Biomedical subjects

M Bagchi

Publications and source records attributed to M Bagchi.

At least 19 recordsLinked to original sources

PubMed2007

Lamins of ocular lens epithelial cells.

Experiments were performed to characterize a prominent nuclear matrix (NM) protein isolated from tissue cultured mouse lens epithelial cells. This NM protein was separated by SDS-PAGE and the stained gel band was analyzed by mass spectroscopy. Blast analysis of the amino acid sequence derived by mass spectroscopy revealed the presence of Lamin C in the NM of the mouse lens epithelial cells. We also examined nuclear proteins of adult and fetal human lenses. Data collected from these experiments showed the presence of Lamin C in both adult and fetal lens cells. However fetal lens cells only show Lamin C dimers, whereas adult human lens contained dimers, monomers and degraded Lamin C. Early and late passaged tissue cultured mouse lens epithelial cells also contained Lamin C in the nucleus with a preponderance of the dimer in the early passaged cells. The biological significance of the presence of dimers in human fetal lens cells and early passaged mouse lens cells is not known. However, it could suggest an enhanced docking capability of Lamin C dimers for other physiologically important nuclear proteins.

Adult↗

PubMed2005

Efficacy and safety of glycosylated undenatured type-II collagen (UC-II) in therapy of arthritic dogs.

DeParle L. A., Gupta R. C., Canerdy T. D., Goad J. T., D'Altilio M., Bagchi M., Bagchi D. Efficacy and safety of glycosylated undenatured type-II collagen (UC-II) in therapy of arthritic dogs. J. vet. Pharmacol. Therap.28, 385-390. In large breed dogs, arthritis is very common because of obesity, injury, aging, immune disorder, or genetic predispositions. This study was therefore undertaken to evaluate clinical efficacy and safety of undenatured type-II collagen (UC-II) in obese-arthritic dogs. Fifteen dogs in three groups received either no UC-II (Group I) or UC-II with 1 mg/day (Group II) or 10 mg/day (Group III) for 90 days. Lameness and pain were measured on a weekly basis for 120 days (90 days treatment plus 30 days post-treatment). Blood samples were assayed for creatinine and blood urea nitrogen (markers of renal injury); and alanine aminotransferase and aspartate aminotransferase (evidence of hepatic injury). Dogs receiving 1 mg or 10 mg UC-II/day for 90 days showed significant declines in overall pain and pain during limb manipulation and lameness after physical exertion, with 10 mg showed greater improvement. At either dose of UC-II, no adverse effects were noted and no significant changes were noted in serum chemistry, suggesting that UC-II was well tolerated. In addition, dogs receiving UC-II for 90 days showed increased physical activity level. Following UC-II withdrawal for a period of 30 days, all dogs experienced a relapse of overall pain, exercise-associated lameness, and pain upon limb manipulation. These results suggest that daily treatment of arthritic dogs with UC-II ameliorates signs and symptoms of arthritis, and UC-II is well tolerated as no adverse effects were noted.

Administration, Oral↗

PubMed2005

Efficacy of a novel calcium/potassium salt of (-)-hydroxycitric acid in weight control.

The weight-loss efficacy of a novel, water-soluble, calcium-potassium salt of (-)-hydroxycitric acid (HCA-SX) was re-examined in 90 obese subjects (BMI: 30-50.8 kg/m2). We combined data from two previously reported randomized, double-blind, placebo-controlled clinical studies in order to achieve a better statistical evaluation based on a larger population. This re-examination of data also allowed us to reflect more intensely on various aspects of weight loss studies. Subjects were randomly divided into three groups: group A received a daily dose of HCA-SX 4, 667 mg (providing 2,800 mg HCA per day); group B was given a daily dose of a combination of HCA-SX 4,667 mg, niacin-bound chromium (NBC) 4 mg (providing 400 microg elemental chromium), and Gymnema sylvestre extract (GSE) 400 mg (providing 100 mg gymnemic acid); and group C received a placebo in three equally divided doses 30-60 min before each meal. All subjects were provided a 2,000 kcal diet/day and participated in a supervised walking program for 30 min/day, 5 days/week. Eighty-two subjects completed the study. At the end of 8 weeks, in group A, both body weight and BMI decreased by 5.4%, low-density lipoprotein and triglycerides levels were reduced by 12.9% and 6.9%, respectively, while high-density lipoprotein levels increased by 8.9%, serum leptin levels decreased by 38%, serotonin levels increased by 44.5% and urinary excretion of fat metabolites increased by 32-109%. Group B demonstrated similar beneficial changes, but generally to a greater extent. No significant adverse effects were observed. The combined results confirm that HCA-SX and, to a greater degree, the combination of HCA-SX plus NBC and GSE reduce body weight and BMI, suppress appetite, improve blood lipid profiles, increase serum leptin and serotonin levels and increase fat oxidation more than placebo. We conclude that dosage levels, timing of administration, subject compliance and bioavailability of HCA-SX significantly affect results and that when taken as directed, HCA-SX is a highly effective adjunct to healthy weight control.

