Mihir Y. Parmar

Protective effect of naringenin on acetic acid-induced ulcerative colitis in rats

AIM To evaluate the ameliorative effect of naringenin (NG) during ulcerative colitis (UC) in rats. METHODS Rats were treated with three different doses (25, 50 and 100 mg/kg per day) of NG and a single dose of mesalazine (MES, 300 mg/kg per day) for seven days prior to ulcerative colitis induction by 4% acetic acid (AA). Twenty four hours after AA rectal administration, animals were scarified and the colonic tissues were dissected. Colonic mucus content was estimated using Alcian blue dye binding technique. In colon tissues, levels of total glutathione sulphadryls (T-GSH), non-protein sulphadryls (NP-SH) and thiobarbituric acid reactive substances (TBARS) were evaluated. The activities of the antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD) were measured. Concentrations of nucleic acids (DNA and RNA) and total protein were also estimated in colon tissues. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO) were estimated. In cross section of colitis tissue the histopathological changes were observed. RESULTS Colonic mucus content was decreased in AA compared to controls (587.09 ± 65.59 mg/kg vs 941.78 ± 68.41 mg/kg, P < 0.001). AA administration markedly reduced T-GSH (5.25 ± 0.37 nmol/L vs 3.04 ± 0.24 nmol/L, P < 0.01), NP-SH (3.16 ± 0.04 nmol/L vs 2.16 ± 0.30 nmol/L, P < 0.01), CAT (6.77 ± 0.40 U/mg vs 3.04 ± 0.2 U/mg, P < 0.01) and SOD (3.10 ± 0.11 U/mg vs 1.77 ± 0.18 U/mg, P < 0.01) while TBARS, TNF-α, IL-1β, IL-6, PGE2 and NO levels (15.09 ± 3.84 nmol/L vs 59.90 ± 16.34 nmol/L, P < 0.01; 113.56 ± 1.91 pg/mg vs 134.24 ± 4.77 pg/mg, P < 0.01; 209.20 ± 36.38 pg/mg vs 422.19 ± 31.47 pg/mg, P < 0.01; 250.83 ± 25.09 pg/mg vs 638.58 ± 115.9 pg/mg, P < 0.01; 248.19 ± 36.98 pg/mg vs 541.74 ± 58.34 pg/mg, P < 0.01 and 81.26 ± 2.98 mmol/g vs 101.90 ± 10.73 mmol/g, P < 0.001) were increased in colon of rats with UC compared controls respectively.Naringenin supplementation, significantly and dose dependently increased the colonic mucus content. The elevated TBARS levels were significantly decreased (39.35 ± 5.86 nmol/L, P < 0.05; 26.74 ± 3.17 nmol/L, P < 0.01 nmol/L and 17.74 ± 2.69 nmol/L, P < 0.01) compared to AA (59.90 ± 16.34 nmol/L) group while the decreased levels of T-GSH and NP-SH and activities of CAT and SOD found increased by NG treatments in dose dependent manner. The decreased values of nucleic acids and total protein in AA group were also significantly (P < 0.01) increased in all three NG supplemented groups respectively. NG pretreatment inhibited the TNF-α levels (123.76 ± 3.76 pg/mg, 122.62 ± 3.41 pg/mg and 121.51 ± 2.61 pg/mg vs 134.24 ± 4.78 pg/mg, P < 0.05) compared to AA group, respectively. Interleukins, IL-1β and IL-6 levels were also decreased in NG50 + AA (314.37 ± 16.31 pg/mg and 292.58 ± 23.68 pg/mg, P < 0.05) and NG100 + AA (416.72 ± 49.62 pg/mg and 407.96 ± 43.87 pg/mg, P < 0.05) when compared to AA (352.46 ± 8.58 pg/mg and 638.58 ± 115.98 pg/mg) group. Similar decrease (P < 0.05) was seen in PGE2 and NO values when compared to AA group. The group pretreated with MES, as a reference drug, showed significant (P < 0.01) protection against the changes induced in colon tissue by AA administration respectively. CONCLUSION In present study, NG produced antioxidant and anti-inflammatory effects demonstrating protective effect in inflammatory bowel disease.

Alleviating effects of morin against experimentally-induced diabetic osteopenia

BackgroundPlant flavonoids are emerging as potent therapeutic drugs effective against a wide range of aging diseases particularly bone metabolic disorders. Morin (3,5,7,20,40-pentahydroxyflavone), a member of flavonols, is an important bioactive compound by interacting with nucleic acids, enzymes and protein. The present study was designed to investigate the putative beneficial effect of morin on diabetic osteopenia in rats.MethodsStreptozotocin (STZ)-induced diabetic model was used by considering 300 mg/dl fasting glucose level as diabetic. Morin (15 and 30 mg/kg) was treated for five consecutive weeks to diabetic rats. Serum levels of glucose, insulin, deoxypyridinoline cross links (DPD), osteocalcin (OC), bone specific alkaline phosphatase (BALP), telopeptides of collagen type I (CTX), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), thiobarbituric acid reactive substance (TBARS) and reduced glutathione (GSH) were estimated. Femoral bones were taken for micro CT scan to measure trabecular bone mineral density (BMD) and other morphometric parameters.ResultsSignificant bone loss was documented as the level of bone turnover parameters including DPD, OC, BALP and CTX were increased in serum of diabetic rats. Morin treatment significantly attenuated these elevated levels. Bone micro-CT scan of diabetic rats showed a significant impairment in trabecular bone microarchitecture, density and other morphometric parameters. These impairments were significantly ameliorated by morin administration. Serum levels of glucose, TBARS, IL-1β, IL-6 and TNF-α were significantly elevated, while the level of insulin and GSH was decreased in diabetic rats. These serum changes in diabetic rats were bring back to normal values after 5 weeks morin treatment.ConclusionThese findings revealed the protective effect of morin against diabetic induced osteopenia. We believed that this effect is through its both the anti-inflammatory and antioxidant properties.

