Olga Cvijanović

Berberine exerts nephroprotective effect against cisplatin-induced kidney damage through inhibition of oxidative/nitrosative stress, inflammation, autophagy and apoptosis.

The aim of this study was to investigate the therapeutic activity of isoquinoline alkaloid berberine against cisplatin (CP)-induced nephrotoxicity in mice. Berberine was administered at daily doses of 1, 2 and 3 mg/kg by gavage for two successive days, 48 h after intraperitoneal CP injection (13 mg/kg). Mice were sacrificed 24 h after the last dose of berberine. Histopathological changes and the increase in serum creatinine and blood urea nitrogen (BUN) induced by CP were significantly ameliorated by berberine in a dose-dependent manner. Additionally, oxidative/nitrosative stress, evidenced by the increase in renal 4-hydroxynonenal (4-HNE), 3-nitrotyrosine (3-NT), cytochrome P450 E1 (CYP2E1) and heme oxygenase (HO-1) expression, was significantly reduced. The expression of nuclear factor-kappaB (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was markedly suppressed by berberine, indicating the inhibition of inflammatory response. Treatment of CP-intoxicated animals with berberine also significantly reduced the expression of p53, active caspase-3 as well as autophagy marker light chain 3B (LC3B) in the kidneys. The results of the current study showed the nephroprotective activity of berberine against CP-induced renal injury, which could be attributed to the inhibition of oxidative/nitrosative stress, inflammation, autophagy and apoptosis.

Differential hepatoprotective mechanisms of rutin and quercetin in CCl 4 -intoxicated BALB/cN mice

Aim:To investigate the mechanisms underlying the protective effects of quercetin-rutinoside (rutin) and its aglycone quercetin against CCl4-induced liver damage in mice.Methods:BALB/cN mice were intraperitoneally administered rutin (10, 50, and 150 mg/kg) or quercetin (50 mg/kg) once daily for 5 consecutive days, followed by the intraperitoneal injection of CCl4 in olive oil (2 mL/kg, 10% v/v). The animals were sacrificed 24 h later. Blood was collected for measuring the activities of ALT and AST, and the liver was excised for assessing Cu/Zn superoxide dismutase (SOD) activity, GSH and protein concentrations and also for immunoblotting. Portions of the livers were used for histology and immunohistochemistry.Results:Pretreatment with rutin and, to a lesser extent, with quercetin significantly reduced the activity of plasma transaminases and improved the histological signs of acute liver damage in CCl4-intoxicated mice. Quercetin prevented the decrease in Cu/Zn SOD activity in CCl4-intoxicated mice more potently than rutin. However, it was less effective in the suppression of nitrotyrosine formation. Quercetin and, to a lesser extent, rutin attenuated the inflammation in the liver by down-regulating the CCl4-induced activation of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α) and cyclooxygenase (COX-2). The expression of inducible nitric oxide synthase (iNOS) was more potently suppressed by rutin than by quercetin. Treatment with both flavonoids significantly increased NF-E2-related factor 2 (Nrf2) and heme oxygenase (HO-1) expression in injured livers, although quercetin was less effective than rutin at an equivalent dose. Quercetin more potently suppressed the expression of transforming growth factor-β1 (TGF-β1) than rutin.Conclusion:Rutin exerts stronger protection against nitrosative stress and hepatocellular damage but has weaker antioxidant and anti-inflammatory activities and antifibrotic potential than quercetin, which may be attributed to the presence of a rutinoside moiety in position 3 of the C ring.

Rosmarinic acid ameliorates acute liver damage and fibrogenesis in carbon tetrachloride-intoxicated mice

The aim of this study was to investigate the therapeutic potential of rosmarinic acid (RA), a natural phenolic, in the treatment of acute liver toxicity. RA at 10, 25 and 50mg/kg was administered by gavage once daily for 2 consecutive days, 6h after CCl(4) intoxication. CCl(4) intoxication caused hepatic necrosis and increased serum ALT activity. In the livers, oxidative/nitrosative stress was evidenced by increased 3-nitrotyrosine (3-NT) and thiobarbituric acid reactive substances (TBARS) formation and a significant decrease in Cu/Zn superoxide dismutase (SOD) activity. CCl(4) administration triggered inflammatory response in mice livers by activating nuclear factor-kappaB (NF-κB), which coincided with the induction of tumor necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2). RA improved histological and serum markers of liver damage and significantly ameliorated oxidative/nitrosative stress and inflammatory response in liver tissue. Additionally, RA prevented transforming growth factor-beta1 (TGF-β1) and alpha-smooth muscle actin (α-SMA) expression, suggesting suppression of profibrotic response. Furthermore, RA significantly inhibited the CCl(4)-induced apoptosis, which was evident from decreased cleavage of caspase-3. The hepatoprotective activity of RA coincided with enhanced NF-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression. The results of this study indicates that RA possesses antioxidant, anti-inflammatory, antiapoptotic and antifibrotic activity against acute liver toxicity.

