Volume 69, Issue 11-12

As a part of ongoing research to develop antioxidant and anti-inflammatory nutraceuticals, an ethanolic extract of Spergularia marina Griseb. was tested for its ability to scavenge radicals and suppress inflammation. The extract was able to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals, respectively, in cell-free environments as well as intracellular radicals in H 2 O 2 -stimulated mouse macrophages. Inflammation in mouse macrophages induced by lipopolysaccharides was suppressed by S. marina according to the measurement of nitric oxide generation and expression of inflammatory cytokines, i.e. tumour necrosis factor-α (TNFα), interleukin (IL)-1β, and IL-6. The anti-inflammatory effect of S. marina was substantiated by the finding that the expression of the inflammatory modulators, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), was significantly decreased. The chemical composition of S. marina was evaluated by FT-IR analysis of the extract indicating the presence of polyphenols and flavonoids. In conclusion, S. marina is suggested as a novel source for antioxidant and anti-inflammatory agents.

Galetin 3,6-dimethyl ether (FGAL), a flavonoid from the aerial parts of Piptadenia stipulacea (Benth.) Ducke, was found to exert a relaxant effect on carbachol (CCh)-pre-contracted guinea-pig trachea. Based on cumulative concentration-response curves to CCh, FGAL antagonized muscarinic receptors pseudo-irreversibly and noncompetitively, since it inhibited and shifted these curves towards higher concentrations in a nonparallel manner. In addition, FGAL was more potent in relaxing contractions induced by 18 mM as compared to 60 mM KCl (pD 2 = 5:50 ±0:36 and 4.80 ±0.07, respectively), indicating the participation of K + channels. In the presence of 10 mM tetraethylammonium (TEA + ) chloride, a nonselective K + channel blocker, the relaxant potency of FGAL was reduced (from pD 2 = 5:12 ±0:07 to 4.87 ±0.02). Among several selective blockers of K + channel subtypes, only apamin, an SKCa (small-conductance Ca 2+ -activated K+ channels) blocker, attenuated the relaxant potency of FGAL (pD 2 = 4:85±0:06), suggesting SKCa activation. FGAL was equipotent in relaxing trachea contracted by 60 mM KCl (pD 2 =4:80 ±0:07) or 10-6 M CCh (pD 2 = 5:02 ±0:07), suggesting Ca V (voltage-gated calcium channel), but not ROCs (receptor-operated calcium channels) participation. Furthermore, aminophylline-induced relaxation (pD 2 = 4:12 ±0:06) was potentiated around 4-fold (pD 2 = 4:80 ±0:44) in the presence of FGAL. Moreover, forskolininduced relaxation (pD 2 = 6:51 ±0:06) was potentiated around 2.5-fold (pD 2 = 6:90 ±0:05) by FGAL. Conversely, sodium nitroprusside-induced relaxation was unaffected, indicating that the AC/cAMP/PKA pathway, but not the NO pathway, may be modulated by the flavonoid. These results suggest that, in guinea-pig trachea, FGAL induces relaxation by pseudo-irreversible noncompetitive antagonism on muscarinic receptors, modulation of K + and Ca 2+ channels, as well as activation of the AC/cAMP/PKA pathway.

Ethanol extracts obtained from two Salvia species, S. triloba and S. dominica, collected from the flora of Jordan, were evaluated for their antiproliferative activity against MCF7 and T47D breast cancer cell lines by the sulforhodamine B assay. The ethanol extracts were biologically active with IC 50 values of (29.89 ±0.92) and (38.91 ±2.44) μg/mL for S. triloba against MCF7 and T47D cells, respectively, and (5.83 ±0.51) and (12.83 ±0.64) μg/mL for S. dominica against MCF7 and T47D cells, respectively. Flow cytometry analysis and the annexinV-propidium iodide (PI) assay revealed apoptosismediated, and to a lesser extent necrosis-induced, cell death by the S. triloba and S. dominica ethanolic extracts in T47D cells. The mechanism of apoptosis was further investigated by determining the levels of p53, p21/WAF1, FasL (Fas ligand), and sFas (Fas/APO-1). The extract from S. triloba induced a more pronounced enrichment in cytoplasmic mono- and oligonucleosomes than that from S. dominica (p < 0:05) in T47D cells. In response to the extract from S. dominica, but not from S. triloba, the proapoptotic efficacy was specifically regulated by p21. Extracts from both Salvia spp. did not enhance p53 levels, and apoptosis induced by them was not caspase-8- or sFas/FasL-dependent. Thus, our findings indicate that S. triloba and S. dominica ethanolic extracts may be useful in breast cancer management/treatment via proapoptotic cytotoxic mechanisms.

