A Phenolic Fraction from Catharanthus roseus L. Stems Decreases Glycemia and Stimulates Insulin Secretion

Table 4

Quantification of total polyphenols, total flavonoids and antioxidant activity (IC50) of aqueous alkaloid-free extract and its fractions.

Extract/fraction	Polyphenols ()	Flavonoids ()	Antioxidant activity CI50 (g/mL)
Aqueous alkaloid-free extract	6.33	2.37	120.54
Aqueous fraction	1.86	0.67	181.08
Organic fraction	3.60	1.52	140.36
Precipitate	1.20	0.67	300.15

Polyphenols (%) based on mgGAE/100 mg of sample. Flavonoids (%) based on mgCTE/100 mg.