Lipid-lowering property of Clausena anisum-olens in hypercholesterolemic rats

Context: Clausena anisum-olens (Blanco) Merr. (Rutaceae) is a medicinal shrub which has been reported to have various pharmacological uses. No study regarding the effects of C. anisum-olens on cholesterol-lowering has been reported.

Objective: The effects of the ethanol extract of C. anisum-olens leaves on the cholesterol level of hypercholesterolemic rats were evaluated.

Materials and methods: Acute oral toxicity of the extract (175, 550 and 2000?mg/kg) was determined using female Sprague-Dawley rats, as described in OECD 425 Main test guidelines. The lipid-lowering assay utilized 30 male Sprague-Dawley rats divided into five groups (A–E). Triton X-100 was administered to induce hypercholesterolemia. After hypercholesterolemia induction, oral treatment of Atorvastatin and crude ethanol extract was given daily to the treatment groups for 14 days. The total cholesterol, triglycerides, HDL and LDL were determined before induction, after induction, after first week of treatment and after second week of treatment.

Results: Acute oral toxicity showed the crude extract is nontoxic up to 2000?mg/kg. The lipid-lowering assay indicated reduction of serum cholesterol (87.21?±?5.10?mg/dL), triglycerides (58.09?±?4.10?mg/dL) and LDL (27.82?±?4.11?mg/dL) for 200?mg/kw extract. Reduction in serum cholesterol (74.72?±?3.64?mg/dL), triglycerides (52.79?±?2.98?mg/dL) and LDL (12.06?±?5.51?mg/dL) were observed for 400?mg/kg group. The result is comparable to Atorvastatin, which showed serum cholesterol (80.90?±?9.72?mg/dL), triglycerides (55.94?±?7.19?mg/dL) and LDL (22.09?±?7.60?mg/dL) reduction.

Discussion and conclusion: The crude extract of C. anisum-olens proved to be useful in lowering of cholesterol.     

Appraisal of anti-arthritic and nephroprotective potential of Cuscuta reflexa

Context: Cuscuta reflexa Roxb. (Cuscutaceae) has been used traditionally for treating sore knees and kidney problems, but its efficacy has not been scientifically examined in treating arthritis and nephrotoxicity.

Objective: Present study determines antiarthritic and nephroprotective potential of the aqueous methanolic extract of Cuscuta reflexa (AMECR).

Materials and methods: Antiarthritic activity of Cuscuta reflexa in formaldehyde and turpentine oil-induced rat arthritis models was appraised at 200, 400 and 600?mg/kg doses for 10 days and 6?h period, respectively, and in vitro protein denaturation (bovine serum albumin, egg albumin) inhibition was studied at 25–800?μg/mL concentration. The nephroprotective effect involved gentamicin-induced nephrotoxicity in rats at 200, 400 and 600?mg/kg doses.

Results: Plant extract at 600?mg/kg significantly reduced paw oedema and joint swelling with maximal inhibition of 71.22% at the 6th hour for turpentine oil and 76.74% on 10th day for formaldehyde. Likewise, in vitro results corroborated significant concentration-dependent increase in percentage protection at 800?μg/mL against both bovine serum albumin (89.30%) and egg albumin (93.51%) denaturation. Similarly, 600?mg/kg dose showed maximum nephroprotection by reducing serum urea (41.400?±?0.510?mg/dL), uric acid (0.740?±?0.032?mg/dL), blood urea nitrogen (18.370?±?0.328), creatinine (3.267?±?0.076) and minimizing kidney weight gain (0.586?±?0.005) and histopathological alterations on 8th day. Furthermore, phytochemical and HPLC analysis revealed the presence of important phytoconstituents.

Discussion and conclusions: These results suggest that AMECR provides protection against arthritis and nephrotoxicity that might be due to the existence of phytoconstituents, thus supporting folkloric claim.     

Effect of pramlintide as an adjunct to basal insulin on markers of cardiovascular risk in patients with type 2 diabetes

ABSTRACT

Objective: Intensification of insulin therapy in patients with type 2 diabetes, while improving glycemic control, often leads to an increase in body weight and other markers of cardiovascular risk. The effects of pramlintide as an adjunct to basal insulin titration (without mealtime insulin) on glycemia and cardiovascular risk markers were examined.

Research design and methods: This was a post hoc analysis of a 16-week, double-blind, placebo-controlled study in patients with type 2 diabetes (N?=?211) using insulin glargine (without mealtime insulin)?±?oral agents. Patients were randomized to treatment with placebo or pramlintide (60 or 120?µg with major meals), and insulin glargine was titrated to target a fasting plasma glucose concentration of ≥70 to <100?mg/dL.

