The Effect of the Prethanol Extract of Trifolium pratense Leaves on Interleukin-1ß-Induced Cartilage Matrix Degradation in Primary Rat Chondrocytes.

BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease, characterized by cartilage degradation and inflammation. The proinflammatory cytokine, interleukin (IL)-1ß, plays a crucial role in the pathogenesis of OA by inducing the release of other catabolic factors that contribute to cartilage degradation. Trifolium pratense L. (red clover) has been used as a medicinal plant in many countries and as a source of nutraceuticals to alleviate the symptoms of menopause. Ob-jectives: In this study, we aimed to evaluate the anticatabolic effect of 40% prethanol extract of T. pratense (40% PeTP) on IL-1ß-stimulated chondrocytes. METHODS: Primary rat chondrocytes were pretreated with 40% PeTP for 1 h before stimulation with IL-1ß (20 ng/mL). The production of nitrite, prostaglandin E2 (PGE2), and aggrecan was measured by using Griess reagent and ELISA. Protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, A disintegrin and metalloproteinase with thrombospondin motif (ADAMTS)-4, mitogen-activated protein kinase (MAPK), and the nuclear factor (NF)-κB p65 subunit was measured by using Western blotting. RESULTS: PeTP (40%) significantly inhibited the IL-1ß-induced expression of nitrite, iNOS, PGE2, COX-2, MMP-1, MMP-3, MMP-13, and ADAMTS-4 in isolated primary rat chondrocytes. Furthermore, 40% PeTP decreased the IL-1ß-induced degradation of aggrecan, the phosphorylation of MAPKs, and the nuclear translocation of the NF-κB p65 subunit. CONCLUSION: These results suggested that 40% PeTP has a chondroprotective effect on inflammation and may be a potential preventative agent for OA progression.

Chondroprotective Effects of Ulva prolifera on Osteoarthritis through MAPKs Signaling Inhibition.

Osteoarthritis (OA) is a typical degenerative disease that mainly appears in the elderly aged 65 and over. OA is characterized by inflammation and decomposition of the cartilage matrix due to irreversible wear and tear. Ulva prolifera, a green macroalgae species, contains polysaccharides, amino acids, polyunsaturated fatty acids, and polyphenols, which are major active components responsible for anti-inflammatory and antioxidant effects. This study evaluated the chondro-protective effect of 30% prethanol extract of U. prolifera (30% PeUP). Rat primary chondrocytes were pre-treated with 30% PeUP for 1 h before interleukin-1ß (10 ng/mL) stimulation. The production of nitrite, prostaglandin E2 (PGE2), collagen type II (Col II), and aggrecan (ACAN) were detected by Griess reagent and enzyme-linked immunosorbent assay. The protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin (ADAMTS)-4, ADAMTS-5, and mitogen-activated protein kinases (MAPKs) (extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase, and p38) were assessed by western blot. Thirty percent of PeUP significantly inhibited the expression of nitrite, iNOS, PGE2, COX-2, MMP-1, MMP-3, MMP-13, ADMATS-4, and ADMATS-5 in interleukin (IL)-1ß-stimulated chondrocytes. Moreover, 30% PeUP decreased the IL-1ß-induced degradation of Col II and ACAN. Additionally, 30% of PeUP suppressed IL-1ß-induced phosphorylation of MAPKs. Therefore, 30% PeUP is a potential therapeutic agent to mitigate OA progression.

Mechanistic insights into the anti-restenotic effects of HSP27 and HO1 modulated by reconstituted HDL on neointimal hyperplasia.

