Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatocytes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats.
A simple high-performance liquid chromatography (HPLC) method to determine the content of betulinic acid (BA) in rat plasma collected at different times (0-8 h) after oral administration of Orthosiphon stamineus leaf extract was developed. The features of the assay include protein precipitation using acetonitrile and isocratic elution using reverse phase C-18 column with ultraviolet (UV) detection. The recovery of BA from plasma varied from 98.4 to 102.5%. The R.S.D of intra- and inter-day precision from rat plasma ranged from 4.2 to 9.8%. The maximum concentration of BA in the plasma was 1.2 +/- 0.3 microg/ml at 1 h after oral administration of the extract.
The ability of the antioxidants in the mulberry leaves to protect Sprague-Dawley rats from injuries caused by immobilization stress was studied as an indicator of the tissue bioavailability of antioxidants. Nitrite level, lipid peroxidation and total antioxidant activity (TAA) in the plasma and tissues were measured. There were hypertrophy of the adrenal glands and kidneys, significant increased levels of nitrite in the plasma and adrenal glands, elevated thiobarbituric acid reactive substances (TBARS) in the plasma, kidneys and spleen, and a reduction of TAA in the plasma, liver, adrenal glands, kidneys and spleen of the immobilized rats. Antioxidants in the mulberry leaf extract suppressed the increase of nitrite and TBARS. Adrenal glands appeared to be the target organ of the antioxidants in the leaf extract. The low dose mulberry antioxidants were more effective than pure rutin (4 mg/day) to protect the cells against inflammation and peroxidation induced by stress.
The ethanol and water extracts of Sansevieria trifasciata leaves showed dose-dependent and significant (P < 0.05) increase in pain threshold in tail-immersion test. Moreover, both the extracts (100 - 200 mg/kg) exhibited a dose-dependent inhibition of writhing and also showed a significant (P < 0.001) inhibition of both phases of the formalin pain test. The ethanol extract (200 mg/kg) significantly (P < 0.01) reversed yeast-induced fever. Preliminary phytochemical screening of the extracts showed the presence of alkaloids, flavonoids, saponins, glycosides, terpenoids, tannins, proteins and carbohydrates.
Survivin is an inhibitor of apoptosis protein and regulates the cell cycle in the G2/M phase. Survivin is expressed during embryonic and fetal development, selectively over-expressed in common human cancers and completely down-regulated in normal adult tissue. This work was aimed at studying the expression of the survivin homologues and their subcellular distribution in fetal and normal adult tissues of rat. Survivin expression was evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of fetal and normal adult tissues of rat using the polyclonal serum SUR12A-CFI. This serum demonstrated intense positive survivin staining in adult kidney, ovary and oviduct, and a variable expression in different fetal organs, with particularly intense expression detected in the adrenal gland, liver, stomach, small intestine, colon, kidney and skin. In both fetal and adult tissues, the expression was predominantly cytoplasmic. It was concluded that survivin was abundantly and prominently expressed during fetal development in rat and that the polyclonal anti-human survivin antibody SUR12A-CFI is reactive with rat survivin.
The acute toxicity of standardized extract of Orthosiphon stamineus was studied in Sprague Dawley rats. The rats were administered a single dose of 5000 mg/kg body weight (BW) orally on Day 0 and observed for 14 days. There were no deaths recorded and the animals did not show signs of toxicity during the experimental period. The effect of the extract on general behavior, BW, food and water intake, relative organ weight per 100 g BW, hematology and clinical biochemistry were measured. All the parameters measured were unaffected as compared to the control. The acute toxicity LD(50) was estimated to be > 5000 mg/kg BW.
This study investigates the effect of preservation methods on the performance of bovine parietal pericardium grafts in a rat model. Mid-ventral full thickness abdominal wall defects of 3 x 2.5 cm in size were created in 90 male Sprague-Dawley rats (300-400 g), which were divided into three groups of 30 rats each. The abdominal defects of group one and two were repaired with lyophilized and glycerolized bovine pericardium grafts, while the defects of group three were repaired with expanded polytetrafluoroethylene (ePTFE) Mycro Mesh as a positive control. Another group of 30 rats underwent sham operation and was used for comparison as negative control. Each group of rats (n = 30) was divided into five subgroups (n = 6) and killed at 1, 3, 6, 9 and 18 weeks post-surgery for gross and morphological evaluations. The rats tolerated the surgical procedure well with a total mortality of 0.05%. No serious post-operative clinical complications or signs of rejection were encountered. Adhesions between the grafts and the underlying visceral organs observed in the study were mostly results of post-surgical complications. Glycerol preservation delayed degradation and replacement of the grafts, whereas lyophilization caused early resorption and replacement of the grafts. The glycerolized grafts were replaced with thick dense fibrous tissue, and the lyophilized grafts were replaced with thin loose fibrous tissue. The healing characteristic of the bovine pericardium grafts was similar to those of the sham-operated group, and quite different from those of the ePTFE Mycro Mesh. The outcome of the present study confirmed the superiority of glycerolized bovine pericardium grafts over its lyophilized counter part.
