Inhibitory Effects of Siegesbeckia orientalis Extracts on Advanced Glycation End Product Formation and Key Enzymes Related to Metabolic Syndrome.

Metabolic syndrome typically includes Type 2 diabetes associated with hyperglycemia, central obesity, dyslipidemia and hypertension. It is highly related to oxidative stress, formation of advanced glycated end products (AGEs) and key enzymes, such as carbohydrate digesting enzymes like pancreatic α-amylase and intestinal α-glucosidase, pancreatic lipase and angiotensin I-converting enzyme (ACE). This study used an in vitro approach to assess the potential of four extracts of Siegesbeckia orientalis linne on key enzymes relevant to metabolic syndrome. In this research, S. orientailis was firstly extracted by ethanol. The ethanol extract (SE) was then partitioned sequentially with hexane, ethyl acetate and methanol, and these extracts were named SE-Hex, SE-EA and SE-MeOH, respectively. The experimental results showed that SE-EA had the highest total phenolic content (TPC, 76.9 ± 1.8 mg/g) and the total flavonoids content (TFC, 5.3 ± 0.3 mg/g). This extract exhibited the most significant antioxidant activities, including DPPH radical-scavenging capacity (IC50 = 161.8 ± 2.4 µg/mL), ABTS radical-scavenging capacity (IC50 = 13.9 ± 1.5 µg/mL) and reducing power. For anti-glycation activities, SE-EA showed the best results in the inhibition of AGEs, as well as inhibitory activities against α-glucosidase (IC50 = 362.3 ± 9.2 µg/mL) and α-amylase (IC50 = 119.0 ± 17.7 µg/mL). For anti-obesity activities, SE-EA indicated the highest suppression effect on pancreatic lipase (IC50 = 3.67 ± 0.52 mg/mL). Finally, for anti-hypertension activity, SE-EA also demonstrated the strongest inhibitory activity on ACE (IC50 = 626.6 ± 15.0 µg/mL). Close relationships were observed among the parameters of TPC, antioxidant activities, inhibitory activities on α-amylase, α-glucosidase, lipase and ACE (R > 0.9). Moderate correlations were found among the parameters of TFC, antioxidant activities, and suppression of dicarbonyl compounds formation (R = 0.5-0.9). Taken together these in vitro studies reveal the therapeutic potential of SE-EA extract in the prevention and treatment of metabolic disorders.

Siegesbeckia orientalis Extract Inhibits TGFß1-Induced Migration and Invasion of Endometrial Cancer Cells.

Type II endometrial carcinoma typically exhibits aggressive metastasis and results in a poor prognosis. Siegesbeckia orientalis Linne is a traditional Chinese medicinal herb with several medicinal benefits, including the cytotoxicity against various cancers. This study investigates the inhibitory effects of S. orientalis ethanol extract (SOE) on the migration and invasion of endometrial cancer cells, which were stimulated by transforming growth factor ß (TGFß). The inhibitory effects were evaluated by determining wound healing and performing the Boyden chamber assay. This study reveals that SOE can inhibit TGFß1-induced cell wound healing, cell migration, and cell invasion in a dose-dependent manner in RL95-2 and HEC-1A endometrial cancer cells. SOE also reversed the TGFß1-induced epithelial-mesenchymal transition, including the loss of the cell-cell junction and the lamellipodia-like structures. Western blot analysis revealed that SOE inhibited the phosphorylation of ERK1/2, JNK1/2, and Akt, as well as the expression of MMP-9, MMP-2, and u-PA in RL95-2 cells dose-dependently. The results of this investigation suggest that SOE is a potential anti-metastatic agent against human endometrial tumors.

Anti-proliferative effects of Siegesbeckia orientalis ethanol extract on human endometrial RL-95 cancer cells.

Endometrial cancer is a common malignancy of the female genital tract. This study demonstrates that Siegesbeckia orientalis ethanol extract (SOE) significantly inhibited the proliferation of RL95-2 human endometrial cancer cells. Treating RL95-2 cells with SOE caused cell arrest in the G2/M phase and induced apoptosis of RL95-2 cells by up-regulating Bad, Bak and Bax protein expression and down-regulation of Bcl-2 and Bcl-xL protein expression. Treatment with SOE increased protein expression of caspase-3, -8 and -9 dose-dependently, indicating that apoptosis was through the intrinsic and extrinsic apoptotic pathways. Moreover, SOE was also effective against A549 (lung cancer), Hep G2 (hepatoma), FaDu (pharynx squamous cancer), MDA-MB-231 (breast cancer), and especially on LNCaP (prostate cancer) cell lines. In total, 10 constituents of SOE were identified by Gas chromatography-mass analysis. Caryophyllene oxide and caryophyllene are largely responsible for most cytotoxic activity of SOE against RL95-2 cells. Overall, this study suggests that SOE is a promising anticancer agent for treating endometrial cancer.