High-density lipoprotein (HDL) therapy has demonstrated beneficial effects in acute stroke and acute myocardial infarction models by reducing infarct size. In this study, we investigated the inhibitory effects of reconstituted HDL (rHDL) on neointimal hyperplasia and elucidated its underlying mechanism using a balloon injury rat model. Our finding revealed a significant 37% reduction in the intima to media ratio in the arteries treated with 80 mg/kg rHDL compared to those subjected to injury alone (p < 0.05), indicating a specific inhibition of neointimal hyperplasia. In vivo analysis further supported the positive effects of rHDL by demonstrating a reduction in smooth muscle cell (SMC) proliferation and an increase in endothelial cell (EC) proliferation. Additionally, rHDL treatment led to decreased infiltration of leukocytes and downregulated the expression of matrix metallopeptidase 9 (MMP9) in the neointimal area. Notably, rHDL administration resulted in decreased expression of VCAM1 and HIF1α, alongside increased expression of heme oxygenase 1 (HO1) and heat shock protein 27 (HSP27). Overexpression of HSP27 and HO1 effectively inhibited SMC proliferation. Moreover, rHDL-mediated suppression of injury-induced HIF1α coincided with upregulation of HSP27. Interestingly, HSP27 and HO1 had varying effects on the expression of chemokine receptors and rHDL did not exert significant effect on chemokine receptor expression in THP1 cells. These findings underscore the distinct roles of HSP27 and HO1 as potential regulatory factors in the progression of restenosis. Collectively, our study demonstrates that rHDL exerts a potent anti-neointimal hyperplasia effect by reducing leukocytes infiltration and SMC proliferation while promoting EC proliferation.

Anti-inflammatory potential of Trifolium pratense L. leaf extract in LPS-stimulated RAW264.7 cells and in a rat model of carrageenan-induced inflammation.

This study evaluated the anti-inflammatory potential of a 40% prethanol extract of Trifolium pratense leaves (40% PeTP) using in vitro (RAW264.7 cells) and in vivo (carrageenan-induced inflammation model) experiments. Pretreatment with 40% PeTP significantly inhibited the LPS-induced expression of nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and inflammatory cytokines, including tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 in RAW264.7 cells, without inducing cytotoxicity. The inhibitory effects of 40% PeTP are mediated through suppression of the nuclear translocation of nuclear factor (NF)-κB and the phosphorylation of mitogen-activated protein kinases (MAPKs). Oral administration of 40% PeTP at 50, 100, and 200 mg/kg of body weight suppressed carrageenan-induced oedema in a dose-dependent manner. Collectively, our results suggested that 40% PeTP exerts potential anti-inflammatory effects by suppressing the activation of the NF-κB and MAPK pathways in vitro, and by reducing carrageenan-induced paw oedema in vivo.

Chondroprotective effects of aqueous extract of Anthriscus sylvestris leaves on osteoarthritis in vitro and in vivo through MAPKs and NF-κB signaling inhibition.

Osteoarthritis (OA) is a common degenerative joint disease, characterized by cartilage degradation and inflammation, in the elderly population. Anthriscus sylvestris has been used in Korean traditional medicine and contains many polyphenolic compounds such as cynaroside and chlorogenic acid, which are major active components responsible for its antioxidant effect. In this study, we aimed to evaluate the chondroprotective effect of an aqueous extract of A. sylvestris leaves (AE-ASL) on OA, both in vitro and in vivo. Rat primary chondrocytes were pretreated with AE-ASL for 1 h before interleukin-1ß (20 ng/mL) stimulation. The production of nitrite, PGE2, aggrecan, and collagen type II were detected by Griess reagent and ELISAs. The mRNA levels of iNOS, COX-2, MMP-3, and MMP-13 were measured by RT-PCR. In addition, protein levels of iNOS, COX-2, MMP-3, MMP-13, ADAMTS-4, MAPKs, and NF-κB p65 subunit were measured by western blot analysis. Sulfated glycosaminoglycan (sGAGs) were detected by dimethylmethylene blue (DMMB) assay. During in vivo study, the effects of AE-ASL were evaluated for 8 weeks in a rat model of destabilization of the medial meniscus (DMM) surgery-induced OA. AE-ASL significantly inhibited expression of nitrite, iNOS, PGE2, COX-2, MMP-3, MMP-13, and ADAMTS-4 in IL-1ß-stimulated chondrocytes. Moreover, it decreased the IL-1ß-induced degradation of aggrecan, collagen type II, and proteoglycan. In addition, AE-ASL suppressed IL-1ß-induced phosphorylation of MAPKs and NF-κB p65 subunit translocation to nucleus. In vivo, AE-ASL inhibited DMM surgery-induced cartilage destruction and proteoglycan loss. Taken together, these results suggest that AE-ASL may be a potential therapeutic agent for the alleviation of OA progression.

