Studies on total polyphenols and reducing power of aqueous extracts from selected lamiaceae species

Abstract

Certain phytochemicals in species are attracting increased attention because of a wide range of biological activities especially the possible cancer preventive properties. Polyphenols, the natural
antioxidants are present in plant extracts and they play a key role in antioxidative defence mechanisms in biological systems and they act as free radicals scavenging agents. Polyphenols might therefore inhibit development of coronary heart disease and cancers. Basil, oregano and sage are highly fragrant plants whose leaves are used as a seasoning herb for many different types of foods. Aqueous extracts were prepared from basil (Ocimum basilicum L.), oregano (Origanum vulgare L.) and sage (Salvia officinalis L.). To check the phenols presence, the UV-VIS spectrum was made. The amount of polyphenolic compounds from selected Lamiaceae species was determined by spectrophotometry method using the Folin - Ciocalteau reagent and gallic acid as standard. The range of polyphenols total was between 516,352 mg/100g dried species and 859,617 mg/100g dried species. Reducing power has been established by measuring the redox potential of aqueous extracts. Antioxidant activity was directly correlated with the total amount of polyphenols in the species extracts. The free reducing sugars in aqueous extracts from species were analyzed and correlated to the total content of polyphenols.