Xirley P. Nunes

Plants with anticonvulsant properties: a review

Seizures are resistant to treatment with currently available anticonvulsant drugs in about 1 out of 3 patients with epilepsy. Thus, there is a need for new, more effective anticonvulsant drugs for intractable epilepsy. However, nature is a rich source of biological and chemical diversity and a number of plants in the world have been used in traditional medicine remedies, i.e., anticonvulsant, anxiolytic, analgesic, antidepressant. This work constitutes a literature review on medicinal plants showing anticonvulsant properties. The review refers to 16 Brazilian plants and a total 355 species, their families, geographical distribution, the utilized parts, method and references. Some aspects of research on medicinal plants and a brief review of the most common animal models to discover antiepileptic drugs are discussed. For this purpose over 170 references were consulted.

Sources of alpha-, beta-, gamma-, delta- and epsilon-carotenes: a twentieth century review

Since humans cannot synthesize carotenoids, they depend upon the diet exclusively for the source of these micronutrients. It has claimed that they may alleviate chronic diseases such as cancers. The present communication constitutes a global review of the scientific literature on plants and others organisms that biosynthesize carotenoids, which include the series alpha-, beta-, gamma-, delta- and epsilon-carotenes. The results of the literature survey lists more than five hundred sources.

Effects of umbelliferone in a murine model of allergic airway inflammation

The therapeutic effects of umbelliferone (30, 60 and 90 mg/kg), a coumarin isolated from Typha domingensis (Typhaceae) were investigated in a mouse model of bronchial asthma. BALB/c mice were immunized and challenged by nasal administration of ovalbumin. Treatment with umbelliferone (60 and 90 mg/kg) caused a marked reduction of cellularity and eosinophil numbers in bronchoalveolar lavage fluids from asthmatic mice. In addition, a decrease in mucus production and lung inflammation were observed in mice treated with umbelliferone. A reduction of IL-4, IL-5, and IL-13, but not of IFN-gamma, was found in bronchoalveolar lavage fluids of mice treated with umbelliferone, similar to that observed with dexamethasone. The levels of ovalbumin-specific IgE were not significantly altered after treatment with umbelliferone. In conclusion, our results demonstrate that umbelliferone attenuates the alteration characteristics of allergic airway inflammation. The investigation of the mechanisms of action of this molecule may contribute for the development of new drugs for the treatment of asthma.

Antinociceptive Activity of Structural Analogues of Rotundifolone: Structure-Activity Relationship

Rotundifolone, a monoterpene isolated from the essential oil of the leaves of Mentha x villosa, is a constituent of several essential oils and known to have antinociceptive activity. Our recent study demonstrated that the analogues of rotundifolone showed also a significant antinociceptive effect. In the present report, to investigate the correlation between the structure and antinociceptive activity, rotundifolone and its analogues were evaluated in the acetic acid-induced writhing test in mice. All compounds showed to be more antinociceptive than rotundifolone against the pain response induced by acetic acid. Comparing the antinociceptive effect of rotundifolone with limonene oxide and (+)-pulegone, the results demonstrated that the epoxide group contributes as much as the ketone group to the antinociceptive activity of rotundifolone. Similarly, pulegone oxide and carvone epoxide were more antinociceptive than rotundifolone, thereby suggesting that the position of the functional group on the ring also influences the antinociceptive activity. (D)-Carvone produced maximal inhibition of the writhing response and was slightly more active than (+)-carvone. The study showed that by appropriate structural modification it may be possible to develop novel antinociceptive agents.

