Influence of phenological growth stages on the bioactivity and chemical profile of Buddleja saligna (Willd.) extracts

Buddleja saligna (Willd.) has been reported to have promising pharmacological activities due to its antioxidant, antimutagenic, and antibacterial properties. In this study, the plant material of B. saligna (Willd.) was harvested at the flowering, fruiting, and vegetative stages and extracted by maceration and ultrasound-assisted extraction (UAE). The extracts were then analyzed to determine the antioxidant activity, total phenolic content, antiproliferative (SK-MEL1 [melanoma cell lines] and A375M [cell line exhibiting epithelial morphology]), and genotoxic ([Chinese hamster ovary] CHO-K1) activities. Hydrogen-1 proton nuclear magnetic resonance (1H-NMR) and high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) analysis were performed to determine the chemical profile of the extracts. Regardless of the applied extraction method, results showed that samples collected during the flowering stage exhibited the highest antioxidant and antiproliferative activities; they also reported high cytotoxicity against melanoma cell lines but low genotoxicity against CHO-K1 cells. Moreover, samples collected during the flowering stage presented a higher concentration of bioactive compounds (verbascoside, hydroxycoumarin, isoacteroside, and luteonin derivatives) compared to those collected during the fruiting and vegetative stages. The results of this study highlight the potential benefits of B. saligna (Willd.) to produce extracts with important bioactive properties.