Badr Abdullah Aldahmash

Photoperiod‐ and temperature‐mediated control of phenology in trees – a molecular perspective

Contents 511 I. 511 II. 512 III. 513 IV. 513 V. 517 VI. 517 VII. 521 VIII. 521 Acknowledgements 521 References 521 SUMMARY: Trees growing in boreal and temperate regions synchronize their growth with seasonal climatic changes in adaptive responses that are essential for their survival. These trees cease growth before the winter and establish a dormant state during which growth cessation is maintained by repression of responses to growth-promotive signals. Reactivation of growth in the spring follows the release from dormancy promoted by prolonged exposure to low temperature during the winter. The timing of the key events and regulation of the molecular programs associated with the key stages of the annual growth cycle are controlled by two main environmental cues: photoperiod and temperature. Recently, key components mediating photoperiodic control of growth cessation and bud set have been identified, and striking similarities have been observed in signaling pathways controlling growth cessation in trees and floral transition in Arabidopsis. Although less well understood, the regulation of bud dormancy and bud burst may involve cell-cell communication and chromatin remodeling. Here, we discuss current knowledge of the molecular-level regulation of the annual growth cycle of woody trees in temperate and boreal regions, and identify key questions that need to be addressed in the future.

Antioxidant effect of Arabic gum against mercuric chloride-induced nephrotoxicity

The effects of Arabic gum (AG) against nephrotoxicity of mercury (Hg), an oxidative-stress inducing substance, in rats were investigated. A single dose of mercuric chloride (5 mg/kg intraperitoneal injection) induced renal toxicity, manifested biochemically by a significant increase in serum creatinine, blood urea nitrogen, thiobarbituric acid reactive substances, and total nitrate/nitrite production in kidney tissues. In addition, reduced glutathione, glutathione peroxidase, and catalase enzymes in renal tissues were significantly decreased. Pretreatment of rats with AG (7.5 g/kg/day per oral administration), starting 5 days before mercuric chloride injection and continuing through the experimental period, resulted in a complete reversal of Hg-induced increase in creatinine, blood urea nitrogen, thiobarbituric acid reactive substances, and total nitrate/nitrite to control values. Histopathologic examination of kidney tissues confirmed the biochemical data; pretreatment of AG prevented Hg-induced degenerative changes of kidney tissues. These results indicate that AG is an efficient cytoprotective agent against Hg-induced nephrotoxicity by a mechanism related at least in part to its ability to decrease oxidative and nitrosative stress and preserve the activity of antioxidant enzymes in kidney tissues.

Biotin amelioration of nephrotoxicity in streptozotocin-induced diabetic mice

The current study was carried out to investigate the protective role of biotin in kidney injury and oxidative stress in diabetic mice type 1. Male Swiss albino mice were randomly divided into 3 groups. Control group received saline. Diabetes type 1 was induced in second and third groups by intraperitoneal injection of streptozotocin as a single dose (150 mg/kg). Second group remained as the untreated diabetic group and the third group received 15 mg/kg daily oral dose of biotin for 12 successive days. Biochemical results showed significant elevation in blood glucose and urea levels in both diabetic groups. Also, there is an increase in glomerular areas and decrease in glomerular cellularity in both diabetic groups. Histopathological results showed severe alterations in the untreated diabetic group represented by distorted glomeruli, inflammatory cells, and giant macrophages. In addition, there was an intense immune-reaction response toward acrolein indicator of oxidative damage. Upon biotin administration of diabetic mice, the above mentioned histopathological changes were reduced and also acroline reaction of oxidative damage was diminished. Our findings prove that biotin has a protective role against streptozotocin-induced oxidative damage in kidneys of laboratory mice.

