Chemical Constituents of Eupatorium japonicum and Anti-Inflammatory, Cytotoxic, and Apoptotic Activities of Eupatoriopicrin on Cancer Stem Cells

Eupatorium japonicum Thunb. of the plant family Asteraceae is a popular traditional herb in Vietnam. However, its chemical constituents as well as bioactive principles have not been investigated yet. We investigated the phytochemistry of E. japonicum in Vietnam and isolated seventeen compounds (1–17) including phytosterols, terpenoids, phenolic acids, flavonoids, fatty alcohols, and fatty acids. They were structurally determined by MS and NMR analysis. Except for compounds 6 and 12, all the other compounds were identified for the first time from E. japonicum. Since many sesquiterpene lactones with α-methylene γ-lactone ring are reported as anti-inflammatory and anticancer agents, eupatoriopicrin (10), 1-hydroxy-8-(4,5-dihydroxytigloyloxy)eudesma-4(15),11(13)-dien-6,12-olide (11) were selected among the isolates for biological assays. Compound 10 was identified as the main bioactive sesquiterpene lactone of E. japonicum showing its potent anti-inflammatory and cytotoxic activity through inhibiting NO production and the growth of HepG2 and MCF-7 human cancer cell lines. For the first time, eupatoriopicrin (10) was demonstrated to strongly inhibit NTERA-2 human cancer stem cell (CSC) line in vitro. It is noticeable that the cytotoxicity of eupatoriopicrin against NTERA-2 cells is mediated by its apoptosis-inducing capability of 10 as demonstrated by the results of Hoechst 33342 staining, flow cytometry apoptosis analysis, and caspase-3 activity assays. The biological activities of the main bioactive constituents 1–7, 10, 12, and 15 supported the reported anti-inflammatory and anticancer properties of extracts from E. japonicum.

A 90-Day Oral Toxicity Study of the Ethanol Extract from Eupatorium japonicum Thunb and Foeniculum vulgare in Rats

Eupatorium japonicum Thunb and Foeniculum vulgare are two of the most widely used folk herbs and constituents in many traditional Chinese herbal formulas. Nonetheless, little toxicological and safety information associated with following daily repeated exposure is obtained according to previous research. The present study was performed to assess the toxicity of ethanol extract from Eupatorium japonicum Thunb and Foeniculum vulgare (EFE) in male rats administered by dietary oral gavage at target doses of 0.39, 0.78, and 1.56 g/kg body weight/day for 90 days. There were no significant adverse effects on clinical signs, body weight, food conversion efficiency, and vital hematological indices. However, some hematology and biochemical indices such as WCV, MCH, MCHC, LY, MPV, T-CHO, as well as TG revealed significant changes in Sprague–Dawley rats and organ weights in lung and spleen showed diminished in male rats. Necropsy and histopathology findings suggested that no significant differences in absolute weights were found in all organs except lung and spleen, and no treatment-related alteration was identified in any organs. All results obtained in the present study indicated that the proper use of EFE in traditional medicine at oral dosages up to 1.56 g/kg/day body weight may harbor no prolonged toxicity to rats. However, further studies of EFE are still necessary to assess its oral safety in patients.

Apoptotic and Anti-Inflammatory Effects of Eupatorium japonicum Thunb. in Rheumatoid Arthritis Fibroblast-Like Synoviocytes

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovitis, hyperplasia, and the destruction of bone and cartilage. A variety of immunosuppressive biological agents have been developed because the pathogenesis of RA is related predominantly to the inflammatory response. However, rheumatoid arthritis fibroblast-like synovial cells (RAFLS), which are known to play an important role in RA progression, exhibit resistance to immunosuppressants through cancer-like properties. In this study, we identified a novel therapeutic compound for RA, which reduced inflammation and the abnormal proliferation of RAFLS in natural product library made from Korean native plants. Eupatorium japonicum Thunb. (EJT) extract, a component of the natural product library, most effectively reduced viability through the induction of ROS-mediated apoptosis in a dose-dependent manner. In addition, the increased ROS induced the expression of ATF4 and CHOP, key players in ER stress-mediated apoptosis. Interestingly, EJT extract treatment dose-dependently reduced the expression of IL-1β and the transcription of MMP-9, which were induced by TNF-α treatment, through the inhibition of NF-κB and p38 activation. Collectively, we found that EJT extract exerted apoptotic effects through increases in ROS production and CHOP expression and exerted anti-inflammatory effects through the suppression of NF-κB activation, IL-1β expression, and MMP-9 transcription.