Evaluation of changes in the growth and chemical constituents of Anoectochilus formosanus Hayata grown under hydroponic conditions

<I>Anoectochilus formosanus</i> Hayata is an important medicinal plant with various pharmaceutical properties. In this study, <I>A. formosanus</i> plants were hydroponically cultivated in different nutrient solutions to achieve enhanced biomass and secondary metabolites production. Three months-old <I>A. formosanus</i> plants were grown for 8 weeks under controlled environment in plastic pots containing Murashige and Skoog (MS), Nitrophoska Foliar (NF), Hydro Green (HG), or Hydro Bee (HB) media. Among 4 nutrient solutions tested, HB was the most efficient medium for the plant growth with the highest fresh weight (FW, 2.56 g/plant) and dry weight (DW, 0.18 g/plant) values. The results of phytochemical screening showed the presence of alkaloids, flavonoids, terpenoids, glycosides, and steroids in the extracts of <I>A. formosanus</i> cultivated in HB, HG, and MS medium. The level of these compounds was significantly different in plants cultivated in tested media. The highest alkaloids (34.87 μg/g DW) and terpenoids (56.43 μg/g DW) contents were obtained on HG medium, whereas flavonoids were present in highest amounts (90.13 μg QE/g DW) in plants grown in NF medium. On the other hand, HB medium stimulated the production of the highest glycoside (64.33 μg/g DW) and steroids (22.83 μg/g DW) levels. The antioxidant activity of the extracts was also tested using the 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity assay and the results demonstrated strong antioxidant activities of <I>A. formosanus</i> extracts with IC<SUB>50</SUB> of 136.19 to 248.85 μg/ml. Concluding, the hydroponic-cultivation of <I>A. formosanus</i> is a promising way for obtaining highly valuable compounds for pharmaceutical and nutraceutical industries.