RESUMEN

Citral is a mixture of monoterpenes present in the essential oil of several plants, such as Cymbopogon citratus and Zingiber officinale, possessing anti-inflammatory, anti-ulcerogenic, and antipyretic actions. We investigated the action of citral on body temperature (Tb) and inflammatory signaling in eutrophic and obese mice during Systemic Inflammation (SI) induced by Lipopolysaccharide (LPS). Thus, we assessed the effect of citral (25, 100, and 300 mg/kg) and ibuprofen in LPS-induced SI in Swiss male mice fed a standard diet (SD) or high-fat diet (HFD) for 12 weeks. Following SI induction, we measured Tb and collected the serum, hypothalamus, and gastric mucosa for biochemical measurements. Acute treatment with citral decreased the Tb of both SD and HFD-fed animals. Citral (300 mg/kg) treatment caused a significantly lower Tb variation in HFD-fed animals than in those fed the SD. Citral reduced peripheral levels of tumor necrosis factor (TNF)-α in SD and HFD mice and decreased serum leptin concentration in HFD mice 90 min after the LPS challenge. Furthermore, citral also reduced interleukin (IL)-6 levels in the hypothalamus of obese mice. In summary, citral effectively reduced Tb during SI by reducing inflammatory mediators with a distinct action profile in HFD mice when compared with SD.

Asunto(s)

Monoterpenos Acíclicos/farmacología , Inflamación/tratamiento farmacológico , Leptina/sangre , Factor de Necrosis Tumoral alfa/sangre , Monoterpenos Acíclicos/química , Animales , Antiinflamatorios/química , Antiinflamatorios/farmacología , Citocinas/sangre , Dieta Alta en Grasa/efectos adversos , Zingiber officinale/química , Humanos , Inflamación/sangre , Inflamación/inducido químicamente , Inflamación/patología , Interleucina-6/sangre , Leptina/genética , Lipopolisacáridos/toxicidad , Ratones , Ratones Obesos , Aceites Volátiles/química , Aceites Volátiles/farmacología

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: An ethnopharmacological survey indicated that leaves from Eugenia punicifolia (Kunth) DC. (Myrtaceae) are popularly used as a natural therapeutic agent to treat pain and inflammation. AIM OF THE STUDY: The overall objective of the present study was to evaluate the antinociceptive, anti-inflammatory and gastroprotective activities of a hydroalcoholic extract of leaves from Eugenia punicifolia (HEEP) in rodents. MATERIAL AND METHODS: The antinociceptive effects of HEEP were evaluated in mice after oral administration in chemical (formalin and glutamate) and thermal (hot-plate) tests. We evaluated the involvement of the glutamatergic, opioidergic and nitrergic pathways in the antinociception of HEEP and the effect of HEEP on the inhibition of p38α MAPK. The anti-inflammatory effect of HEEP was evaluated in mice and rats using xylene-induced ear edema and carrageenan-induced paw edema, respectively. Furthermore, the gastroprotective effect of HEEP was evaluated in rats with acute gastric lesions induced by ethanol or indomethacin. Finally, we performed a phytochemical analysis of HEEP. RESULTS: The oral administration of HEEP (125, 250 and 500mg/kg, p.o.) significantly inhibited the neurogenic and inflammatory phases of formalin-induced licking, and HEEP (250mg/kg, p.o.) also significantly inhibited the nociception caused by glutamate. The antinociceptive effects of HEEP were significantly reversed by l-arginine (500mg/kg, i.p.) but not by naloxone (1mg/kg, i.p.) in the formalin test. HEEP did not affect animal motor performance in the rotarod model. In addition, HEEP also increased the paw withdraw latency in the hot-plate test. HEEP significantly inhibited ear edema induced by xylene (64%) and paw edema induced by carrageenan (50%) compared to the control group. Furthermore, HEEP (3-30mg/mL) also inhibited the phosphorylation of p38α MAPK by approximately 90%. In addition, HEEP (125, 250 and 500mg/kg, p.o.) protected the rats against ethanol (88.4-99.8%) and indomethacin (53-72.3%) and increased the mucus levels of the gastric mucosa without producing an antisecretory effect. The phytochemical profile of HEEP obtained using HPLC-PDA showed secondary metabolites already reported for the genus, mostly flavonoids, gallotannins and proanthocyanidins. CONCLUSIONS: These data show for the first time that HEEP has significant antinociceptive and anti-inflammatory effects, which appear to be related to the inhibition of the glutamatergic system, the synthesis of nitric oxide and the inhibition of the phosphorylation of p38α MAPK. HEEP also has interesting gastroprotective effects related to the maintenance of protective factors, such as mucus production. These results support the use of Eugenia punicifolia in popular medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with antinociceptive, anti-inflammatory and gastroprotective properties.

