Investigating the Anti-inflammatory Mechanism of <i>Alpinia purpurata</i> (Vieill.) K. Schum. Rhizome Extract: Metabolite Profiling, Network Pharmacology, in vitro Safety, and in vivo Validation

Abstract

Background: Alpinia purpurata has shown promising effects in alleviating inflammatory conditions; however, its underlying mechanisms require further investigation. Objectives: This study aimed to elucidate the molecular mechanisms underlying the anti-inflammatory activity of A. purpurata rhizome extract (EEAP) and its active metabolites through the TLR4/MyD88 pathway. Methods: The EEAP was analyzed for proximate composition, vitamin C content, total phenolic content (TPC), total flavonoid content (TFC), total monomeric anthocyanin content (TMAC), and metabolite profile, followed by a network pharmacology analysis. Cytotoxicity was evaluated in HEK-293 cells. An in vivo study of carrageenan-induced paw edema in rats was conducted to validate the findings. Results: EEAP contained 42.12% ash, 34.66% moisture, 6.03% protein, 16.60% fat, and 0.59% carbohydrate. The vitamin C content was 941.55 mg/100 g extract, the TPC was 452.9 mg GAE/100 g extract, the TFC was 416.1 mg QUE/100 g extract, and the TMAC was 2770 mg/100 g extract. Functional enrichment analysis identified the TLR4/MyD88 signaling pathway as contributing to IL-23 production. Eight metabolites with anti-inflammatory properties were verified based on their Pa values: glycidyl oleate, 1-stearoylglycerol, alpha-linolenic acid, methyl palmitate, shogaol, 4-methoxybenzaldehyde, ginkgoneolic acid, and curcumene. EEAP was not toxic to HEK-293 cells (IC50= 741.1 μg/mL) compared with quercetin (IC50= 96.73 μg/mL) and cisplatin (IC50= 7.44 μg/mL). EEAP reduced edema volume but did not alter TLR4 or MyD88 expression under the present experimental conditions. Conclusions: EEAP is not toxic to normal cells and exerts an anti-inflammatory effect by reducing edema volume in carrageenan-induced rats; however, it does not alter the TLR4/MyD88 pathway.