Adult↗

PubMed2004

ERM proteins of the lens.

Ezrin and radixin and protein 4.1 were detected in the lens of the eye. These proteins were mainly present in the young elongating cortical fiber cells and localized to the plasma membranes. Moesin was not detected. Ezrin, radixin, and protein 4.1 provide another means whereby actin is linked to the plasma membrane in addition to the known adherens junctions in the lens.

Animals↗

PubMed2004

Anti-angiogenic, antioxidant, and anti-carcinogenic properties of a novel anthocyanin-rich berry extract formula.

Edible berry anthocyanins possess a broad spectrum of therapeutic and anti-carcinogenic properties. Berries are rich in anthocyanins, compounds that provide pigmentation to fruits and serve as natural antioxidants. Anthocyanins repair and protect genomic DNA integrity. Earlier studies have shown that berry anthocyanins are beneficial in reducing age-associated oxidative stress, as well as in improving neuronal and cognitive brain function. Six berry extracts (wild blueberry, bilberry, cranberry, elderberry, raspberry seeds, and strawberry) were studied for antioxidant efficacy, cytotoxic potential, cellular uptake, and anti-angiogenic (the ability to reduce unwanted growth of blood vessels, which can lead to varicose veins and tumor formation) properties. We evaluated various combinations of edible berry extracts and developed a synergistic formula, OptiBerry IH141, which exhibited high ORAC (Oxygen-Radical Absorbing Capacity) value, low cytotoxicity, and superior anti-angiogenic properties compared to the other combinations tested. Anti-angiogenic approaches to treat cancer represent a priority area in vascular tumor biology. OptiBerry significantly inhibited both H2O2- and TNF-alpha-induced VEGF (Vascular Endothelial Growth Factor) expression by human keratinocytes. VEGF is a key regulator of tumor angiogenesis. Matrigel assay using human microvascular endothelial cells showed that OptiBerry impaired angiogenesis. In an in vivo model of angiogenesis, OptiBerry significantly inhibited basal MCP-1 and inducible NF-kappaB transcriptions. Endothelioma cells pretreated with OptiBerry showed a diminished ability to form hemangioma and markedly decreased tumor growth by more than 50%. In essence, these studies highlight the novel anti-angiogenic, antioxidant, and anti-carcinogenic potential of a novel anthocyanin-rich berry extract formula, OptiBerry.

Angiogenesis Inhibitors↗

PubMed2004

Effects of a natural extract of (-)-hydroxycitric acid (HCA-SX) and a combination of HCA-SX plus niacin-bound chromium and Gymnema sylvestre extract on weight loss.

