Assessment of bioactive metabolites and hypolipidemic effect of polyphenolic-rich red cabbage extract

Cardiovascular disease is the leading cause of death worldwide and the consumption of red cabbage (Brassica oleracea var. capitata f. rubra DC. - Brassicaceae) has been linked with the reduction risk of chronic diseases.

The present study assesses the bioactive metabolites and hypolipidemic effect of red cabbage on rats.

The content of total phenols, flavonoids, anthocyanins, carotenoids, ascorbic acid and antioxidant capacity were assessed, while individual phenolic acids and flavonoids were detected using reverse phase-high performance liquid chromatography (HPLC) analysis. Acute hypolipidemic activity of aqueous extract of red cabbage (RC - 125, 250 and 500 mg/kg) was investigated using a Triton WR-1339 (400 mg/kg) induced hyperlipidemic Wistar rats compared to fenofibrate (65 mg/kg).

The HPLC analysis of extracts revealed eight phenolic acids, gallic, protocatechuic, p-hydroxybenzoic, m-coumaric, syringic, caffeic, cinnamic, dicaffeoylquinic and three flavonoids, epicatechin, epigallocatechin, gallocatechin. Furthermore, the aqueous extract showed higher amounts of total phenolics (116.00 mg/g), flavonoids (161.32 μg/g) and, antioxidant activity (87.19%) than the hydromethanolic (89.33 mg/g, 123.34 μg/g and 75.07%), respectively. The RC significantly (p < 0.001) ameliorated the levels of cholesterol, triglycerides and lipoproteins alterations in hyperlipidemic rats without toxicity.

Herein, the RC presented the higher amounts of phenolics and flavonoids comparing with the hydromethanolic extract. Additionally, the RC showed as the majority compounds, dicaffeoylquinic and cinnamic acids, and the flavonoids epicatechin and gallocatechin. Furthermore, the RC demonstrated a beneficial effect against hypercholesterolemia and hypertriglyceridemia, demonstrating its potential therapeutic effect on these risk factors of cardiovascular diseases.