Bacteriostatic and Bactericidal Activities of Camel Lactoferrins Against Salmonella enterica Serovar Typhi

Probiotics and Antimicrobial Proteins - Lactoferrin is an iron-binding glycoprotein present in various secretions (e.g., milk, tears, saliva, pancreatic juice), which performs multiple functions,...     

Anticarcinogenic effect of brucine in diethylnitrosamine initiated and phenobarbital-promoted hepatocarcinogenesis in rats

We evaluated the effects of brucine on N-nitrosodiethylamine (DENA)-induced hepatocarcinogenesis in rats. Initiation of hepatocarcinogenesis was done by intraperitoneal injection of diethylnitrosamine (DENA) followed by promotion with phenobarbital. The rats were exposed to dietary brucine for 4 weeks prior to initiation, and the treatment was continued for 22 consecutive weeks. Brucine decreased the incidence, total number, multiplicity, size and volume of preneoplastic hepatic nodules in a dose-dependent manner. Administration of DENA induced hepatocellular carcinoma (HCC), as evidenced by changes in histopathological architecture, increased activity of cytochrome P450, decreased activity of glutathione Stransferase (GST) as well as decreased antioxidant status, enhanced lipid peroxidation, increased liver marker enzymes. Western blot analysis showed decreased expression of cyclin D1 and Bcl-2 with activation of caspase-3 and increased expression of Bax. Immunohistochemical demonstrated the decreased expression of the PCNA and VEGF. These results indicate that brucine prevents lipid peroxidation and hepatic cell damage and also protects the antioxidant system in DENA-induced hepatocarcinogenesis.     

Ursolic acid inhibits tumor angiogenesis and induces apoptosis through mitochondrial-dependent pathway in Ehrlich ascites carcinoma tumor

Ursolic acid (UA) is a pentacyclic triterpene naturally occurring in many plant foods. In the present study, we investigated anti-cancer activity of UA in vivo in Ehrlich ascites carcinoma (EAC) tumor. 15 × 10⁶ EAC cells were implanted intraperitoneally (i.p., ascitic tumor) and subcutaneous (s.c., solid tumor) in Swiss albino mice. Mice with established tumors received UA i.p. at 25, 50 and 100 mg/kg bw for 14 d in ascitic and 100 mg/kg bw in solid tumor for 30 d. On day 15, blood samples were collected for hematological assessment of hemoglobin (Hb%), RBCs, WBCs and PCV. Tumor volume, cell viability, angiogenic, anti-angiogenic, anti-inflammatory factors and antioxidant parameters were determined. Immunohistochemistry analysis for VEGF, iNOS, CD31, caspase-3 and Bax were also performed. UA significantly inhibited tumor growth, cell viability, in both ascites and solid tumor model in vivo (p < 0·001). The anti-angiogenic effects were accompanied with decreased VEGF, iNOS, TNF-α and increased IL-12 levels. UA at 100 mg/kg bw dose significantly increased SOD and CAT activity (p < 0.01). GSH and TBARS were increased as compared to control group (p < 0.001). Furthermore, UA increased total RBCs, WBCs as well as Hb% significantly (p < 0.05) compared to cyclophosphamide (CP). Histopathological examination of tumor cells in the treated group demonstrated signs of apoptosis with chromatin condensation and cell shrinkage. Decreased peritoneal angiogenesis showed the anti-angiogenic potential. UA downregulated VEGF & iNOS expression whereas bax and caspase-3 expressions were upregulated suggesting drug induced tumor cell apoptosis through activating the pro-apoptotic bcl-2 family and caspase-3 and downregulation of VEGF. The present study sheds light on the potent antitumor property of the UA and can be extended further to develop therapeutic protocols for treatment of cancer.     

Chronic psychosocial stress enhances long-term depression in a subthreshold amyloid-beta rat model of Alzheimer's disease

In addition to genetic aspects, environmental factors such as stress may also play a critical role in the etiology of the late onset, sporadic Alzheimer's disease (AD). The present study examined the effect of chronic psychosocial stress in a sub-threshold Aβ (subAβ) rat model of AD on long-term depression by two techniques: electrophysiological recordings of synaptic plasticity in anesthetized rats, and immunoblot analysis of memory- and AD-related signaling molecules. Chronic psychosocial stress was induced using a rat intruder model. The subAβ rat model of AD, which was intended to represent outwardly normal individuals with a pre-disposition to AD, was induced by continuous infusion of 160 pmol/day Aβ???? via a 14-day i.c.v. osmotic pump. Results from electrophysiological recordings showed that long-term depression evoked in stress/subAβ animals was significantly enhanced compared with that in animals exposed to stress or subAβ infusion alone. Molecular analysis of various signaling molecules 1 h after induction of long-term depression revealed an increase in the levels of calcineurin and phosphorylated CaMKII in groups exposed to stress compared with other groups. The levels of the brain-derived neurotrophic factor (BDNF) were significantly decreased in stress/subAβ animals but not in stress or subAβ animals. In addition, the levels of beta-site amyloid precursor protein cleaving enzyme were markedly increased in stress/subAβ. These findings suggest that chronic stress may accelerate the impairment of synaptic plasticity and consequently cognition in individuals 'at-risk' for AD.     