AIM: The efficacy of optimal doses of highly bioavailable (-)-hydroxycitric acid (HCA-SX) alone and in combination with niacin-bound chromium (NBC) and a standardized Gymnema sylvestre extract (GSE) on weight loss in moderately obese subjects was evaluated by monitoring changes in body weight, body mass index (BMI), appetite, lipid profiles, serum leptin and excretion of urinary fat metabolites. HCA-SX has been shown to reduce appetite, inhibit fat synthesis and decrease body weight without stimulating the central nervous system. NBC has demonstrated its ability to maintain healthy insulin levels, while GSE has been shown to regulate weight loss and blood sugar levels. METHODS: A randomized, double-blind, placebo-controlled human study was conducted in Elluru, India for 8 weeks in 60 moderately obese subjects (ages 21-50, BMI >26 kg/m(2)). Subjects were randomly divided into three groups. Group A was administered HCA-SX 4667 mg, group B was administered a combination of HCA-SX 4667 mg, NBC 4 mg and GSE 400 mg, while group C was given placebo daily in three equally divided doses 30-60 min before meals. All subjects received a 2000 kcal diet/day and participated in supervised walking. RESULTS: At the end of 8 weeks, body weight and BMI decreased by 5-6% in both groups A and B. Food intake, total cholesterol, low-density lipoproteins, triglycerides and serum leptin levels were significantly reduced in both groups, while high-density lipoprotein levels and excretion of urinary fat metabolites increased in both groups. A marginal or non-significant effect was observed in all parameters in group C. CONCLUSION: The present study shows that optimal doses of HCA-SX and, to a greater degree, the combination of HCA-SX, NBC and GSE can serve as an effective and safe weight-loss formula that can facilitate a reduction in excess body weight and BMI, while promoting healthy blood lipid levels.

Adult↗

PubMed2004

Antioxidant properties of Aller-7, a novel polyherbal formulation for allergic rhinitis.

Allergic rhinitis, a frequently occurring immunological disorder affecting men, women and children worldwide, is a state of hypersensitivity that occurs when the body overreacts to a substance such as pollen, mold, mites or dust. Allergic rhinitis exerts inflammatory response and irritation of the nasal mucosal membranes leading to sneezing; stuffy/runny nose; nasal congestion; and itchy, watery and swollen eyes. A novel, safe polyherbal formulation (Aller-7/NR-A2) has been developed for the treatment of allergic rhinitis using a unique combination of extracts from seven medicinal plants including Phyllanthus emblica, Terminalia chebula, Terminalia bellerica, Albizia lebbeck, Piper nigrum, Zingiber officinale and Piper longum. In this study, the antioxidant efficacy of Aller-7 was investigated by various assays including hydroxyl radical scavenging assay, superoxide anion scavenging assay, 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2-azinobis-ethyl-benzothiozoline-sulphonic acid diammonium salt (ABTS) radical scavenging assays. The protective effect of Aller-7 on free radical-induced lysis of red blood cells and inhibition of nitric oxide release by Aller-7 in lipopolysaccharide-stimulated murine macrophages were determined. Aller-7 exhibited concentration-dependent scavenging activities toward biochemically generated hydroxyl radicals (IC50 741.73 microg/ml); superoxide anion (IC50 24.65 microg/ml by phenazine methosulfate-nicotinamide adenine dinucleotide [PMS-NADH] assay and IC50 4.27 microg/ml by riboflavin/nitroblue tetrazolium [NBT] light assay), nitric oxide (IC50 16.34 microg/ml); 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical (IC50 5.62 microg/ml); and 2,2-azinobis-ethyl-benzothiozoline-sulphonic acid diammonium salt (ABTS) radical (IC50 7.35 microg/ml). Aller-7 inhibited free radical-induced hemolysis in the concentration range of 20-80 microg/ml. Aller-7 also significantly inhibited nitric oxide release from lipopolysaccharide-stimulated murine macrophages. These results demonstrate that Aller-7 is a potent scavenger of free radicals and that it may serve.

Animals↗

PubMed2004

Anti-inflammatory activities of Aller-7, a novel polyherbal formulation for allergic rhinitis.

