α-Amylase and α-glucosidase inhibitors from the aerial parts of Chamaecrista pumila (Lam.) K. Larsen.

One new compound, 4,7-dihydroxy-2-hydroxymethyl-5,6-dimethoxyanthraquinone (1), along with eight known compounds (2-9) were isolated from the methanol extracts of the aerial parts of Chamaecrista pumila (Lam.) K. Larsen. Their chemical structure was determined based on spectroscopic data interpretation and comparison with the reported data. The inhibitory effects of them on α-amylase and α-glucosidase were performed. The results showed that compounds 4, 6, 8, and 9 against potent α-glucosidase with the inhibition values of 98.14 ± 0.05, 98.19 ± 0.04, 97.01 ± 0.49, 84.43 ± 0.6% at 50 µM, respectively. Compounds 4 and 6 displayed significance against α-amylase at 200 µM with inhibition values of 22.35 ± 1.10 and 60.47 ± 0.91%.

Chemicals from Cimicifuga dahurica and Their Inhibitory Effects on Pro-inflammatory Cytokine Production by LPS-stimulated Bone Marrow-derived Dendritic Cells

Inflammation is a biological response caused by overactivation of the immune system and is controlled by immune cells via a variety of cytokines. The overproduction of pro-inflammatory cytokines enhances abnormal host immunity, resulting in diseases such as rheumatoid arthritis, cardiovascular disease, Alzheimer's disease, and cancer. Inhibiting the production of pro-inflammatory cytokines such as interleukin (IL)-12p40, IL-6, and tumor necrosis factor (TNF)-α might be one way to treat these conditions. Here, we investigated the anti-inflammatory activity of compounds isolated from Cimicifuga dahurica (Turcz.) Maxim., which is traditionally used as an antipyretic and analgesic in Korea. In primary cell culture assays, 12 compounds were found to inhibit the production of pro-inflammatory cytokines (IL-12p40, IL-6, and TNF-α) in vitro in bone marrow-derived dendritic cells stimulated with LPS.

Anti-osteoporotic and Antioxidant Activities by Rhizomes of Kaempferia parviflora Wall. ex Baker

In this report, we investigated the antioxidant (peroxyl radical-scavenging and reducing capacities) and anti-osteoporotic activities of extracts and isolated constituents (1 - 16) from the rhizomes of Kaempferia parviflora Wall. ex Baker on pre-osteoclastic RAW 264.7 cells. Compound 5 exhibited significant peroxyl radical-scavenging capacity, with TE value of 8.47 ± 0.52 µM, while compound 13 showed significant reducing capacity, with CUPRAC value of 5.66 ± 0.26 µM, at 10.0 µM. In addition, flavonoid compounds 2, 4, 6, 8, 10, 12, and terpene compound 15 showed significant inhibition of tartrate-resistant acid phosphatase (TRAP) in NF-κB ligand-induced osteoclastic RAW 264.7 cells, with values ranging from 16.97 ± 1.02 to 64.67 ± 2.76%. These results indicated that K. parviflora could be excellent sources for the antioxidant and anti-osteoporotic traditional medicinal plants.

In vitro evaluation of the antioxidant and cytotoxic activities of constituents of the mangrove Lumnitzera racemosa Willd.

This study performed phytochemical and bioactive assessments of the mangrove Lumnitzera racemosa Willd. leaves. Bioassay-guided fractionation of the methanolic extracts led to the identification of thirty-six compounds (1-36), their structures were elucidated using detailed NMR spectroscopic and MS analysis. The extracts, fractions, and the isolated compounds were screened for potential antioxidant and cytotoxic activities. Antioxidant assays were performed using peroxyl radical-scavenging and reducing assays, whereas cytotoxicity was measured using MTT assays in HL-60 and Hel-299 cell lines. The methanolic extract, CH2Cl2 and n-BuOH fractions (10.0 µg/mL) exhibited potent antioxidant activity, with Trolox equivalent (TE) values of 24.94 ± 0.59, 28.34 ± 0.20, and 27.09 ± 0.37 (µM), respectively. In addition, the isolated compounds exerted cytotoxic effects in a dose-dependent manner; compounds 1 and 14 exhibited the most potent cytotoxicity in HL-60 cells, with IC50 values of 0.15 ± 0.29 and 0.60 ± 0.16 µM, respectively. To clarify the mechanism(s) behind these cytotoxic effects, we measured the time-dependent changes in apoptotic markers including the condensation and fragmentation of nuclear chromatin, and the downregulation of p-ERK1/2, p-AKT, and c-Myc levels.

