## 1 Introduction  
Nowadays, herbal infusions are placed in most consumed beverages [1]. This consumption is increasing worldwide due to their significant role in the human diet as a source of antioxidants. Herbal infusions contain various bioactive phenolic compounds, which are considered beneficial for human health [2]. Herbal infusions are consumed traditionally, without safety. Since \"safety\" and \"natural\" are not synonymous and some phenolics have shown toxicity, it is essential to estimate and know their potential toxicity [3; 4]. The modern and cost-effective _Vibrio fischeri_ bioluminescence inhibition test has proved to be a reliable and sensitive method for the evaluation of acute toxicity of herbal infusions [5; 6].  
Chamomile (_Matricaria chamomilla_ L., syn: _Matricaria recutta_) is a medicinal herb and one of the most consumed single-ingredient herbal tea [7], considered as a source of important chemicals with bioactive properties [8]. Chamomile is consumed as an infusion (with over a million cups per day),due to its healing benefits according to traditional medicine but also for its antioxidant, anti- nociceptive, and anticancer activities [9; 10]. These benefits are partly due to the phenolic content [7], specifically the subfamily of flavonoids are the most responsible for its high antioxidant activity [2].  
Sage (_Salvia officinalis_ L.) is considered as one of the most popular herbs consumed widely and traditionally as an herbaceous infusion [11; 12]. The incorporation of sage infusion in the daily diet can provide considerable benefits such as anti-mycotic [11], anti-carcinogenic [13; 14], antidiabetic, antimicrobial [14], anti-inflammatory, and anti-proliferative [15]. In addition to these effects, sage infusion exhibits antiradical activity which correlates strongly with their high level of total phenolic content [11; 13].  
In general, preparation of infusion differs, depending on the tradition of each region where it is prepared with water at different temperatures. Habitually, according to the traditional use, the water temperature in household conditions of infusion preparation usually ranges from 80 to 100 \({}^{\circ}\)C [16; 17]. However, the application of water at low temperature is also nominated in comparison with boiling water due to the feasibility to eliminate or diminish toxic components in the final obtained infusion [14]. Furthermore, there is no universal procedure for herbal infusion preparation that is proper for the extraction of antioxidant compounds [18]. There are a few works reporting the influence of extraction temperature on bioactivity [17; 19] and acute toxicity [5] of herbal aqueous extracts.  
There are no data, particularly for the preparation of chamomile and sage infusions, evaluating antioxidant properties and toxicity based on the extraction temperature. Therefore, the objective of this study is to evaluate the total phenolic content, antioxidant activity, and toxicity towards _V. fischeri_ at three different temperatures (25, 80, and 100 \({}^{\circ}\)C) using in vitro spectrometric assays in order to define the optimum temperature. In addition, determination of phenolic profile of the optimum extract was obtained.