CHONDROPROTECTIVE ACTIVITY OF POMEGRANATE EXTRACT

描述(申请人提供)：骨关节炎(OA)是美国和世界各地老年人口中最常见的肌肉骨骼疾病。骨性关节炎的特征是手、膝、脊柱和髋关节的关节软骨退变。虽然已经确定了易患骨性关节炎的条件，但实际原因仍不清楚，目前的治疗选择仅限于使用非甾体抗炎药缓解症状。然而，非类固醇类药物的使用可能会因严重的副作用而复杂化，包括胃肠道出血、心血管不良事件和肾毒性。石榴果实(石榴L)因其药用价值而历来受到推崇。石榴果(PF)或其提取物(PFE)在印度的乌纳尼和阿育吠陀医学系统中被广泛用于治疗糖尿病和结肠炎。PF的可食用部分是 富含花青素，是一组具有抗氧化和抗炎特性的多酚化合物。我们先前报道，PFE对IL-1β诱导的人软骨外植体和软骨细胞中MAPK亚群p38-MAPK和JNK、转录因子NF-β的激活以及MMPs的表达具有明显的抑制作用。最近我们发现：(1)口服PFE可抑制小鼠胶原诱导性关节炎(CIA)的发展；(2)生物可利用的PFE成分/代谢产物可抑制COX-2活性和IL-1β诱导的软骨细胞NO和PGE2的产生。拟议的研究利用了这些新的发现，因为在这里，我们将扩展这些研究，并将确定体外发现与体内PFE在动物模型中的应用的相关性。我们将验证“口服PFE可抑制前交叉韧带切断(ACLT)诱导的兔膝关节骨性关节炎(OA)的软骨退化和进展”的假设。在AIM-1中，我们将确定几种已知的PFE衍生花青素(ET)在给予不同剂量PFE的兔体内的生物可利用性；在AIM-2中，我们将测定并比较含有PFE衍生的ET和花色苷的血浆和SF在体外抑制IL-1β诱导的人和兔软骨移植的分解代谢反应的有效性；在AIM-3中，我们将使用上述研究中确定的最相关的剂量来喂养兔，并评估口服PFE对关节软骨退变的影响。 与公共卫生相关：骨关节炎(OA)的特征是高水平的IL-1，ROS的过度产生和关节软骨的退变。然而，其病因和确切的发病机制仍不清楚。在这里，我们将确定食用标准化的石榴果提取物(PFE)是否可以减缓或延缓体内关节软骨的退化。拟议研究的主要目标是(A)确定PFE体外与软骨保护活性相关的分子机制；以及(B)使用广泛使用的人骨关节炎动物模型来测试体外研究与体内情况的相关性。我们的发现可能会为开发治疗骨性关节炎的新治疗策略打开大门。

DESCRIPTION (provided by applicant): Osteoarthritis (OA) is the most common musculoskeletal disease among the aging population in the United States and throughout the world. OA is characterized by degeneration of articular cartilage of the joints in hands, knees, spine and hips. While conditions predisposing to the development of OA have been identified, the actual causes remain unknown and the current treatment options are limited to relief of symptoms using NSAIDS. However, use of NSAIDS may be complicated by significant side effects that include gastrointestinal bleeding, cardiovascular adverse events and nephrotoxicity. Pomegranate fruit (Punica granatum L) is revered through the ages for its medicinal properties. Pomegranate fruit (PF) or its extract (PFE) is widely used in Unani and Ayurvedic medicinal systems in India for the treatment of diabetes and Colitis. Edible part of PF is rich in anthocyanins, a group of polyphenolic compounds that possess antioxidant and anti-inflammatory properties. We previously reported that PFE exert a potent inhibitory effect on IL-1¿-induced activation of MAPK sub-groups p38-MAPK and JNK, transcription factor NF-?B and the expression of MMPs by human cartilage explants and chondrocytes in vitro. Recently we have shown that (1) oral consumption of PFE inhibited the development of collagen-induced arthritis in mice(CIA); and (2) bioavailable PFE constituents/metabolites inhibited COX-2 activity and IL-1¿-induced production of NO and PGE2 in chondrocytes. Proposed studies capitalizes on these novel findings as here we will extend these studies and will determine the relevance of the in vitro findings to in vivo PFE use in an animal model of OA. We will test the hypothesis that "oral consumption of PFE inhibits cartilage degradation and suppresses the progression of knee OA in rabbits induced by anterior cruciate ligament transection (ACLT)". In aim-1 we will establish the identity and concentration of several of the known PFE-derived anthocyanins and ellagitanins (ET) that become bioavailable in plasma and synovial fluid (SF) in rabbits given different doses of PFE; in aim-2 we will determine and compare the efficacy of plasma and SF containing PFE-derived ET and anthocyanins in inhibiting the IL-1¿-induced catabolic responses in human and rabbit cartilage explants in vitro; in aim-3 we will use the dose determined to be most relevant from above studies for feeding rabbits and evaluate the effect of oral consumption of PFE on articular cartilage degeneration in the ACLT model of OA. Public Health Relevance: Osteoarthritis (OA) is characterized by high high levels of IL-1¿, excessive production of ROS and articular cartilage degeneration in the affected joints. However, its etiology and precise pathogenetic mechanisms remain unclear. Here, we will determine whether consumption of a standardized extract of pomegranate fruit (PFE) can slow or retard the artciular cartilage degeneration in vivo. The broad objectives of the proposed studies are (a) to identify the molecular mechanism in vitro associated with cartilage/chondroprotective activity of PFE; and (b) to test the relevance of in vitro studies to the in vivo situation using a widely used animal model of human OA. Our findings are likely to open the door for the development of novel therapeutic strategies for the treatment of OA.