curcumin and Intervertebral-Disc-Displacement

Zhiqiao Gancao (ZQGC) decoction is widely used in China due to its therapeutic effect on lumbar disc herniation (LDH). In this study, we compared the clinical therapeutic effects among oral ZQGC decoction treatment, bed rest, and oral anti-inflammatory drug celecoxib treatment using visual analog scale, Oswestry Disability Index, and MacNab scores. The results showed that ZQGC decoction can significantly improve the symptoms of patients with LDH. A selective, sensitive, and rapid ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of eight bioactive components in rat plasma. The plasma samples were extracted by simple protein precipitation with methanol. The protonated analytes were quantitated simultaneously in positive and negative ion modes by multiple reaction monitoring with a mass spectrometer. The calibration curve of eight components in plasma showed good linearity (r > .996) and the extraction recovery was 81.19% ± 2.15% - 100.39 ± 3.36 (relative standard deviation: 1.21%-10.70%). The accuracy of all the lower limit of quantitation values was quantified within 80%-120%, and the precision was less than 15%. This validated method was successfully applied to the pharmacokinetics study in rat plasma after ZQGC decoction oral treatment. Our research can provide experimental basis for the rational clinical application of ZQGC decoction in the treatment of LDH.

Topics: Administration, Oral; Analgesics; Animals; Curcumin; Drugs, Chinese Herbal; Flavones; Glycyrrhetinic Acid; Humans; Intervertebral Disc Degeneration; Intervertebral Disc Displacement; Linear Models; Male; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sensitivity and Specificity

Current non-surgical treatments for lumbar radiculopathy [e.g. epidural steroids and Tumour necrosis factor-α (TNF-α) antagonists] are neither effective nor safe. As a non-toxic natural product, curcumin possesses an exceptional anti-inflammatory profile. We hypothesised that curcumin alleviates lumbar radiculopathy by attenuating neuroinflammation, oxidative stress and nociceptive factors. In a dorsal root ganglion (DRG) culture, curcumin effectively inhibited TNF-α-induced neuroinflammation, in a dose-dependent manner, as shown by mRNA and protein expression of IL-6 and COX-2. Such effects might be mediated via protein kinase B (AKT) and extracellular signal regulated kinase (ERK) pathways. Also, a similar effect in combating TNF-α-induced neuroinflammation was observed in isolated primary neurons. In addition, curcumin protected neurons from TNF-α-triggered excessive reactive oxygen species (ROS) production and cellular apoptosis and, accordingly, promoted mRNA expression of the anti-oxidative enzymes haem oxygenase-1, catalase and superoxide dismutase-2. Intriguingly, electronic von Frey test suggested that intraperitoneal injection of curcumin significantly abolished ipsilateral hyperalgesia secondary to disc herniation in mice, for up to 2 weeks post-surgery. Such in vivo pain alleviation could be attributed to the suppression, observed in DRG explant culture, of TNF-α-elicited neuropeptides, such as substance P and calcitonin gene-related peptide. Surprisingly, micro-computed tomography (μCT) data suggested that curcumin treatment could promote disc height recovery following disc herniation. Alcian blue/picrosirius red staining confirmed that systemic curcumin administration promoted regeneration of extracellular matrix proteins, visualised by presence of abundant newly-formed collagen and proteoglycan content in herniated disc. Our study provided pre-clinical evidence for expediting this natural, non-toxic pleiotropic agent to become a new and safe clinical treatment of radiculopathy.

Topics: Animals; Apoptosis; Cells, Cultured; Curcumin; Cytoprotection; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Ganglia, Spinal; Hyperalgesia; Inflammation; Intervertebral Disc Displacement; Lumbar Vertebrae; Male; Mice, Inbred BALB C; Neurons; Neuropeptides; Nociception; Oxidative Stress; Radiculopathy; Reactive Oxygen Species; Staining and Labeling; Tumor Necrosis Factor-alpha

Radiculopathy, a painful neuroinflammation that can accompany intervertebral disc herniation, is associated with locally increased levels of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα). Systemic administration of TNF antagonists for radiculopathy in the clinic has shown mixed results, and there is growing interest in the local delivery of anti-inflammatory drugs to treat this pathology as well as similar inflammatory events of peripheral nerve injury. Curcumin, a known antagonist of TNFα in multiple cell types and tissues, was chemically modified and conjugated to a thermally responsive elastin-like polypeptide (ELP) to create an injectable depot for sustained, local delivery of curcumin to treat neuroinflammation. ELPs are biopolymers capable of thermally-triggered in situ depot formation that have been successfully employed as drug carriers and biomaterials in several applications. ELP-curcumin conjugates were shown to display high drug loading, rapidly release curcumin in vitro via degradable carbamate bonds, and retain in vitro bioactivity against TNFα-induced cytotoxicity and monocyte activation with IC50 only two-fold higher than curcumin. When injected proximal to the sciatic nerve in mice via intramuscular (i.m.) injection, ELP-curcumin conjugates underwent a thermally triggered soluble-insoluble phase transition, leading to in situ formation of a depot that released curcumin over 4days post-injection and decreased plasma AUC 7-fold.

Topics: Animals; Anti-Inflammatory Agents; Cell Line, Tumor; Curcumin; Delayed-Action Preparations; Drug Delivery Systems; Elastin; Female; Genetic Engineering; Hot Temperature; Humans; Inflammation; Intervertebral Disc Displacement; Mice; Mice, Inbred C57BL; Peptides; Sciatic Nerve; U937 Cells