Brazilin blocks catabolic processes in human osteoarthritic chondrocytes via inhibition of NFKB1/p50.

This study aimed to evaluate the chondroprotective and anti-inflammatory activity of brazilin in human osteoarthritic (OA) cartilage and chondrocytes with particular focus on the nuclear factor-kappa B (NF-κB) pathway. Therefore, brazilin was isolated from Caesalpinia sappan and identified using high performance liquid chromatography (HPLC). The effect of brazilin was assessed in cartilage explants treated with 10 ng/ml interleukin (IL)-1ß and 10 ng/ml tumor necrosis factor (TNF)-α using histological and biochemical glycosaminoglycan (GAG) analyses and in primary chondrocytes treated with 10 ng/ml IL-1ß using RT-qPCR, ELISA, and Western blot. The involvement of NF-κB signaling was examined using a human NF-κB signaling array and in silico pathway analysis. Brazilin was found to reduce the GAG loss from cartilage explants stimulated with IL-1ß and TNF-α. NF-κB pathway analysis in chondrocytes revealed NFKB1/p50 as a central player regulating the anti-inflammatory activities of brazilin. Brazilin suppressed the IL-1ß-mediated up-regulation of OA markers and the induction of NFKB1/p50 in chondrocytes. In conclusion, brazilin effectively attenuates catabolic processes in human OA cartilage and chondrocytes-at least in part due to the inhibition of NFKB1/p50-which indicates a chondroprotective potential of brazilin in OA. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2431-2438, 2018.

Compounds from Caesalpinia sappan with anti-inflammatory properties in macrophages and chondrocytes.

The heartwood of Caesalpinia sappan is a traditional ingredient of food and beverages in South East Asia and has been used in traditional medicine as an analgesic and anti-inflammatory drug or to promote blood circulation. Scientific studies have confirmed different bioactivities associated with its use. Here, five fractions were isolated from the ethanolic extract of C. sappan heartwood, including episappanol (1), protosappanin C (2), brazilin (3), (iso-)protosappanin B (4) and sappanol (5) using high-performance liquid chromatography (HPLC). All compounds were tested for their anti-inflammatory effects in two different cell lines. Cytokine concentrations in the cell supernatant were determined using enzyme-linked immunosorbent assay (ELISA), and mRNA levels were measured using reverse-transcription quantitative polymerase chain reaction (RT-qPCR). In lipopolysaccharide-stimulated macrophages, all compounds significantly inhibited the secretion of the pro-inflammatory cytokines interleukin (IL-6) and tumor necrosis factor-alpha (TNF-α). Sappanol (5) increased the secretion of the anti-inflammatory IL-10. In IL-1ß-stimulated chondrocytes, all fractions reduced the mRNA expression and the secretion of the pro-inflammatory cytokines IL-6 and TNF-α. The highest anti-inflammatory effect was found for brazilin (3) in both cell lines. Of note, this is the first study which shows the anti-inflammatory effect of sappanol and episappanol. This study provides evidence for the efficacy of the traditional use of C. sappan as an anti-inflammatory remedy. Given the high prevalence of inflammation-related pathologies including arthritis, and the urgent need to clinically intervene with these diseases, the anti-inflammatory activity of diverse compounds from C. sappan may be of interest for the development of complementary and alternative treatment strategies.

Medical Plant Extracts for Treating Knee Osteoarthritis: a Snapshot of Recent Clinical Trials and Their Biological Background.

In light of the growing global health problem associated with osteoarthritis, herbal remedies have become an important research focus in the scientific and medical community, and numerous studies have been published to identify their biological effects and mechanisms in vitro and in vivo. This review is a snapshot of the most recent clinical trials on the efficacy of medical plant extracts in knee osteoarthritis patients, and provides relevant background information on the biological mechanisms that may underlie the clinical observations. Therefore, we performed a PubMed literature survey and discussed a selection of clinical trials in the field, with special attention being drawn to the design and outcome measures of the studies. We further spotlighted on issues relating to the efficacy and safety of the plant extracts and discussed major challenges for upcoming studies in the field, which include the need for rigorously designed in vivo and in vitro studies, as well as the elucidation of potential additive effects and structure-modifying activities beyond symptom relief.

