Host-Dependent Phytochemical Profiles and Antioxidant and Hypoglycemic Activities of Mexican Mistletoe (Psittacanthus calyculatus) Organs

Mexican mistletoe (<i>Psittacanthus calyculatus</i>) is an ecologically and pharmacologically relevant hemiparasitic plant whose phytochemical composition varies according to host, organ, and processing. This study analyzed the pericarp, flower, leaf, and peduncle in fresh and freeze-dried conditions. The samples were collected from <i>Forestiera phillyreoides</i> and <i>Mimosa</i> sp. High-performance thin-layer chromatography revealed the presence of malvidin-3-O-glucoside (27.43 ± 1.88 mg/g dry weight [DW]) in freeze-dried pericarps, cyanidin-3-O-glucoside (26.55 ± 1.19 mg/g DW) in freeze-dried flowers, and rutin (5.39 ± 1.24 mg/g DW) in freeze-dried leaves collected from <i>Mimosa</i> sp. Gas chromatography coupled with mass spectrometry (GC-MS) confirmed the presence of gallic acid (40.40 ± 0.228 mg/g DW in freeze-dried pericarps of <i>Mimosa</i> sp.), which was 42.9% higher than the amount found in <i>F. phillyreoides</i> plants. Regarding antioxidant activity, freeze-dried mistletoe pericarps collected from <i>Mimosa</i> sp. exhibited the highest capacity (85.7-94.9% DPPH· and ABTS·⁺ inhibition, respectively). For α-glucosidase inhibition, the half-maximal inhibitory concentration (IC₅₀) values of freeze-dried flowers and pericarps were low (84-85 μg/mL), comparable to acarbose (62 μg/mL). Freeze-drying increased metabolite concentration by up to 54% for gallic acid in the pericarp of plants collected from <i>Mimosa</i> sp. and enhanced bioactivity. Overall, Mexican mistletoe is established as a nutraceutical source with therapeutic potential and sustainable use value.