Attenuation of hepatotoxicity and oxidative stress in diabetes STZ-induced type 1 by biotin in Swiss albino mice

Diabetes mellitus is one of the major health problems. This study was designed to investigate the effect of biotin to regulate blood glucose level, reduced toxicity and oxidative stress in liver of diabetic mice STZ-induced type 1. Male mice were divided into three groups, the first one served as the control group, the second and the third groups received single ip dose of 150 mg/kg of STZ, the second group served as the untreated diabetic group, the third group received daily oral dose of 15 mg/kg of biotin, livers and liver index showed insignificant difference among groups. Blood glucose level showed a significant decrease in treated diabetic mice compared to untreated diabetic mice. Biochemical analysis showed a significant decrease in liver enzymes AST and ALT compared to the control group. Histopathological examination showed severe changes in untreated diabetic liver tissue manifested by dilated portal vein, leukocytic infiltration, fatty degeneration and moderate to severe histopathological score, whereas, treated diabetic mice with biotin showed reduction in hepatotoxicity represented by appearance of relative healthy hepatocytes and normal histopathological score. Immunohistochemistry of acrolein showed intense immunoreactions in liver section of untreated diabetic mice and faint immunoreactions in treated diabetic mice with biotin as evidence to oxidative stress reduction.

Effect of corn oil, flaxseed oil and black seed oil on testicular damage induced by lead acetate in albino mice: A histological study

A such as Tetraethyl orthosilicate (TEOS) and trimethyl orthosilicate (TMOS) are expensive precursors to silicate-based sol-gel-derived bioactive glasses. Facile approaches involving low cost substitutes are desirable for bioactive glass implants in bone regeneration therapy. Quaternary system SiO2-Na2O-CaO-P2O5 bioactive glass was prepared by the sol-gel method from sand as precursor. The glass monolith was sintered at 950 oC, before carrying out immersion studies in simulated body fluid (SBF) for 28 days. The monolith was characterized by SEM-EDX, FTIR, XRD and compression testing. The surface morphology of the sintered monolith from SEM revealed prominent macropores with interconnected micropores and evidently dense pore struts. Porosity determined was about 82 %. After immersion the surface became heterogeneous showing agglomeration of hydroxyapatite. EDX analysis determined before and after immersion in SBF indicated an increase in Ca, P and C concentration with immersion time, attributed to the formation of carbonated hydroxyapatite (HCA). The Ca/P atomic ratio reached a value of 1.56 after immersion in SBF for 14 days tending towards 1.67 for non-stoichiometric hydroxyapatite. pH of the SBF gradually increased from 7.4 to 8.7 over the first 9 days. Result of the FTIR analysis gave bands at 872, 604 and 554 cm-1 diagnostic for HCA. Compression test indicated strength of 0.37 MPa which falls in range for cancellous bone. XRD analysis further confirmed presence of (HCA). The bioactive material obtained from locally sourced precursor in this study shows promising properties that can be explored as porous scaffold for bone repair. Luqman A. Adams, J Tissue Sci Eng 2013, 4:2 http://dx.doi.org/10.4172/2157-7552.S1.012

Seasonal variation effects on the composition of blood in Nubian ibex ( Capra nubiana ) in Saudi Arabia

The aim of this study was to investigate the effect of seasonal variation on the haematological and biochemical parameters in adult captive wild male Nubian ibex ( Capra nubiana ), a group of 20 Nubian ibex was selected for the study. Haemoglobin (Hb), glucose concentration (Glu), blood urea nitrogen (BUN), total proteins (TP), albumin (Alb), globulin (Glob), calcium (Ca), magnesium (Mg) and phosphorous (P) were studied. However, haemoglobin, glucose concentration, total plasma protein were higher during summer season, while BUN, albumin and globulin were higher in rainy season. On the other hand, calcium, magnesium, phosphorous did not show any significant alteration. Key words : Ibex, blood, haemoglobin, blood urea nitrogen (BUN), total plasma protein, albumin, globulin, calcium, phosphorus.

Effect of corn oil, flaxseed oil and black seed oil on lead acetate-induced hepatic tissue damage: A histological study

Lead is considered as one of the major environmental pollutants that continued to pose health hazards in animal and man in many parts of the world. The current study aimed to investigate the histological effects of corn oil, flaxseed oil and black seed oil against lead acetate-induced hepatic tissue damage in mice. Animals were divided into five groups. The first group served as a control group. The second group was inoculated with 20 mg/kg lead acetate. The third, fourth and fifth groups were inoculated with lead acetate then, treated with 1000 mg/kg of corn oil, flaxseed oil and black seed oil, respectively. At day 5 post-treatment, the liver sections were prepared for the histological study. Lead acetate induced severe hepatic tissue damage mainly in the form of inflammatory cellular infiltration, hepatocytic vacuolation and sinusoidal dilatation. Mice treated with corn oil for 5 days still have histopathological lesions. Both flaxseed oil and black seed oil could reduce the lead acetate-induced hepatic tissue damage.

