High resolution UHPLC-MS characterization and isolation of main compounds from the antioxidant medicinal plant Parastrephia lucida (Meyen).

High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in medicinal plants and food and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. Forty-two metabolites including several phenolic acids, flavonoids, coumarines, tremetones and ent-clerodane diterpenes were accurately identified for the first time in the resin of the medicinal plant Parastrephia lucida (Asteraceae) a Chilean native species, commonly called umatola, collected in the pre-cordillera and altiplano regions of northern Chile, by means of UHPLC-PDA-HR-MS. This could be possible by the state of the art technology employed, which allowed well resolved total ion current peaks and the proposal of some biosynthetic relationships between the compounds detected. Some mayor compounds were also isolated using HSCCC. The ethanolic extract showed high total polyphenols content and significant antioxidant capacity. Furthermore, several biological assays were performed that determined the high antioxidant capacity found for the mayor compound isolated from the plant, 11- p-coumaroyloxyltremetone.

Inhibition of pro-inflammatory enzymes by medicinal plants from the Argentinean highlands (Puna).

ETHNOPHARMACOLOGICAL RELEVANCE: Human groups in the Argentinean Andes highlands (Puna) selected native plants as anti-inflammatory agents. The indications of use are mainly to relieve pain, as infusions, ethanolic extracts or plasters. AIM OF THE STUDY: The objective of the study was to assess the effect of hydroalcoholic extracts from native highland plants as anti-inflammatory agents according to the traditional indications of use. The chemical profile of the three most active species was analyzed by HPLC-ESI-MS to get an insight into the constituents and the effects observed according to the ethnopharmacological information. MATERIALS AND METHODS: Hydroalcoholic extracts from 13 Argentinean Puna plants used as anti-inflammatory were evaluated as inhibitors of the pro-inflammatory enzymes phospholipase A2 (sPLA2), lipoxygenase (LOX), hyaluronidase, and for their capacity to stabilize red blood cells membrane. In addition, the extracts were evaluated to determine their reducing power, iron chelating capacity and ABTS•+ radical scavenging effect. The chemical profiles of the most active species were analyzed by HPLC-ESI-MS. RESULTS: Among the species investigated, Ephedra multiflora was the most active as LOX inhibitor (IC50:132µg/mL), by reducing the non-heme iron group and by scavenging radicals. The IC50 values of the reference compounds caffeic acid and naproxen were 57.0 and 14.0µg/mL, respectively. Parastrephia lucida showed the highest sPLA2 inhibitory effect (63% of inhibition at 200µg/mL). Under the same experimental conditions, the IC50 of the reference compound acetylsalicylic acid was 65±1µg/mL. Tessaria absinthioides exhibited the best inhibition towards hyaluronidase with an IC50 of 93.2±4.3µg/mL. Under the same experimental conditions, the reference compounds quercetin and indomethacin presented IC50 values of 340.0±17.0 and 502.0±10.0µg/mL, respectively. Among the most active species, 13 compounds were tentatively identified by HPLC-ESI-MS in E. multiflora and P. lucida, and 12 compounds in T. absinthioides. The constituents included caffeoyl- and feruloylquinic acid derivatives, flavonoids, simple phenolics and sesquiterpene glycosides. CONCLUSIONS: Six out of the 13 species investigated showed a moderate to strong effect towards the enzyme sPLA2 (>40% inhibition at 200µg/mL) while three species presented a strong activity against LOX with IC50<250µg/mL and three were very active against hyaluronidase. Most of the crude drug extracts were able to stabilize the red blood cells membrane, preventing their lysis. The compounds identified in the extracts explain, at least in part, the activity found in the samples. The effect observed for the most active species supports their traditional use as anti-inflammatory agents. However, more studies should be undertaken to disclose the potential of the Puna plants as anti-inflammatory crude drugs.

Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2●-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 µg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 µM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.