Metabolite profiling and biological properties of aerial parts from Leopoldia comosa (L.) Parl.: Antioxidant and anti-obesity potential

Different anti-obesity drugs have proved unsuccessful due to their adverse effects. As a consequence, there is a growing interest in herbal remedies, with the aim to find new well-tolerated effective drugs. Leopoldia comosa (L.) Parl. grows in Central and Southern Europe, Northern Africa and Central and South-Western Asia, and the bulbs have been commonly used for food throughout history. In this study the effectiveness of L. comosa (L.) Parl. leaves and inflorescences hydroalcoholic extracts and fractions was verified through the evaluation of pancreatic lipase inhibitory activity. The metabolite profiling and the antioxidant activity were also investigated. Chemical composition of L. comosa leaves and inflorescences was assessed by means of GC–MS and HPTLC analyses. The ethyl acetate fraction of leaves sample showed the best antioxidant activity, tested through DPPH and β-carotene bleaching test. The effects on pancreatic lipase activity were assessed through the in vitro evaluation of the capacity to prevent p-nitrophenyl caprylate hydrolysis. Interestingly, leaves and inflorescences extracts and all their fractions were effective in inhibiting pancreatic lipase. The best anti-obesity potential was demonstrated by the n-hexane and the ethyl acetate fractions of leaves sample, with IC50 values of 0.369 ± 0.020 and 0.336 ± 0.007 mg/mL. The same fractions of the inflorescences hydroalcoholic extract were also effective, with IC50 values equal to 0.736 ± 0.045 and 0.780 ± 0.009 mg/mL. These results suggest that investigated samples could be a source of interesting compounds able to suppress dietary fat absorption.