Asunto(s)

Analgésicos/farmacología , Antiinflamatorios/farmacología , Eugenia/química , Extractos Vegetales/farmacología , Analgésicos/administración & dosificación , Analgésicos/aislamiento & purificación , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/aislamiento & purificación , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Edema/tratamiento farmacológico , Femenino , Ácido Glutámico/metabolismo , Inflamación/tratamiento farmacológico , Masculino , Medicina Tradicional , Ratones , Dolor/tratamiento farmacológico , Dimensión del Dolor , Extractos Vegetales/administración & dosificación , Hojas de la Planta , Ratas , Ratas Wistar

RESUMEN

Citral (3,7-dimethyl-2,6-octadienal) is an open-chain monoterpenoid present in the essential oils of several medicinal plants. The aim of this work was to evaluate the effects of orally administered citral in experimental models of acute and chronic nociception, inflammation, and gastric ulcers caused by non-steroidal anti-inflammatory drugs (NSAIDs). Oral treatment with citral significantly inhibited the neurogenic and inflammatory pain responses induced by intra-plantar injection of formalin. Citral also had prophylactic and therapeutic anti-nociceptive effects against mechanical hyperalgesia in plantar incision surgery, chronic regional pain syndrome, and partial ligation of sciatic nerve models, without producing any significant motor dysfunction. In addition, citral markedly attenuated the pain response induced by intra-plantar injection of glutamate and phorbol 12-myristate 13-acetate (PMA, a protein kinase C activator), as well as by intrathecal (i.t.) injection of ionotropic and metabotropic glutamate receptor agonists (N-methyl-D-aspartic acid [NMDA] and 1-amino-1,3-dicarboxycyclopentane [trans-ACPD], respectively), substance P, and cytokine tumour necrosis factor-α. However, citral potentiated behaviours indicative of pain caused by i.t., but not intra-plantar, injection of a transient receptor potential vanilloid receptor type 1 (TRPV1) agonist. Finally, the anti-nociceptive action of citral was found to involve significant activation of the 5-HT2A serotonin receptor. The effect of citral was accompanied by a gastro-protective effect against NSAID-induced ulcers. Together, these results show the potential of citral as a new drug for the treatment of pain.

Asunto(s)

Dolor Agudo/tratamiento farmacológico , Analgésicos/uso terapéutico , Dolor Crónico/tratamiento farmacológico , Monoterpenos/uso terapéutico , Receptor de Serotonina 5-HT2A/metabolismo , Dolor Agudo/inducido químicamente , Dolor Agudo/metabolismo , Monoterpenos Acíclicos , Analgésicos/farmacología , Animales , Capsaicina , Dolor Crónico/etiología , Dolor Crónico/metabolismo , Aminoácidos Excitadores , Formaldehído , Ácido Glutámico , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/metabolismo , Isquemia/complicaciones , Ketanserina/farmacología , Masculino , Ratones , Monoterpenos/farmacología , Neuralgia/tratamiento farmacológico , Neuralgia/metabolismo , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/metabolismo , Ratas Wistar , Antagonistas del Receptor de Serotonina 5-HT2/farmacología , Úlcera Gástrica/tratamiento farmacológico , Úlcera Gástrica/metabolismo , Sustancia P , Acetato de Tetradecanoilforbol , Factor de Necrosis Tumoral alfa

RESUMEN

The monoterpene ß-myrcene has been widely used in cosmetics, food and beverages, and it is normally found in essential oil from citrus fruit. The aim of this study was to investigate the anti-ulcer effects of ß-myrcene on experimental models of ulcers that are induced by ethanol, NSAIDs (non-steroidal anti-inflammatory drugs), stress, Helicobacter pylori, ischaemia-reperfusion injury (I/R) and cysteamine in order to compare with the essential oil of Citrus aurantium and its major compound limonene. The results indicate that the oral administration of ß-myrcene at a dose of 7.50mg/kg has important anti-ulcer activity with significantly decreased gastric and duodenal lesions as well as increased gastric mucus production. The results showed treatment with ß-myrcene caused a significant increase in mucosal malondialdehyde level (MDA), an important index of oxidative tissue damage. The ß-myrcene was also endowed with marked enhancement of antioxidant enzyme activity from GR system as evidenced by the decreased activity of superoxide dismutase (SOD) and increased levels of glutathione peroxidase (GPx), glutathione reductase (GR), and total glutathione in gastric tissue. Our results also shown that treatment with ß-myrcene is not involved with thioredoxin reductase (TrxR) activity. Our results reveal, for the first time, the importance of ß-myrcene as an inhibitor of gastric and duodenal ulcers and demonstrate that an increase in the levels of gastric mucosa defence factors is involved in the anti-ulcer activity of ß-myrcene.

Asunto(s)

Antiulcerosos/farmacología , Citrus/química , Monoterpenos/farmacología , Aceites Volátiles/química , Úlcera Péptica/prevención & control , Monoterpenos Acíclicos , Animales , Masculino , Ratas , Ratas Wistar

RESUMEN

Alchornea triplinervia (Spreng.) Muell. Arg (Euphorbiaceae) is a medicinal plant commonly used by people living in the Cerrado region of Brazil to treat gastrointestinal ulcers. We previously described the gastroprotective action of methanolic extract (ME) of Alchornea triplinervia and the ethyl acetate fraction (EAF) in increasing of prostaglandin E2 (PGE2) gastric levels in the mucosa. In this work we evaluated the effect of EAF in promoting the healing process in rats with acetic acid-induced gastric ulcers. In addition, toxicity was investigated during treatment with EAF. After 14 days of treatment with EAF, the potent stimulator of gastric cell proliferation contributed to the acceleration of gastric ulcer healing. Upon immunohistochemical analysis, we observed a pronounced expression of COX-2, mainly in the submucosal layer. The 14-day EAF treatment also significantly increased the number of neutrophils in the gastric mucosa regeneration area. The EAF induced angiogenesis on gastric mucosa, observed as an increase of the number of blood vessels supplying the stomach in rats treated with EAF. Oral administration for 14 days of the ethyl acetate fraction from Alchornea triplinervia accelerated the healing of gastric ulcers in rats by promoting epithelial cell proliferation, increasing the number of neutrophils and stimulation of mucus production. This fraction, which contained mainly phenolic compounds, contributed to gastric mucosa healing.