Anti-inflammatory Triterpenes and Glyceryl Glycosides from Kandelia candel (L.) Druce

Phytochemical investigation of Kandelia candel resulted in the isolation of six triterpenes (1 - 5) and two glyceryl glycosides (6 and 7) and their structures were determined by comparing the spectroscopic data with those of reported values. In present study, we described the inhibitory effects of fractions and isolated compounds from K. candel on pro-inflammatory cytokines (IL-12 p40, IL-6, and TNF-alpha) production in lipopolysaccharide (LPS) stimulated bone marrow-derived dendritic cells (BMDCs). Results indicated that compounds 3, 6, and 7 showed potent inhibition on IL-6 production (IC50 values at less than 0.5 microM, respectively). Meanwhile, compounds 6 and 7 exhibited strong inhibitory effects on the production of TNF-alpha (IC50 values of 1.7 +/- 0.1 and 5.5 +/- 0.2 microM). Compounds 1 and 3 were also showed the inhibitory effects on IL-12 p40 production (IC50 values of 8.9 +/- 0.4 and 3.3 +/- 0.1 microM, respectively).

Soluble Epoxide Hydrolase Inhibitory Activity from Euphorbia supina Rafin

In our search for natural soluble epoxide hydrolase (sEH) inhibitors from plants, an extract of the dried whole plants of Euphorbia supina Rafin was found to significantly inhibit sEH activity in vitro. Phytochemical investigation of E. supina resulted in isolation of 17 compounds (1 - 17), including triterpenes (1 - 4), phenolic compounds (5 - 8), and flavonoid derivatives (9 - 17). The structures of the isolated compounds were established mainly by extensive analysis of the 1D and 2D NMR, and MS data. All of the isolated compounds were evaluated for their sEH inhibitory activity. Among the isolated phenolic compounds, 8 was identified as a significant inhibitor of sEH, with an IC50 value of 15.4 +/- 1.3 microM. Additionally, a kinetic analysis of isolated compounds (2, 5, 8 - 11, 13, and 17) indicated that the inhibitory effects of flavonoid derivatives 10 and 11 were of mixed-type, with inhibitory constants (Ki) ranging from 3.6 +/- 0.8 to 21.8 +/- 1.0 microM, whereas compounds 2, 5, 8, 9, 13, and 17 were non-competitive inhibitors with inhibition Ki values ranging from 3.3 +/- 0.2 to 39.5 +/- 0.0 microM.

Effects of Cynaroside, Cynarin and Linarin on Secretion, Production and Gene Expression of Airway MUC5AC Mucin in NCI-H292 Cells

In this study, we investigated whether cynaroside, cynarin and linarin derived from Chrysanthemum indicum L. affect the secretion, production and gene expression of MUC5AC mucin in airway epithelial cells. Confluent NCI-H292 cells were pretreated with cynaroside, cynarin or linarin for 30 min and then stimulated with PMA (phorbol 12-myristate 13-acetate) for 24 h. The MUC5AC mucin gene expression, mucin protein production and secretion were measured by RT-PCR and ELISA, respectively. Effect of linarin on EGF (epidermal growth factor) - or TNF-alpha (tumor necrosis factor-alpha)-induced MUC5AC mucin gene expression and mucin protein production was also examined. The results were as follows: (1) Cynaroside and cynarin did not significantly affect PMA-induced MUC5AC mucin secretion from NCI-H292 cells. However, linarin decreased MUC5AC mucin secretion; (2) Cynaroside did not affect PMA-induced MUC5AC mucin production and gene expresion from NCI-H292 cells. However, cynarin and linarin inhibited the production and gene expression of MUC5AC mucin; (3) Linarin also inhibited the production and gene expression of MUC5AC mucin induced by EGF- or TNF-alpha from NCI-H292 cells. These results suggest that linarin can regulate the gene expression, production and secretion of mucin, by directly acting on airway epithelial cells.