Quali/quantitative research on herbal supplements containing black elder (Sambucus nigra L.) fruits

Black elder (Sambucus nigra L.), rich in phenolics, is used as antiviral, especially to treat common cold and flu. The flower of black elder has been approved by German Commission E and ESCOP for its mentioned usage, and in several pharmacopoeias, its qualification parameters were described. However, its fruits with a similar use as the flowers have not been considered by the pharmacopoeias. Even so, the number of black elder fruit supplements marketing with different brands is increasing steadily. This study aimed to evaluate the availability and concentrations of marker components (chlorogenic acid, rutin, and isoquercitrin) in herbal supplements containing black elder fruits comparatively with the reference plant material by high-performance thin-layer chromatography (HPTLC) and a validated high-performance liquid chromatography (HPLC) techniques. Additionally, the total anthocyanin amount was calculated by spectrophotometry in these samples, and the results were expressed as equivalents of cyanidin-3-O-glucoside (C3G). HPTLC fingerprints showed that most of the marketed products did not contain rutin, chlorogenic acid and isoquercitrin. Moreover, their fingerprint comparison with the reference was found to be different. The highest chlorogenic acid, rutin and isoquercitrin amounts were found as 0.742 mg/effervescent tablet (E3), 1.445 mg/capsule (C1), and 0.082 mg/capsule (C1), respectively by HPLC. According to the total anthocyanin content, C1 was determined to have the highest anthocyanin content as 8.705 mg C3G/capsule, whereas E6 was found to have the lowest anthocyanin content as 0.024 mg C3G/effervescent tablet. Consequently, there is an urgent need to establish standardization parameters for black elder fruits.