A simple and sensitive RP-HPLC-UV method was developed and validated for simultaneous determination of atenolol and propranolol and subsequently applied to investigate the effect of dimethyl sulfoxide in rat in situ intestinal permeability studies. Atenolol (400 microm) and propranolol (100 microm) were perfused in the small intestine of anaesthetized (pentobarbitone sodium 60 mg/kg, i.p.) male Sprague-Dawley rats either in the presence (1, 3 and 5%) or in the absence of dimethyl sulfoxide. There was no significant alteration (p > 0.05) in the permeability of atenolol and propranolol, which indicated there was no effect of various concentrations of dimethyl sulfoxide (1-5%) on the membrane integrity of the rat intestinal tissues. The analytical method was validated on a C(4) column with a mobile phase comprising ammonium acetate buffer (pH 3.5, 0.02 m) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 mL/min. The validated method was found to be accurate and precise and stability studies were carried out at different storage conditions and both analytes were found to be stable. These findings are applicable for determining the absorbability of water-insoluble drugs and new chemical entities for the purpose of classifying them in the biopharmaceutical classification system.
Bioassay-guided fractionation was performed on a crude dichloromethane extract of Kaempferia galanga L. using chromatography techniques. Screening of the extract for biological activity started with the brine shrimp lethality bioassay, followed by the study of its antihypertensive activity on anaesthetized rats, which involved monitoring of the extract's effect on mean arterial blood pressure. The components of the fractions obtained from the separation procedures were analyzed using gas chromatography (GC). The yield of the CH(2)Cl(2) extract was 0.29% of the crude plant extract. Analysis of the data for brine shrimp lethality test using the Finney computer program showed that this extract exhibited potent bioactivity with an ED(50) value of 7.92+/-0.13 microgml(-1). Intravenous administration of the extract induced a dose-related reduction of basal mean arterial pressure (MAP) (130+/-5 mmHg) in the anaesthetized rat, with maximal effects seen after 5-10 min of injection. The gas chromatogram showed that the common compound in the active fractions obtained from the bioassay-guided fractionation of the CH(2)Cl(2) extract was ethyl cinnamate. This vasorelaxant active compound, ethyl cinnamate, was isolated as a colorless oil. Ethyl p-methoxycinnamic acid was also isolated as white needles but did not exhibit any relaxant effect on the precontracted thoracic rat aorta.
In this study, the hypothesis was tested that behaviour of rats under the open field test condition and effects of subsequent acute stress relate to conformational properties of the main plasma carrier protein, albumin.To evaluate albumin properties, fluorescence intensity of a molecular probe CAPIDAN (N-carboxyphenylimide of dimethylaminonaphthalic acid) at N (at pH 7.4) and F (at pH 4.2) albumin conformations was measured and the N-F signal ratio was calculated. The data obtained showed that CAPIDAN fluoresces selectively from albumin in rat serum and its fluorescence is sensitive to binding of fatty acids and some other ligands to albumin. Behaviour of 78 Wistar male rats was characterized from the fraction of time taken for exploratory and ambulatory activity during the open field test. In rats not subjected to stress (n = 40), a negative correlation was revealed between open field activity and CAPIDAN N-to-F ratio for albumin (r = - 0.55, p < 0.0005). In the group of rats subjected to acute stress (immobilization plus stochastic electrocutaneous stimulation) the correlation between behavioural activity and the albumin conformational properties was significantly positive (r = 0.59, p < 0.0001): the CAPIDAN albumin fluorescence ratio increased in the highly active rats and decreased in the low-activity rats. The mechanisms of the observed effects may involve differences in nonesterified fatty acid production during stress.
To compare the potential retinal toxicity of two commercially Brilliant blue G dyes (Brilliant Peel and Ocublue Plus) and Indocyanine green (ICG) at usual clinical concentration.
The present study aimed to determine the hepatoprotective activity of a methanol extract of Melastoma malabathricum leaves (MEMM) using two established rat models. Ten groups of rats (n=6) were given a once-daily administration of 10% dimethyl sulfoxide (negative control), 200 mg/kg silymarin (positive control), or MEMM (50, 250, or 500 mg/kg) for 7 days followed by induction of hepatotoxicity either using paracetamol or carbon tetrachloride. Blood samples and livers were collected for biochemical and microscopic analysis. Based on the results obtained, MEMM exhibited a significant (p<0.05) hepatoprotective activity against both inducers, as indicated by an improvement in the liver function test. These observations were supported by the histologic findings. In conclusion, M. malabathricum leaves possessed hepatoprotective activity, which could be linked to their phytochemical constituents and antioxidant activity; this therefore requires further in-depth studies.