Allergic rhinitis is an immunological disorder and an inflammatory response of nasal mucosal membranes. Allergic rhinitis, a state of hypersensitivity, occurs when the body overreacts to a substance such as pollens or dust. A novel, safe polyherbal formulation (Aller-7/NR-A2) has been developed for the treatment of allergic rhinitis using a unique combination of extracts from seven medicinal plants including Phyllanthus emblica, Terminalia chebula, Terminalia bellerica, Albizia lebbeck, Piper nigrum, Zingiber officinale and Piper longum. Since inflammation is an integral mechanistic component of allergy, the present study aimed to determine the anti-inflammatory activity of Aller-7 in various in vivo models. The efficacy of Aller-7 was investigated in compound 48/80-induced paw edema both in Balb/c mice and Swiss Albino mice, carrageenan-induced paw edema in Wistar Albino rats and Freund's adjuvant-induced arthritis in Wistar Albino rats. The trypsin inhibitory activity of Aller-7 was also determined and compared with ovomucoid. At a dose of 250 mg/kg, Aller-7 demonstrated 62.55% inhibition against compound 48/80-induced paw edema in Balb/c mice, while under the same conditions prednisolone at an oral dose of 14 mg/kg exhibited 44.7% inhibition. Aller-7 significantly inhibited compound 48/80-induced paw edema at all three doses of 175, 225 or 275 mg/kg in Swiss Albino mice, while the most potent effect was observed at 225 mg/kg. Aller-7 (120 mg/kg, p.o.) demonstrated 31.3% inhibition against carrageenan-induced acute inflammation in Wistar Albino rats, while ibuprofen (50 mg/kg, p.o.) exerted 68.1% inhibition. Aller-7 also exhibited a dose-dependent (150-350 mg/kg) anti-inflammatory effect against Freund's adjuvant-induced arthritis in Wistar Albino rats and an approximately 63% inhibitory effect was observed at a dose of 350 mg/kg. The trypsin inhibitory activity of Aller-7 was determined, using ovomucoid as a positive control. Ovomucoid and Aller-7 demonstrated IC50 concentrations at 1.5 and 9.0 microg/ml, respectively. These results demonstrate that this novel polyherbal formulation is a potent anti-inflammatory agent that can ameliorate the symptoms of allergic rhinitis.

Animals↗

PubMed2003

Paralemnin of the lens.

Paralemmin was identified in the chicken lens as a protein with mol. wt 65 kDa and a splice variant of 60 kDa, both soluble in Triton X-100. Paralemmin is localized to the plasma membrane of fiber cells, and was not detected in the annular pad cells. Thus in the chick lens it is another feature of fiber cell differentiation. Its localization to the short side of the fiber cell and the sites of fiber cell interlocking suggests that paralemmin may play a role in the development of such interdigitating processes.

Amino Acid Sequence↗

PubMed2003

Mast cell stabilization, lipoxygenase inhibition, hyaluronidase inhibition, antihistaminic and antispasmodic activities of Aller-7, a novel botanical formulation for allergic rhinitis.

Allergic rhinitis, also known as hay fever, rose fever or summer catarrh, is a major challenge to health professionals. A large number of the world's population, including approximately 40 million Americans, suffers from allergic rhinitis. A novel, botanical formulation (Aller-7) has been developed for the treatment of allergic rhinitis using a combination of extracts from seven medicinal plants, including Phyllanthus emblica, Terminalia chebula, T. bellerica, Albizia lebbeck, Piper nigrum, Zingiber officinale and P. longum, which have a proven history of efficacy and health benefits. The clinical manifestations of allergy are due to a number of mediators that are released from mast cells. The effect of Aller-7 on rat mesenteric mast cell degranulation was studied by incubating different concentrations of Aller-7 and challenging them with a degranulating agent, compound 48/80. The inhibitory activity of Aller-7 was determined against lipoxygenase and hyaluronidase, the key enzymes involved in the initiation and maintenance of inflammatory responses. Furthermore, most of these manifestations are due to histamine, which causes vasodilatation, increasing capillary permeability and leading to bronchoconstriction. Hence, the antihistaminic activity of Aller-7 was determined is isolated guinea pig ileum substrate using cetirizine as a positive control. The antispasmodic effect of Aller-7 on contractions of guinea pig tracheal chain was determined using papaverine and cetirizine as controls. Aller-7 exhibited potent activity in all these in vitro models tested, thus demonstrating the novel anti-allergic potential of Aller-7.

Animals↗

PubMed2002

Associated proteins of lens adherens junction.

Cytoplasmic proteins associated with adherens junctions were identified in the chicken ocular lens. The catenins, alpha, beta, and gamma, were present in epithelial and fiber cells, although their pattern of distribution changed with fiber cell differentiation. The sharp decline in alpha-catenin with fiber cell formation and the increasing Triton-insolubility of N-cadherin suggests that another subtype of alpha-catenin exists in the lens.

