The present work deals with the development and validation of a novel dual CD-MEKC system for the systematic flavonoid fingerprinting of Ligaria cuneifolia (R. et P.) Tiegh.-Loranthaceae-extracts. The BGE consisted of 20 mM pH 8.3 borate buffer, 50 mM SDS, a dual CD system based on the combination of 5 mM β-CD and 2% w/v S-β-CD, and 10% v/v methanol. The proposed method has been successfully applied to the comparative analysis of extracts from aerial parts and different hosts, geographical areas, and extraction procedures in order to establish the flavonoid fingerprint of L. cuneifolia. The method was validated according to international guidelines. LOD and LOQ, intra and interday precision, and linearity were determined for catechin, epicatechin, procyanidin B2, rutin, quercetin-3-O-glucoside, quercetin-3-O-xyloside, quercetin-3-O-rhamnoside, quercetin-3-O-arabinofuranoside, quercetin-3-O-arabinopyranoside, and quercetin. The CD-MEKC methodology emerges as a suitable alternative to the traditional HPLC for quality control, fingerprinting, and standardization of L. cuneifolia extracts from different sources.

Ligaria cuneifolia (Ruiz & Pav.) Tiegh. (Loranthaceae), the 'Argentine mistletoe', is a hemiparasite species largely used in folk medicine. The aim of this study was to evaluate the antioxidant activity using in vitro, ex vivo, and in vivo methods. A screening of phenolics was performed by UV spectroscopy on different fractions. The antioxidant capacity was evaluated in vitro by the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH *) assay on a crude extract (CE), ethyl acetate fraction (EAF), and aqueous fraction (AF). The results suggest that EAF concentrates the antioxidant capacity and was selected for further analysis. Capillary electrophoresis was employed to monitor the individual antioxidant capacity and the potential contributors to this effect. Ex vivo assays showed an efficient inhibition of tert-butyl hydroperoxide-induced rat liver phospholipid oxidation, as well as rat brain autoxidation, and H 2 O 2-induced DNA damage in blood monocytes. In vivo, the topical application of EAF significantly decreased skin chemiluminescence in a mice model.

Ligaria cuneifolia (R. et P.) Tiegh. (Loranthaceae) is a South American hemiparasitic species with antioxidant, antitumoral, antimicrobial, and antilipidemic activities attributed to its polyphenolic content. We studied the polyphenolic pattern of L. cuneifolia during different phenological stages: flowering, fruiting, and post-fruiting. The highest total phenolic content was found in stems at post-fruiting (214 ± 12.1 mg gallic acid eq·g−1 DW) and fruiting (209 ± 13.7 mg gallic acid eq·g−1 DW), followed by post-fruiting leaves (207 ± 17.5 mg gallic acid eq·g−1 DW). Flavonoids accumulated at higher levels in leaves and hydroxycinnamic acids in leaves at flowering and post-fruiting. The polyphenolic pattern was similar between organs from wild plants and in vitro cultures, although at a significantly lower level in the latter ones. The performance of calli growing under a 16 h photoperiod in a modified White medium with 1-naphthalene acetic acid (2.50 μM) and Kinetin (9.20 μM) was better than in the dark. When calli grew in media only with auxins (IAA, NAA, and 2,4-D, all at 2.50 µM concentration), its growth and polyphenolic content improved. Cell suspensions with 2.50 µM NAA and 9.20 µM KIN grew slowly and produced very small amounts of polyphenols. As for the antioxidant activity, it was detected in all samples (approximately 1000 µmol trolox eq·g−1 DW) except fruits, where a lower value was found (328 µmol trolox eq·g−1 DW). In vitro cultures have the lowest antioxidant activity when compared to methanolic extracts from organs of wild specimens. Finally, antimutagenic or mutagenic activity in wild plants and in vitro culture extracts was not detected by the Ames test.

Ligaria cuneifolia (R. et P.) Tiegh (Loranthaceae), known as liga, muérdago criollo, or Argentinean mistletoe, is a hemiparasitic plant with a broad distribution in central and northern Argentina. Pharmacological studies showed that L. cuneifolia extracts have hypolipemic, antioxidant, antibacterial, and immunomodulatory effects. We have established callus cultures from embryo and haustoria fragments. The highest frequency of callus formation from embryos (85%) was obtained on White medium with 4% (w/v) sucrose and 2.5 µM 1-naphtalene acetic acid and 9.2 µM kinetin as plant growth regulators (PGRs). From haustoria, the best result (35%) was obtained on Gamborg medium with 3% (w/v) sucrose and 0.45 µM 2,4-dichlorephenoxyacetic acid and 0.47 µM zeatin as PGRs. Thin layer chromatography showed that callus methanolic extract (2.5% w/v) had a lower content of flavonoids and proanthocyanins as compared to the wild plant (5% w/v for leaves, stems, and flowers), but a higher content of hydroxycinnamic acids. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) showed the presence of quercetin glycosides and phenolic acids in the methanolic extracts both from the parent plant and the callus obtained from embryo. Key messageCallus cultures were established from embryo and haustorium explants of Ligaria cuneifolia. Leaves, stems, and meristems were recalcitrant to in vitro culture. Callus tissues contained quercetin glycosides and phenolic acids. KeywordsMedicinal plants • Liga • Hemiparasitic plant • Callus culture • Flavonoids Communicated by Sergio J. Ochatt.