METHODS: Immunohistochemistry was performed on GCA temporal artery biopsy specimens (n = 12) and aortas (n = 10) for detection of YKL-40, its receptor interleukin-13 receptor α2 (IL-13Rα2), macrophage markers PU.1 and CD206, and the tissue-destructive protein matrix metalloproteinase 9 (MMP-9). Ten noninflamed temporal artery biopsy specimens served as controls. In vitro experiments with granulocyte-macrophage colony-stimulating factor (GM-CSF)- or macrophage colony-stimulating factor (M-CSF)-skewed monocyte-derived macrophages were conducted to study the dynamics of YKL-40 production. Next, small interfering RNA-mediated knockdown of YKL-40 in GM-CSF-skewed macrophages was performed to study its effect on MMP-9 production. Finally, the angiogenic potential of YKL-40 was investigated by tube formation experiments using human microvascular endothelial cells (HMVECs).
RESULTS: YKL-40 was abundantly expressed by a CD206+MMP-9+ macrophage subset in inflamed temporal arteries and aortas. GM-CSF-skewed macrophages from GCA patients, but not healthy controls, released significantly higher levels of YKL-40 compared to M-CSF-skewed macrophages (P = 0.039). In inflamed temporal arteries, IL-13Rα2 was expressed by macrophages and endothelial cells. Functionally, knockdown of YKL-40 led to a 10-50% reduction in MMP-9 production by macrophages, whereas exposure of HMVECS to YKL-40 led to significantly increased tube formation.
CONCLUSION: In GCA, a GM-CSF-skewed, CD206+MMP-9+ macrophage subset expresses high levels of YKL-40 which may stimulate tissue destruction and angiogenesis through IL-13Rα2 signaling. Targeting YKL-40 or GM-CSF may inhibit macrophages that are currently insufficiently suppressed by glucocorticoids.
METHODS: Different parts of the plants were subjected to sequential extraction method. Cytotoxicity of the extracts was determined by dimethylthiazol-2-yl)- 2,5diphenyl tetrazolium bromide (MTT) assay on 2 human cancer (colon and breast) and normal (endothelial and colon fibroblast) cells. Anti-angiogenic potential was tested using ex vivo rat aortic ring assay. DPPH (1,1-diphenyl-2-picrylhydrazyl) assay was conducted to screen the antioxidant capabilities of the extracts. Finally, total phenolic and flavonoid contents were estimated in the extracts using colorimetric assays.
RESULTS: The results indicated that out of 6 plants tested, 4 plants (Nicotiana glauca, Tephrosia apollinea, Combretum hartmannianum and Tamarix nilotica) exhibited remarkable anti-angiogenic activity by inhibiting the sprouting of microvessels more than 60%. However, the most potent antiangiogenic effect was recorded by ethanol extract of T. apollinea (94.62%). In addition, the plants exhibited significant antiproliferative effects against human breast (MCF-7) and colon (HCT 116) cancer cells while being non-cytotoxic to the tested normal cells. The IC50 values determined for C. hartmannianum, N. gluaca and T. apollinea against MCF-7 cells were 8.48, 10.78 and 29.36 μg/ml, respectively. Whereas, the IC50 values estimated for N. gluaca, T. apollinea and C. hartmannianum against HCT 116 cells were 5.4, 20.2 and 27.2 μg/ml, respectively. These results were more or less equal to the standard reference drugs, tamoxifen (IC50 = 6.67 μg/ml) and 5-fluorouracil (IC50 = 3.9 μg/ml) tested against MCF-7 and HCT 116, respectively. Extracts of C. hartmannianum bark and N. glauca leaves demonstrated potent antioxidant effect with IC50s range from 9.4-22.4 and 13.4-30 μg/ml, respectively. Extracts of N. glauca leaves and T apollinea aerial parts demonstrated high amount of flavonoids range from 57.6-88.1 and 10.7-78 mg quercetin equivalent/g, respectively.
CONCLUSIONS: These results are in good agreement with the ethnobotanical uses of the plants (N. glauca, T. apollinea, C. hartmannianum and T. nilotica) to cure the oxidative stress and paraneoplastic symptoms caused by the cancer. These findings endorse further investigations on these plants to determine the active principles and their mode of action.
HYPOTHESIS/PURPOSE: We hypothesized that LPva extracts can modulate the lipid profiles and serum antioxidant status of hypercholesterolemic rats. In the present study, we investigated the effects of aqueous and 80% ethanol extracts of LPva on atherogenic and serum antioxidant parameters as well as changes in abdominal aorta of high-cholesterol diet rats.
METHODS: The major components of the extracts, gallic acid, flavonoids and alkyl resorcinols were analyzed by using a validated reversed phase HPLC method. The rats were induced to hypercholesterolemic status with daily intake of 2% cholesterol for a duration of 8 weeks. Three different doses (100, 200 and 400mg/kg) of the extracts were administered daily on the 4th week onwards. The rats were then sacrificed and the blood was collected via abdominal aorta and serum was separated by centrifugation for biochemical analysis. Part of the aorta tissues were excised immediately for histopathological examination.
RESULTS: The serum of LPva treated rats showed significant reduction in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels and the abdominal aorta showed a significant decrease of atheroma lesions in treated rats. Serum lipid profiles of treated rats showed a decrease in total cholesterol, total triglycerides and low-density lipoprotein (LDL) levels as compared to control group. The atherogenic indices in treated rats were significantly improved along with an increasing level of serum high-density lipoprotein (HDL). The extracts also exhibited significant increase of antioxidant enzymes and decrease of MDA as a product of lipid peroxidation.