Myricitrin exhibits antioxidant, anti-inflammatory and antifibrotic activity in carbon tetrachloride-intoxicated mice

Myricetin-3-O-α-rhamnoside (myricitrin) is a naturally occurring phenolic compound which possesses antioxidant and anti-inflammatory activity. The aim of this study was to determine the hepatoprotective effects of myricitrin. Myricitrin at doses of 10, 30 and 100 mg/kg and silymarin at dose of 100mg/kg were administered to BALB/cN mice by oral gavage, once daily for two consecutive days following carbon tetrachloride (CCl4)-intoxication. Myricitrin significantly ameliorated CCl4-induced increase in serum aspartate transaminase (AST) and alanine transaminase (ALT) levels and histopathological changes in the liver. Hepatic oxidative stress was reduced by myricitrin, as evidenced by the decrease in lipid peroxidation, with concomitant increase in glutathione (GSH) level and cytochrome P450 2E1 (CYP2E1) expression. In addition, cyclooxygenase-2 (COX-2) and tumor necrosis factor-alpha (TNF-α) overexpression in the liver was reduced, suggesting the suppression of inflammation. The expression of transforming growth factor-beta1 (TGF-β1) and alpha-smooth muscle actin (α-SMA) was markedly ameliorated, indicating the inhibition of profibrotic response. Myricitrin also improved the regeneration of hepatic tissue after CCl4-intoxication, as evidenced by increased proliferating cell nuclear antigen (PCNA) expression. The results of the current study suggest that myricitrin exhibits a significant hepatoprotective activity. Myricitrin provided better hepatoprotection when compared to silymarin, which is consistent with its higher in vitro antioxidant potential.

Luteolin ameliorates cisplatin-induced nephrotoxicity in mice through inhibition of platinum accumulation, inflammation and apoptosis in the kidney

The aim of this study was to investigate the effects of flavone luteolin against cisplatin (CP)-induced kidney injury in mice. Luteolin at doses of 10mg/kg was administered intraperitoneally (ip) once daily for 3 days following single CP (10 or 20mg/kg) ip injection. Mice were sacrificed 24h after the last dose of luteolin. The CP treatment significantly increased serum creatinine and blood urea nitrogen and induced pathohistological changes in the kidneys. Renal oxidative/nitrosative stress was evidenced by decreased glutathione (GSH) levels and increased 3-nitrotyrosine (3-NT) and 4-hydroxynonenal (4-HNE) formation as well as cytochrome P450 2E1 (CYP2E1) expression. The CP administration triggered inflammatory response in mice kidneys through activation of nuclear factor-kappaB (NF-κB) and overexpression of tumor necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2). Simultaneously, the increase in renal p53 and caspase-3 expression indicated apoptosis of tubular cells. The administration of luteolin significantly reduced histological and biochemical changes induced by CP, decreased platinum (Pt) levels and suppressed oxidative/nitrosative stress, inflammation and apoptosis in the kidneys. These results suggest that luteolin is an effective nephroprotective agent, with potential to reduce Pt accumulation in the kidneys and ameliorate CP-induced nephrotoxicity.

Renoprotective mechanisms of chlorogenic acid in cisplatin-induced kidney injury

The aim of this study was to investigate the renoprotective activity of chlorogenic acid (CA) in a murine model of cisplatin (CP)-induced kidney injury. Male BALB/cN mice were gavaged daily with CA at 3, 10 and 30mg/kg for two successive days, 48h after intraperitoneal injection of CP (13mg/kg). On the fifth day, serum creatinine and blood urea nitrogen (BUN) levels were significantly increased in CP-intoxicated mice, which was recovered by CA. Renal oxidative stress, evidenced by increased 4-hydroxynonenal (4-HNE) expression, was significantly reduced with CA. Simultaneously, the overexpression of heme oxygenase 1 (HO-1) and cytochrome P450 E1 (CYP2E1) was attenuated. The inhibition of inflammatory response by CA was achieved through the reduction of tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) expression. Additionally, CA significantly suppressed p53, Bax active caspase-3, cyclin D1 and microtubule-associated protein 1 light chain 3 isoform B (LC3B) expression, suggesting the inhibition of both apoptosis and autophagy. The expression of multidrug resistance-associated proteins (Mrp1 and Mrp2) increased and organic cation transporter 2 (Oct2) decreased by CP, protecting the kidneys from nephrotoxicity by reducing the burden of tubular cells. CA dose-dependently restored Mrp1, Mrp2 and Oct2 expression. The recovery of kidney tissue form CP injury was accompanied by increased proliferating nuclear cell antigen (PCNA) expression. The results of this study suggest that CA attenuates CP-induced kidney injury through suppression of oxidative stress, inflammation, apoptosis and autophagy, with the improvement in kidney regeneration.