Anti-inflammatory activity of an ethanolic Caesalpinia sappan extract in human chondrocytes and macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: Caesalpinia sappan is a common remedy in Traditional Chinese Medicine and possesses diverse biological activities including anti-inflammatory properties. Osteoarthritis (OA) is a degenerative joint disease with an inflammatory component that drives the degradation of cartilage extracellular matrix. In order to provide a scientific basis for the applicability of Caesalpinia sappan in arthritic diseases, the present study aimed to assess the effects of an ethanolic Caesalpinia sappan extract (CSE) on human chondrocytes and macrophages. MATERIALS AND METHODS: Primary human chondrocytes were isolated from cartilage specimens of OA patients. Primary cells, SW1353 chondrocytes and THP-1 macrophages were serum-starved and pretreated with different concentrations of CSE prior to stimulation with 10 ng/ml of interleukin-1beta (IL-1ß) or lipopolysaccharide (LPS). Following viability tests, nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) were evaluated by Griess assay and ELISA, respectively. Using validated real-time PCR assays, mRNA levels of IL-1ß, TNF-α, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were quantified. SW1353 cells were cotransfected with a COX-2 luciferase reporter plasmid and nuclear factor-kappa-B (NF-κB) p50 and p65 expression vectors in the presence or absence of CSE. RESULTS: CSE dose-dependently inhibited the expression of pro-inflammatory cytokines IL-1ß and TNF-α in IL-1ß-stimulated chondrocytes and LPS-stimulated THP-1 macrophages. CSE further suppressed the synthesis of NO in primary OA chondrocytes by blocking iNOS mRNA expression. The inhibition of COX-2 transcription was found to be related with the CSE inhibition of the p65/p50-driven transactivation of the COX-2 promoter. CONCLUSIONS: The present report is first to demonstrate the anti-inflammatory activity of CSE in an in vitro cell model of joint inflammation. CSE can effectively abrogate the IL-1ß-induced over-expression of inflammatory mediators at the transcriptional level in human chondrocytes and macrophages, most likely by inhibiting NF-κB (p65/p50) signaling. Blockade of IL-1ß-induced NF-κB signaling and its downstream pro-inflammatory targets by CSE may be beneficial for reducing cartilage breakdown in arthritis.

Preparation and pre-vivo evaluation of no-carrier-added, carrier-added and cross-complexed [(68)Ga]-EDTMP formulations.

PURPOSE: The present study aimed to develop convenient preparation and quality control protocols for [(68)Ga]-EDTMP, a potential radiotracer for skeletal PET imaging. Furthermore, bone binding characteristics with special focus on the influence of carrier addition were evaluated. METHODS: No-carrier-added (nca), carrier-added and novel cross-complexed [(68)Ga]-EDTMP formulations were prepared using [(68)Ga]-gallium chloride and a commercial EDTMP kit. Respective bone binding characteristics were determined on the basis of an established in-vitro method using hydroxyapatite and human bone powders as binding matrices. RESULTS: Pre-vivo evaluation of nca [(68)Ga]-EDTMP yielded irreversible binding on the mineral bone phase characterised by fast binding kinetics. Generally, nca [(68)Ga]-EDTMP showed low uptake values comparable to nca [(99m)Tc]-EDTMP. Interestingly, the bone binding affinity of [(68)Ga]-EDTMP could be increased by the addition of carriers, presumably by changing the complex structure. CONCLUSIONS: This fast and reliable preparation protocol could enable small PET facilities without onsite cyclotron to perform PET bone scans. A comparison of all cross-complexed [(68)Ga]-EDTMP preparations further strengthens the recently presented "foreign carrier theory", which highlights carrier addition as a factor strongly affecting bone uptake of radiolabelled polyphosphonates. The clinical applicability of [(68)Ga]-EDTMP - particularly with respect to lesion specificity and sensitivity - should be clarified in forthcoming in-vivo studies.