Bioactive Peptide Fractions from Mung Bean Protein Hydrolysate: Antioxidant Activity, Anti-Inflammatory Effects, and Immunomodulatory Responses in RAW 264.7 Macrophages

Amid growing concerns over climate change and the need for sustainable agriculture, the study investigated the antioxidant, anti-inflammatory, and immunomodulatory activities of MBPH fractions. MBPH was produced via alcalase hydrolysis and fractionated by ultrafiltration into >5, 3–5, 1–3, and <1 kDa fractions. Bioactivity exhibited a clear inverse correlation with molecular weight. The <1 and 1–3 kDa fractions demonstrated their highest antioxidant capabilities through their performance in ORAC and ABTS tests, which produced results of 836.51 ± 11.81 µmol TE/g and 19.36 ± 0.71 µmol TE/g, respectively. Both fractions also demonstrated significant in vitro anti-inflammatory potential, with the <1 kDa fraction showing superior activity by inhibiting LOX activity (76.93 ± 1.53%) and heat-induced albumin denaturation (81.82 ± 2.72%). All fractions were non-cytotoxic, preserving >90% cell viability in RAW 264.7 macrophages at 100 µg/mL. The 1–3 kDa MBPH fraction exhibited distinct context-dependent immunomodulatory activity in RAW 264.7 macrophages. At 3 h, the fraction markedly suppressed Tnf-α and Il-1β expression under LPS stimulation, indicating strong early-stage anti-inflammatory effects. At 6 h, IL-6 secretion further confirmed this dual behavior, with a mild increase under basal conditions (33.15–36.42 pg/mL) and a reduced level under inflammatory conditions (28.25–28.81 pg/mL). This represents an approximate 15–22% lower IL-6 production technology under LPS stimulation compared to basal conditions at equivalent concentrations. The results demonstrate that low-molecular-weight MBPH peptides, particularly the 1–3 kDa fraction, exhibit dual functionality by providing robust antioxidant protection while dynamically rebalancing immune homeostasis, highlighting their immense potential as bioactive ingredients for functional foods of agroindustry.