Age- and region-dependent changes in human lumbar vertebral bone: a histomorphometric study.

Study Design. Histomorphometric evaluation of autopsy material. Objectives. To explore region-dependent changes that occur with aging in trabecular and cortical bone of the human vertebral body. Summary of Background Data. Human vertebral bone is continuously subjected to external forces (loads) that promote changes in inner architecture. This functional adaptability is limited, however, and when lost, vertebral bone progressively deteriorates and becomes subject to injury with increases in mechanical loading. Methods. Bone cylinders were drilled with a trephine from three regions (central anterior, central posterior, and lateral) of the third lumbar vertebral bodies of 48 autopsy cases 31 to 76 years old. Two consecutive 5-&mgr;m sections obtained 150 &mgr;m apart were stained with toluidine blue and Masson trichrome and photographed at ×40. Differences in numerous morphometric factors were evaluated by age and region of the vertebra using repeated-measures analysis of variance and Tukey’s Honestly Significant Difference test. Results. Starting at about 50 years of age, significant, linearly progressive decreases occurred in trabecular and cortical bone volume (P < 0.005), trabecular surface area (P < 0.001), number of trabeculae (P < 0.001), and thickness of trabeculae (P < 0.001). Space between trabeculae increased from ages 31 to 70 years and then decreased (P < 0.001). Trabecular deterioration was significantly more pronounced in central versus lateral regions (P < 0.001). Cortical bone thickness decreased significantly with aging in central regions but increased in lateral regions between ages 61 and 70 years (P < 0.001). Conclusions. The balance between cortical and trabecular bone maintains the strength of the vertebral body until about the age of 50 years, when irreversible deterioration begins in central regions and subsequently involves lateral regions.

Hepatoregenerative role of bone morphogenetic protein-9

Summary Bone morphogenetic protein-9 (BMP-9) is a member of the transforming growth factor beta (TGF-β) superfamily of cytokines, which regulate cell growth and differentiation during embryogenesis. Apart of that, the hypoglycemic potential of BMP-9 is of great interest. It has been confirmed that BMP-9, like insulin, improves glycemia in diabetic mice and regulates directional glucose metabolism in hepatocytes; therefore it is proposed to be a candidate hepatic insulin-sensitizing substance (HISS). In liver fibrosis, due to the portocaval shunt, insulin bypasses the organ and the liver undergoes atrophy. Parenteral administration of insulin reverses atrophy by stimulating mitogenic activity of the hepatocytes. Because BMP-9 has a signaling pathway similar to other BMPs and insulin, it is to be expected that BMP-9 has a certain regenerative role in the liver, supporting the above-mentioned is evidence of BMP-9 expression in Dissè’s spaces and BMP-7’s mitogenic activity in mucosal cells. However, further studies are needed to confirm the possible regenerative role of BMP-9.

How activity of inflammatory bowel disease influences bone loss.

Bone loss is a common problem for individuals with inflammatory bowel disease (IBD). The aim of our study was to assess bone mineral density (BMD) in patients with IBD and to investigate the role of corticosteroid (CS) use and duration and activity of disease on BMD. Ninety-two patients (56 men and 36 women) with IBD, of whom 32 had ulcerative colitis (UC) and 60 had Crohns disease (CD), underwent clinical assessment. Lumbar and femoral neck BMDs were measured by dual-energy X-ray absorptiometry. Osteopenia was observed in 14 patients (43%) with UC and in 24 patients (40%) with CD (p=0.187). Four patients (12%) with UC and 7 patients (11%) with CD had osteoporosis (p=0.308). Femoral BMD decreased in patients with long duration of CS use and correlated inversely with disease activity. Multiple regression analysis of BMD showed that statistically significant risk factors were duration of active disease and body mass index as well. Based on our results, it is necessary to take into account the risk of decreased BMD in patients with IBD. It is most important to achieve disease remission as soon as possible in addition to nutritional support.

Vomiting as a reliable sign of concussion

Concussion is the most common type of traumatic brain injury, with headache being the most frequent symptom of mild traumatic brain injury (MTBI) (including dizziness, vomiting, nausea, lack of motor coordination or difficulty balancing). Concussion may be caused by a blow to the head, or by acceleration forces without a direct impact. Often, MTBI occurs as the result of a sports injury. Loss of consciousness is always present, unlike vomiting. Therefore, we hypothesize vomiting to be considered as a cardinal sign of concussion. Stimulation of vomiting centres finally triggers vomiting. Professional boxers and mixed martial arts competitions reluctantly agree with stringent rules and protective clothing. We discuss the issue of further protection for those engaged in these and other sports.