Antinociceptive and anti-inflammatory activities of Philodendron bipinnatifidum Schott ex Endl (Araceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Popular medicine use stems of Philodendron bipinnatifidum (Araceae) in inflammation cases, such as in erysipelas, as well as orchitis and rheumatism treatment. The present study, conducted for the first time in literature, investigate the antinociceptive and anti-inflammatory activities of P. bipinnatifidum stems ethyl acetate extract (EPB). MATERIALS AND METHODS: GC/MS and HPLC analysis were performed for EPB extract. We used EPB at 250, 375 and 500 mg/kg (oral route, p.o.) in male Swiss mice. The antinociceptive activity of the plant extract assessed by acetic acid induced writhing and formalin tests. To investigate the possible participation of opioid system in EPB-mediated effects, we previously administered naloxone to the mice. Anti-inflammatory activity was evaluated using carrageenan-induced paw oedema. The open-field test aimed to investigate the possible EPB effects on the locomotor and exploratory activities. To assess the protective role of EPB on carrageenan-induced oxidative stress, the levels of NPSH, TBARS, as well as SOD and CAT activities were evaluated in blood and paw tissue. The acute toxicity of the EPB was investigated using OECD 423 guideline. RESULTS: The EPB chemical analysis by GC/MS and HPLC revealed the presence of flavonoids (luteolin and quercetin) and phytosterols (ß-sitosterol and stigmasterol). The oral treatment with the EPB inhibited mice abdominal writhings (P < 0.01) at 375 and 500 mg/kg, and reduced the formalin effect at the first-phase (500 mg/kg, P < 0.05) and also at the second-phase (500 mg/kg, P < 0.001) of the test. EPB (375 and 500 mg/kg) did not alter spontaneous locomotion in open field test, however the number of fecal bolus was significantly lower for the EPB group at 500 mg/kg when compared to the vehicle group (P < 0.05). The pretreatment with naloxone caused significant inhibition of antinociceptive activity induced by EPB in the formalin test, revealing the possible involvement of opioid receptors. EPB extract administered at 500 mg/kg (p.o.) prevented carrageenan-induced paw oedema (P < 0.05 and 0.01) until 6 h after carragenan injection. Evaluation of TBARS and NPSH levels, SOD and CAT activities in the blood and paw tissue of animals submitted to the carrageenan assay suggested that the anti-inflammatory effect of EPB may be linked to oxidative stress inhibition. The acute administration of the EPB (2000 mg/kg, p.o.) caused no mortality, demonstrating low toxicity. CONCLUSIONS: The extract of P. bipinnatifidum displays antinociceptive and anti-inflammatory activities, causing no toxicological effects. The pharmacological activity of this vegetal species may be related to the presence of flavonoids and phytosterols. Our results support the ethnomedical use of this vegetal species as analgesic and anti-inflammatory agent.

Differential Accumulation of Volatile Organic Compounds by Leaves and Roots of Two Guianese Philodendron Species, P. fragrantissimum Kunth and P. melinonii Brongn.

Leaf and root essential oils of two closely related but ecologically distant Philodendron species were extracted in natural conditions in French Guiana and analysed by GC/MS to i) describe the blends of volatile organic compounds (VOCs) produced by those species and ii) analyse species and environment-based variations in extracts composition. A total of 135 VOCs were detected with a majority of aliphatic sesquiterpenes. P. fragrantissimum produced mainly ß-bisabolene (on average 29.12% of the extract) as well as α- and ß-selinene (14.52% and 17.50%, respectively) while in P. melinonii, four aliphatic sesquiterpenes could alternatively be the main component: (E)-ß-farnesene (up to 91.42% of the extract), germacrene-D (73.74%), ß-caryophyllene (51.63%) and trans-α-bergamotene (41.26%). A significant effect of species and organs on extracts composition was observed while the environment (sun exposure) only affected the relative proportions of monoterpenes and sesquiterpenes in roots of P. melinonii. These results are discussed in the light of the potential role of leaf and root terpenes in Philodendron species.

Evidence for behavioral attractiveness of methoxylated aromatics in a dynastid scarab beetle-pollinated araceae.

Many plants attract their pollinators with floral scents, and these olfactory signals are especially important at night, when visual signals become inefficient. Dynastid scarab beetles are a speciose group of night-active pollinators, and several plants pollinated by these insects have methoxylated aromatic compounds in their scents. However, there is a large gap in our knowledge regarding the compounds responsible for beetle attraction. We used chemical analytical analyses to determine temporal patterns of scent emission and the composition of scent released from inflorescences of Philodendron selloum. The attractiveness of the main components in the scent to the dynastid scarab beetle Erioscelis emarginata, the exclusive pollinator of this plant, was assessed in field biotests. The amount of scent increased rapidly in the evening, and large amounts of scent were released during the activity time of the beetle pollinators. Inflorescences emitted a high number of compounds of different biosynthetic origin, among them both uncommon and also widespread flower scents. Methoxylated aromatic compounds dominated the scent, and 4-methoxystyrene, the most abundant compound, attracted E. emarginata beetles. Other compounds, such as (Z)-jasmone and possibly also the methoxylated aromatic compound 3,4-dimethoxystyrene increased the attractiveness of 4-methoxystyrene. Methoxylated aromatics, which are known from other dynastid pollinated plants as well, are important signals in many scarab beetles in a different context (e.g., pheromones), thus suggesting that these plants exploit pre-existing preferences of the beetles for attracting this group of insects as pollinators.