Modulation of Inflammation by Plant-Derived Nutraceuticals in Tendinitis

Inhibiting JAK1, not NF-κB, reverses the effect of pro-inflammatory cytokines on engineered human ligament function

The role of inflammation in chronic tendon/ligament injury is hotly debated. There is less debate about inflammation following acute injury. To better understand the effect of acute inflammation, in this study we developed a multi-cytokine model of inflammatory tendinitis. The combined treatment with TNF-α, IL-1β, and IL-6, at dosages well below what are routinely used in vitro, decreased the mechanical properties and collagen content of engineered human ligaments. Treatment with this cytokine mixture resulted in an increase in phospho-NF-κB and MMP-1, did not affect procollagen production, and decreased STAT3 phosphorylation relative to controls. Using this more physiologically relevant model of acute inflammation, we inhibited NF-κB or JAK1 signaling in an attempt to reverse the negative effects of the cytokine mixture. Surprisingly, NF-κB inhibition led to an even greater decrease in mechanical function and collagen content. By contrast, inhibiting JAK1 led to an increase in mechanical properties, collagen content and thermal stability concomitant with a decrease in MMP-1. Our results suggest that inhibition of JAK1, not NF-κB, reverses the negative effects of pro-inflammatory cytokines on collagen content and mechanics in engineered human ligaments.

In Vitro Study of the Anti-inflammatory and Antifibrotic Activity of Tannic Acid-Coated Curcumin-Loaded Nanoparticles in Human Tenocytes

Tendinitis is a tendon disorder related to inflammation and pain, due to an injury or overuse of the tissue, which is hypocellular and hypovascular, leading to limited repair which occurs in a disorganized deposition of extracellular matrix that leads to scar formation and fibrosis, ultimately resulting in impaired tendon integrity. Current conventional treatments are limited and often ineffective, highlighting the need for new therapeutic strategies. In this work, acetalated-dextran nanoparticles (AcDEX NPs) loaded with curcumin and coated with tannic acid (TA) are developed to exploit the anti-inflammatory and anti-fibrotic properties of the two compounds. For this purpose, a microfluidic technique was used in order to obtain particles with a precise size distribution, aiming to decrease the batch-to-batch variability for possible future clinical translation. Coating with TA increased not only the stability of the nanosystem in different media but also enhanced the interaction and the cell-uptake in primary human tenocytes and KG-1 macrophages. The nanosystem exhibited good biocompatibility toward these cell types and a good release profile in an inflammatory environment. The efficacy was demonstrated by real-time quantitative polymerase chain reaction, in which the curcumin loaded in the particles showed good anti-inflammatory properties by decreasing the expression of NF-κb and TA-coated NPs showing anti-fibrotic effect, decreasing the gene expression of TGF-β. Overall, due to the loading of curcumin and TA in the AcDEX NPs, and their synergistic activity, this nanosystem has promising properties for future application in tendinitis.

Curcumin, calebin A and chemosensitization: How are they linked to colorectal cancer?

Colorectal cancer (CRC) is one of the leading malignant diseases worldwide with a high rate of metastasis and poor prognosis. Treatment options include surgery, which is usually followed by chemotherapy in advanced CRC. With treatment, cancer cells could become resistant to classical cytostatic drugs such as 5-fluorouracil (5-FU), oxaliplatin, cisplatin, and irinotecan, resulting in chemotherapeutic failure. For this reason, there is a high demand for health-preserving re-sensitization mechanisms including the complementary use of natural plant compounds. Calebin A and curcumin, two polyphenolic turmeric ingredients derived from the Asian Curcuma longa plant, demonstrate versatile anti-inflammatory and cancer-reducing abilities, including CRC-combating capacity. After an insight into their epigenetics-modifying holistic health-promoting effects, this review compares functional anti-CRC mechanisms of multi-targeting turmeric-derived compounds with mono-target classical chemotherapeutic agents. Furthermore, the reversal of resistance to chemotherapeutic drugs was presented by focusing on calebin A's and curcumin's capabilities to chemosensitize or re-sensitize CRC cells to 5-FU, oxaliplatin, cisplatin, and irinotecan. Both polyphenols enhance the receptiveness of CRC cells to standard cytostatic drugs converting them from chemoresistant into non-chemoresistant CRC cells by modulating inflammation, proliferation, cell cycle, cancer stem cells, and apoptotic signaling. Therefore, calebin A and curcumin can be tested for their ability to overcome cancer chemoresistance in preclinical and clinical trials. The future perspective of involving turmeric-ingredients curcumin or calebin A as an additive treatment to chemotherapy for patients with advanced metastasized CRC is explained.

Anti-Inflammatory, Antioxidative, and Nitric Oxide-Scavenging Activities of a Quercetin Nanosuspension with Polyethylene Glycol in LPS-Induced RAW 264.7 Macrophages

Quercetin (Qu) is a dietary antioxidant and a member of flavonoids in the plant polyphenol family. Qu has a high ability to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) molecules; hence, exhibiting beneficial effects in preventing obesity, diabetes, cancer, cardiovascular diseases, and inflammation. However, quercetin has low bioavailability due to poor water solubility, low absorption, and rapid excretion from the body. To address these issues, the usage of Qu nanosuspensions can improve physical stability, solubility, and pharmacokinetics. Therefore, we developed a Qu and polyethylene glycol nanosuspension (Qu-PEG NS) and confirmed its interaction by Fourier transform infrared analysis. Qu-PEG NS did not show cytotoxicity to HaCaT and RAW 264.7 cells. Furthermore, Qu-PEG NS effectively reduced the nitrogen oxide (NO) production in lipopolysaccharide (LPS)-induced inflammatory RAW 264.7 cells. Additionally, Qu-PEG NS effectively lowered the levels of COX-2, NF-κB p65, and IL-1β in the LPS-induced inflammatory RAW 264.7 cells. Specifically, Qu-PEG NS exhibited anti-inflammatory properties by scavenging the ROS and RNS and mediated the inhibition of NF-κB signaling pathways. In addition, Qu-PEG NS had a high antioxidant effect and antibacterial activity against Escherichia coli and Bacillus cereus. Therefore, the developed novel nanosuspension showed comparable antioxidant, anti-inflammatory, and antibacterial functions and may also improve solubility and physical stability compared to raw quercetin.

Wistin Exerts an Anti-Inflammatory Effect via Nuclear Factor-κB and p38 Signaling Pathways in Lipopolysaccharide-Stimulated RAW264.7 Cells

Inflammation is an immune response to cellular damage caused by various stimuli (internal or external) and is essential to human health. However, excessive inflammatory responses may be detrimental to the host. Considering that the existing drugs for the treatment of inflammatory diseases have various side effects, such as allergic reactions, stomach ulcers, and cardiovascular problems, there is a need for research on new anti-inflammatory agents with low toxicity and fewer side effects. As 4′,6-dimethoxyisoflavone-7-O-β-d-glucopyranoside (wistin) is a phytochemical that belongs to an isoflavonoid family, we investigated whether wistin could potentially serve as a novel anti-inflammatory agent. In this study, we found that wistin significantly reduced the production of nitric oxide and intracellular reactive oxygen species in lipopolysaccharide-stimulated RAW 264.7 cells. Moreover, wistin reduced the mRNA levels of pro-inflammatory enzymes (inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2)) and cytokines (interleukin (IL)-1β and IL-6) and significantly reduced the protein expression of pro-inflammatory enzymes (iNOS and COX-2). Furthermore, wistin reduced the activation of the nuclear factor-κB and p38 signaling pathways. Together, these results suggest that wistin is a prospective candidate for the development of anti-inflammatory drugs.