Main outcome measures: Endpoints included the change from baseline to Week 16 in body weight, high sensitivity C-reactive protein (hsCRP), triglycerides, HDL, LDL, and blood pressure.

Results: Pramlintide-treated patients lost weight and placebo-treated patients gained weight during 16 weeks of treatment (?1.6?±?0.3?kg vs. +0.7?±?0.3?kg, p?<?0.001; mean?±?SE). hsCRP was reduced in pramlintide-treated versus placebo-treated patients (?0.8?±?0.2?mg/L vs. 0.1?±?0.2?mg/L, p?<?0.01; mean?±?SE). Patients with baseline hsCRP?>?3?mg/L (high cardiovascular risk) demonstrated greater hsCRP reductions with pramlintide versus placebo treatment at Week 16 (p?<?0.05). Patients with baseline triglycerides ≥150?mg/dL or ≥200?mg/dL (high cardiovascular risk) showed significant reductions from baseline in triglyceride concentrations with pramlintide (?43?±?14?mg/dL or ?59?±?19?mg/dL; p?<?0.05; mean?±?SE) but not with placebo (1?±?29?mg/dLor ?3?±?54?mg/dL; mean?±?SE). No significant differences between pramlintide and placebo were observed for changes in HDL, LDL, or blood pressure. Pramlintide treatment was generally well tolerated. The most frequent adverse event related to pramlintide was mild-to-moderate nausea (31% pramlintide vs. 10% placebo). Pramlintide added to basal insulin did not increase the incidence of hypoglycemia. A limitation of the study was its relatively short duration.

Conclusions: Pramlintide, as an adjunct to basal insulin, was associated with improvements in several cardiovascular risk markers, warranting long-term clinical studies to determine its potential effects on cardiovascular risk.     

Beneficial effect of Citrus limon peel aqueous methanol extract on experimentally induced urolithic rats

Context: Citrus limon (L.) Burm.f. (Rutaceace) is a commonly available fruit variety with high medicinal and industrial values.

Objective: Lemon peel (LP) extract was studied as a potent preventive and curative agent for experimentally induced hyperoxaluric rats.

Materials and methods: Gas chromatography–mass spectrometry (GC–MS) analyses and toxicity study were performed for aqueous methanol LP extract. Twenty-four Wistar rats were segregated into four groups. Group 1: Control; Group 2: Urolithic (ethylene glycol (EG) – 0.75%); Group 3: Preventive study (EG?+?LP extract administration from 0th to 7th week); Group 4: Curative study (EG?+?LP extract administration from 4th to 7th week). Animals received LP extract daily by oral administration (100?mg/kg body weight) for 7 weeks.

Results and discussion: GC–MS analyses revealed that compound 6 was abundant in the LP extract (32%) followed by compound 1 (～21%). The LD₅₀ value of LP extract was found to be >5000?mg/kg of body weight. Urolithic rats showed significantly higher urinary calcium and oxalate (4.47?±?0.44 and 18.86?±?0.55?mg/24 h, respectively) excretion compared with control and experimental rats. Renal function parameters like urea (84?±?8.5 and 96.1?±?3.6?mg/dL), creatinine (1.92?±?0.27 and 1.52?±?0.22?mg/dL), and urinary protein (2.03?±?0.02 and 2.13?±?0.16?mg/24 h) were also reduced by LP extract (p?<?0.001) and corroborated with tissue analyses (SOD, catalase, and MDA levels) and histological studies in normal and experimental animals. Immunohistochemical staining of THP and NF-κB in urolithic animals showed elevated expression than the control, while LP extract suppressed the expression of these proteins.

Conclusion: In conclusion, lemon peel is effective in curing kidney stone disease and also can be used to prevent the disease and its recurrence.     

Prevention of arsenic-mediated reproductive toxicity in adult female rats by high protein diet

Abstract

Context: The detrimental effects of arsenic on female reproductive functions may involve overt oxidative stress. Casein and pea [Pisum sativum Linn. (Fabaceae)] proteins have antioxidant properties.

Objective: To investigate the role of casein- and pea-supplemented high-protein diet (HPD) in utero-ovarian protection from arsenic toxicity.

Materials and methods: Adult female Wistar rats were orally gavaged with vehicle (Gr-I) or arsenic at 3?ppm/rat/d (Gr-II and Gr-III) for 30 consecutive days, when they were maintained on either regular diet containing 18% protein (Gr-I and Gr-II), or HPD containing 27% protein in the form of casein (20%) and pea (7%) (Gr-III). Reproductive functions were evaluated using a battery of biochemical and histological techniques.