Rats are considered the principal maintenance hosts of Leptospira. The objectives of this study were isolation and identification of Leptospira serovars circulating among urban rat populations in Kuala Lumpur. Three hundred urban rats (73% Rattus rattus and 27% R. norvegicus) from three different sites were trapped. Twenty cultures were positive for Leptospira using dark-field microscopy. R. rattus was the dominant carrier (70%). Polymerase chain reaction (PCR) confirmed that all isolates were pathogenic Leptospira species. Two Leptospira serogroups, Javanica and Bataviae, were identified using microscopic agglutination test (MAT). Pulsed-field gel electrophoresis (PFGE) identified two serovars in the urban rat populations: L. borgpetersenii serovar Javanica (85%) and L. interrogans serovar Bataviae (15%). We conclude that these two serovars are the major serovars circulating among the urban rat populations in Kuala Lumpur. Despite the low infection rate reported, the high pathogenicity of these serovars raises concern of public health risks caused by rodent transmission of leptospirosis.
The effects of indomethacin and nabumetone on urine and electrolyte excretion in conscious rats were examined. Male Sprague-Dawley rats were housed individually for a five-week duration, consisting of acclimatization, control, experimental, and recovery phases. During the experimental phase, rats were given either indomethacin (1.5 mg . kg(-1) body weight . day(-1) in 0.5 ml saline, n = 10), nabumetone (15 mg . kg(-1) body weight . day(-1) 0.5 ml saline, n = 10), or 0.5 ml saline alone (n = 10) for a period of two weeks. Water and food intake, body weight, urine output, and electrolyte excretions were estimated. Data were analyzed using two-way ANOVA. Urine output in the indomethacin- and nabumetone-treated groups was not different from the controls, but was significantly different between the drug-treated groups (P<0.01). Sodium, potassium, calcium, and magnesium excretions were not different between nabumetone-treated and control rats. However, sodium and potassium excretion was significantly lower in rats receiving indomethacin when compared to the control rats. Calcium and magnesium outputs, although did not differ from the controls, nevertheless decreased significantly with indomethacin (P<0.01). It appears that indomethacin and nabumetone when given at maximum human therapeutic doses may affect urine and electrolyte output in conscious rats.
Carbamzepine (CBZ) was encapsulated in a parenteral oil-in-water nanoemulsion, in an attempt to improve its bioavailability. The particle size, polydispersity index and zeta potential were measured using dynamic light scattering. Other parameters such as pH, osmolality, viscosity, drug loading efficiency and entrapment efficiency were also recorded. Transmission electron microscopy revealed that emulsion droplets were almost spherical in shape and in the nano-range. The in vitro release profile was best characterized by Higuchi's equation. The parenteral nanoemulsion of CBZ showed significantly higher AUC0→5, AUC0→∞, AUMC0→5, AUMC0→∞, Cmax and lower clearance than that of CBZ solution in plasma. Additionally, parenteral nanoemulsion of CBZ showed significantly higher AUC0→∞, AUMC0→∞ and Cmaxthan that of CBZ solution in brain. The parenteral nanoemulsion of CBZ could therefore use as a carrier, worth exploring further for brain targeting.
Nypa fruticans Wurmb. vinegar, commonly known as nipa palm vinegar (NPV) has been used as a folklore medicine among the Malay community to treat diabetes. Early work has shown that aqueous extract (AE) of NPV exerts a potent antihyperglycemic effect. Thus, this study is conducted to evaluate the effect of AE on postprandial hyperglycemia in an attempt to understand its mechanism of antidiabetic action. AE were tested via in vitro intestinal glucose absorption, in vivo carbohydrate tolerance tests and spectrophotometric enzyme inhibition assays. One mg/mL of AE showed a comparable outcome to the use of phloridzin (1 mM) in vitro as it delayed glucose absorption through isolated rat jejunum more effectively than acarbose (1 mg/mL). Further in vivo confirmatory tests showed AE (500 mg/kg) to cause a significant suppression in postprandial hyperglycemia 30 min following respective glucose (2 g/kg), sucrose (4 g/kg) and starch (3 g/kg) loadings in normal rats, compared to the control group. Conversely, in spectrophotometric enzymatic assays, AE showed rather a weak inhibitory activity against both α-glucosidase and α-amylase when compared with acarbose. The findings suggested that NPV exerts its anti-diabetic effect by delaying carbohydrate absorption from the small intestine through selective inhibition of intestinal glucose transporters, therefore suppressing postprandial hyperglycemia.
Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. Transforming growth factor-beta (TGF-β), a cytokine superfamily, regulates cell function, including differentiation and proliferation. Although the function of the TGF-βs in various cell types has been investigated, their function in cartilage repair is as yet not fully understood. The effect of TGF-β3 in biological regulation of primary chondrocyte was investigated in this work. TGF-β3 provided fibroblastic morphology to chondrocytes and therefore overall reduction in cell proliferation was observed. The length of the cells supplemented with TGF-β3 were larger than the cells without TGF-β3 treatment. This was caused by the fibroblast like cells (dedifferentiated chondrocytes) which occupied larger areas compared to cells without TGF-β3 addition. The healing process of the model wound closure assay of chondrocyte multilayer was slowed down by TGF-β3, and this cytokine negatively affected the strength of chondrocyte adhesion to the cell culture surface.
The main focus of this study is the incorporation of collagen peptides to fabricate P(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] nano-fiber construct to further enhance surface wettability and support cell growth while harbouring desired properties for biodegradable wound dressing. Simultaneous electrospinning of nanofiber P(3HB-co-4HB)/collagen peptides construct was carried out using dual syringe system. The wettability of the constructs increased with the increase in 4HB molar fraction from 20mol% 4HB [53.2°], P(3HB-co-35mol%4HB)[48.9°], P(3HB-co-50mol%4HB)[44.5°] and P(3HB-co-82mol%4HB) [37.7°]. In vitro study carried out using mouse fibroblast cells (L929) grown on nanofiber P(3HB-co-4HB)/collagen peptides construct showed an increase in cell proliferation. In vivo study using animal model (Sprague Dawley rats) showed that nanofibrous P(3HB-co-4HB)/collagen peptides construct had a significant effect on wound contractions with the highest percentage of wound closure of 79%. Hence, P(3HB-co-4HB)/collagen peptides construct suitable for wound dressing have been developed using nano-fabrication technique.
Brewers' rice is one of abundant agricultural waste products in the rice industry. The present study is designed to investigate the potential of brewers' rice to inhibit the development of aberrant crypt foci (ACF) in colon of azoxymethane (AOM)-treated rats. The effects on the attenuation of hepatic toxicity and kidney function enzymes were also evaluated. Male Sprague-Dawley rats were randomly divided into five groups: (G1) normal; (G2) AOM alone; and (G3), (G4), and (G5), which were AOM fed with 10%, 20%, and 40% (w/w) of brewers' rice, respectively. The rats in group 2-5 were injected intraperitoneally with AOM (15 mg/kg body weight) once weekly for two weeks. After 8 weeks of treatment,the total number of ACF/colon and the number of ACF in the distal and middle colon were significantly reduced in all treatment groups compared to G2 (p<0.05). Brewers' rice decreased the number of ACF with dysplastic morphology in a dose-dependent manner. Alkaline phosphatase (ALP) level in G5 was significantly lower compared to the G2 (p<0.05). In conclusion, this study found the potential value of brewers' rice in reducing the risk of cancer susceptibility in colon.
The consistency of the cervical mucus changes with the reproductive cycle, which we hypothesized involved changing levels of cystic fibrosis transmembrane regulator (CFTR), adenylate cyclase (AC), and cyclic adenosine mono-phosphate (cAMP). We therefore measured the abundance of each in the rat cervix under estrogen and progesterone influence to determine if the activity of these components could explain the changes in the consistency of cervical mucus. Ovariectomised adult female rats were treated with three days of either estrogen (1 μg/kg/day) or progesterone (20 mg/kg/day), or three days of estrogen followed by two days of either vehicle or progesterone or estrogen plus progesterone. In some groups, mifepristone (7 mg/kg/day) was concurrently given with progesterone. Animals were then sacrificed, and the cervix was harvested for protein and mRNA expression analyses by Western blot and real-time PCR, respectively. The distribution of proteins was investigated by immunohistochemistry, and levels of cAMP were determined by enzyme-linked immunosorbent assay (ELISA). Cftr mRNA, AC protein, and cAMP levels in cervical homogenates as well as the tissue distribution of CFTR and AC in endocervical epithelia were highest under estrogen influence; the opposite pattern was seen under progesterone influence. Cervical lumen circumference was highest under estrogen and lowest under progesterone. The effects of progesterone were antagonized by mifepristone. Therefore, increased abundance of CFTR, AC, and cAMP under estrogen influence could account for the increased fluid accumulation within the cervical lumen, which would contribute to lower cervical mucus consistency, whereas progesterone reverses this effect at the molecular and organ level.