Punarnavine,an alkaloid from Boerhaavia diffusa exhibits anti-angiogenic activity via downregulation of VEGF in vitro and in vivo

Punarnavine, a quinolizidine alkaloid isolated from Boerhaavia diffusa is known to possess analgesic, anti-inflammatory, hepato-protective, immunomodulatory and anti-proliferative properties. However, its roles in tumor angiogenesis and the involved molecular mechanism are still unknown. Therefore, we examined its anti-angiogenic effects and mechanisms in vitro and in vivo. We examined the effect of punarnavine on VEGF-A expression by RT-PCR, Western blotting and ELISA. In vivo antiangiogenic activity was determined using sponge implant angiogenesis assay and antitumor activity was evaluated against Ehrlich ascites carcinoma tumor. Punarnavine significantly inhibited endothelial cell migration and invasion and capillary structure formation of HUVECs. Punarnavine significantly at 50 μM inhibited MMP-2 and MMP-9 expression in HUVECs in vitro. Punarnavine inhibited neovascularization in sponge implant assay. Punarnavine (15 mg/kg bw/d) treatment showed dose-dependent decrease in the ascitic fluid volume by 60.94% and tumor volume by 86.40% in Ehrlich ascites model. Reduction in peritoneal angiogenesis with punarnavine treatment suggests the anti-angiogenic activity of punarnavine. The present study sheds light on the potent anti-angiogenic of the punarnavine and can be extended further to develop therapeutic protocols for treatment of cancer.     

Assessment of genomic instability in normal and diabetic rats treated with metformin

To examine if a single or multiple oral administration of metformin, a member of the biguanide class of anti-diabetic agents, has any genotoxic and cytotoxic potential in normal and diabetic rats, a mammalian model, cytogenetic assays through several endpoints such as induction of micronuclei, chromosome aberrations, mitotic activity of bone marrow cells, sperm-head anomaly and assays of some oxidative stress markers have been conducted by the use of standard techniques. Diabetes was induced by streptozotocin injection. Metformin was administrated to both diabetic and non-diabetic rats in single doses of 100, 500 or 2500 mg/kg along with vehicle control groups for diabetic and non-diabetic rats. The animals were killed by cervical dislocation at 24 h after treatment, and then bone marrow cells were sampled. Also, a multiple dose study has done in which diabetic and non-diabetic animals were treated with 100 or 500 mg/kg of metformin daily for 4 or 8 weeks after which the animals were killed by cervical dislocation, and then bone marrow and sperm cells were collected. Concurrent control groups were also included in each experiment. The obtained results revealed that metformin was neither genotoxic nor cytotoxic for the rats in all groups at all tested doses. Moreover, metformin significantly reduced the diabetes-induced genomic instability and cell proliferation changes in somatic and germinal cells in a dose-dependent manner (2500, 500, >100 mg/kg). In addition, diabetes induced marked biochemical alterations characteristic of oxidative stress including, enhanced lipid peroxidation and reduction in the reduced glutathione level. Treatment with metformin ameliorated these biochemical markers. In conclusion, metformin is a non-genotoxic or cytotoxic compound and may protect from genomic instability induced by hyperglycemia. Apart from its well-known anti-diabetic effect, the antigenotoxic effect of metformin could be possibly ascribed to its radical scavenger effect that modulated the genomic instability responses and cell proliferation changes induced by hyperglycemia.     

Cryopreservation of dog semen: the effects of Equex STM paste on plasma membrane fluidity and the control of intracellular free calcium

Understanding cryoinjury of dog spermatozoa is crucial to preserving fertilizing ability. This study examined flow cytometric indicators of sperm function to explore the reported benefits of Equex STM paste. The motility of cryopreserved spermatozoa immediately and 1h after thawing was higher in the extender containing 0.5% Equex; no significant differences between the two extenders were observed regarding viability, acrosomal integrity and intracellular Ca(2+) concentration. The proportion of spermatozoa having high membrane fluidity increased significantly post-thawing. The interaction between time after thawing and treatment was significant for plasma membrane fluidity. Dilution in a commercial diluent for transport before processing caused a significant increase in intracellular Ca(2+), which may affect functional survival. No significant difference with or without Equex was detected in plasma membrane fluidity. However, a significant interaction between Equex and dogs was detected. A significant decrease in intracellular Ca(2+) was detected in the live cell population both after dilution in Andersen's buffer and again after cooling and equilibration. One hour post-thaw, the proportion of live spermatozoa with high calcium concentration increased to a similar proportion as that seen in diluted semen; the interaction between diluent and dog was significant. The results suggest that Equex in the diluent benefited motility after cryopreservation. Live spermatozoa with high intracellular Ca(2+) after cryopreservation seem to have a favoured survival in the first hour after thawing. Nevertheless, survival after cryopreservation was severely compromised, explaining the relatively poor fertility of cryopreserved dog semen.