Results: As compared to Gr-I, the Gr-II rats suffered from loss of estrous cyclicity, reduction in weight (mg/100?g body weight) of ovary (Gr-I: 54.3?±?4.2 versus Gr-II: 35.8?±?1.6; p?<?0.001) and uterus (Gr-I: 161.7?±?24.6 versus Gr-II: 94.44?±?13.2; p?<?0.05), utero-ovarian degeneration, attenuated ovarian activities (unit/mg tissue/h) of Δ⁵, 3β-hydroxysteroid dehydrogenase (Gr-I: 3.41?±?0.12 versus Gr-II: 2.31?±?0.09; p?<?0.01) and 17β-hydroxysteroid dehydrogenase (Gr-I: 3.82?±?0.57 versus Gr-II: 1.24?±?0.19; p?<?0.001), and decreased serum estradiol level (pg/ml) (Gr-I: 61.5?±?2.06 versus 34.1?±?2.34; p?<?0.001). Ovarian DNA damage was preponderant with blatant generation of malondialdehyde (nM/mg tissue; Gr-I: 15.10?±?2.45 versus Gr-II: 29.51?±?3.44; p?<?0.01) and attenuated superoxide dismutase activity (unit/mg tissue) (Gr-I: 2.18?±?0.19 versus Gr-II: 1.33?±?0.18; p?<?0.05). The Gr-III rats were significantly protected from these ill effects of arsenic.

Discussion and conclusion: HPD, by way of antioxidant properties, may find prospective role in the protection of reproductive damage caused by arsenic.     

Protective effect of curcumin against myocardium injury in ischemia reperfusion rats

Context: Curcumin has long been used as a condiment and a traditional medicine worldwide.

Objective: The current study investigates the possible protective effect of curcumin on heart function in myocardium ischemia-reperfusion (MIR) rats.

Materials and methods: We fed Sprague–Dawley (SD) rats (10 in each group) either curcumin (10, 20 or 30?mg/kg/d) or saline. Twenty days later, the rats were subjected to myocardial injuries by ligating the left anterior descending coronary artery (60?min), and subsequently, the heart (3?h) reperfused by releasing the ligation. Then, lipid profile, lipid peroxidation products, antioxidant enzymes and gene expression were assessed in myocardium tissue.

Results: Only the rats that were supplemented with curcumin (10, 20 or 30?mg/kg/d) showed significant (p?Discussion and conclusion: Curcumin intake might reduce the risk of coronary heart disease by stimulating JAK2/STAT3 signal pathway, decreasing oxidative damage and inhibiting myocardium apoptosis.     

GC-MS analysis and hepatoprotective activity of the n-hexane extract of Acrocarpus fraxinifolius leaves against paracetamol-induced hepatotoxicity in male albino rats

Context: In Egypt, the burden of liver diseases is exceptionally high.

Objective: To investigate the components of the n-hexane extract of Acrocarpus fraxinifolius Arn. (Leguminosae) and its hepatoprotective activity against paracetamol (APAP)-induced hepatotoxicity in rats.

Material and methods: TRACE GC ultra gas chromatogaphic spectrometry was used for extract analysis. Thirty albino rats were divided into six groups (five rats in each). Group 1 was the healthy control; Groups 2 and 3 were healthy treated groups (250 and 500?mg/kg b.w. of the extract, respectively) for seven days. Group 4 was hepatotoxicity control (APAP intoxicated group). Groups 5 and 6 received APAP?+?extract 250 and APAP?+?extract 500, respectively.

Results: Chromatographic analysis revealed the presence of 36 components. Major compounds were α-tocopherol (18.23%), labda-8 (20)-13-dien-15-oic acid (13.15%), lupeol (11.93%), phytol (10.95%) and squalene (7.19%). In the acute oral toxicity study, the mortality rates and behavioural signs of toxicity were zero in all groups (doses from 0 to 5?g/kg b.w. of A. fraxinifolius). LD₅₀ was found to be greater than 5?g/kg of the extract. Only the high dose (500?mg/kg b.w.) of extract significantly alleviated the liver relative weight (4.01?±?0.06) and biomarkers, as serum aspartate aminotransferase (62.87?±?1.41), alanine aminotransferase (46.74?±?1.45), alkaline phosphatase (65.96?±?0.74), lipid profiles (180.39?±?3.51), bilirubin profiles (2.30?±?0.06) and hepatic lipid peroxidation (114.20?±?2.06), and increased body weight (11.58?±?0.20), serum protein profile (11.09?±?0.46) and hepatic total antioxidant capacity (23.78?±?0.66) in APAP-induced hepatotoxicity in rats.

Conclusion: Our study proves the antihepatotoxic/antioxidant efficacies of A. fraxinifolius hexane extract.     

Crataegus Aronia protects and reverses vascular inflammation in a high fat diet rat model by an antioxidant mechanism and modulating serum levels of oxidized low-density lipoprotein

Context: Crataegus aronia (Willd.) Bosc (Rosaceae) (syn. Azarolus L) is traditionally used to treat cardiovascular disorders.

