2.3. Preparation of extracts
For total phenolic content and antioxidant activity assessment tests, the extracts were prepared by adding 2 g of individual freshly crushed herb (n = 5) in 200 mL (1 cup) deionized water and steeped under three different processes. (a) at 85◦C, (b) at room temperature and, (c) at room temperature with the assistance of ultrasound water bath (35 MHz). Each treatment lasted for 15 min. The herbal infusions were then filtered through a Whatman filter No. 1. Prior to analysis, an aliquot was further filtrated with a PTFE filter with 0.45 um pore size.
For toxicity determination, infusions were prepared as above and were then filtrated through a nylon 0.2 m membrane filter,in order to remove any suspended material that may interfere with luminescence readings
Total phenolic content, antioxidant activity and toxicity determination was performed for all plant species. All the infusions described above were then extracted three times with petroleum ether in order to further analyze the aqueous phase derived from this extraction. Three individual preparations for each extract were prepared.