背景:水稻(OryzasativaL.),占全球人口很大一部分的主食,几个世纪以来一直以其传统药用特性而闻名。米糠,碾米的副产品,含有许多具有潜在药物和治疗益处的生物活性化合物。近年来,研究强调了米糠的抗炎潜力,由集中在麸皮中的生物活性成分贡献,但是,不幸的是,被困在麸皮基质中,生物利用度有限。先前的研究报道,米糠的酶处理改善了米糠的生物活性化合物谱,但没有研究其对慢性疾病如炎症的影响。
目的:本研究调查了经内-1,4-β-木聚糖酶(ERB)和粘酶(VRB)处理的红米糠提取物对RAW264.7巨噬细胞中脂多糖诱导的炎症的抗炎作用。与非酶处理的麸皮(CRB)相比。用已知的抗炎化合物阿魏酸(FA)进一步证实了它们的功效,儿茶素(CAT),γ-生育酚(GTP),和γ-谷维素(ORZ)。
方法:用无毒浓度(10-200μg/mL)的FA预处理RAW264.7巨噬细胞,CAT,GTP,ORZ,CRB,ERB,和VRB,然后用LPS进行炎症刺激24小时。收集细胞上清液和颗粒,通过评估和测量其抑制促炎细胞因子(TNF-α,IL-6,IL-10,IL-1β)和介质(ROS,NO,PGE2,COX2,iNOS)通过生化,ELISA,和mRNA表达研究。
结果:研究结果表明,ERB和VRB均有效抑制促炎标志物的产生(TNF-α,IL-6)和介体(ROS,NO,PGE2)通过下调炎症基因(TNF-α,IL-1β,IL-6、IL-10、COX2、iNOS)和显示的抗炎功效高于CRB。相比之下,ERB通过降低ROS48%表现出卓越的疗效,20%的TNF-α,和23%的PGE2在10μg/mL,超越所有生物活性化合物的抗炎能力,FA和ORZ,分别。同时,VRB通过在200μg/mL时减少52%的NO产生和在10μg/mL时减少66%的IL-6表现出显著的功效。超越FA,CAT,ORZ,和GTP。Further,ERB下调IL-10和iNOS的mRNA表达,而VRB下调TNF-α,IL-1β,和COX2表达。两种提取物在10μg/mL时同样下调IL-6表达,与已建立的抗炎化合物相比,其功效更为显着/相同。
结论:总体而言,酶处理米糠/提取物,特别是ERB,具有优异的抗炎特性,使它们成为有前途的药物,用于替代当代营养品/功能性食品,以对抗炎症性疾病。
BACKGROUND: Rice (Oryza sativa L.), a staple food for a significant portion of the global population, has been recognized for its traditional medicinal properties for centuries. Rice bran, a by-product of rice milling, contains many bioactive compounds with potential pharmaceutical and therapeutic benefits. In recent years, research has highlighted the anti-inflammatory potential of rice bran, contributed by the bioactive components concentrated in their bran but, unfortunately, entrapped in the bran matrix, with limited bioavailability. Previous studies have reported that the enzymatic treatment of rice bran improves the bran\'s bioactive compound profile but did not investigate its impact on chronic conditions such as inflammation.
OBJECTIVE: This study investigates the anti-inflammatory effects of endo-1,4-β-xylanase (ERB) and Viscozyme (VRB) treated red rice bran extracts against lipopolysaccharide-induced inflammation in RAW264.7 macrophages in comparison with non-enzyme-treated bran (CRB). Further established their efficacy with known anti-inflammatory compounds-ferulic acid (FA), catechin (CAT), γ-tocopherol (GTP), and γ-oryzanol (ORZ).
METHODS: The RAW 264.7 macrophage cells were pre-treated with non-toxic concentrations (10-200 μg/mL) of FA, CAT, GTP, ORZ, CRB, ERB, and VRB, followed by inflammatory stimulation with LPS for 24 h. Further, the cell supernatant and pellets were harvested to study the anti-inflammatory effects by evaluating and measuring their efficacy in inhibiting pro-inflammatory cytokines (TNF-α, IL-6, IL-10, IL-1β) and mediators (ROS, NO, PGE2, COX2, iNOS) through biochemical, ELISA, and mRNA expression studies.
RESULTS: The findings showed that both ERB and VRB effectively inhibited the production of pro-inflammatory markers (TNF-α, IL-6) and mediators (ROS, NO, PGE2) by downregulating mRNA expressions of inflammatory genes (TNF-α, IL-1β, IL-6, IL-10, COX2, iNOS) and demonstrated anti-inflammatory efficacy higher than CRB. On comparison, ERB demonstrated exceptional efficacy by causing a reduction of 48% in ROS, 20% in TNF-α, and 23% in PGE2 at 10 μg/mL, surpassing the anti-inflammatory capabilities of all the bioactive compounds, FA and ORZ, respectively. At the same time, VRB exhibited remarkable efficacy by reducing NO production by 52% at 200 μg/mL and IL-6 by 66% at 10 μg/mL, surpassing FA, CAT, ORZ, and GTP. Further, ERB downregulated the mRNA expression of IL-10 and iNOS, while VRB downregulated TNF-α, IL-1β, and COX2 expression. Both extracts equally downregulated IL-6 expression at 10 μg/mL, demonstrating the efficacy more remarkable/on par with established anti-inflammatory compounds.
CONCLUSIONS: Overall, enzyme-treated rice bran/extract, particularly ERB, possesses excellent anti-inflammatory properties, making them promising agents for alternatives to contemporary nutraceuticals/functional food against inflammatory diseases.