Objectives: To investigate C. aronia protection against a high-fat diet (HFD)-induced vascular inflammation in rats.

Materials and methods: Wistar Male rats (180–220?g) were divided (n?=?10/group) as control fed a standard diet (STD), STD + C. aronia (200?mg/kg, orally), HFD, HFD + C. aronia and HFD post-treated with C. aronia. Simvastatin (20?mg/kg) was co- or post-administered as a positive control drug. HFD was given for 8?weeks, and all other treatments were administered for 4?weeks.

Results: Most significantly, co-administration of C. aronia to HFD-fed rats reduced the thickness of aorta tunica media (90?±?5 vs. 160?±?11.3?µm) and adventitia (54.3?±?3.8 vs. 93.6?±?9.4?µm). It also lowered protein levels of TNF-α (0.51?±?0.15 and 0.15?±?0.16 vs. 0.1?±?0.09%) and IL-6 (0.52?±?0.19 vs. 1.0?±?0.2%) in their aorta or serum (5.9?±?0.91 vs. 12.98?±?1.3?ng/mL and 78.1?±?6.7 vs. 439?±?78?pg/mL, respectively). It also lowered all serum lipids and increased aorta levels of GSH levels (70.4?±?4.0 vs. 40.7?µM) and activity of SOD (5.7?±?0.7 vs. 2.9?±?0.6?U/mg) and decreased serum levels of ox-LDL-c (566.7?±?46 vs. 1817?±?147?ng/mL). Such effects were more profound than all other treatments.

Conclusions: C. aronia inhibits the HFD-induced vascular inflammation and its use in clinical trials is recommended.     

Epigallocatechin-3-gallate counters cisplatin toxicity of rat testes

Context: Epigallocatechin-3-gallate (EG), the main active flavonoid in green tea, has well-known anti-inflammatory, antioxidant, and anti-apoptotic activities.

Objective: The EG protection against testicular injury induced by cisplatin was studied in Sprague–Dawley rats.

Materials and methods: Cisplatin (10?mg/kg, i.p) was given as a single injection to rats. EG was given at 40 and 80?mg/kg/day, i.p., for 5 days, starting the same day of cisplatin insult. Serum testosterone, and testicular malondialdehyde, total antioxidant status, nitric oxide, interleukin-6, interleukin-1β, cytochrome C, Bax/Bcl-2 ratio, and caspase-3 were measured. In addition, testicular histopathological examination and immunohistochemical expression of testicular tumour necrosis factor-α were evaluated.

Results: Cisplatin, compared to the control, significantly decreased serum testosterone (6.48?±?0.7 vs. 50.8?±?4.91?ng/10?mL), and testicular tissue antioxidant status (17.3?±?1.21 vs. 64.12?±?5.4?μmol/g), and significantly increased interleukin-6 (85.81?±?6.11 vs. 38.2?±?2.79?pg/100?mg), interleukin-1β (98.09?±?8.31 vs. 32.52?±?2.08?pg/100?mg), malondialdehyde (74.5?±?5.88 vs. 23.8?±?1.91?nmol/g), nitric oxide (104.98?±?8.5 vs. 52.68?±?5.12?nmol/100?mg), cytochrome C (5.97?±?0.33 vs. 1.6?±?0.99?ng/mg protein), Bax/Bcl-2 ratio (4.01?±?0.38 vs. 0.71?±?0.0), and caspase-3 (3.2?±?0.21 vs. 0.98?±?0.08?O.D. 405?nm) in rat testes. EG (40 and 80?mg/kg, respectively) caused significant increases of serum testosterone (33.9?±?2.89 and 47.88?±?4.4?ng/10?mL), and testicular antioxidant status (47.1?±?3.92 and 58.22?±?3.58?μmol/g), and significant decreases of interleukin-6 (57.39?±?4.2 and 48.18?±?3.98?pg/100?mg), interleukin-1β (65.12?±?5.88 and 41.96?±?3.51?pg/100?mg), malondialdehyde (42.3?±?3.9 and 28.67?±?2.49?nmol/g), nitric oxide (70.6?±?6.79 and 61.31?±?5.18?nmol/100?mg), cytochrome C (3.4?±?0.27 and 2.21?±?0.18?ng/mg protein), Bax/Bcl-2 ratio (1.49?±?0.14 and 1.1?±?0.09), and caspase-3 (2.1?±?0.17 and 1.48?±?0.13?O.D. 405?nm) in testes of cisplatin-treated rats. Additionally, both doses of EG significantly ameliorated the histopathological injury and reduced tumour necrosis factor-α expression in rat testes.

Conclusion: EG can afford testicular protection in cisplatin-challenged rats by its antioxidant, antinitrative, anti-inflammatory and antiapoptotic effects.     

