Phenolic compounds of Hibiscus sabdariffa and influence of organic residues on its antioxidant and antitumoral properties

Abstract

The aim of this study was to evaluate the phenolic and flavonoids contents and the antioxidant and antitumoral activity of leaf and calyx methanolic extracts from Hibiscus sabdariffa (roselle) cultivated with poultry litter and organosuper  under three modes of application. The total phenolic content in the each extract was determined using the Folin-Ciocalteu reagent and for aluminium chloride flavonoids. The antioxidant parameters were analyzed using a 2, 2-diphenyl-1-picrylhydrazyl (DPPH . ) free radical scavenging assay. An antitumor colorimetric assay using sulforhodamine B. The highest contents of phenolic and flavonoids were observed in leaf extracts (389.98 ) demonstrou que ambos têm substâncias que podem contribuir para a ação seqüestradora de radicais livres. O extrato metanólico dos cálices mostrou seletividade na linhagem de leucemia (K-562), com valores de IC 50 de 0,12 mg mL -1 (organosuper  ) e 1,16 mg mL -1 (cama-de-

Screening for total antioxidant activity, flavonoids and phenolics variability in forty-five accessions of roselle (Hibiscus sabdariffa L.)

“…Statistical analysis, however, did not show significant differences (p ≥ 0.05) among all the accessions in terms of TPC. Total phenolic contents observed in the current study were lower than values obtained in similar studies in ethanolic and aqueous extraction systems of roselle leaves in Brazil (Formagio et al, 2015) or elsewhere (Sirag et al, 2014;Al-Hashimi, 2012). The values are also lower than those obtained for moringa (Owusu-Ansah et al, 2011) and cassava leaves (Quartey et al, 2016) which are also used in preparation of herbal drinks and sauces for similar purposes as roselle leaves.…”

“…The lowest TFC was observed in WH-S2V (10.04 ± 0.31 µg/g). These values are lower than those determined in Brazil by Formagio et al (2015) in roselle leaves (140.29 ± 3.14 to 148 ± 2.42 mg/g) and calyces (95.85 ±1.85 to 104.52 ± 4.85 mg/g) possibly because the cultivation media were highly enriched with organic substrates or it is simply a factor of inherent genetic attribute of those varieties. Phenolic and flavonoid contents of plant materials have been shown to vary considerably depending on variety and environment (Yang et al, 2006;Burkill, 1997).…”

“…Flavonoids are the principal phytochemicals found in roselle (Tsai et al, 2002). This implies that higher proportion of the free radical scavenging activity in the leaf samples could be attributable to flavonoid rather than phenolic antioxidant activity as also suggested by Formagio et al (2015).…”

“…Indeed, ethanolic and aqueous extracts of roselle leaves showed a reduced lipid peroxidation in rats which confirmed their antioxidant properties (Ochani and D'Mello, 2009). Extracts evaluated for in vitro anticancerous activity against several cultured human cancer lines also demonstrated significant selective activity against leukemia lines (Formagio et al, 2015). Flavonoids and polyphenols are powerful free radical scavengers which regulate the activities of most enzyme systems as they interact with other biomolecules.…”

Thermal and photo-stability of the antioxidant potential of Spirulina platensis powder

“…Studies aimed at understanding these functional activities, especially with regard to antioxidants, are justified because of the growing appeal of the importance of food in health and longevity of man (Benites et al, 2015;Bittencourt-Oliveira et al, 2015;Formagio et al, 2015).…”