmolytic and antidiarrheal activities of Lippia thymoides (Verbenaceae) essential oil

Abstract Lippia thymoides (‘alecrim-do-mato’ or ‘alecrim-do-campo’) is used in Brazilian folk medicine to treat various illnesses, including diarrhea. This work aimed to evaluate in vitro spasmolytic and in vivo antidiarrheal activities of the L. thymoides essential oil (OOS) and to correlate with the traditional use of this plant. In isolated guinea-pig ileum, OOS presented a concentration-dependent spasmolytic activity in preparations pre-contracted with KCl 40 mM [EC50 = 16.89 (11.56–24.66) μg/mL], and antagonized phasic contractions induced by 1 μM carbachol [IC50 = 42.71 (37.35–48.83) μg/mL] or histamine [IC50 = 32.38 (27.44–38.20) μg/mL]. In mice, OOS at 400 mg/kg reduced intestinal transit, at 200 and 400 mg/kg reduced total stool mass and at 400 mg/kg reduced intestinal fluid accumulation. It was shown that the antidiarrheal effect of OOS is related to the inhibition of smooth muscle contraction and may be due to the presence of major compound β-caryophyllene in this essential oil.

Relaxant effect of Lippia origanoides essential oil in guinea-pig trachea smooth muscle involves potassium channels and soluble guanylyl cyclase

ETHNOPHARMACOLOGICAL RELEVANCEnLippia origanoides H.B.K. is an aromatic species used in folk medicine to treat respiratory diseases, including asthma.nnnAIM OF THE STUDYnThe aim of this work was to evaluate the relaxing potential and mechanism of action of the L. origanoides (LOO) essential oil in isolated guinea-pig trachea.nnnMATERIALS AND METHODSnLeaves from L. origanoides were collected at experimental fields under organic cultivation, at the Forest Garden of Universidade Estadual de Feira de Santana. Essential oil was extracted by hydrodistillation, analyzed by GC/FID and GC/MS and the volatile constituents were identified. Spasmolytic activity and relaxant mechanism of LOO were assayed in isolated guinea-pig trachea contracted with histamine, carbachol or hyperpolarizing KCl.nnnRESULTSnChemical analysis revealed the presence of carvacrol (53.89%) as major constituent. LOO relaxed isolated guinea-pig trachea pre-contracted with KCl 60u202fmM [EC50 =u202f30.02u202fμg/mL], histamine 1u202fµM [EC50 =u202f9.28u202fμg/mL] or carbachol 1u202fµM [EC50 =u202f51.80u202fμg/mL]. The pre-incubation of glibenclamide, CsCl, propranolol, indomethacin, hexamethonium, aminophylline or L-NAME in histamine-induced contractions did not alter significantly the relaxant effect of LOO. However, the presence of 4-aminopyridine, tetraethylammonium or methylene blue reduced LOO effect, while the presence of dexamethasone or atropine potentialized the LOO relaxant effect. LOO pre-incubation inhibited carbachol-evoked contractions, with this effect potentialized in the presence of sodium nitroprusside and blocked in the presence of ODQ.nnnCONCLUSIONSnThe relaxant mechanism of LOO on the tracheal smooth muscle possibly involves stimulating of soluble guanylyl cyclase with consequent activation of the voltage-gated and Ca2+-activated K+ channels.