Ceratophyllum demersum L. is a medical plant of the family Ceratophyllaceae that has been traditionally used for the treatment of diseases such as ulcer, diarrhoea, wounds and fever since ancient times. This study presents antioxidant activities of water and methanol extracts of in vitro propagated C. demersum. Shoot tip explants of C. demersum for in vitro plant regeneration were cultured on liquid Murashige and Skoog (MS) medium containing 0.25–1.25 mg/L 6-Benzylaminopurine (BAP) and 0.10 mg/L Thidiazuron (TDZ) combinations for eight weeks. Maximum number of plantlets per explant (110.67) was obtained on MS medium supplemented with 0.75 mg/L BAP + 0.10 mg/L TDZ. In order to determine antioxidant activities of C. demersum, antioxidant contents (β-carotene, flavonoid, lycopene and total phenols), metal chelating and reducing power capacities of methanol and water extracts obtained from C. demersum were investigated. It was detected that water extract was more effective in all activities. Total phenols (76.55 μg/mg) in water extract were measured as the highest antioxidant component. Based on the water extracts data, as IC50 value for chelating on ferrous ions was 9.24 mg/mL, EC50 value for reducing power activity was 8.23 mg/mL. It was also determined that the metal chelating and reducing power activities of the both extracts are increased depending on the concentration. Therefore, all these data suggest that both tested extracts of in vitro propagated C. demersum would exert beneficial effects by virtue of their antioxidant properties and may be utilized as a promising source of therapeutics.
In situ decomposition of the hornwort (Ceratophyllum demersum L.), the buckbean (Menyanthes trifoliata L.) and leaf blades of the yellow water lily (Nuphar lutea L.) was studied with the litter bag method in three small mid-forest lakes of different pH and nutrient content. Time course of decomposition and of nutrient release from decomposing plant material was best fitted with a logarithm approximation and not by usually used exponential fit. pH of lake waters strongly affected decomposition rates of C. demersum and M. trifoliata. No effect of nutrient concentrations in lake water or in plant tissues on decomposition was noted for any of the analysed plants. Organic carbon deficit is speculated as a possible reason for the observed pH effect on decomposition rates. Modification of particulate and soluble N:P ratios are underlined as a consequence of different N and P release from decomposing plant material.