Atividade antimicrobiana "in vitro" e determinação da concentração inibitória mínina (CIM) de fitoconstituintes e produtos sintéticos sobre bactérias e fungos leveduriformes

Regarding the problem of microbial resistance, the researches point to the use of new antibiotic which can be active against the emergent pathogens. This work aims to test the activity against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli e Pseudomonas aeruginosa) and leveduriform fungi (Candida albicans), and also the Minimum Inhibitory Concentration (MIC) of the constituent of Ocotea duckei Vattimo, lapachol and its synthetic derivatives a-lapachone, b-nor-lapachone, b-lapachone, a-nor-lapachone, b-3-iodin-lapachone and a-3-iodin-lapachone, as well as seven nitrogenated derivatives of lapachol obtained through semi synthesis. The achieved results stimulate the deepening of the studies for some of theses substances such as lapachol and its analogous which demonstrated antimicrobial activity. The substances which were active against S. aureus, were lapachol and the ethanolic extract of Ocotea duckei Vattimo, against Escherichia coli iangambin and against C. albicans the imides. The other substances did not show any activity against the tested bacteria.

Mechanisms involved in the antinociceptive effects of 7-hydroxycoumarin.

7-Hydroxycoumarin (umbelliferone, 1), the main metabolite of coumarin, has been reported to produce potent antinociceptive effects in animal models of pain. However, the biochemical events involved in antinociception mediated by 1 are currently not well understood. In the present study, the mechanisms by which 1 exerts its pharmacological actions were investigated. Acute pretreatment of mice with 1 produced a long-lasting antinociceptive effect against complete Freunds adjuvant (CFA)-induced hyperalgesia. The subchronic administration of 1 inhibited CFA-induced hyperalgesia and paw edema, while it did not cause any apparent toxicity. Another set of experiments showed that 1 inhibited carrageenan-induced mechanical hyperalgesia, but not mechanical hyperalgesia induced by prostaglandin E(2) (PGE(2)), suggesting that it acts upstream of PGE(2.) Treatment with 1 was able to prevent the plantar tissue neutrophil influx induced by local inflammatory stimuli. In addition, 1 exhibited inhibitory effects on the release of hyperalgesic cytokines (TNF-α and IL-1β) and the production of PGE(2), a directly acting hyperalgesic mediator. The present results suggest that the antinociceptive effect of 1 is correlated with the inhibition of neutrophil migration, cytokine release, and PGE(2) production and are supportive of the further investigation of the therapeutic potential of 1 to control inflammatory pain.

Antinociceptive and anti-inflammatory properties of 7-hydroxycoumarin in experimental animal models: potential therapeutic for the control of inflammatory chronic pain

Objectives In the present study we investigated the antinociceptive, anti‐inflammatory and antipyretic effects of 7‐hydroxycoumarin (7‐HC) in animal models.

Antinociceptive effect of ethanolic extract of Selaginella convoluta in mice.

BackgroundSelaginella convoluta (Arn.) Spring (Selaginellaceae), commonly known as “jericó”, is a medicinal plant found in northeastern Brazil. S. convoluta is used in folk medicine as an antidepressant, aphrodisiac, diuretic, analgesic, anti-inflammatory and it is used to combat amenorrhea, coughing and bleeding. This study was performed to evaluate the antinociceptive effects of ethanolic extract from S. convoluta in mice exposed to chemical and thermal models of nociception.MethodsPreliminary phytochemical analysis of the ethanolic extract was performed. The ethanolic extract from Selaginella convoluta (Sc-EtOH) was examined for its intraperitoneal (i.p.) antinociceptive activity at the doses of 100, 200 and 400 mg/kg body weight. Acetic acid-induced writhing, formalin injection and hot plate tests were used to evaluate the antinociceptive activity of Sc-EtOH extract. The rota-rod test was used to evaluate motor coordination.ResultsA preliminary analysis of Sc-EtOH revealed that it contained phenols, steroids, terpenoids and flavonoids. In the acetic acid-induced writhing test, mice treated with Sc-EtOH (100, 200 and 400 mg/kg, i.p.) exhibited reduced writhing (58.46, 75.63 and 82.23%, respectively). Secondly, Sc-EtOH treatment (100, 200 and 400 mg/kg, i.p.) decreased the paw licking time in mice during the first phase of the formalin test (by 44.90, 33.33 and 34.16%, respectively), as well as during the second phase of the test (by 86.44, 56.20 and 94.95%, respectively). Additionally, Sc-EtOH treatment at doses of 200 and 400 mg/kg increased the latency time in the hot plate test after 60 and 90 minutes, respectively. In addition, Sc-EtOH did not impair motor coordination.ConclusionOverall, these results indicate that Sc-EtOH is effective as an analgesic agent in various pain models. The activity of Sc-EtOH is most likely mediated via the inhibition of peripheral mediators and central inhibitory mechanisms. This study supports previous claims of traditional uses for S. convoluta.

