Antioxidant and Anticancer Potentials and Metabolic Profiling of Benjakul, A Thai Herbal Preparation

Benjakul (BJK), a Thai folk remedy has been used in traditional medicine for the treatment ofvarious illnesses. This study aimed to assess the antioxidant, and anticancer properties, andmetabolic profile of Benjakul. The antioxidant activity of the ethanol extract of BJK and itscomponent medicinal plants (Piper retrofractum Vahl., Piper sarmentosum Roxb., Piperinteruptum Opiz., Plumbago indica L., and Zingiber officinale Rosc.) was assessed using theFerric Reducing Antioxidant Power (FRAP) assay, and 2,2-diphenyl-1-picrylhydrazyl (DPPH)free radical scavenging assay. The anticancer activity was assessed through cytotoxic effectagainst cholangiocarcinoma (CCA) (bile duct cancer) cell lines (KKU-213B and KKU-100) usingthe 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The metabolicfingerprint and potential bioactive compounds in the ethanol extract of BJK and componentmedicinal plants was investigated using Nuclear Magnetic Resonance (NMR) spectroscopy. TheFRAP and DPPH assays revealed that the ethanol extracts of BJK and its component medicinalplants possessed antioxidant activity with Zingiber officinale exhibiting the highest activity. TheFRAP value and EC50 for DPPH radical scavenging activity for Zingiber officinale were 94.860 ±0.156 µg AAE/mg extract and 86.63 g/mL, respectively. The metabolic profiling identifiedvanillic acid and curcumin as the main bioactive metabolites in BJK and its component medicinalplants. The partial least squares (PLS) loading plot revealed that the methoxy group is associatedwith the inhibition of CCA cells, and phenolic hydroxyl protons as the potential pharmacophoreof the bioactive molecules. Therefore, BJK could be considered as a potentially effective treatmentfor bile duct cancer.