EXPERIMENTAL APPROACH: The leaves of three F. deltoidea varieties, namely Ficus deltoidea var. angustifolia, Ficus deltoidea var. trengganuensis and Ficus deltoidea var. kunstleri, were subjected to water extraction. The resulting crude extracts were fractionated using water and ethyl acetate. Palmitic acid was used to induce lipid accumulation (steatosis) in human liver (WRL68) cells, before all the samples were tested for their lipid-reducing activity. Several proteomic approaches were incorporated. The changes in protein expression were determined using 2-dimensional gel electrophoresis separation, whereas identification of our protein spots of interest was carried out via matrix-assisted laser desorption/ionization time-of-flight.

RESULTS AND CONCLUSIONS: Ficus deltoidea var. kunstleri alone demonstrated the ability to reduce lipids at the highest tested concentration (200 µg/mL) and was, therefore, used for subsequent experiments. Treatment with Ficus deltoidea var. kunstleri was found to restore redox status by increasing superoxide dismutase and glutathione peroxidase amounts and decreasing malondialdehyde formation. Six proteins were successfully identified; these were heat shock protein beta-1 (HSPB1), proteasome subunit alpha type 1 (PSMA1), glutathione S-transferase omega 1 (GSTO1), peroxiredoxin-1 (PRDX1), histone H2B (HIST1H2BD) and ubiquitin c-terminal hydrolase L3 (UCHL3). Through bioinformatics analysis, it was found that these proteins were significantly involved in specific pathways such as oxidative stress (PRDX1 and GSTO1), protein homeostasis (HSPB1) and degradation (UCHL3 and PSMA1).