Naringenin neutralises oxidative stress and nerve growth factor discrepancy in experimental diabetic neuropathy

Abstract Objectives: Present study aims to investigate the ameliorative effects of naringenin (NG) on experimentally induced diabetic neuropathy (DN) in rats. Methods: Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). Naringenin (25 and 50 mg/kg/day) treatment was started 2 weeks after the diabetes induction and continued for five consecutive weeks. Pain threshold behaviour tests were performed at the end of the treatment. Serum levels of glucose, insulin and pro-inflammatory cytokines were assessed. In sciatic tissues, markers oxidative stress, cytokines and neurotrophic factors were measured. Results: NG treatments showed significant decrease in paw-withdrawal (P < 0.01) and tail-flick latency (P < 0.01). The drug attenuated the diabetic-induced changes in serum glucose, insulin and pro-inflammatory cytokines including tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interleukin-6 (IL-6). In sciatic nerve, the diabetic-induced alterations in interleukins and oxidative stress biomarkers were significantly attenuated by NG. Decreased sciatic expressions of insulin growth factor (IGF) and nerve growth factor (NGF) in diabetic rats were also ameliorated by NG. Diabetes-induced dysregulated levels of nitric oxide (NO), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) were ameliorated by NG. Histological analysis showed that NG corrected the altered sciatic changes in diabetic animals. Discussion: We suggest that neuro-protective effect of NG molecules in sciatic nerve of diabetic rats, through its anti-diabetic as well as antioxidant and anti-inflammatory properties.

Myrrh attenuates oxidative and inflammatory processes in acetic acid-induced ulcerative colitis

The pathogenesis of ulcerative colitis (UC) has been associated with a weakened antioxidant capacity and increased inflammatory processes. Myrrh is traditionally used for the treatment of inflammatory diseases due to its antioxidant and anti-inflammatory properties. The present study aimed to evaluate the effects of myrrh on an experimental rat model of UC. UC was induced in rats using acetic acid (AA) after pre-treatment with myrrh (125, 250 or 500 mg/kg/day) or mesalazine (MES; 300 mg/kg/day) for 7 days. The levels of various inflammatory cytokines, prostaglandin E2 (PGE2) and nitric oxide (NO) in the rat colon tissues were assessed. In addition, the colonic levels of thiobarbituric acid reactive substances (TBARS) and non-protein sulfhydryl groups (NP-SH), as well as the activities of superoxide dismutase (SOD) and catalase (CAT), were estimated. Furthermore, total protein (TP) contents and the levels of DNA and RNA were measured, and histopathological changes in colonic tissues were analyzed. The results indicated that the levels of pro-inflammatory cytokines, PGE2, NO and TBARS were markedly increased. By contrast, the levels of interleukin-10, NP-SH, TP and nucleic acids, and the enzymatic activities of SOD and CAT were significantly decreased in the AA model group. In addition, pretreatment with myrrh and MES was able to attenuate the impaired oxidative stress response and upregulation of inflammatory biomarkers. Furthermore, the enzymatic activities of SOD and CAT were near to normal in the myrrh and MES pretreated groups. The ability of myrrh to protect against UC was further confirmed by histopathological analysis, and the high dose of myrrh exerted an effect comparable to MES. In conclusion, the results of the present study suggested that myrrh has potent therapeutic value in the amelioration of experimental colitis in laboratory animals by downregulating the expression of proinflammatory mediators and improving endogenous antioxidative activities.

Carvedilol Attenuates Inflammatory Biomarkers and Oxidative Stress in a Rat Model of Ulcerative Colitis

Preclinical Research

Protective effect of lutein supplementation on oxidative stress and inflammatory progression in cerebral cortex of streptozotocin-induced diabetes in rats

Oxidative stress and inflammation are deemed to play a vital role in diabetic cerebral and neurological dysfunction. The present study was designed to investigate the protective effect of the naturally occurring antioxidant, lutein, against oxidative injury and inflammation in cerebral cortex (CCT) of diabetic animals. Using single IP injection of streptozotocin (STZ, 65 mg/kg) diabetes was induced in rats. Lutein dietary supplement was provided to diabetic animals for 5 consecutive weeks in three different doses. The extent of lipid peroxidation and cellular damage were estimated in CCT. Endogenous antioxidants molecules such as non-protein sulfhydryl groups (NP-SH) and enzymes including superoxide dismutase (SOD) and catalase (CAT) were also estimated in CCT. Levels of neurotrophic factors such as brain derived nerve factor (BDNF), nerve growth factor (NGF) and insulin growth factor (IGF) and pro-inflammatory cytokines, as markers for neural inflammation, were assessed in CCT. Lutein dietary supplement, significantly inhibited the diabetes induced increased in CCT levels of thiobarbituric acid reactive substances (TBARS), caspase-3, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6. Diabetes caused inhibition in the levels of NP-SH, DNA and RNA was significantly increased following lutein dietary supplementation to diabetic group compared to normal diet fed animals in dose dependent manner. Diabetes induced down regulation of BDNF, NGF and IGF was also attenuated by lutein dietary supplementation to diabetic model for 5 weeks. These findings suggest that lutein has the potential to ameliorate diabetes-induced oxidative and inflammatory damage and neural degeneration in the CCT.