Nusrat Subhan

Effect of citrus flavonoids, naringin and naringenin, on metabolic syndrome and their mechanisms of action

Flavonoids are important natural compounds with diverse biologic activities. Citrus flavonoids constitute an important series of flavonoids. Naringin and its aglycone naringenin belong to this series of flavonoids and were found to display strong anti-inflammatory and antioxidant activities. Several lines of investigation suggest that naringin supplementation is beneficial for the treatment of obesity, diabetes, hypertension, and metabolic syndrome. A number of molecular mechanisms underlying its beneficial activities have been elucidated. However, their effect on obesity and metabolic disorder remains to be fully established. Moreover, the therapeutic uses of these flavonoids are significantly limited by the lack of adequate clinical evidence. This review aims to explore the biologic activities of these compounds, particularly on lipid metabolism in obesity, oxidative stress, and inflammation in context of metabolic syndrome.

Hydroxycinnamic acid derivatives: A potential class of natural compounds for the management of lipid metabolism and obesity

Hydroxycinnamic acid derivatives are important class of polyphenolic compounds originated from the Mavolanate-Shikimate biosynthesis pathways in plants. Several simple phenolic compounds such as cinnamic acid, p-coumaric acid, ferulic acid, caffeic acid, chlorgenic acid, and rosmarinic acid belong to this class. These phenolic compounds possess potent antioxidant and anti-inflammatory properties. These compounds were also showed potential therapeutic benefit in experimental diabetes and hyperlipidemia. Recent evidences also suggest that they may serve as valuable molecule for the treatment of obesity related health complications. In adipose tissues, hydroxycinnamic acid derivatives inhibit macrophage infiltration and nuclear factor κB (NF-κB) activation in obese animals. Hydroxycinnamic acid derivatives also reduce the expression of the potent proinflammatory adipokines tumor necrosis factor-α (TNFα), monocyte chemoattractant protein-1 (MCP-1), and plasminogen activator inhibitor type-1 (PAI-1), and they increase the secretion of an anti-inflammatory agent adiponectin from adipocytes. Furthermore, hydroxycinnamic acid derivatives also prevent adipocyte differentiation and lower lipid profile in experimental animals. Through these diverse mechanisms hydroxycinnamic acid derivatives reduce obesity and curtail associated adverse health complications.

Bioactivity of Excoecaria agallocha

The results of neuropharmacological, microbiological and toxicological studies on the ethanol extract of the bark of Excoecaria agallocha are reported. The extract (100 and 200 mg/kg dosages) was found to produce a profound decrease in exploratory activity in a dose-dependent manner. It also showed a marked sedative effect as evidenced by a significant reduction in gross behaviour and potentiation of sodium thiopental-induced sleeping time. The totality of these effects showed that the extract possesses depressant action on the central nervous system (CNS). The extract of E. agallocha exhibited significant in vitro antibacterial activity against Staphylococcus aureus, Shigella dysenteriae, Shigella sonnei and Enterococci with the zones of inhibition ranging from 11 to 15 mm. While the extract showed considerable brine shrimp toxicity (LD50 = 20 mg/mL), it displayed only low level of toxicity in mice.

HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

PURPOSE Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. METHODS Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power and total antioxidant capacity expressed as equivalent to ascorbic acid were employed. Moreover, phenolic compounds were detected by high-performance liquid chromatography (HPLC) coupled with diode-array detection. RESULTS The methanol extract showed significant free radical scavenging activities in DPPH radical scavenging antioxidant assays compared to the reference antioxidant ascorbic acid. Total antioxidant activity was increased in a dose dependent manner. The extract also showed strong reducing power. The total phenolic content was determined as 190.97 mg/g of gallic acid equivalent. HPLC coupled with diode-array detection was used to identify and quantify the phenolic compounds in the extracts. Gallic acid, (+)-catechin, rutin hydrate and quercetin have been identified in the plant extracts. Among the phenolic compounds, catechin and rutin hydrate are present predominantly in the extract. The accuracy and precision of the presented method were corroborated by low intra- and inter-day variations in quantitative results in leaves extract. CONCLUSION These results suggest that phenolic compounds and flavonoids might contribute to high antioxidant activities of Gardenia jasminoides leaves.

Beneficial Role of Bitter Melon Supplementation in Obesity and Related Complications in Metabolic Syndrome

Diabetes, obesity, and metabolic syndrome are becoming epidemic both in developed and developing countries in recent years. Complementary and alternative medicines have been used since ancient era for the treatment of diabetes and cardiovascular diseases. Bitter melon is widely used as vegetables in daily food in Bangladesh and several other countries in Asia. The fruits extract of bitter melon showed strong antioxidant and hypoglycemic activities in experimental condition both in vivo and in vitro. Recent scientific evaluation of this plant extracts also showed potential therapeutic benefit in diabetes and obesity related metabolic dysfunction in experimental animals and clinical studies. These beneficial effects are mediated probably by inducing lipid and fat metabolizing gene expression and increasing the function of AMPK and PPARs, and so forth. This review will thus focus on the recent findings on beneficial effect of Momordica charantia extracts on metabolic syndrome and discuss its potential mechanism of actions.

Antidiarrhoeal property of the hydroethanolic extract of the flowering tops of Anthocephalus cadamba

The antidiarrhoeal property of the hydroethanolic extract of the flowering tops of Anthocephalus cadamba was assessed on experimental animals. The dry hydroethanolic extract (250-500 mg/kg body mass, p.o.) exhibited a dose-dependent decrease in the total number of faecal droppings in castor oil-induced diarrhoea in mice. The extract also produced a significant (p < 0.01) and dose-dependent reduction in intestinal fluids accumulation and in the gastrointestinal transit from 64.59 % and 71.19% at doses of 250 and 500 mg/kg. The reduction rates were 37.85% and 74.91%, respectively, with the control and standard drug group.