Aqueous extract of Codium fragile alleviates osteoarthritis through the MAPK/NF-κB pathways in IL-1ß-induced rat primary chondrocytes and a rat osteoarthritis model.

BACKGROUND: Codium fragile (Suringar) Hariot has been used as a potential remedy in traditional medicine because of its anti-inflammatory and anti-oxidant effects. Osteoarthritis is a chronic progressive joint disease, characterized by complex mechanisms related to inflammation and degeneration of articular cartilage. In this study, we aimed to evaluate the cartilage protective effect of an aqueous extract of Codium fragile (AECF) using rat primary chondrocytes and the osteoarthritis animal model induced by destabilization of the medial meniscus (DMM). METHODS: In vitro, rat primary cultured chondrocytes were pre-treated with AECF (0.5, 1, and 2mg/mL) for 1h and then incubated with interleukin-1ß (10ng/mL) for 24h. Nitrite production was detected by the Griess reagent. Alteration of the protein levels of iNOS, MMP-13, ADAMTS-4, ADAMTS-5, mitogen-activated protein kinases (MAPKs), and nuclear factor-κB (NF-κB) was detected by western blotting. In vivo, osteoarthritis was induced by DMM of Sprague Dawley (SD) rats. The rats subjected to destabilization of the medial meniscus (DMM) surgery were orally administered with AECF (50, 100, and 200mg/kg bodyweight) or distilled water for 8w. The severity of cartilage lesions was evaluated by safranin O staining and the Osteoarthritis Research Society International (OARSI) score. RESULTS: These results demonstrated that AECF significantly inhibited nitrite production and inhibited the levels of iNOS, MMP-13, ADAMTS-4, and ADAMTS-5 in interleukin-1ß-induced rat primary cultured chondrocytes. Moreover, AECF suppressed interleukin-1ß-induced NF-κB activation in the nucleus and phosphorylation of ERK1/2 and JNK in the cytosol. In vivo, the cartilage lesions in AECF-treated osteoarthritis rats exhibited less proteoglycan loss and lower OARSI scores. CONCLUSIONS: These results suggested that AECF is a potential therapeutic agent for the alleviation of osteoarthritis progression.

In Vivo and In Vitro Anti-Inflammatory Effects of Aqueous Extract of Anthriscus sylvestris Leaves.

Anthriscus sylvestris (L.) Hoffm. is a common perennial herb that is widely distributed in Europe, Korea, and New Zealand. The root of A. sylvestris has been used in Korean traditional medicine as an antitussive and cough remedy. However, the physiologically active function of A. sylvestris leaves is not yet known. In this study, we evaluated the anti-inflammatory effects, as well as the underlying molecular mechanisms of an aqueous extract of A. sylvestris leaves (AE-ASL) in vitro and in vivo. Our results indicated that pretreatment with AE-ASL significantly inhibited the lipopolysaccharide (LPS)-induced secretion of nitric oxide (NO) and prostaglandin E2 in RAW264.7 cells, without showing cytotoxicity. In addition, the LPS-induced mRNA and protein expression of inducible NO synthase, cyclooxygenase-2, and inflammatory mediators such as tumor necrosis factor alpha interleukin (IL)-1ß, and IL-6 was attenuated by pretreatment with AE-ASL in a dose-dependent manner. Therefore, we investigated the activation of nuclear factor (NF)-κB, a transcription factor regulating the expression of inflammation-related genes. AE-ASL inhibited the nuclear translocation of the NF-κB p65 subunit by suppressing the phosphorylation and degradation of the inhibitor of NF-κB (IκBα). Further, AE-ASL inhibited the LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) in RAW264.7 cells. Orally administered AE-ASL (50, 100, and 200 mg/kg of body weight [BW]) suppressed the development of carrageenan-induced rat paw edema by 15%, 31%, and 40%, respectively, after 4 h. Altogether, our results suggest that AE-ASL possesses anti-inflammatory activity, based on the suppression of NF-κB and MAPK pathways in vitro and inhibition of the carrageenan-induced paw edema in vivo.