Curcumin suppresses inflammatory cytokines and heat shock protein 70 release and improves metabolic parameters during experimental sepsis

Context: Curcumin has been reported to have anti-inflammatory, antioxidant and hypoglycaemic properties, besides reducing mortality in sepsis.

Objective: This study evaluates the biological activities of a curcumin dispersion formulated by spray-drying in experimental sepsis.

Materials and methods: Male Wistar rats were subjected to sepsis by caecal ligation and puncture (CLP), controls were sham operated. The animals were treated with curcumin dispersion (100?mg/kg, p.o.) or water for 7 days prior to CLP and at 2?h after surgery. One group was used to analyze curcumin absorption through HPLC; another had the survival rate assessed during 48?h; and from a third group, blood was collected by decapitation to analyze metabolic and inflammatory parameters.

Results: The plasma curcumin levels reached 2.5?ng/mL at 4?h, dropped significantly (p?p?p?p?p?p?Discussion and conclusion: Our results show that the curcumin dispersion dose employed was not detrimental to the septic rats. In fact, it temporarily increased their survival rate, improved important metabolic parameters, reduced proinflammatory cytokines and HSP70 production.     

Antidiabetic,antihyperlipidaemic, and antioxidant activity of Syzygium densiflorum fruits in streptozotocin and nicotinamide-induced diabetic rats

Context Syzygium densiflorum Wall. ex Wight & Arn (Myrtaceae) has been traditionally used by local tribes of the Nilgiris, Tamil Nadu, India, for the treatment of diabetes, however, no definitive experimental studies are available.

Objective This study investigates the antidiabetic, antihyperlipidaemic and antioxidant activities of ethanol extract of S. densiflorum (EFSD) fruits in streptozotocin (STZ) and nicotinamide (NA)-induced diabetic rats.

Materials and methods Acute oral toxicity and oral glucose tolerance were assessed in normal rats. The antidiabetic, antihyperlipidaemic and antioxidant activities were investigated in STZ???NA-induced diabetic rats. Diabetic rats were orally administered with glibenclamide (10?mg/kg b.wt), EFSD (200, 400 and 800?mg/kg b.wt) for 28 d. Further, changes in the blood glucose level (BGL), biochemical parameters, antioxidants were observed and histology of pancreas was performed.

Results No toxicity and lethality were observed. Results of the following parameters are represented by treated versus disease control (STZ?+?NA) groups. BGL (161.33?±?22.8 versus 476.17?±?56.58?mg/dl), glycosylated haemoglobin (5.285?±?0.19 versus 8.05?±?0.55%), urea (40.32?±?1.96 versus 75.37?±?2.91?mg/dl), uric acid (1.2?±?0.07 versus 2.16?±?0.05?mg/dl), total cholesterol (89.3?±?5.14 versus 139.7?±?5.95?mg/dl) and triglycerides (79.65?±?2.52 versus 108.9?±?3.61?mg/dl) were significantly decreased, whereas haemoglobin (11.75?±?0.73 versus 7.95?±?0.42?g/dl), high‐density lipoprotein cholesterol (14.2?±?1.11 versus 6.97?±?0.84?mg/dl), total protein (45%) and liver glycogen (87%) were significantly increased in EFSD-treated diabetic group. Significant changes were observed in the enzymatic and non-enzymatic antioxidants in EFSD-treated groups (p?<?0.001). Histopathological examination showed the regeneration of β-cells in Islets of Langerhans.

Conclusion This study confirms the antidiabetic, antihyperlipidaemic and antioxidant activities of S. densiflorum fruits.     

Effects of rosmarinic acid on acetaminophen-induced hepatotoxicity in male Wistar rats

Context: Drug-induced liver injury is a significant worldwide clinical problem. Rosmarinic acid (RA), a natural phenol, has antioxidant effects.

Objective: The effects of RA against acetaminophen (N-acetyl-p-amino-phenol (APAP))-induced oxidative damage and hepatotoxicity in rats were investigated.

Materials and methods: Male Wistar rats were pretreated with RA (10, 50 and 100?mg/kg, i.g.) for one week. On day 7, rats received APAP (500?mg/kg, i.p.). Then aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, total protein, malondialdehyde (MDA), glutathione (GSH), total antioxidant capacity (TAC), glutathione S-transferase (GST), cytochrome CYP450 and histopathological changes were determined.

