Antioxidant screening of medicinal herbal teas

Abstract

Herbal tea consumption is deeply and widely rooted amongst South-American populations. In view of the involvement of oxygen- and nitrogen-reactive species in the ethiogenesis of several diseases, the antioxidant properties of some of the herbal teas most commonly consumed in the southern regions was assessed in vitro. Around one-third of the 13 examined herbs, displayed a substantially higher ability to scavenge ABTS(+.) radicals (TEAC assay), and to quench the pro-oxidant species, hypochlorite (HClO) and peroxynitrite (ONOO(-)). Amongst the tested herbs, teas prepared from Haplopappus baylahuen, Rosa moschata and Peumus boldus showed the highest TEAC and HClO-quenching activities. These herbs were around 5- to 7-fold more potent than the least active herbs. Based on the TEAC assay, 150 mL of tea prepared from H. baylahuen, R. moschata and P. boldus would be equivalent to around 200 mg of Trolox). Teas from H. baylahuen and P. boldus were also found to be particularly potent in quenching HClO. In the ONOO(-) assay, H. baylahuen and Buddleia globosa showed the highest activities. The results obtained suggest that the regular consumption of teas prepared from some of these herbs may be useful potentially to provide the organism with molecules capable of protecting the gastrointestinal tract against certain pathologically relevant oxidant species.

Screening of Spanish Medicinal Plants for Antioxidant and Antifungal Activities

“…Many additives have long been used by the food industry to preserve their products from oxidation, usually synthetic antioxidants such as butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT), with no clear effects after chronic consumption (Imaida et al 1983;Yanishlieva, 2001). Many plants are a source of compounds with antioxidant activity that might be used as natural preservatives (Dorman et al, 2003;Cai et al, 2004;Ansari et al, 2005;Chen et al, 2005;Hinneburg et al, 2006;Huang et al, 2006;Speisky et al, 2006;Wong & Kitts, 2006). In addition, antioxidants play a special role in human health care as in past years, prevention of cardiovascular diseases and cancer has been associated with the intake of fruits and vegetables rich in natural antioxidants (Patterson et al, 1990;Pietta, 2000;Sun, 1990Hertog et al, 1993.…”

Evaluation of the Nutraceutical Potential of Rytidophyllum tomentosum (L.) Mart.: HPTLC Fingerprinting, Elemental Composition, Phenolic Content, and in vitro Antioxidant Activity

“…Teas and herbal infusions contribute to the major source of phenolic compounds in our diet [30,32]. More specifically, studies have suggested that regular consumption of some herbal teas may be potentially useful in providing protection against certain relevant oxidative species [31,34]. In view of the association between plant phenolics and anti-oxidant activity along with the recent thrust to market teas for their antioxidant properties, the content of total polyphenols, flavonoids and tannins were determined in search-me-heart infusions.…”

Oxygen Radical Antioxidant Capacity (Orac) Values of Herbal Teas Obtained Employing Different Methodologies Can Provide Complementary Data

“…In this sense, it is interesting to note that Rosa moschata infusions were among the most active in the removal of stable radicals (ABTS) 17,18 and reactive oxygen species (hypochlorite and peroxynitrite). 17 Furthermore, Rosa moschata is rich in ascorbic acid, 19 a compound that presents particularly high values of the ORAC-PGR index.…”