Antioxidant Activity and Total Phenolic Content of the Crude Extract from Hibiscus sabdariffa L

Charinthorn  Fakkham; Anongnooch  thumpad; Phanthipha  Phuttamek; Salinthip  Kunsilarak; Saengsit  Kritsadee

Charinthorn Fakkham Department of Applied Thai Traditional Medicine, College of Allied Health Sciences, Suan Sunandha Rajabhat University
Anongnooch thumpad Department of Applied Thai Traditional Medicine, College of Allied Health Sciences, Suan Sunandha Rajabhat University
Phanthipha Phuttamek Department of Applied Thai Traditional Medicine, College of Allied Health Sciences, Suan Sunandha Rajabhat University
Salinthip Kunsilarak Department of Applied Thai Traditional Medicine, College of Allied Health Sciences, Suan Sunandha Rajabhat University
Saengsit Kritsadee Department of Applied Thai Traditional Medicine, College of Allied Health Sciences, Suan Sunandha Rajabhat University

Keywords: Hibiscus sabdariffa L, Antioxidant, Free radical

Abstract

Roselle (Hibiscus sabdariffa L.; HS) is a widely utilized Thai medicinal plant with a long history of therapeutic use, and it is included in the National List of Essential Herbal Medicines . This inclusion highlights its significance in traditional Thai medical wisdom . The objective of this research was t o investigate the antioxidant activity and analyze the total phenolic content of various Roselle parts: the calyx, leaves, and stems. Samples of each plant part, weighing 300 g, were extracted using 95% ethanol and evaporated to dryness using a rotary evaporator to obtain crude extracts for subsequent chemical and biological analysis . Antioxidant activity results showed that the leaf extract exhibited the highest potential, with an IC50 value of 0. 07 mg/ mL. This was followed by the calyx (IC50 = 0.18 mg/mL) and the stem (IC50 = 0.19 mg/mL). The standard antioxidant BHT showed an IC 50 value of 0 . 01 mg / mL. Regarding the total phenolic content, the leaf and stem extracts contained the highest phenolic levels, both registering 50 . 52 ± 0 . 003 mg GAE / mg of dry extract. The calyx followed, with a value of 40. 52 ± 0. 003 mg GAE/ mg of dry extract. This study successfully demonstrates the outstanding antioxidant potential and high phenolic content of Roselle. These findings provide crucial scientific evidence to sup port the development of cosmeceutical products, skin - rejuvenating formulations, and serve as a foundation for further development of traditional Thai medicinal preparations and future pharmaceutical products.