Study ofStevia rebaudianaBertoni antioxidant activities and cellular properties

Abstract

The aim of our study was to determine the antioxidant activities, cytotoxicity and proliferative properties in Stevia rebaudiana leaves and stems. Leaves extracts exhibited a higher antioxidant activity than stems extract, through oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) assays. Stevioside and rebaudioside A, the main sweetening metabolites in stevia leaves, exhibited a low ORAC value in comparison with plant extracts, while did not elicit any CAA. Stevia rebaudiana did not exhibit toxicity against HepG2 (hepatocellular carcinoma) human cells. No proliferative nor catalase modulations were observed in cells treated with such extracts. Our findings support the promising role of stevia that, apart from its sweetness, can act as a source of antioxidants, even at the intracellular level. This activity makes S. rebaudiana crude extract an interesting resource of natural sweetness with antioxidant properties which may find numerous applications in foods and nutritional supplements industries.

Polyphenols from Stevia rebaudiana (Bertoni) leaves and their functional properties

“…As the polyphenols in PPS can be found in most plant polyphenols, so the antioxidant activity of PPS is expectable. The in vitro measurement assay of antioxidant activity is generally dissociated into two major groups: (1) Hydrogen atom transfer ability as like oxygen radical absorbance capacity (ORAC) (Barba, Criado, Belda‐Galbis, Esteve, & Rodrigo, ; Bender, Graziano, & Zimmermann, ; Huang, Ou, & Prior, ; R. Lemus‐Mondaca et al., ; Prior et al., ), and (2) electron transfer ability as like ferric‐reducing antioxidant power, radical scavenging of 2,2′‐azino‐bis‐3‐ethylbenzo‐thiazoline‐6‐sulfonic acid (ABTS), and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assay (Huang et al., ). Since antioxidants may not act in same pathway, it is better to determine the antioxidant activity with multiple assays.…”

Comparison of reduced sugar high quality chocolates sweetened with stevioside and crude stevia ‘green’ extract

“…In addition to steviol glycosides, stevia leaves also contain phenolic compounds, flavonoids and other antioxidants with potential beneficial effects on human health . In particular, crude aqueous extracts from S. rebaudiana were shown to exert a cellular scavenging activity against free radicals …”

Effect of Stevia rebaudiana Bert. Addition on the Antioxidant Activity of Red Raspberry (Rubus idaeus L.) Juices

“…Previous work with the oxygen radical absorbance capacity (ORAC) assay has shown that crude water extracts from stevia leaves exhibit promising antioxidant activity, superior to that of the stem's extract, ranging from about 960 to 1070 µmol Trolox equivalents per gram of dried leaves [19]. Moreover, the crude extracts from stevia exhibit a high antioxidant potential when compared to its purified sweet metabolites [19].…”

“…Moreover, the crude extracts from stevia exhibit a high antioxidant potential when compared to its purified sweet metabolites [19].…”

“…Stevia leaves are several times sweeter than table sugar but have no calories [6][7][8]; steviol glycosides are sweet secondary metabolites that mainly occur in the leaves. Besides its sweetening properties, stevia is a good source of carbohydrates, fiber, proteins, and essential amino acids [9,10] and contains antioxidant compounds with diverse biochemical roles, including ascorbic acid [11], phenolic compounds [12][13][14][15][16], and flavonoids [17][18][19]. Nowadays, stevia's crude extracts, as well as its steviol glycosides, are used to sweeten foods and beverages.…”