Gelatin Extracted From Yanbian Cattle Skin Suppresses LPS-Induced Inflammation in RAW264.7 Cells

Abstract

Objective: To develop an efficient method for extracting gelatin from Yanbian cattle skin and to study its anti-inflammatory effects.

Methods: Gelatin was extracted using enzymatic hydrolysis and water extraction techniques. The basic structures of the prepared gelatin were analyzed using Fourier transform infrared spectroscopy (FT-IR), ultraviolet (UV) spectroscopy, amino acid analysis, scanning electron microscopy (SEM), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). LPS established the RAW264.7 cell inflammation model in vitro. The therapeutic dose range of gelatin, which did not exhibit significant cytotoxicity, was determined using the CCK-8 assay for subsequent experiments. The nitric oxide (NO) content was measured using the Griess method. The content of proinflammatory cytokines was determined using ELISA. Reactive oxygen species (ROS) levels were detected using the DCFH-DA fluorescent probe method, and oxidative stress–related indicators were measured using a kit. The mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines were detected using qRT-PCR. Western blot (WB) was used to detect the protein expression of iNOS and COX-2 in each group.

Results: Characteristic absorption peaks of gelatin were observed in the FT-IR and UV spectra. Additionally, gelatin from Yanbian cattle skin significantly reduced NO content in cells, decreased the secretion of proinflammatory cytokines, inhibited ROS generation, reduced oxidative stress–related indicators, significantly lowered the mRNA expression levels of iNOS, COX-2, and proinflammatory cytokines in cells, and significantly reduced the protein expression of COX-2 and iNOS.

Conclusion: Enzymatic hydrolysis and water extraction efficiently prepare gelatin from Yanbian cattle skin. This gelatin can inhibit LPS-induced inflammation in RAW264.7 cells, potentially by inhibiting the secretion of proinflammatory cytokines and ameliorating oxidative stress.