Berg J, Fellier H, Christoph T, Grarup J, Stimmeder D
Department of Laboratory Medicine, General Hospital Linz, Austria.
Inflamm Res. 1999 Jul;48(7):369-79. doi: 10.1007/s000110050474.
To investigate anti-inflammatory effects of lornoxicam in vitro on COX-1/COX-2, on NO formation from iNOS and on the formation of the pro-inflammatory cytokines TNF-alpha, IL-1beta, IL-6, and IL-8.
COX-1 inhibition in intact cells was assessed employing two systems: measurement of aggregation in human washed platelets and assessment of TXB2 formation in HEL cells. COX-2 inhibition was assessed by measuring 6-keto-PGF1alpha in supernatants of intact cells of LPS-stimulated J774.2 cells (murine) and of Mono Mac 6 cells (human). In whole blood inhibition of COX-1 was performed by measuring TXB2 formation after clotting, and COX-2 inhibition was examined in LPS-stimulated whole blood cultures. The reduction of NO levels as a measure of the inhibition of cellular NO formation was assayed in supernatants of LPS-stimulated RAW 264.7 cells using the Griess reaction. Compound influence on the formation ofTNF-alpha, IL-1beta, IL-6, and IL-8 was examined using LPS-stimulated monocytic cells (THP-1) and measurement of cytokine concentrations by specific ELISAs.
In intact human cells, lornoxicam showed a balanced inhibition of COX-1/-2 exhibiting the lowest IC50 (0.005 microM/0.008 microM) of the large panel of NSAIDs tested. Similar results were obtained in the whole blood for COX-1/-2. NO formation was dose-dependently inhibited by lornoxicam (IC50 of 65 microM) whereas piroxicam, diclofenac, ibuprofen, ketorolac and naproxen inhibited the NO formation markedly less. Indomethacin was approximately equipotent with lornoxicam. In stimulated monocytic cells (THP-1), lornoxicam showed a marked inhibition of IL-6 formation (IC50 54 microM) while the formation ofTNF-alpha, IL-1beta and IL-8 was only moderately affected.
Of the panel of NSAIDs tested, lornoxicam was found to be the most potent balanced inhibitor of human COX-1/-2. The equipotent COX-isoenzyme inhibition by lornoxicam is complemented by a marked inhibition of IL-6 production and of iNOS-derived NO formation. The in vitro activities described support the marked anti-inflammatory and analgesic activities of lornoxicam found in animal models as well as in clinical studies.
研究氯诺昔康在体外对COX-1/COX-2的抗炎作用、对诱导型一氧化氮合酶（iNOS）生成一氧化氮（NO）的作用以及对促炎细胞因子肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和白细胞介素-8（IL-8）生成的影响。
采用两种系统评估氯诺昔康对完整细胞中COX-1的抑制作用：检测人洗涤血小板的聚集情况以及评估人红白血病细胞（HEL细胞）中血栓素B2（TXB2）的生成。通过检测脂多糖（LPS）刺激的J774.2细胞（小鼠）和单核巨噬细胞6（Mono Mac 6）细胞（人）完整细胞上清液中的6-酮-前列腺素F1α（6-keto-PGF1α）来评估COX-2的抑制作用。在全血中，通过检测凝血后TXB2的生成来评估COX-1的抑制作用，并在LPS刺激的全血培养物中检测COX-2的抑制作用。使用格里斯反应检测LPS刺激的RAW 264.7细胞上清液中NO水平的降低，以此作为细胞NO生成抑制作用的指标。使用LPS刺激的单核细胞（THP-1）并通过特异性酶联免疫吸附测定法（ELISA）检测细胞因子浓度，来研究该化合物对TNF-α、IL-1β、IL-6和IL-8生成的影响。
在完整的人细胞中，氯诺昔康对COX-1/-2表现出平衡的抑制作用，在所测试的一大类非甾体抗炎药（NSAIDs）中其半数抑制浓度（IC50）最低（分别为0.005微摩尔/0.008微摩尔）。在全血中对COX-1/-2也获得了类似结果。氯诺昔康对NO生成呈剂量依赖性抑制（IC50为65微摩尔），而吡罗昔康、双氯芬酸、布洛芬、酮咯酸和萘普生对NO生成的抑制作用明显较弱。吲哚美辛与氯诺昔康的效力大致相当。在刺激的单核细胞（THP-1）中，氯诺昔康对IL-6生成表现出显著抑制作用（IC50为54微摩尔），而对TNF-α、IL-1β和IL-8的生成仅产生中度影响。
在所测试的NSAIDs中，氯诺昔康被发现是最有效的人COX-1/-2平衡抑制剂。氯诺昔康对COX同工酶的等效抑制作用，辅之以对IL-6产生和iNOS衍生的NO生成的显著抑制作用。所描述的体外活性支持了氯诺昔康在动物模型以及临床研究中所发现的显著抗炎和镇痛活性。
