Simultaneous quantification of phytochemical contents and evaluation of biological activity of combined pigment rice extract

• A validated HPLC method for simultaneous analysis of phenolic acids and anthocyanins in combined pigmented rice extracts was developed. • Different solvent systems provided a phytochemical-rich extract with diverse bioactive compounds. • The combined pigmented rice extracts demonstrated notable antioxidant and anti-inflammatory activities with low cytotoxicity. • The combined pigmented rice exhibits a potential multifunctional ingredient. Pigmented rice varieties are regarded as abundant sources of phenolic acids, flavonoids, and anthocyanins, which promote their antioxidant and anti-inflammatory benefits. This study developed a combined pigmented rice formulation by blending five pigmented rice cultivars: two black rice varieties (Ma-Led-Fai and Dam-Mong), two red rice varieties (Tubtim Chumphae and Mali-Gomain), and one yellow rice variety (Sewkliang) to investigate the effects of their diverse phytochemical composition. A high-performance liquid chromatography (HPLC) was developed to simultaneously identify the active compounds, notably phenolic acids and anthocyanins, in combination pigmented rice extracts (CPRE). The validated analytical method exhibited satisfactory linearity, precision, accuracy, and sensitivity. Among the solvents evaluated, extraction with 50% ethanol produced the highest total phenolic content and predominant phenolic acids, such as protocatechuic acid, vanillic acid, and ferulic acid, whereas acidified ethanol enhanced the extraction of flavonoids and anthocyanins. The 50% ethanol extract exhibited stronger nitric oxide inhibitory activity, while the acidified ethanol extract showed superior antioxidant activity and greater inhibition of prostaglandin E₂ production. These findings demonstrate that CPRE offers a variety of bioactive compounds, enhancing its antioxidant and anti-inflammatory properties. Moreover, CPRE demonstrated minimal cytotoxicity, highlighting its potential as a multifunctional natural ingredient for functional foods, nutraceuticals, and cosmeceuticals.