Adherens Junctions↗

PubMed2002

Beneficial effects of a novel IH636 grape seed proanthocyanidin extract and a niacin-bound chromium in a hamster atherosclerosis model.

Atherosclerosis is a disease of the arteries in which fatty plaques develop on the inner arterial wall, which eventually obstructs blood flow. Identified risk factors for atherosclerosis include genetics, diet, lifestyle, smoking, circulating lipid and cholesterol levels, and molecular and circulating signals of chronic vascular inflammation. The link between flavonoids and atherosclerosis is based partly on the evidence that some flavonoids possess antioxidant properties and have been shown to be potent inhibitors of LDL oxidation in vitro. Hypercholesterolemia, a significant cardiovascular risk factor is prevalent in the American population. Grape seed proanthocyanidin extracts are known to exhibit a broad spectrum of chemopreventive and cardioprotective properties against oxidative stress. A recent study has shown that a combination of IH636 grape seed proanthocyanidin extract (GSPE) and a niacin-bound chromium (NBC) can decrease total cholesterol, LDL and oxidized LDL levels in hypercholesterolemic human subjects. In this study, we assessed the efficacy of GSPE supplementation in hamsters, singly and in combination with NBC, since these animals have a similar lipid profile to hypercholesterolemic humans when fed a hypercholesterolemic diet of 0.2% cholesterol and 10% coconut oil (HCD). After 10 weeks of feeding HCD, these animals developed foam cells, which is a biomarker of early stages of atherosclerosis. Atherosclerosis (% of aorta covered with foam cells) was reduced by approximately 50% and 63% following supplementation of these animals with 50 mg/kg and 100 mg/kg of GSPE, respectively, in conjunction with a HCD, while approximately 32% reduction was observed following supplementation of GSPE plus NBC. A range of 7-9 animals was used in each study group. GSPE alone and in combination with NBC exerted a pronounced effect on the cholesterol, and triglyceride levels, as well as oxidative lipid damage as demonstrated by the formation of thiobarbituric acid reactive substances (TBARS). This data demonstrates that GSPE and NBC may provide significant health benefits by dramatically ameliorating the incidence of atherosclerosis as demonstrated by reducing the formation of foam cells.

Animals↗

PubMed2002

Heat shock proteins of adult and embryonic human ocular lenses.

We investigated the presence and distribution of heat shock proteins, HSP-70 [Horwitz, J. 1992. Proc Natl Acad Sci 89:10449-10453], HSP-40, HSc-70, HSP-27, and alphabeta-crystallin in different regions of adult and fetal human lenses and in aging human lens epithelial cells. This study was undertaken because heat shock proteins may play an important role in the maintenance of the supramolecular organization of the lens proteins. Human adult and fetal lenses were dissected to separate the epithelium, superficial cortex, intermediate cortex, and nucleus. The water soluble and insoluble protein fractions were separated by SDS-PAGE, and transferred to nitrocellulose paper. Specific antibodies were used to identify the presence of heat shock proteins in distinct regions of the lens. HSP-70 [Horwitz, 1992], HSP-40, and HSc-70 immunoreactivity was mainly detected in the epithelium and superficial cortical fiber cells of the adult human lens. The small heat shock proteins, HSP-27 and alphabeta-crystallin were found in all regions of the lens. Fetal human lenses showed immunoreactivity to all heat shock proteins. An aging study revealed a decrease in heat shock protein levels, except for HSP-27. The presence of HSP-70 [Horwitz, 1992], HSP-40, and HSc-70 in the epithelium and superficial cortical fiber cells imply a regional cell specific function, whereas the decrease of heat shock protein with age could be responsible for the loss of optimal protein organization, and the eventual appearance of age-related cataract.

Electrophoresis, Polyacrylamide Gel↗

PubMed2002

Effects of orally administered undenatured type II collagen against arthritic inflammatory diseases: a mechanistic exploration.

