α-Glucosidase and glycation inhibitory activities of Rumex lunaria leaf extract: a promising plant against hyperglycaemia-related damage.

Rumex lunaria L. is a Canarian medicinal plant, belonging to Polygonaceae. The potential antidiabetic activity of the methanolic extract of the leaves was investigated. For this purpose, the inhibition of α-glucosidase and albumin glycation by the extract was studied. Further, the anti-radical activity and the phytochemical composition were detected. The reduction of α-glucosidase activity was significant from 3 µg/mL, while the BSA glycation inhibition started from 100 µg/mL. Moreover, the extract exhibited a significant free-radical scavenger activity. Its phytochemical characterization showed the presence of carotenoids, phenolic and flavonoid compounds, whereas anthraquinones were not detected. C-flavonoid glycosides were identified and quercetin-O-hexoside-O-deoxyhexoside was the most detected (22.67 ± 0.02 mg/g). The findings indicate that the methanolic R. lunaria leaf extract has significant anti-α-glucosidase, anti-radical and anti-glycation activities. This research is the first showing the potential antidiabetic activity of R. lunaria.[Formula: see text].

Antinociceptive activity of Hypericum grandifolium Choisy in mice.

The present study investigated the antinociceptive activity of different extracts prepared from the aerial parts of blossom of Hypericum grandifolium Choisy-a species native to the Macaronesian Region-using the acetic acid-induced writhing, formalin and tail flick test in mice. Oral administration of methanol extract (500 and 1,000 mg/kg p.o.), the aqueous, butanol and chloroform fractions (500 mg/kg p.o.) as well as subfractions F2 and F3 (45 mg/kg p.o.) from the chloroform fraction significantly inhibited acetic acid-induced writhing, with values ranging from 28 to 50% of inhibition. The methanol extract (1,000 mg/kg p.o.) and chloroform fraction (500 mg/kg p.o.) significantly reduced both phases of formalin-induced pain (with inhibition values ranging from 18 to 53%), whereas subfraction F2 (45 mg/kg p.o.) significantly inhibited the late phase (30%). In the tail flick assay, only the chloroform fraction (500 mg/kg p.o.) significantly prolonged the tail flick response. Different constituents, such as flavonoids and benzophenone derivatives, could account for the effects observed. Taking together, the results indicate that Hypericum grandifolium Choisy possesses both peripheral and central antinociceptive activities in mice, suggesting an interesting therapeutic potential for this species in pain diseases.

HPLC-MS analysis and anti-oedematogenic activity of Hypericum grandifolium Choisy (Hypericaceae).

A study has been carried out on the chemical composition and in vivo anti-oedematogenic activity of several extracts from Hypericum grandifolium Choisy (Hypericaceae) collected in Tenerife (Canary Islands). The HPLC-MS analysis (HPLC-ESI/MS and HPLC-FT/MS) revealed the presence of hyperforin, flavonoids and probably benzophenone derivatives, while naphthodianthrones were absent. Pharmacological results revealed that the methanol extracts and the aqueous, butanol and chloroform fractions obtained therefrom possess anti-oedematogenic activity against TPA-induced ear oedema and carrageenan-induced paw oedema, the chloroform fraction being the most active. Subfractions derived from the chloroform fraction also showed anti-oedematogenic activity. From these results, it can be suggested that different constituents, such as the flavonoids and the benzophenone derivatives, could be responsible, at least in part, for the anti-oedematogenic effects observed for this species.