Comparison of Antioxidant and Antimicrobial Activities of Tilia (Tilia Argentea Desf Ex DC), Sage (Salvia Triloba L.), and Black Tea (Camellia Sinensis) Extracts

Abstract

The antioxidant activity of the water extract of Tilia argentea Desf ex DC was determined by the thiocyanate method. The antioxidant activity of the water extract increased with the increasing amount of lyophilized extract (50-400 microg) added into the linoleic acid emulsion. Statistically significant effect was determined in 100 microg and higher amounts. Antioxidant activities of water extracts of tilia (Tilia argentea Desf ex DC), sage (Salvia triloba L.), and two Turkish black teas commercially called Rize tea and young shoot tea (Camellia sinensis) were compared. For comparison studies, 100 microg portions of extracts were added into test samples. All samples were able to show statistically significant antioxidant effect. Both of the tea extracts showed highest antioxidant activities, nevertheless, differences between tilia and sage and tilia and tea were not statistically significant (for both cases p > 0.05). Like antioxidant activity, the reducing power of water extract of Tilia argentea Desf ex DC was also concentration dependent. Even in the presence of 50 microg of extract, the reducing power was significantly higher than that of the control (p < 0.05) in which there was no extract. Unlike antioxidant activity, the highest reducing power activity was shown by sage extract. Among the tea extracts, young shoot extract was the most effective one, however, it had significantly lower activity than sage (p < 0.05). Although tea flower had the lowest reducing power activity, it was higher than that of tilia. But this difference was not statistically significant (p > 0.05). From these results, we could suggest that although the reducing power of a substance may be an indicator of its potential antioxidant activity, there may not always be a linear correlation between these two activities. In addition, antimicrobial activities of each of the above extracts were studied by disk diffusion methods on different test microorganisms. None of the extracts showed antibacterial activity on the studied microorganisms.

Evaluation of seven different drying treatments in respect to total flavonoid, phenolic, vitamin C content, chlorophyll, antioxidant activity and color of green tea (Camellia sinensis or C. assamica) leaves

“…2 Total flavonoid content (TFC) variation in green tea using seven drying treatments. Bars with different letters are significantly different mechanisms (Yildirım et al 2000). For example, DPPH assay is mostly attributed to such phenolic compounds that participate in scavenging free radicals, while in reducing power the inactivation of the metal ions such as ferric ions is evaluated by phenolics (Gharibi et al 2013).…”

Antioxidant Activity of Pomegranate Juice and Punicalagin

“…The reducing power of pomegranate juice and punicalagin were quantified by the Yildirim et al (2000) method. This method is based on determining the ability of the tested material to reduce Fe 3+ (CN) 6 to Fe 2+ (CN) 6 , in which the formed Perl's Prussian Blue complex was measured at 700 nm.…”

Phenolic Contents and Antioxidant Activities of Green Tea with and without Lemon

“…The reducing power assay was performed as described by [14]. First, 2.5 ml of 0.2 M phosphate buffer pH 6.6 and 2.5 ml of 1% potassium ferric cyanide were added to 1 ml of the sample and mixed well then incubated for 30 minutes at 50˚C.…”