Antioxidant Activity and Total Phenolic Content of the Aqueous Extracts of a Thai Blood Tonic (Bhamrung-Lohit) Remedy and Its Plant Components

Abstract

Introduction: In the Mahachotarata scripture, there was a blood tonic remedy known as Bhamrung-Lohit remedy in Thai which has been used in female adult to treat menstrual irregularities, abnormal menstruation, and for nourishing blood and body. The aims of this study were to determine the amount of total phenolics and antioxidant activities of Bhamrung-Lohit remedy and its
plant components.
Methods: All tested extracts were prepared by decoction as practiced in traditional medicine. All extracts were analyzed for their phenolic content by Folin-Ciocalteu assay and their antioxidant activities by using DPPH radical scavenging assay, ABTS radical scavenging and ferric reducing antioxidant power assay (FRAP). The correlation analysis was evaluated
by curve fitting regression model.
Results: The results showed that the extract of Caesalpinia sappan, a Bhamrung-Lohit plant ingredient, contained the highest total phenolic contents of 781.72 ± 21.19, 269.38 ± 12.88 mg GAE/g. The aqueous extract of Terminalia citrina and Bixa Orellana demonstrated stronger antioxidant activity than positive control (BHT) by DPPH radical scavenging assay (EC₅₀ = 4.51 ± 0.21 µg/ml, 4.92 ± 0.08 µg/ml, and 13.78 ± 0.23 µg/ml, respectively). In ABTS^●+ assay, the extract of Terminalia citrina and Caesalpinia sappan showed stronger activity than positive control (BHT) with (EC₅₀ = 4.16 ± 0.11 µg/ml, 5.19 ± 0.38, and 5.55 ± 0.23 µg/ml, respectively). The extract of Caesalpinia sappan and Bhamrung-Lohit remedy gave the highest TEAC and FRAP value of 1,223.14 ± 25.26 mg Trolox/g, 2,885.64 ± 57.27 mg Fe(II)/g, 338.28 ± 9.13 mg Trolox/g, and 795.06 ± 20.69 mg Fe(II)/g, respectively, it also showed stronger activities than positive control (BHT). DPPH and ABTS^●+ scavenging activity relate to total phenolic content by negative exponential model. Both FRAP assay showed the linear correlation with the total phenolic content.
Conclusion: This study demonstrated that Bhamrung-Lohit remedy and its plant components showed good antioxidant activities. These results support the indication of this preparation as blood tonic.