Arthritis afflicts approximately 43 million Americans or approximately 16.6% of the US population. The two most common and best known types of arthritis are osteoarthritis (OA) and rheumatoid arthritis (RA). A significant amount of scientific research has been done in attempts to explain what initiates forms of arthritis, how it is promoted and perpetuated and how to effectively intervene in the disease process and promote cartilage remodeling. Current pharmacological strategies mainly address immune suppression and antiinflammatory mechanisms and have had limited success. Recent research provides evidence that alterations in the three-dimensional configuration of glycoproteins are responsible for the recognition/response signaling that catalyzes T-cell attack. Oral administration of autoantigens has been shown to suppress a variety of experimentally induced autoimmune pathologies, including antigen-induced RA. The interaction between gut-associated lymphoid tissue in the duodenum and epitopes of orally administered undenatured type II collagen facilitates oral tolerance to the antigen and stems systemic T-cell attack on joint cartilage. Previous studies have shown that small doses of orally administered undenatured type II chicken collagen effectively deactivate killer T-cell attack. A novel glycosylated undenatured type II collagen material (UC-II) was developed to preserve biological activity. The presence of active epitopes in the UC-II collagen is confirmed by an enzyme-linked immunosorbent assay test and distinguishes this form from hydrolyzed or denatured collagen. Oral intake of small amounts of glycosylated UC-II presents active epitopes, with the correct three-dimensional structures, to Peyer's patches, which influences the signaling required for the development of immune tolerance. UC-II has demonstrated the ability to induce tolerance, effectively reducing joint pain and swelling in RA subjects. A pilot study was conducted for 42 days to evaluate the efficacy of UC-II (10 mg/day) in five female subjects (58-78 years) suffering from significant joint pain. Significant pain reduction including morning stiffness, stiffness following periods of rest, pain that worsens with use of the affected joint and loss of joint range of motion and function was observed. Thus, UC-II may serve as a novel therapeutic tool in joint inflammatory conditions and symptoms of OA and RA.

Administration, Oral↗

PubMed2001

Upregulation of oxidant-induced VEGF expression in cultured keratinocytes by a grape seed proanthocyanidin extract.

Angiogenesis plays a central role in wound healing. Among many known growth factors, vascular endothelial growth factor (VEGF) is believed to be the most prevalent, efficacious, and long-term signal that is known to stimulate angiogenesis in wounds. The wound site is rich in oxidants such as hydrogen peroxide mostly contributed by neutrophils and macrophages. Proanthocyanidins or condensed tannins are a group of biologically active polyphenolic bioflavonoids that are synthesized by many plants. This study provides first evidence showing that natural extracts such as grape seed proanthocyanidin extract containing 5000 ppm resveratrol (GSPE) facilitates oxidant-induced VEGF expression in keratinocytes. Using a ribonuclease protection assay (RPA), the ability of GSPE to regulate oxidant-induced changes in several angiogenesis-related genes were studied. While mRNA responses were studied using RPA, VEGF protein release from cells to the culture medium was studied using ELISA. Pretreatment of HaCaT keratinocytes with GSPE upregulated both hydrogen peroxide as well as TNF-alpha-induced VEGF expression and release. The current results suggest that GSPE may have beneficial therapeutic effects in promoting dermal wound healing and other related skin disorders.

Anthocyanins↗

PubMed2001

Heat shock proteins of chicken lens.

The presence of heat shock proteins HSP-40, HSP-70, and HSc-70 in adult and embryonic chicken lenses were determined. The epithelium, cortex, and nucleus of adult chicken lens were separated and tested for the presence of heat shock proteins (hsps) by western blot, using specific antibodies for HSP-40, HSP-70, and HSc-70. Water soluble (WSF) and water insoluble fractions (WIF) of embryonic chicken lenses were isolated and tested for the presence of HSP-40, HSP-70, and HSc-70 by immunoblot. Embryonic chicken lens sections were also analyzed for the presence of heat shock proteins by immunofluorescence technique. Data obtained from these experiments revealed that HSP-40, HSP-70, and HSc-70 are present in all areas of both adult and embryonic chicken lens. Presence of hsps protein in the deep cortex and nucleus is intriguing as no detectable metabolic activities are reported in this area. However it can be proposed that hsps HSP-40, HSP-70, and HSc-70 can interact with protein of these areas and protect them from stress induced denaturation.

