7,4'-Di-O-methylapigenin (4',7-DIMETHOXY-5-HYDROXYFLAVONE) can inhibit α-glucosidase and α-amylase enzymes and enhance 2-NBDG uptake in L6 cells, it has hypolipidemic effect on mouse pre-adipocyte (3T3L1) cell lines.

Antioxidant activity in terms of TRP (196.03 μg/mg GAE), DPPH assay (IC50-173.09 μg/mL), hydroxyl radical scavenging assay (IC50-20.42 μg/mL), inhibiting LDL oxidation (IC50-51.99 μg/mL) and to enhance SOD activity (25.3 %) was higher in ethyl acetate extract (EAP). Phenolic and flavonoid content was measured and showed a positive correlation with antioxidant activity. Presence of 4',7-DIMETHOXY-5-HYDROXYFLAVONE and piperine (Pip) in EAP was determined by HPTLC analysis and was isolated. 4',7-DIMETHOXY-5-HYDROXYFLAVONE inhibited α-glucosidase and α-amylase enzymes and enhanced 2-NBDG uptake in L6 cells. Hypolipidemic effect of 4',7-DIMETHOXY-5-HYDROXYFLAVONE on mouse pre-adipocyte (3T3L1) cell lines also showed a dose dependent reduction on lipid droplet content and effective concentration range was determined as 1-2.5 μg/mL. Suggested that Piper longum fruits can provide a natural source of antioxidants with antidiabetic and anti obesity potential.

Solvent extracts from Piper longum fruits using hexane, ethyl acetate, methanol, 70 % methanol-water were taken and 4',7-DIMETHOXY-5-HYDROXYFLAVONE was isolated from ethyl acetate extract. Antioxidant activity, glucose uptake potential and adipocyte differentiation assay was performed with extract and pure compound.