Untargeted metabolomics analysis of the intervention effects of Parkia speciosa pod extract (PSPE) on 3T3-L1 adipocytes differentiation

Obesity and hyperlipidemia have emerged as significant global health challenges, driving the prevalence of chronic metabolic disorders such as type 2 diabetes, cardiovascular diseases, and hypertension. These pathologies were directly contributed by the excessive accumulation of lipids in adipose tissue, primarily regulated by adipogenesis. While conventional lipid-lowering pharmacotherapies, including statins and fibrates, are widely prescribed, their long-term use is often accompanied by undesirable side effects, prompting the search for safer, plant-based alternatives. Parkia speciosa pods, typically discarded as waste, have emerged as a potential natural source of bioactive compounds with anti-adipogenic and lipid-lowering effects. However, the scientific understanding of the underlying mechanisms by which P. speciosa pod modulates adipogenesis remains limited. Therefore, this study aimed to elucidate the mechanism of anti-adipogenic activity of Parkia speciosa pod extract (PSPE) on 3T3-L1 adipocyte differentiation via metabolomics approach. The extract was prepared, and phytochemical analysis of PSPE including gallic acid and p-coumaric acid was analysed and quantified using HPLC. The total phenolic content (TPC) and total flavonoid content (TFC) were determined, and antioxidant activities were assessed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Following that, 3T3-L1 preadipocytes were induced to differentiate and treated with PSPE (62.5 μg/mL), along with simvastatin (4.19 μg/ml) as a reference drug. Lipid accumulation was evaluated through oil red O staining and triglyceride assays, while metabolomic analysis was performed via LC-QTOF-MS. HPLC analysis revealed the presence of gallic acid (53.97 ± 0.76 µg/mL) and p-coumaric acid (1.74 ± 0.11 µg/mL) in PSPE. The IC50 values for DPPH scavenging were 57.05 ± 0.22 μg/mL, and the highest FRAP value was determined to be 325.3 ± 4.85 μg FeSO4/mL. In vitro studies demonstrated that PSPE treatment significantly reduced lipid droplet formation and triglyceride levels in a dose-dependent manner (p < 0.05). Metabolomics analysis further revealed that PSPE intervention altered several metabolites associated with adipogenesis, including metabolites in lipid metabolism (linoleic acid, gamma-linolenic acid, and arachidonic acid), amino acid metabolism (tryptophan and phenylalanine), carbohydrate metabolism (glyoxylate and dicarboxylate pathway), nucleotide metabolism (pantothenate and CoA biosynthesis), and cofactor and vitamin metabolism (biotin and riboflavin metabolism). These metabolite alterations suggest that PSPE inhibits adipogenesis by regulating lipid signalling, enhancing fatty acid oxidation, modulating redox balance, and suppressing key adipogenic transcription factors. In conclusion, PSPE exhibits significant anti-adipogenic and lipid-lowering properties by modulating multiple metabolic pathways involved in adipocyte differentiation. These findings provide valuable mechanistic insights into the potential of Parkia speciosa pod extract as a natural therapeutic agent for the prevention and management of obesity and related metabolic disorders.