Comparison of flavonoid content and antioxidant activity in calyces of two roselle varieties (Hibiscus sabdariffa L.)

Abstract

Free radicals can cause various degenerative diseases such as cancer and cardiovascular disease. Flavonoids have antioxidant abilities that inhibit damage from free radicals. The roselle antioxidant mechanism is associated with high flavonoid content. Red and purple roselles are two varieties of roselle (Hibiscus sabdariffa L.) cultivated in Indonesia. The aim of this research was to analyze the differences in flavonoid content and antioxidant activity in the calyces of two varieties of roselle (Hibiscus sabdariffa L.), red and purple. Total flavonoid analysis and antioxidant activity testing were done by spectrophotometry in the visible region. Total flavonoid content was analyzed by pretreatment with aluminium chloride and sodium acetate. Antioxidant activity was tested with 2,2-diphenyl-1-picrylhydrazyl. The total flavonoids for both red and purple roselle calyces ethanolic extract were 27.55 and 39.18 mg quercetin equivalent per gram. The half maximal inhibitory concentration values obtained for both red and purple roselle calyces ethanolic extract a were 51.59 and 42.17 μg/mL. The total flavonoid content and antioxidant activity of purple roselle calyces ethanolic extract was higher and stronger than red roselle calyces ethanolic extract.

OPTIMASI KOMBINASI HPMC DAN HEC DALAM SPRAY WAJAH EKSTRAK BUNGA ROSELLA (Hibiscus sabdariffa L.) DAN AKTIVITAS ANTIOKSIDANNYA

“…Penelitian oleh Adrianto (2019), menunjukkan aktivitas antioksidan ekstrak etanol 70% dan 96% bunga rosella berturut-turut memiliki nilai IC50 sebesar 17,57 ppm dan 15,236 ppm. Penelitian oleh Nerdy et al (2022), ekstrak etanol bunga rosella memiliki nilai IC50 sebesar 51,59 μg/mL. Penelitian oleh Shafirany et al (2021), ekstrak bunga rosella memiliki nilai IC50 sebesar 63,77 μg/mL.…”

“…Antioksidan merupakan senyawa non-reaktif dan stabil yang dapat mendonorkan satu atau lebih elektron kepada radikal bebas. Sehingga, antioksidan dapat mengurangi atau menetralkan efek berbahaya dari radikal bebas (Nerdy et al, 2022). Bunga rosella dapat menjadi salah satu alternatif alami sebagai antioksidan .…”

Hibiscus sabdariffa in Diabetes Prevention and Treatment—Does It Work? An Evidence-Based Review

“…The seeds are kidney-shaped, light brown, and up to 5 mm long [ 2 , 7 , 8 ]. The flower calyces are usually red (rose), but there are also white and purple varieties [ 8 , 9 ].…”

“…The white variety is characterized by a higher ability to scavenge free radicals than the red variety [ 8 ]. Another study demonstrated that purple calyces exhibit stronger antioxidative activity and contain more flavonoids than red ones [ 9 ]. However, most studies are conducted on the active compounds of the red variety.…”