Analgesic and anti-inflammatory activity of the ethanolic extract fromSpiranthera odoratissimaA. St. Hillaire (Manacá) roots

The anxiolytic-like effect of an essential oil derived from Spiranthera odoratissima A. St. Hil. leaves and its major component, β-caryophyllene, in male mice

Spiranthera odoratissima A. St. Hil. (manacá) is used in folk medicine to treat renal and hepatic diseases, stomachache, headaches and rheumatism. A central nervous system (CNS) depressant effect of the hexane fraction from the ethanolic extract of this plant has been described. β-caryophyllene, the main component of this essential oil, is a sesquiterpene compound with anti-inflammatory properties that has been found in essential oils derived from several medicinal plants. This work is aimed to evaluate the pharmacological activity of the essential oil obtained from S. odoratissima leaves (EO) and its major component on the murine CNS; we aimed to evaluate a possible anxiolytic-like effect and the underlying mechanisms involved. In an open field test, EO (500 mg/kg) and β-caryophyllene (50, 100 and 200 mg/kg) increased the crossing frequency (P<0.05) and, EO (250 and 500 mg/kg) and β-caryophyllene (200 mg/kg) increased the time spent in the center (P<0.05) without altering total crossings of the open field. EO and β-caryophyllene did not alter the number of falls in the rota-rod test (P>0.05). In the pentobarbital-induced sleep test, EO (500 mg/kg) and β-caryophyllene (200 and 400 mg/kg) decreased the latency to sleep (P<0.05), and EO (125, 250 and 500 mg/kg) (P<0.001) and β-caryophyllene (200 and 400 mg/kg) (P<0.05 and P<0.001) increased the sleep time. In anxiety tests, EO (500 mg/kg) and β-caryophyllene (100 and 200 mg/kg) increased head-dipping behavior (P<0.05) in the hole-board test, entries (P<0.05) into and time spent (P<0.05) on the open arms of the elevated plus maze (EPM), and number of transitions (P<0.05) and time spent in the light compartment (P<0.05) of a light-dark box (LDB). We further investigated the mechanism of action underlying the anxiolytic-like effect of EO and β-caryophyllene by pre-treating animals with antagonists of benzodiazepine (flumazenil) and 5-HT(1A) (NAN-190) receptors prior to evaluation using EPM and LDB. The anxiolytic-like effects of EO were significantly reduced by pre-treatment with NAN-190 (P<0.05) but not flumazenil (P>0.05). The anxiolytic-like effects of β-caryophyllene were not blocked by either NAN-190 or flumazenil (P>0.05). In conclusion, these results suggest that the essential oil derived from S. odoratissima produces an anxiolytic-like effect without altering motor performance and that this effect is mediated by 5-HT(1A) but not via benzodiazepine receptors. In addition, the major component, β-caryophyllene, also has an anxiolytic-like effect that may contribute to the effects of EO, but this effect does not seem to be mediated via 5-HT(1A) or benzodiazepine receptors.

Leishmanicidal effect of Spiranthera odoratíssima (Rutaceae) and its isolated alkaloid skimmianine occurs by a nitric oxide dependent mechanism

Leishmaniasis is one of the neglected diseases. High cost, systemic toxicity, and diminished efficacy due to development of resistance by the parasites has a negative impact on the current treatment options. Thus, the search for a new, effective and safer anti-leishmanial drug becomes of paramount importance. Compounds derived from natural products may be a better and cheaper source in this regard. This study evaluated the in vitro anti-leishmanial activity of Spiranthera odoratíssima (Rutaceae) fractions and isolated compounds, using promastigote and amastigote forms of different Leishmania species. J774 A.1 macrophage was used as the parasite host cell for the in vitro assays. Evaluations of cytoxicity, nitric oxide (NO), interleukin-10 and in silico analysis were carried out. In vitro experiments showed that the fruit hexanic fraction (Fhf) and its alkaloid skimmianine (Skm) have a significant (P<0·001) effect against L. braziliensis. This anti-L. braziliensis activity of Fhf and Skm was due to increased production of NO and attenuation of IL-10 production in the macrophages at concentrations ranging from 1·6 to 40·0 μg/ml. The in silico assay demonstrated significant interaction between Skm and amino acid residues of NOS2. Skm is thus a promising drug candidate for L. braziliensis due to its potent immunomodulatory activity.