Antioxidant properties and antibacterial activity of water extracts from Sambucus nigra L. under different conditions

INTRODUCTION

In folk medicine, dried white flowers of Sambucus nigra L. are used to make infusions, decoctions, and juices.

AIM

The present article aims to study and compare the antioxidant activity of aqueous solutions of leaves and flowers of Sambucus nigra L obtained at different exposure times and assess the antibacterial activity of these solutions against Escherichia coli ATCC 8739, Salmonella NCTC 6017, Listeria monocytogenes NCTC 11994, and Staphylococcus aureus ATCC 25093.

MATERIALS AND METHODS

We studied the physicochemical properties of aqueous extracts of leaves (fresh) and flowers (fresh and dry) of Sambucus nigra L collected from the Rhodope region of Bulgaria. The samples from Sambucus nigra L were analyzed to determine their total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The diameters (in millimeters) of the growth inhibition zones of four pathogens were measured, and a comparative assessment of their antibacterial activity was made.

RESULTS

The infusions of fresh blossoms and fresh leaves of Sambucus nigra L had the highest antioxidant activity at the total contact time of 30 minutes (82.7 mmol TE/100 ml) and 35 minutes (36.5 mmol TE/100 ml), respectively. The phenol-richest infusions were those made from dried flowers of Sambucus nigra L after a 30-minute contact time (86.7 mg GAE/ml). Of the four pathogens we studied, we found that the extracts affected partially only the pathogenic bacteria of Salmonella.

CONCLUSIONS

The highest content of bioactive components was obtained from dried blossoms of Sambucus nigra L. for infusions with a total contact time of 30 minutes and for decoctions at a contact time of 45 minutes.

Cytotoxic activity of butanolic extract from Sambucus nigra L. flowers in natura and vehiculated in micelles in bladder cancer cells and fibroblasts

Bladder cancer has a high incidence and recurrence rate among patients worldwide. This study aimed to evaluate the cytotoxic activity of fractions of Sambucus nigra L. flower extracts on bladder carcinoma cells (T24 cells) and human fibroblast cells (MRC-5). The butanolic fraction (F-BuOH) was characterized by UPLC-DAD-MS/MS and nine flavonoids were identified. Rutin was the major compound. The cytotoxic activity of this fraction was observed in the T24 cells but not in MRC-5 cells, indicating selectivity. F-BuOH was incorporated in micellar solutions of Pluronic® F127 and cytotoxic effect for T24 cells was observed again. In vitro assay demonstrated a controlled release of the fraction from the micelles. The results obtained showed that flavonoids are the possible responsible for cytotoxic activity in bladder carcinoma cells. In addition, micellar solutions act together to increase the action of the butanolic fraction.