Antinociceptive and anti-inflammatory properties of Ruellia tuberosa

The ethanol extract of Ruellia tuberosa L. (Acanthaceae) was evaluated for its antinociceptive and anti-inflammatory properties in experimental mice and/or rat models. In the hot-plate test, the group that received a dose of 300 mg/kg showed maximum time needed for the response against thermal stimuli (5.11 ± 0.12), which was similar to that of diclofenac sodium (5.96 ± 0.18), a well-known painkiller. The maximum possible analgesia (MPH) was 1.93 for the extract dose 300 mg/kg, while that for diclofenac was 2.29 after 60 min of administration in the hot tail-flick method. The extract at 500 and 250 mg/kg doses showed significant reduction in acetic acid-induced writhing in mice with a maximum effect of 63.21% reduction at 500 mg/kg dose, which was similar to positive control diclofenac sodium (66.98%). The extract also demonstrated significant inhibition in serotonin and egg albumin-induced hind paw edema in rats at the doses 100, 200 and 300 mg/kg (serotonin-induced edema 35.85, 46.78 and 55.18%; egg albumin-induced edema 42.96, 48.30, and 55.61% inhibition after 1-4 h). The anti-inflammatory properties exhibited by the extract were comparable to that of indomethacin at a dose of 5 mg/kg (serotonin-induced edema 53.22; egg albumin-induced edema 57.01% inhibition after 4 h).

Astaxanthin Prevented Oxidative Stress in Heart and Kidneys of Isoproterenol-Administered Aged Rats

ABSTRACT The objective of this study was to investigate the effect of astaxanthin on isoproterenol (ISO)-induced myocardial infarction and cardiac hypertrophy in rats. To evaluate the effect of astaxanthin on ISO-induced cardiac dysfunction, 18 aged Long Evans male rats were evenly divided into three groups. Group I (Control group) was given only the laboratory-ground food and normal water. Group II (ISO group) was administered ISO at a dose of 50 mg/kg subcutaneously (SC) twice a week for two weeks. Group III (Astaxanthin + ISO group) was treated with astaxanthin (25 mg/kg) orally every day and ISO 50 mg/kg SC twice a week for two weeks. ISO administration in rats increased the heart and left ventricular wet weights and increased inflammatory cell infiltration and fibrosis. Moreover, ISO administration increased the lipid peroxidation and decreased antioxidant enzyme activities in heart tissues. Astaxanthin treatment prevented the increased wet weight of heart and decreased inflammatory cell infiltration and fibrosis. The protective effect of astaxanthin was associated with reduction of free radicals by improving antioxidant enzyme function, as well as normalization and/or suppression of elevated oxidative stress markers, such as malondialdehyde (MDA), nitric oxide (NO), and advanced protein oxidation product (APOP) in ISO-administered rats. Furthermore, astaxanthin decreased the elevated activities of aspartate transaminase (AST), alanine transaminase (ALT), and creatinin kinase muscle/brain (CK-MB) in ISO-administered rats. In conclusion, astaxanthin may protect cardiac tissues in ISO-administered rats through suppression of oxidative stress and enhancement of antioxidant enzyme functions.

Antioxidant and hepatoprotective action of the crude ethanolic extract of the flowering top of Rosa damascena

SUMMARY The hepatoprotective activity of the alcoholic extract of Rosa damascena was studied againstparacetamol induced acute hepatotoxicity in rats. Liver damage was assessed by estimatingserum enzyme activities of aspartate aminotransferase, alanine aminotransferase, alkalinephosphatase and histopathology of liver tissue. Pre- and post-treatment with ethanolic extractsshowed a dose-dependent reduction of paracetamol induced elevated serum levels of enzymeactivity. The mechanism underlying the protective effects was assayed in vitro and the R.damascena extracts displayed dosedependent free radical activity using DPPH (IC 50 = 162.525 μg/ml)and TBA method. The hepatoprotective action was confirmed by histopathological observation.The ethanolic extracts reversed paracetamol induced liver injury. These results suggest that thehepatoprotective effects of R. damascena extracts are related to its antioxidative activity.Key words: Antioxidant; Paracetamol; Rosa damascene; Liver enzyme INTRODUCTION

Plant Phenols as Antibiotic Boosters: In Vitro Interaction of Olive Leaf Phenols with Ampicillin

The antimicrobial properties of olive leaf extract (OLE) have been well recognized in the Mediterranean traditional medicine. Few studies have investigated the antimicrobial properties of OLE. In this preliminary study, commercial OLE and its major phenolic secondary metabolites were evaluated in vitro for their antimicrobial activities against Escherichia coli and Staphylococcus aureus, both individually and in combination with ampicillin. Besides luteolin 7‐O‐glucoside, OLE and its major phenolic secondary metabolites were effective against both bacteria, with more activity on S. aureus. In combination with ampicillin, OLE, caffeic acid, verbascoside and oleuropein showed additive effects. Synergistic interaction was observed between ampicillin and hydroxytyrosol. The phenolic composition of OLE and the stability of olive phenols in assay medium were also investigated. While OLE and its phenolic secondary metabolites may not be potent enough as stand‐alone antimicrobials, their abilities to boost the activity of co‐administered antibiotics constitute an imperative future research area. Copyright