Aqueous extract of Codium fragile suppressed inflammatory responses in lipopolysaccharide-stimulated RAW264.7 cells and carrageenan-induced rats.

Codium fragile (Suringar) Hariot has been used in Oriental medicine for the treatment of enterobiasis, dropsy, and dysuria and has been shown to have various biological effects. In this study, we evaluated the anti-inflammatory effects of aqueous extract of C. fragile (AECF) using in vitro and in vivo models. Nitric oxide (NO), prostaglandin E2 (PGE2), inflammatory-related mRNAs, and proteins were determined using the Griess assay, enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and western blotting, respectively. Our results indicate that pretreatment of cells with AECF (50, 100 and 200µg/mL) significantly inhibited LPS-induced secretion of NO and PGE2 in RAW264.7 cells without cytotoxicity. We also found that AECF (100 and 200µg/mL) inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 expression in a dose-dependent manner. Additionally, pretreatment of cells with AECF (100 and 200µg/mL) inhibited LPS-induced production of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. It also prevented the nuclear translocation of nuclear factor (NF)-κB by suppressing the phosphorylation and degradation of inhibitor of NF-κB (IκB)-α. Furthermore, AECF (100 and 200µg/mL) inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinase (JNK), and p38. In addition, orally administered 50, 100, and 200mg/kg body weight of AECF dose-dependently suppressed carrageenan-induced rat paw edema thickness by 6%, 31%, and 50% respectively, after 4h. Furthermore, the anti-inflammatory effect was comparable to that observed in animals treated with the standard drug diclofenac sodium (56%) in vivo. Collectively, our results suggest that AECF exerts potential anti-inflammatory effects by suppressing NF-κB activation and MAPKs pathways in vitro, as well as inhibiting carrageenan-induced rat paw edema thickness in vivo. These findings indicate that AECF could be further developed as an anti-inflammatory drug.

Simvastatin and losartan differentially and synergistically inhibit atherosclerosis in apolipoprotein e(-/-) mice.

BACKGROUND AND OBJECTIVES: Since statins and angiotensin receptor blockers are a frequently prescribed combination in patients with atherosclerotic cardiovascular diseases, we tested the interactive effects of simvastatin and losartan on atherosclerosis in apolipoprotein E (apoE)(-/-) mice. MATERIALS AND METHODS: Apolipoprotein E(-/-) mice were fed a high-fat, high-cholesterol (HFHC) diet for 12 weeks, with and without simvastatin (40 mg/kg) and/or losartan (20 mg/kg). The mice were divided into 5 groups and were fed as follows: regular chow (control diet, n=5), HFHC diet (n=6), HFHC diet with losartan (n=6), HFHC diet with simvastatin (n=6), and HFHC diet with both losartan and simvastatin (n=6). RESULTS: Losartan treatment in apoE(-/-) mice significantly decreased atherosclerotic lesion areas in whole aortic strips stained with Oil Red O. The plaque area measured at the aortic sinus level was reduced significantly by 17% (HFHC; 346830.9±52915.8 µm(2) vs. HFHC plus losartan; 255965.3±74057.7 µm(2), p<0.05) in the losartan-treated group. Simvastatin and simvastatin plus losartan treatments reduced macrophage infiltration into lesions by 33% (HFHC; 183575.6±43211.2 µm(2) vs. HFHC plus simvastatin; 120556.0±39282.8 µm(2), p<0.05) and 44% (HFHC; 183575.6±43211.2 µm(2) vs. HFHC plus simvastatin and losartan; 103229.0±8473.3 µm(2), p<0.001, respectively). In mice fed the HFHC diet alone, the smooth muscle cell layer in the aortic media was almost undetectable. In mice co-treated with losartan and simvastatin, the smooth muscle layer was more than 60% preserved (p<0.05). Given alone, losartan showed a slightly stronger effect than simvastatin; however, treatment with losartan plus simvastatin induced a greater inhibitory effect on atherosclerosis than either drug given alone. Serum lipid profiles did not differ significantly among the groups. CONCLUSION: Losartan displayed anti-atherosclerotic effects in apoE(-/-) mice that were equivalent to or greater than the effects of simvastatin. Combined treatment with these drugs had greater effect than either drug alone.