Phytochemical Screening and Determination of in vitro Antioxidant Potential of Aqueous Leaf Extract of Camellia sinensis.

Abstract

Background: Camellia sinensis, commonly known as the tea plant, is a species of evergreen shrub native to Asia. It is not only one of the most popular beverages consumed in Sri Lanka, but it has also variously reported health benefits such as antidiabetic, anti-inflammatory, anti-ageing, antibacterial, antiviral, hypocholesterolemic, anticarcinogenic and chemopreventive properties.

Objectives: To determine phytochemicals in the aqueous extract of C. sinensis leaves (AECL) qualitatively and quantitatively. Further, the study determined the antioxidant effect of AECL, as supportive evidence for developing an anti-ageing cosmetic cream formula in future Methods: The qualitative phytochemical screening was done following standard methods. The flavonoids and total phenol contents were determined quantitatively by the Aluminium chloride method and the Folin-Ciocalteu (FC) method, respectively. Quercetin and Gallic acid were used as reference compounds respectively in Aluminium chloride and FC method. The in vitro antioxidant activity was assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the radical scavenging activity of the test sample was expressed as an IC50, which is defined as the mean concentration of the antioxidants required to lower the initial DPPH concentration by 50%. Results: The results showed that AECL is rich in various phytochemicals such as alkaloids, flavonoids, tannins, and phenolics, with the absence of saponin. The total phenol content present in AECL was 93.075±2.3 mg Gallic acid equivalent/g dried weight and the total flavonoids were 942±1 mg quercetin equivalent/g dried weight. The study showed that AECL has dose-dependent antioxidant activity with an IC50 value of 211.53 µg/mL. It was 14.44 µg/mL for Ascorbic acid which was the positive standard.

Conclusions: The results showed the antioxidant properties of crude AECL. This antioxidant activity may be due to the presence of phytoconstituents such as alkaloids, flavonoids, tannins, and phenolics. However, as the AECL contain phytochemicals which can create an antioxidant activity, it is recommended to incorporate it for the developing cosmetic cream formula. However, the antioxidant activity was less compared to the Ascorbic acid which was the positive control.