Results: APAP-induced oxidative stress in liver by a significant increase in the level of MDA (7.6?±?0.21?nmol/mg) as well as a decrease in the contents of TAC (1.75?±?0.14?μmol/g), GSH (1.9?±?0.22?μmol/g) and GST) 3.2?±?0.28?U/mg). RA treatment decreased MDA (4.32?±?0.35?nmol/mg) but increased the contents of TAC (3.51?±?0.34?μmol/g), GSH (3.42?±?0.16?μmol/g) and GST (5.71?±?0.71?μmol/g) in APAP group. RA 100?mg/kg decreased ALT (91.5?±?1.5?U/L), AST (169?±?8.8?U/L) and CYP450 (3?±?0.2?nmol/min/mg) in APAP group. Histologically RA attenuated hepatic damage by decreasing necrosis, inflammation, and haemorrhage in liver sections of APAP group.

Discussion and conclusions: This is the first report that oral administration of RA dose-dependently elicited significant hepatoprotective effects in rats through inhibition of hepatic CYP2E1 activity and lipid peroxidation. RA-protected hepatic GSH and GST reserves and total tissue antioxidant capacity.     

Galangin,a dietary flavonoid,ameliorates hyperglycaemia and lipid abnormalities in rats with streptozotocin-induced hyperglycaemia

Context: Galangin, a natural flavonoid, is found in honey and Alpinia officinarum Hance (Zingiberaceae). Galangin has antiviral, antimicrobial, antidiabetic and anticancer properties, without side effects. The effects of galangin on hyperglycaemia and lipid abnormalities are not known.

Objective: To elucidate the effectiveness of galangin on hyperglycaemia-associated complications and lipid changes in rats with streptozotocin (STZ)-induced hyperglycaemia.

Materials and methods: Diabetes was induced in adult Wistar rats by administering 40?mg/kg of STZ. In our previous study, galangin had no toxicity at concentrations up to 320?mg/kg. Therefore three doses of galangin (4, 8 or 16?mg/kg BW) or glibenclamide (600 µg/kg BW) were administered daily to diabetic rats orally for 45 days.

Results: Diabetic rats showed a significant (p?p?p?Discussion and conclusions: Administration of galangin reduced hyperlipidaemia related to the risk of diabetic complications and could be beneficial for diabetic hyperlipidaemic patients. Further work detailing its mechanism-of-action for improving hyperglycaemic-associated lipid abnormalities is needed.     

Hesperidin,a citrus flavonoid,protects against l-methionine-induced hyperhomocysteinemia by abrogation of oxidative stress,endothelial dysfunction and neurotoxicity in Wistar rats

Context: Hesperidin (HSP), a flavanoglycone found in citrus fruits, has antioxidant, anti-inflammatory and neuroprotective properties.

Objective: This study evaluates the protective effect of HSP on l-methionine-induced hyperhomocysteinemia (HHcy) in rats.

Materials and methods: Male Wistar rats were randomly divided into seven groups as DMSO, l-methionine, HSP (25, 50 and 100?mg/kg), HSP-per se (100?mg/kg) and donepezil (0.1?mg/kg). HHcy was induced by oral administration of l-methionine (1.7?g/kg) for 32 days. From the 14^th day of study HSP (25, 50 and 100?mg/kg) and donepezil was administered orally to l-methionine-treated rats. Cognitive impairment induced by HHcy was determined using the Morris water maze (MWM) and Y-maze on video tracking system (28^th–32^nd day). Different biomarkers of HHcy in serum and brain and vascular reactivity were evaluated and histopathology (thoracic aorta and brain) was done.

Results: HSP (100?mg/kg) treatment in l-methionine-treated rats exhibited significant (p?p?l-methionine on acetylcholine-induced endothelial-dependent relaxation and increased serum nitrite and vascular nitric oxide bioavailability along with the restoration of histological aberrations.

Conclusion: HSP exerts a protective effect on HHcy by abrogating oxidative stress, ED and neurotoxicity.     

Amelioration of hyperglycaemia and modulation of antioxidant status by Alcea rosea seeds in alloxan-induced diabetic rats

Context: Alcea rosea L. (Malvaceae) has various medicinal uses including anticancer, anti-inflammatory and analgesic properties. However, there is no report on its antidiabetic activity.

Objective: Alcea rosea seed extracts were evaluated for antihyperglycaemic and antioxidative potential in diabetic rats.

Materials and methods: Single intra-peritoneal injection of alloxan (130?mg/kg b.w.) was used for induction of diabetes in Albino Wistar rats. Antihyperglycaemic and antioxidant activities of methanol and aqueous extracts of Alcea rosea seed (100 and 300?mg/kg b.w.), administered orally on daily basis for 15 days, were assessed in vivo for fasting blood glucose level and antioxidant status of liver and pancreas. Metformin was used as a positive control.

Results: Aqueous and methanol extracts (300?mg/kg b.w.) decreased blood glucose level in diabetic rats by 24% and 46%, respectively. Administration of aqueous and methanol extracts at 300?mg/kg b.w. significantly (p?2O₂ decomposed/min/mg of protein), respectively. Similar results were observed for pancreas.

