Trachelogenin alleviates osteoarthritis by inhibiting osteoclastogenesis and enhancing chondrocyte survival.

BACKGROUND: Osteoarthritis (OA) is a prevalent global health concern associated with the loss of articular cartilage and subchondral bone. The lack of disease-modifying drugs for OA necessitates the exploration of novel therapeutic options. Our previous study has demonstrated that traditional Chinese medical herb Trachelospermum jasminoides (Lindl.) Lem. extract suppressed osteoclastogenesis and identified trachelogenin (TCG) as a representative compound. Here, we delved into TCG's potential to alleviate OA. METHODS: We initially validated the in vivo efficacy of TCG in alleviating OA using a rat OA model. Subsequently, we isolated primary bone marrow-derived macrophages in vitro to investigate TCG's impact on osteoclastogenesis. We further employed a small molecule pull-down assay to verify TCG's binding target within osteoclasts. Finally, we isolated primary mouse chondrocytes in vitro to study TCG's regulatory effects and mechanisms on chondrocyte survival. RESULTS: TCG preserved subchondral bone integrity and protected articular cartilage in a rat OA model. Subsequently, in vitro experiments unveiled TCG's capability to inhibit osteoclastogenesis and function through binding to Ras association proximate 1 (Rap1) and inhibiting its activation. Further study demonstrated that TCG inhibited Rap1/integrin αvß3/c-Src/Pyk2 signaling cascade, and consequently led to failed F-actin ring formation. Besides, TCG promoted the proliferation of mouse primary chondrocytes while suppressing apoptosis in vitro. This is attributed to TCG's ability to upregulate HIF1α, thereby promoting glycolysis. CONCLUSION: TCG exerted inhibitory effects on osteoclastogenesis through binding to Rap1 and inhibiting Rap1 activation, consequently preventing subchondral bone loss. Moreover, TCG enhanced chondrocyte survival by upregulating HIF1α and promoting glycolysis. These dual mechanisms collectively provide a novel approach to prevented against cartilage degradation.

Effects of dibenzylbutyrolactone lignans arctigenin and trachelogenin on the motility of isolated rat ileum.

Dibenzylbutyrolactone-type lignans are phenolic compounds of medical importance. The purpose of the study was to determine the effects of two such lignans, arctigenin and trachelogenin on the motility of isolated rat ileum and obtain indications on their mechanism of action. They were isolated from Arctium lappa and Cirsium arvense, respectively, which have been used traditionally to treat gastrointestinal disorders. 1-1.5 cm long segments of distal ileum were obtained from adult male Wistar rats. The intestinal segments were suspended vertically in a well-aerated organ-bath according to Magnus mounting method. The intestinal motility was monitored for 30 min before treatment to obtain the baseline, followed by treatment with 1 µM, 10 µM, 20 µM and 40 µM concentrations of arctigenin and 0.5 µM, 1 µM, 10 µM and 20 µM of trachelogenin concentrations. The amplitude, tone, and period of spontaneous contractions were measured after 15 and 30 min of treatment. To investigate their mechanism of action, cholinergic, glutamatergic, adrenergic antagonists and compounds inhibiting nitric oxide synthase and L-type calcium channels were also tested. Arctigenin and trachelogenin decreased the frequency of contractions in a dose-dependent manner. At the concentration of 20 µM and 40 µM of trachelogenin and arctigenin, respectively, there was a marked alteration in spontaneous contraction pattern with an observable increase in the period time. This activity was comparable to 0.5 µM nifedipine (L-type calcium channel blocker) treatment. Our results demonstrate relaxant effect of arctigenin and trachelogenin on the ileum motility that may be mediated by L-type calcium ion channel blockade.

Endogenous enzyme-hydrolyzed fruit of Cirsium brachycephalum: optimal source of the antiproliferative lignan trachelogenin regulating the Wnt/ß-catenin signaling pathway in the SW480 colon adenocarcinoma cell line.

The molecular constituents of Cirsium brachycephalum fruits were identified, quantified and isolated for the first time. The lignan glycoside tracheloside was the main compound, which was transformed quantitatively into its aglycone trachelogenin by endogenous enzymatic treatment of the fruit. Following this transformation by high performance liquid chromatography (HPLC) hyphenated with UV and mass spectrometry (MS) detections on a quantitative basis, the enzyme-hydrolyzed fruit was found to be the richest raw material containing trachelogenin (17.2mg/g) reported to date. Thus, the enzyme-hydrolyzed fruit was used to isolate trachelogenin using preparative HPLC in order to (1) unambiguously confirm its identity by gas chromatography-MS, nuclear magnetic resonance spectroscopy and optical rotation, and (2) investigate its in vitro antiproliferative activities against the SW480 colon adenocarcinoma cell line. Trachelogenin significantly affected the phosphorylation of key proteins such as ß-Catenin, c-Myc and GSK3 in the ß-Catenin signaling pathway in a concentration-dependent manner. These changes account for the antiproliferative effects of trachelogenin.

Specific hydrolysis and accumulation of antiproliferative lignans in the fruit of Leuzea carthamoides (Willd.) DC.

Dibenzylbutyrolactone-type lignan glycosides (tracheloside and carthamoside), their aglycones (trachelogenin and carthamogenin) and feruloyl-serotonin isomers were determined in the fruits of Leuzea carthamoides by using LC-UV, LC-MS/MS and GC-MS techniques. The composition of the embryo and wall parts of the fruits was analysed before and after their hydrolysis. As a result of these studies, fruit part-specific accumulation of lignan glycosides and feruloyl-serotonins were confirmed, demonstrating that the embryo contains a high amount of lignan glycosides (tracheloside 32.9 mg/g, carthamoside 45.3 mg/g), while the wall part of the fruit accumulates feruloyl-serotonins (63.0 mg/g). Enzymatic hydrolysis of the embryo resulted in the quantitative transformation of lignan glycosides into their corresponding aglycones, allowing selective isolation of trachelogenin and carthamogenin. These aglycones were subjected to an antiproliferative study against the SW480 colon adenocarcinoma cell line. In this test, moderate activity of carthamogenin and a significant effect of trachelogenin were demonstrated in a concentration range of 22-185 µM.