Organ-Specific Distribution of Bioactive Compounds in Valeriana microphylla and Their Antioxidant, Antimicrobial, Haemolytic, and Nematicidal Activities

Valeriana microphylla is a medicinal species traditionally used in the Andean region. The study aimed to evaluate the bioactive compounds and the antioxidant, antimicrobial, haemolytic, and nematode locomotion-disrupting l activities in the flowers and leaves of V. microphylla. Minerals were quantified by atomic absorption spectrometry, whereas bioactive compounds were analysed by liquid chromatography. Antioxidant, antimicrobial and biological activities were determined by microplate spectrophotometry. Antimicrobial activity was tested against ATCC and multidrug-resistant microorganisms. Haemolytic activity was assessed by haemolysis of sheep erythrocytes, and nematode locomotion-disrupting activity by analysis of the locomotor behaviour of Caenorhabditis elegans. Potassium was the predominant mineral in leaves (2372.1 mg/100 g DW). In contrast, flowers contained the highest concentrations of citric acid (567.0 mg/100 g DW), total carotenoids (58.9 mg/100 g DW), and total phenolics (24,788.1 mg/100 g DW). Both extracts inhibited the growth of several ATCC bacterial strains, showing the lowest inhibitory concentrations against Staphylococcus epidermidis, Edwardsiella tarda and Listeria monocytogenes, but showed no activity against multidrug-resistant bacteria or against Candida species. Furthermore, both extracts exhibited haemolysis rates of less than 1.3% and affected the locomotion of C. elegans by eliminating the frequency of body bends and reducing locomotion speed. These findings provide an initial phytochemical and in vitro biological characterisation of V. microphylla and support further investigation of its bioactive constituents.