Discussion and conclusions: Antihyperglycaemic and antioxidative potentials of Alcea rosea seeds suggest its usefulness in management of diabetes and its complications. This is the first report on antidiabetic activity of this plant.     

Effects of exenatide versus sitagliptin on postprandial glucose,insulin and glucagon secretion,gastric emptying,and caloric intake: a randomized,cross-over study

ABSTRACT

Background: This study evaluated the effects of exenatide, a GLP-1 receptor agonist, and sitagliptin, a DPP-4 inhibitor, on 2-h postprandial glucose (PPG), insulin and glucagon secretion, gastric emptying, and caloric intake in T2D patients.

Methods: This double-blind, randomized cross-over, multi-center study was conducted in metformin-treated T2D patients: 54% female; BMI: 33?±?5?kg/m²; HbA_1c: 8.5?±?1.2%; 2-h PPG: 245?±?65?mg/dL. Patients received exenatide (5?µg BID for 1 week, then 10?µg BID for 1 week) or sitagliptin (100?mg QAM) for 2 weeks. After 2 weeks, patients crossed-over to the alternate therapy. Postprandial glycemic measures were assessed via standard meal test; caloric intake assessed by ad libitum dinner (subset of patients). Gastric emptying was assessed by acetaminophen absorption (Clinicaltrials.gov Registry Number: NCT00477581).

Results: After 2 weeks of therapy, 2-h PPG was lower with exenatide versus sitagliptin: 133?±?6?mg/dL versus 208?±?6?mg/dL, p?<?0.0001 (evaluable, N?=?61). Switching from exenatide to sitagliptin increased 2-h PPG by +73?±?11?mg/dL, while switching from sitagliptin to exenatide further reduced 2-h PPG by ?76?±?10?mg/dL. Postprandial glucose parameters (AUC, C_ave, C_max) were lower with exenatide than sitagliptin (p?<?0.0001). Reduction in fasting glucose was similar with exenatide and sitagliptin (?15?±?4?mg/dL vs. ?19?±?4?mg/dL, p?=?0.3234). Compared to sitagliptin, exenatide improved the insulinogenic index of insulin secretion (ratio exenatide to sitagliptin: 1.50?±?0.26, p?=?0.0239), reduced postprandial glucagon (AUC ratio exenatide to sitagliptin: 0.88?±?0.03, p?=?0.0011), reduced postprandial triglycerides (AUC ratio exenatide to sitagliptin: 0.90?±?0.04, p?=?0.0118), and slowed gastric emptying (acetaminophen AUC ratio exenatide to sitagliptin: 0.56?±?0.05, p?<?0.0001). Exenatide reduced total caloric intake compared to sitagliptin (?134?±?97?kcal vs. +130?±?97?kcal, p?=?0.0227, N?=?25). Common adverse events with both treatments were mild to moderate in intensity and gastrointestinal in nature.

Conclusions: Although this study was limited by a 2-week duration of exposure, these data demonstrate that, exenatide had: (i) a greater effect than sitagliptin to lower postprandial glucose and (ii) a more potent effect to increase insulin secretion and reduce postprandial glucagon secretion in T2D patients. In contrast to sitagliptin, exenatide slowed gastric emptying and reduced caloric intake. These key findings differentiate the therapeutic actions of the two incretin-based approaches, and may have meaningful clinical implications.     

The protective effect of qiancao naomaitong mixture on neuronal damage and cerebral ischemia/reperfusion injury

Context Qiancao Naomaitong Mixture (QNM) is mainly used to treat ischemic stroke patients in the clinic.

Objective This study evaluates the protective effect of QNM on neuronal damage in vitro, and clarifies the underlying mechanism against cerebral ischemia-reperfusion (I/R) injury in vivo.

Materials and methods Activity assay of caspase 3 (C-3) and caspase 8 (C-8) were measured with microplate reader and cell apoptosis was investigated. Cerebral I/R injury was induced by MCAO model. QNM groups were given at 0.27, 0.54 and 1.08?mL/100?g body weight. The weight ratio of cerebral infarction tissue was obtained. The cytokine levels in serum and brain tissue were measured using ELISA.

Results Compared with the OGD group (C-3: 29.69?±?5.63, C-8: 74.05?±?6.86), 100?mg/mL QNM (C-3: 19.80?±?2.62, C-8: 48.94?±?6.41) and 200?mg/mL QNM (C-3: 16.28?±?4.55, C-8: 41.08?±?4.05) treatments decreased C-3 and C-8 activities significantly, and inhibited apoptosis of SH-SY5Y cells. The weight ratios of cerebral tissues in low, medium and high dose groups were 17.33?±?5.1%, 17.78?±?5.4% and 14.25?±?4.2%, respectively, significantly lower than in control group. QNM also improved the cytokine levels in serum and brain tissue. In addition, histological examination indicated that dense neuropil and largely surviving neurons were seen in treated rats.