Investigation of Antiulcer and Antioxidant Activity of Juniperus phoenicea L. (1753) Essential Oil in an Experimental Rat Model

Juniperus phoenicea is a tree of the Cupressaceae family that is popularly known in the south of Tunisia because of its wide application in herbal medicine, including the use of its leaves to treat many diseases such as diarrhea, rheumatism, and intestinal disorders. The aim of this study was to evaluate the ulceroprotective and antioxidant activity of essential oil extracted from the leaves of J. phoenicea (EOJp) against hydrogen chloride (HCl)/ethanol-induced ulcers in rats. The antiulcer activities of 50, 75 and 100 mg/kg body weight (b.w.) EOJp were investigated on 0.3 M HCl/ethanol-induced ulcers in rats. The essential oil yield was 0.69% with 48 compounds; α-pinene was the principal component (20.24%). In vivo pretreatment with EOJp given orally provided dose-dependent protection against HCl/ethanol-induced gastric ulcers in rats. Furthermore, pretreatment with EOJp significantly decreased malondialdehyde (MDA) content and increased the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). The activity of the antiulcerogenic EOJp could be from synergistic antioxidant and anti-secretory effects. Oral use of EOJp has excellent preventive effects on induced gastric ulcers comparable to those of the proton pump inhibitor (PPI) omeprazole.

Reno-protective effects of propolis on gentamicin-induced acute renal toxicity in swiss albino mice.

BACKGROUND Kidney is a vital organ which plays an important and irreplaceable role in detoxification and removal of xenobiotics. And therefore is vulnerable to develop various forms of injuries. Hence, making it immensely important to search for natural reno-protective compounds. OBJECTIVES This study therefore, aims to evaluate the reno-protective properties of propolis against gentamicin induced renal toxicity in mice. METHODS Three groups of 10 male mice each were used for this study. First group served as control, the second group (Gm group) was administered orally 80mg/kg body weight gentamicin for 7 days, and the third group (GmP group) was administered same dose of gentamicin with propolis (500mg/kg body weight) for 7 days. Various parameters were used to study the renal toxicity. RESULTS Gentamicin caused significant renal damage as evident by the rise in BUN levels, diminished glomeruli hypocellularity, moderately dilated tubules, and mild loss of brush border, severe infiltration, extensive tubular degeneration and presence of tubular cast. Histochemistry results show presence of collagen and reticular fibres. Immunohistochemical reactions show kidney injury (Kim-1 gene-expression), oxidative stress (MDA gene-expression), and an increase in apoptosis (caspase-3 gene-expression). Co-administration of propolis with gentamicin showed significant decrease in BUN levels, appearance of healthy glomeruli with normal cellularity, reduction of tubular injury, decrease of collagen and reticular fibres deposition, reduction of apoptosis, kidney injury and oxidative stress. CONCLUSION Results presented in this study clearly show the reno-protective role of propolis against gentamicin-induced toxicity on mice kidney.

Antioxidant effects of captopril against lead acetate-induced hepatic and splenic tissue toxicity in Swiss albino mice

Considering that lead caused a lot of health problems in the world, the present study was carried out to investigate the protective effect of captopril as antioxidants to reduce liver and spleen toxicity induced by lead. Animals were divided into 3 groups, the 1st group served as control group, the 2nd group received 20 mg/kg of lead acetate and the 3rd group received 50 mg/kg of captopril one hour prior to lead administration for 5 days. Results showed that lead intake caused severe alterations in the liver and spleen manifested by hepatocytes degeneration, leukocytic infiltration, fibrosis in liver and moderate to severe liver pathological score. Spleen showed ill-defined architecture, presence of large macrophages and lymphoid necrosis. Administration of captopril reduced hepatotoxicity, liver fibrosis and decrease in pathological scoring system. Moreover, reduced toxicity in spleen is represented by reduction in necrotic areas, more or less healthy lymphoid follicles and decreasing in pathological scoring system.