Ethyl acetate partition obtained from the methanol extract of Muntingia calaburaleaf exerts effective in vitroantiproliferative activity against the HT-29 colon cancer / La partición de acetato de etilo obtenido del extracto metanólico de la hoja de Muntingia calabura ejerce una actividad antiproliferativa in vitro eficaz contra el cáncer de colon HT-29

Methanol extract of Muntingia calabura L. leaf (MEMCL) has been shown to exert the antiproliferative activity against the HT-29 (human colon adenocarcinoma) cell line. To further investigate on the medicinal potential of this plant, MEMCL was sequentially partitioned to obtain the petroleum ether, ethyl acetate and aqueous partitions, whichwas then tested against the HT-29 cell line and also subjected to the in vitro anti-inflammatory study. The most effective partition was also subjected to the phytoconstituents analysis using the UHPLC-ESI-MS. Findings showed that the ethyl acetate partition (EAP) exerts the most effective antiproliferative activity (IC50 = 58.0 ± 12.9 µg/mL) without affecting the 3T3 normal fibroblast cells, exhibits the highest anti-inflammatory effect when assessed using the lipoxygenase (> 95%) and xanthine oxidase (> 70%) assays, and contained various types of polyphenolics. In conclusion, M. calabura exerts apoptotic-mediated antiproliferative activity, partly via the anti-inflammatory action and synergistic action between the polyphenolics.

Se ha demostrado que el extracto metanólico de hoja de Muntingia calabura L. (MEMCL) ejerce actividad antiproliferativa contra la línea celular HT-29 (adenocarcinoma de colon humano). Para investigar más a fondo el potencial medicinal de esta planta, MEMCL se dividió secuencialmente para obtener el éter de petróleo, el acetato de etilo y las particiones acuosas, que luego se probó contra la línea celular HT-29 y también se sometió al estudio antiinflamatorio in vitro. La partición más eficaz también se sometió al análisis de fitoconstituyentes utilizando UHPLC-ESI-MS. Los resultados mostraron que la partición de acetato de etilo (EAP) ejerce la actividad antiproliferativa más efectiva (IC50= 58.0 ± 12.9 µg/mL) sin afectar las células de fibroblastos normales 3T3, exhibe el mayor efecto antiinflamatorio cuando se evalúa usando la lipoxigenasa (> 95%) y ensayos de xantina oxidasa (> 70%), y contenían varios tipos de polifenoles. En conclusión, M. calabura ejerce una actividad antiproliferativa mediada por apoptosis, en parte a través de la acción antiinflamatoria y la acción sinérgica entre los polifenoles.

Possible mechanisms of antinociception of methanol extract of Melastoma malabathricum leaves

ABSTRACT Melastoma malabathricum L., Melastomaceae, has been traditionally used to relieve diverse pain-related ailments. The objectives of the present study were to determine the antinociceptive activity of methanol extract of M. malabathricum leaves and to elucidate the possible mechanisms of antinociception involved using various rats' models. The extract (100, 250, and 500 mg/kg) was administered orally 60 min prior to subjection to the respective test. The in vivo acetic acid-induced abdominal constriction, formalin-induced paw licking, and hot plate tests were used as the models of nociception to evaluate the extract antinociceptive activity. Further studies were carried out to determine the role of opioid and vanilloid receptors, glutamate system and nitric oxide/cyclic guanosine phosphate (NO/cGMP) pathway in modulating the extract antinociceptive activity. From the results obtained, M. malabathricum exhibited significant (p < 0.05) antinociceptive activity in all the chemical- and thermal-induced nociception models. Naloxone (5 mg/kg), a non-selective opioid antagonist, failed to significantly affect the antinociceptive activity of MEMM when assessed using the abdominal constriction-, hot plate- and formalin-induced paw licking-test. M. malabathricum also significantly (p < 0.05) reversed the nociceptive response in capsaicin- and glutamate-induced paw licking test. Furthermore, only L-arginine (a nitric oxide precursor) alone, but not, NG-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase), methylene blue (MB; an inhibitor of cGMP), or their combination thereof, significantly (p < 0.05) block the antinociceptive activity of M. malabathricum. In conclusion, M. malabathricum exerted a non-opioid antinociceptive activity at the central and peripheral levels partly via the inhibition of vanilloid receptors and glutamatergic system, and activation of the NO-mediated/cGMP-independent pathway.

Suppressions of serotonin-induced increased vascular permeability and leukocyte infiltration by Bixa orellana leaf extract.

The aim of the present study was to evaluate the anti-inflammatory activities of aqueous extract of Bixa orellana (AEBO) leaves and its possible mechanisms in animal models. The anti-inflammatory activity of the extract was evaluated using serotonin-induced rat paw edema, increased peritoneal vascular permeability, and leukocyte infiltrations in an air-pouch model. Nitric oxide (NO), indicated by the sum of nitrites and nitrates, and vascular growth endothelial growth factor (VEGF) were measured in paw tissues of rats to determine their involvement in the regulation of increased permeability. Pretreatments with AEBO (50 and 150 mg kg⁻¹) prior to serotonin inductions resulted in maximum inhibitions of 56.2% of paw volume, 45.7% of Evans blue dye leakage in the peritoneal vascular permeability model, and 83.9% of leukocyte infiltration in the air-pouch model. 57.2% maximum inhibition of NO and 27% of VEGF formations in rats' paws were observed with AEBO at the dose of 150 mg kg⁻¹. Pharmacological screening of the extract showed significant (P < 0.05) anti-inflammatory activity, indicated by the suppressions of increased vascular permeability and leukocyte infiltration. The inhibitions of these inflammatory events are probably mediated via inhibition of NO and VEGF formation and release.

A synthetic curcuminoid derivative inhibits nitric oxide and proinflammatory cytokine synthesis.

Curcumin is a highly pleiotropic molecule with significant regulatory effects upon inflammation and inflammatory related diseases. However curcumin has one major important limitation in which it has poor bioavailability. Design of synthetic structural derivatives of curcumin is but one approach that has been used to overcome its poor bioavailability while retaining, or further enhancing, its drug-like effects. We have synthesized a series of curcumin analogues and describe the effects of 2,6-bis-4-(hydroxyl-3-methoxy-benzylidine)-cyclohexanone or BHMC upon nitric oxide and cytokine synthesis in cellular models of inflammation. BHMC showed a significant dose-response inhibitory action upon the synthesis of NO and we have shown that this effect was due to suppression of both iNOS gene and enzyme expression without any effects upon scavenging of nitrite. We also demonstrated that BHMC has a very minimal effect upon iNOS activity with no effect at all upon the secretion of PGE(2) but has a strong inhibitory effect upon MCP-1 and IL-10 secretion and gene expression. Secretion and gene expression of TNF-alpha and IL-6 were moderately inhibited whereas IL-8 and IL-1beta were not altered. We conclude that BHMC selectively inhibits the synthesis of several inflammatory mediators. BHMC should be considered a promising drug lead for preclinical and further pharmacological studies.