Cadmium, a non-essential and toxic metal, negatively affects plant growth and productivity, and alters the plant’s physiological processes necessary for its survival. The present study was designed to explore the individual and combined effects of calcium and salicylic acid (SA) on the morphology and physiology of Brassica juncea L. cv. Varuna under cadmium stress. The application of calcium (2 mM) through the soil and/or SA (10 -5 M) as foliar spray enhanced the growth, photosynthetic parameters, and proline content determined after 45 days of treatment. The application of cadmium (6 mg kg -1 ) through the soil was toxic and decreased both growth and the photosynthetic parameters. The application of calcium and SA in combination was most effective in alleviating the harmful effects of cadmium on growth and photosynthesis. Calcium and SA clearly induced plant protection mechanisms by enhancing proline and chlorophyll accumulation in the leaves.

Doxorubicin (DOX) is an anthracycline antibiotic routinely used as a chemotherapeutic agent for the treatment of solid tumours. However, DOX possesses an acute and cumulative cardiotoxicity due to free radical production. The present study was designed to investigate the possible protective effects of saffron (Crocus sativus) extracts against DOX-induced acute cardiotoxicity in isolated rabbit hearts submitted to 30 min global ischemia followed by 40 min reperfusion. DOX was delivered during reperfusion, without or with saffron given 5 min before ischemia or at reperfusion. Cardiodynamic, biochemical, and histopathological parameters were determined. In addition, to determine the expression of the AKT/mTOR/4EBP1 pathway, the levels of p38 MAPK and cardiac troponin T in heart homogenates were visualized by Western blotting. DOX administration during 40 min of reperfusion increased ischemic tissue damage, but did not act synergistically. Administration of saffron extracts during the first minutes of reperfusion significantly reduced oxidative myocardial damage, but was less effective when given before ischemia. Subsequent Western blot analysis revealed that saffron administration preserved cardiac troponin T proteins, inhibited the p38 MAPK pathway, and activated the AKT/mTOR/4EBP1 pathway in reperfusion- and DOX-treated rabbit hearts. In conclusion, saffron extracts, acting through antioxidant and antiapoptotic mechanisms, exhibited a protective effect against DOX-induced cardiotoxicity under ischemic condition.

Histone deacetylases (HDACs) are a group of enzymes that deacetylate ε-N-acetyl lysine residues of histone and non-histone proteins and play an important role in gene regulation. HDAC4, a class-IIa HDAC, has been reported to shuttle between nucleus and cytoplasm in response to various cellular stimuli. The nucleo-cytoplasmic shuttling of HDAC4 is critical, and an anomalous nuclear localization might affect the cellular differentiation program. While the subcellular localization of HDAC4 has been reported to be vital for myoblast differentiation and chondrocyte hypertrophy, nuclear accumulation of HDAC4 during Runx2-induced osteoblast differentiation of stem cells has not been characterized. Ratjadone C is a natural compound that inhibits the nuclear export of proteins. Here, we show that Runx2 is a more potent transcription factor than Osterix in inducing osteoblast differentiation. Under the influence of ratjadone C, HDAC4 is retained in the nucleus and co-localizes with Runx2. However, forced nuclear accumulation of HDAC4 by ratjadone C or overexpression of the nuclear resident form of HDAC4 does not inhibit osteoblast differentiation, suggesting that the Runx2- induced osteogenic program of C3H10T1/2 cells is not affected by HDAC4. Even though phosphorylation of HDAC4 affects its compartmentalization and the stemness of progenitor cells, we found that total HDAC4 and phosphorylated HDAC4 remain cytoplasmic under both osteogenic and nonosteogenic conditions. Collectively, this work demonstrates that, regardless of the nucleo-cytoplasmic presence of HDAC4, the Runx2-induced osteoblast differentiation program of C3H10T1/2 cells remains unaffected. Additionally, the ratjadone C-mediated nuclear retention assay can potentially be used as a screening tool to identify novel regulatory mechanisms of HDAC4 and its functional partners in various pathophysiological conditions.

The two genes lacZ1 and lacZ2 from Klebsiella pneumoniae 285, encoding β-galactosidase isoenzymes II and III (KpBGase-II and -III), were each cloned downstream of a T7 promoter for expression in Escherichia coli BL21(DE3), and the resulting recombinant enzymes were characterized in detail. The optimum temperature and pH value of KpBGase-II were 40 °C and 7.5, and those of KpBGase-III were 50 °C and 8.0, respectively. KpBGase-III was more stable than KpBGase-II at higher temperature (>60°C). Both β-galactosidases were more active towards o-nitrophenyl-β- D-galactopyranoside as compared to lactose. The enzymatic synthesis of lactulose and 1-lactulose catalyzed by KpBGase-II and KpBGase-III was investigated. Using 400 g/L lactose and 200 g/L fructose as substrates, the resulting lactulose and 1-lactulose yields with KpBGase-II were 6.2 and 42.3 g/L, while those with KpBGase-III were 5.1 and 23.8 g/L, respectively. KpBGase-II has a potential for the production of 1-lactulose from lactose and fructose. Like other β-galactosidases, the two isozymes catalyze the transgalactosylation in the presence of fructose establishing the β-(1→1) linkage.