CONCLUSION: LPva extracts can reduce the risk of dyslipidemia by improving the serum lipid profiles and modulating serum antioxidants.
METHODS: Pharmacokinetics of KKA was studied after intravenous and oral administration in SD rats using HPLC. Anti-angiogenic efficacy of KKA was investigated in rat aorta, human endothelial cells (EA.hy926) and nude mice implanted with matrigel.
RESULTS: Pharmacokinetic study revealed that KKA was readily absorbed into blood and stayed for a long time in the body with Tmax 2.89 ± 0.12 h, Cmax 7.24 ± 0.36 μg/mL and T1/2 1.46 ± 0.03 h. The pharmacological results showed that KKA significantly suppressed sprouting of microvessels in rat aorta with IC50 18.4 ± 4.2 μM and demonstrated remarkable inhibition of major endothelial functions such as migration, differentiation and VEGF expression in endothelial cells. Further, KKA significantly inhibited vascularization in matrigel plugs implanted in nude mice.
CONCLUSIONS: The results indicate that bioabsorption of KKA from oral route was considerably efficient with longer retention in body than compared to that of the intravenous route. Further, improved antiangiogenic activity of KKA was recorded which could probably be due to its increased solubility and bioavailability. The results revealed that KKA inhibits angiogenesis by suppressing endothelial functions and expression of VEGF.
METHODS: C. nutans leaves was extracted with 50-100% ethanol or deionised water at 1% (w/v). Human umbilical veins endothelial cell (HUVEC) proliferation was examined using MTT assay. The in vitro anti-angiogenic effects of C. nutans were assessed using wound scratch, tube formation and transwell migration assays. The VEGF levels secreted by human oral squamous cell carcinoma (HSC-4) cell and HUVEC permeability were also measured. Besides, the rat aortic ring and chick embryo chorioallantoic membrane (CAM) assays, representing ex vivo and in vivo models, respectively, were performed.
RESULTS: The MTT assay revealed that water extract of C. nutans leaves exhibited the highest activity, compared to the ethanol extracts. Therefore, the water extract was chosen for subsequent experiments. C. nutans leaf extract significantly suppressed endothelial cell proliferation and migration in both absence and presence of VEGF. However, the water extract failed to suppress HUVEC transmigration, differentiation and permeability. C. nutans water extract also did not suppress HSC-4 cell-induced VEGF production. Importantly, C. nutans water extract significantly abolished the sprouting of vessels in aortic rings as well as in chick embryo CAM.
CONCLUSION: In conclusion, these findings reveal potential anti-angiogenic effects of C. nutans, providing new evidence for its potential application as an anti-angiogenic agent.
OBJECTIVE: To identify the bioactive proteins and evaluate their ability in cell proliferation and angiogenesis promotion.
MATERIAL AND METHODS: Freeze-Dried Water Extracts (FDWE) and Spray-Dried Water Extracts (SDWE) of C. striata were tested with MTT assay using EA.hy926 endothelial cell line and ex-vivo aortic ring assay. Later the proteins were fractionated and analysed using an LC-QTOF mass spectrometer. The data generated were matched with human gene database for protein similarity and pathway identification.
RESULTS: Both samples have shown positive cell proliferation and pro-angiogenic activity. Four essential proteins/genes were identified, which are collagen type XI, actin 1, myosin light chain and myosin heavy chain. The pathways discovered that related to these proteins are integrin pathway, Slit-Robo signalling pathway and immune response C-C Chemokine Receptor-3 signalling pathway in eosinophils, which contribute towards wound healing mechanism.
CONCLUSIONS: The results presented have demonstrated that C. striata FDWE and SDWE protein fractions contain bioactive proteins that are highly similar to human proteins and thus could be involved in the wound healing process via specific biological pathways.
EXPERIMENTAL APPROACH: 3H-deoxycytidine-labeled PGs (17 or 41 kDa) and 3H-deoxycytidine were administered intravenously to normal rats and streptozotocin-induced diabetic rats. The biodistribution of these compounds was determined over 24 h. Accumulation of PG in normal kidneys was also tracked using 5-(aminoacetamido) fluorescein (fluoresceinyl glycine amide)-labeled PG (PG-AF). To evaluate the potential of PGs in ferrying renal protective anti-oxidative stress compounds, the model drug 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF) was conjugated to 41 kDa PG to form PG-AEBSF. PG-AEBSF was then characterized and evaluated for intracellular anti-oxidative stress efficacy (relative to free AEBSF).
RESULTS: In the normal rat kidneys, 17 kDa radiolabeled PG (PG-Tr) presents a 7-fold higher, while 41 kDa PG-Tr shows a 15-fold higher renal accumulation than the free radiolabel after 24 h post injection. The accumulation of PG-AF was primarily found in the renal tubular tissues at 2 and 6 h after an intravenous administration. In the diabetic (oxidative stress-induced) kidneys, 41 kDa PG-Tr showed the greatest renal accumulation of 8-fold higher than the free compound 24 h post dose. Meanwhile, the synthesized PG-AEBSF was found to inhibit intracellular nicotinamide adenine dinucleotide phosphate oxidase (a reactive oxygen species generator) at an efficiency that is comparable to that of free AEBSF. This indicates the preservation of the anti-oxidative stress properties of AEBSF in the conjugated state.
CONCLUSION/IMPLICATIONS: The favorable accumulation property of 41 kDa PG in normal and oxidative stress-induced kidneys, along with its capabilities in conserving the pharmacological properties of the conjugated renal protective drugs, supports its role as a potential renal targeting drug carrier.