Structure and Spasmolytic Activity Relationships of Monoterpene Analogues Found in Many Aromatic Plants

Abstract Rotundifolone, a monoterpene isolated from the essential oil of the leaves of Mentha x villosa, is a constituent of several essential oils and known to have spasmolytic activity. The present study aimed to investigate the correlation between structure and spasmolytic activity of rotundifolone and its analogues in ileum isolated from guinea-pig. Five of the seven tested analogues were found to have a spasmolytic effect more potent than rotundifolone itself, except for pulegone and (+)-limonene. The comparison between rotundifolone and limonene oxide showed that the absence of the keto group did not decrease the relaxant effect. Comparison of the spasmolytic activity between rotundifolone and (+)-pulegone showed that the absence of the epoxy group did not decrease the relaxation of the ileum. Carvone epoxide was found to be significantly more potent than rotundifolone. The monoterpene (-)-carvone produced ileum relaxation and was more potent than its enantiomer (+)-carvone. (+)-Limonene and pulegone oxide showed a similar effect. The study showed that the functional groups and their position at the ring of rotundifolone contributed to the relaxation activity of the ileum. The absence of the oxygenated molecular structure is not a critical requirement for the molecule to be bioactive.

Rotundifolone-Induced Relaxation is Mediated by BKCa Channel Activation and Cav Channel Inactivation

Rotundifolone is the major constituent of the essential oil of Mentha x villosa Hudson. In preliminary studies, rotundifolone induced significant hypotensive, bradycardic and vasorelaxant effects in rats. Thus, to gain more insight into the pharmacology of rotundifolone, the aim of this study was to characterize the molecular mechanism of action involved in relaxation produced by rotundifolone. The relaxant effect was investigated in rat superior mesenteric arteries by using isometric tension measurements and whole-cell patch-clamp techniques. Rotundifolone relaxed phenylephrine-induced contractions in a concentration-dependent manner. Pre-treatment with KCl (20 mM), charybdotoxin (10(-7) M) or tetraethylammonium (TEA 10(-3) or 3 × 10(-3) M) significantly attenuated the relaxation effect induced by rotundifolone. Additionally, whole-cell patch-clamp recordings were made in mesenteric smooth muscle cells and showed that rotundifolone significantly increased K(+) currents, and this effect was abolished by TEA (10(-3)  M), suggesting the participation of BK(Ca) channels. Furthermore, rotundifolone inhibited the vasoconstriction induced by CaCl(2) in depolarizing nominally Ca(2+) -free medium and antagonized the contractions elicited by an L-type Ca(2+) channel agonist, S(-)-Bay K 8644 (2 × 10(-7)  M), indicating that the vasodilatation involved inhibition of Ca(2+) influx through L-type voltage-dependent calcium channels (Ca(v) type-L). Additionally, rotundifolone inhibited L-type Ca(2+) currents (I(Ca) L), affecting the voltage-dependent activation of I(Ca) L and steady-state inactivation. Our findings suggest that rotundifolone induces vasodilatation through two distinct but complementary mechanisms that clearly depend on the concentration range used. Rotundifolone elicits an increase in the current density of BK(Ca) channels and causes a shift in the steady-state inactivation relationship for Ca(v) type-L towards more hyperpolarized membrane potentials.