Conclusion QNM exerted protective effect by inhibiting the cell apoptosis in vitro. The protective mechanisms of QNM were associated with its properties of anti-apoptosis and antioxidation as well as improved neuronal nutrition in I/R rats.     

Effects of Piper nigrum extracts: Restorative perspectives of high-fat diet-induced changes on lipid profile,body composition,and hormones in Sprague–Dawley rats

Abstract

Context: Piper nigrum Linn (Piperaceae) (PnL) is used in traditional medicine to treat gastric ailments, dyslipidemia, diabetes, and hypertension.

Objective: The present study explores the possible protective effects of P. nigrum extracts on high-fat diet-induced obesity in rats.

Materials and methods: High-fat diet-induced obese rats were treated orally with 200?mg/kg bw of different extracts (hexane, ethylacetate, ethanol, and aqueous extracts) of PnL for 42?d. The effects of PnL extracts on body composition, insulin resistance, biochemical parameters, leptin, adiponectin, lipid profile, liver marker enzymes, and antioxidants were studied.

Results and discussion: The HFD control group rats showed a substantial raise in body weight (472.8?±?9.3?g), fat% (20.8?±?0.6%), and fat-free mass (165.9?±?2.4?g) when compared with normal control rats whose body weight, fat%, and fat-free mass were 314.3?±?4.4?g, 6.4?±?1.4%, and 133.8?±?2.2?g, respectively. Oral administration of ethyl acetate or aqueous extracts of PnL markedly reduced the body weight, fat%, and fat-free mass of HFD-fed rats. In contrast to the normal control group, a profound increase in plasma glucose, insulin resistance, lipid profile, leptin, thiobarbituric acid reactive substance (TBARS), and the activities of lipase and liver marker enzymes, and a decrease in adiponectin and antioxidant enzymes were noted in HFD control rats. Administration of PnL extracts to HFD-induced obese rats significantly (p?<?0.05) restored the above profiles.

Conclusion: PnL extracts significantly reduced the body weight, fat%, and ameliorated HFD-induced hyperlipidemia and its constituents.     

Anti-inflammatory effects of curcumin are associated with down regulating microRNA-155 in LPS-treated macrophages and mice

Context: The natural polyphenolic compound curcumin has been proved to modulate innate immune responses and possess anti-inflammatory properties. Nevertheless, the mechanism remains poorly understood, particularly regarding curcumin-regulated miRNAs under inflammatory response.

Objective: This study investigates the role of miRNA-155 in the effects of curcumin on inflammatory response in cell and a mouse model.

Materials and methods: The anti-inflammatory activity of curcumin (5, 10 and 15?μM, 2?h) in lipopolysaccharide (LPS, 200?ng/mL)-induced cells were measured by quantitative PCR. The animals were treated orally by 20?mg/kg curcumin for 3?days before an LPS intraperitoneal injection (10?mg/kg, 16?h). MicroRNA (miRNA) expression and the underlying molecular mechanisms were assessed using transfection technique and western blotting.

Results and discussion: Curcumin efficiently inhibited LPS-induced cytokines (TNF-α, IL-6) and microRNA-155 (miR-155) expression (p?50 21.8 and 22.3?μM at 48?h, respectively). Moreover, the levels of cytokines were suppressed by curcumin in miR-155 mimics transfected cells (p?p?p?Conclusions: Curcumin’s ability to suppress LPS-induced inflammatory response may be due to the inhibition of miR-155.     

Beneficial effects of tyrosol on altered glycoprotein components in streptozotocin-induced diabetic rats

Context: Olive oil is the major source of tyrosol which is a natural phenolic antioxidant. Olive oil constitutes a major component of the Mediterranean diet that is linked to a reduced incidence of chronic diseases.

Objective: This study evaluates the effects of tyrosol on altered glycoprotein components in streptozotocin-induced diabetic rats.

Materials and methods: Diabetes mellitus was induced in male Wistar rats by streptozotocin (40?mg/kg body weight). These rats were administered tyrosol (20?mg/kg body weight) and glibenclamide (600?μg/kg body weight) orally daily for 45?days. Plasma glucose, plasma insulin, glycoprotein components such as hexose, hexosamine, sialic acid and fucose in the plasma, liver and kidney, and histopathogy of tissues were analyzed.

Results: Diabetic rats revealed significant (p?p?p?in vitro study revealed the antioxidant effect of tyrosol.

Discussion and conclusions: Thus, tyrosol protects streptozotocin-induced diabetic rats from the altered glycoprotein components. Further, this study can be extrapolated to humans.