Identification and quantification of cytotoxic phenolic acids and flavonoids in Ixora brachiata by UHPLC-DAD and UHPLC-ESI-MS/MS

Abstract

Ixora brachiata a plant with ethnomedicinal value is used in the treatment of skin diseases. The present study was carried out to evaluate the cytotoxic effect of methanolic extract of I. brachiata leaf samples against human breast (MDA-MB-231) and pancreatic (PANC-1) cancer cell lines. An attempt was also made to identify and quantify the phenolic acids and flavonoids using ultra high performance liquid chromatography (UHPLC) – diode array detector (DAD) coupled with electrospray ionization mass spectroscopy (UHPLC-ESI-MS/MS). The study revealed dose dependant cytotoxicity with 50% inhibitory (IC50) effect of I. brachiata at a concentration of 115.77 and 80 μg/ml against MDA-MB-231 and PANC-1 cells respectively. The IC50 value of cisplatin was recorded at a concentration of 19.76 and 6.22 μg/ml against MDA-MB-231 and PANC-1 cells respectively. UHPLC-DAD and UHPLC-ESI-MS/MS analysis showed the presence of 13 phenolic acids and 10 flavonoids. Quantitative determination of the compounds revealed the presence of significantly high quantity of protocatechuic acid (20.19 ± 0.17 mg/g) with a total yield of 58.55 ± 0.9 mg/g of phenolics. Similarly, a significantly high quantity of myrcetin (5.03 ± 0.02 mg/g) was detected as a major flavonoid out of the total yield of 5.17 ± 0.02 mg/g. The presence of phenolic acids and flavonoids in the leaf methanol extract of I. brachiata might have contributed towards the cytotoxic effect of this plant. However, further investigations are warranted to confirm the specific phenolic acid/flavonoid responsible for the cytotoxic effect of this plant.