Pine needles attenuate receptor activator for nuclear factor-B ligand (RANKL)-induced trabecular bone loss by inhibiting osteoclast differentiation

Pinus densiflora Root Extract Attenuates Osteoarthritis Progression by Inhibiting Inflammation and Cartilage Degradation in Interleukin-1β and Monosodium Iodoacetate-Induced Osteoarthritis Models

BACKGROUND

Osteoarthritis (OA) is a common degenerative joint condition caused by an imbalance between cartilage synthesis and degradation, which disrupts joint homeostasis. This study investigated the anti-inflammatory and joint-improving effects of Pinus densiflora root extract powder (PDREP) in both in vitro and in vivo OA models.

METHODS/RESULTS

In an in vitro OA model, in which SW1353 human chondrosarcoma cells were treated with interleukin (IL)-1β, PDREP treatment significantly reduced the mRNA levels of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 while enhancing collagen type II alpha 1 (Col2a1) mRNA level, and decreased IL-6 and prostaglandin E2 (PGE2) levels. In addition, PDREP inhibited the phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinase (JNK), p38, nuclear factor-kappa B (NF-κB), and the expression of inducible nitric oxide synthase (iNOS). In a monosodium iodoacetate (MIA)-induced OA rat model, the administration of PDREP resulted in decreased OA clinical indices, improved weight-bearing indices and gait patterns, reduced histological damage, and lowered serum inflammatory cytokine and MMPs expression. Furthermore, PDREP downregulated the phosphorylation of ERK, JNK, p38, and NF-κB, as well as the expression of iNOS, consistent with the in vitro findings.

CONCLUSIONS

These results suggest that PDREP exhibits anti-inflammatory and joint-improving effects and has potential as a therapeutic strategy or functional food for the treatment of OA.

Quantitative Changes of Flavonol Glycosides from Pine Needles by Cultivar, Harvest Season, and Thermal Process

Five flavonol glycosides including quercetin 3-O-β-D-glucoside (QG), kaempferol 3-O-β-D-glucoside (KG), quercetin 3-O-(6″-O-acetyl)-β-D-glucoside (QAG), kaempferol 3-O-(6″-O-acetyl)-β-D-glucoside (KAG), and quercetin 3-O-(3″-O-p-coumaroyl)-β-D-glucoside (QCG) were isolated and purified from red pine (Pinus densiflora Sieb. et Zucc.) nee-dles, and identified by nuclear magnetic resonance and mass spectrometer spectral analyses. In addition, the quantification of the five flavonol glycosides in pine needles was performed by high-performance liquid chromatography analysis according to cultivar, growing district, harvest season, and thermal processing. The red pine needles had higher amounts of the five flavonol glycosides than the black pine needles except for QCG. There were no large differences in flavonoid composition and content among pine needles grown in three different areas. Levels of the five flavonol glycosides in red pine needles harvested during Spring ranged from 6.13 to 27.03 mg/100 g dry weight. Levels of two flavonol glycosides, QG and KG, gradually decreased with increasing harvest time, whereas the acylated flavonol glycoside, QCG, a predominant flavo-noid in pine needles, increased gradually with increasing harvest time. Two acetyl flavonol glycosides, QAG and KAG, increased steadily through Spring to Autumn, and then decreased gradually by Winter. Meanwhile heat treatments, such as roasting and steaming, increased the five flavonol glycosides during heating for 3 min, but then slowly decreased these when heating for 10 min. Microwave processing increased to some extent the five flavonol glycosides when heating for 3 min, and remained unchanged during the 10 min heating. These results suggest that the pretreated red pine needles with enhanced flavonoid content may be useful as potential sources for nutraceuticals and cosmeceuticals.

Water extract of tendril of Cucurbita Moschata Duch. suppresses RANKL-induced osteoclastogenesis by down-regulating p38 and ERK signaling

Background: Pumpkin (Curcubita sp.) is a natural product that is commonly used in folk medicine. However, the inhibitory effect and molecular mechanisms of tendril of Cucurbita Moschata Duch. (TCMD) on osteoclast differentiation have yet to be clearly elucidated. Thus, the present study aimed to investigate the effect and underlying mechanism of water extract of TCMD on osteoclast differentiation. Methods: Bone marrow-derived macrophages (BMDMs), osteoclast precursors, were cultured with macrophage colony stimulating factor (M-CSF) 30 ng/ml and receptor activator of nuclear factor-kappa B ligand (RANKL) 100 ng/ml for four days. We investigated the effect of TCMD on RANKL-induced osteoclast differentiation, tartrate-resistant acid phosphatase (TRAP) staining, F-actin ring formation, and bone resorption assay. RANKL signaling pathways were determined through Western blotting, and osteoclast differentiation marker genes were confirmed by Real-time PCR. Results: TCMD inhibited the RANKL-induced osteoclast differentiation in a dose-dependent manner without cytotoxicity. Further, F-actin ring formation and bone resorption were reduced by TCMD in RANKL-treated BMDMs. In addition, TCMD decreased the phosphorylation of p38 and ERK as well as the expression of osteoclast-related genes in BMDMs treated with RANKL. Conclusion: These findings suggest that TCMD may have preventive and therapeutic effects for destructive bone diseases.

Anti-inflammatory properties of fermented pine (Pinus morrisonicola Hay.) needle on lipopolysaccharide-induced inflammation in RAW 264.7 macrophage cells

This study was aimed to explore the antioxidant and anti-inflammatory activity of various pine needle products (non-fermented, fermented, and commercial) extracted with different solvents (hexane, ethyl acetate, and water) in lipopolysaccharide (LPS) induced RAW 264.7 cells. The phenolic/flavonoid contents of ethyl acetate extract of fermented pine needle (EAE-FPN) is higher than other pine product extracts (hexane/water). The levels of antioxidant indices (TEAC, DPPH) as well as free radical scavenging activity (H₂ O₂ ) were significantly improved in EAE-FPN than other pine needle product extracts. The levels of ROS and various inflammatory markers (NO, PGE2, TNF-α, and IL-1β/6) were considerably abolished by EAE-FPN in a dose-dependent manner (50-200 μg/ml). Moreover, the protein expressions of inducible NO synthase (iNOS), cyclooxygenase 2 (COX-2), and nuclear factor Kappa B (NF-κB) p65 subunit were also markedly downregulated by EAE-FPN. Collectively, EAE-FPN with phenolic/flavonoid content showed excellent antioxidant and anti-inflammatory properties via modulating NF-κB signaling pathway. PRACTICAL APPLICATIONS: Pine needle drink (Pinus morrisonicola Hay) has been used as a functional beverage for many years due to its various biological properties in Asia especially in Taiwan, China, and Korea. Many researchers hinted various biological activity of fermented pine needle product but none of them explored the in-depth mechanism underpinning its antioxidant and anti-inflammatory properties in LPS-induced RAW 264.7 cell model. Hence, the current cell line study was designed to assess the underlying mechanism behind the antioxidant and anti-inflammatory activity of Pine needles extract (both non-fermented and fermented) in LPS-induced RAW 264.7 cells (macrophage). The outcome of this study distinctly showed that EAE-FPN displayed potent antioxidant and anti-inflammatory activities by regulating NF-κB signaling pathway. Therefore, pine needle could be developed into functional drink to abolish the progression of inflammatory responses in various disease condition.