Animals↗

PubMed2001

Differential effects of IH636 grape seed proanthocyanidin extract and a DNA repair modulator 4-aminobenzamide on liver microsomal cytochrome 4502E1-dependent aniline hydroxylation.

Previous studies from our laboratories have linked the protective abilities of IH636 grape seed proanthocyanidin extract (GSPE) with inactivation of anti-apoptotic gene bcl-XL, and modification of several other critical molecular targets such as DNA-damage/DNA-repair, lipid peroxidation and intracellular Ca2+ homeostasis. Especially, GSPE provided dramatic protection against acetaminophen (APAP)-induced hepatotoxicity, significantly increased bcl-XL expression in the liver, and antagonized both necrotic and apoptotic deaths of liver cells in vivo. However, it was not clear from this study whether anti-apoptogenic and anti-necrotic effects of GSPE were: (i) due to its interference with endonuclease activity, (ii) due to its antioxidant effect, or, (iii) due to its ability to inhibit microsomal drug metabolizing enzyme(s), such as CYP-4502E1. Since CYP-4502E1 primarily metabolizes acetaminophen in mice and rats, this study specifically focused on CYP-4502E1's catalytic activity in vitro. Overall this investigation compared the in vitro aniline hydroxylation patterns of: (i) in vivo GSPE-exposed and unexposed (control) mouse liver microsomes, (ii) induced (1% acetone in drinking water for 3 days) and uninduced rat liver microsomes in the presence and absence of GSPE in vitro, and (iii) control rat liver microsomes in the presence of an anti-APAP agent 4-aminobenzamide (4-AB) in vitro. For the in vivo assessment, male B6C3F1 mice were fed GSPE diet (ADI 100 mg/kg body wt) for 4 weeks, and liver microsomes were isolated from both control and GSPE-fed mice for aniline hydroxylation, a specific marker of CYP-4502E1 activity. Data show that hydroxylation was 40% less in microsomes from GSPE-exposed livers compared to control microsomes. Similarly, when rat liver microsomes were incubated with various concentrations of GSPE in vitro (100 and 250 microg/ml), aniline hydroxylation was inhibited to various degrees (uninduced: 40 and 60% and induced: 25 and 50%, respectively with 100 and 250 microg/ml). Influence of GSPE on hydroxylation patterns were compared with another hepatoprotective agent 4-aminobenzamide (4-AB), a well-known modulator of nuclear enzyme poly(ADP-ribose) polymerase, and the data shows that 4-AB did not alter aniline hydroxylation at all. Collectively, these results may suggest that GSPE has the ability to inhibit CYP-4502E1, and this is an additional cytoprotective attribute, in conjunction with its novel antioxidant and/or antiendonucleolytic potential.

4-Aminobenzoic Acid↗

PubMed2001

Protective effect of melatonin on naphthalene-induced oxidative stress and DNA damage in cultured macrophage J774A.1 cells.

Naphthalene is a bicyclic aromatic compound that is widely used in various domestic and commercial applications. Previous studies in our laboratory have demonstrated enhanced production of reactive oxygen species, lipid peroxidation and DNA fragmentation in both in vitro and in vivo models following treatment with naphthalene. Melatonin (N-acetyl-5-methoxytryptamine), an indole hormone, is the chief secretory product of the pineal gland and is an efficient free radical scavenger and antioxidant, both in vitro and in vivo. In this study, we have investigated the ability of 1 mM melatonin to protect against naphthalene-induced oxidative stress and DNA damage in cultured macrophage J774A.1 cells. No significant changes were observed when these macrophage cells were treated with 100 microM naphthalene. Approximately 2.0-, 4.2- and 4.4-fold increases in cytochrome c reduction were observed at 200, 400 and 500 mM concentrations of naphthalene, demonstrating the increased production of superoxide anion. At 24 h, lipid peroxidation increased by approximately 1.4-, 2.1- and 2.2-fold following treatment of these cells with 200, 400 and 500 mM concentrations of naphthalene, respectively, while 1.6-, 2.8- and 2.8-fold increases in DNA fragmentation were observed at these same concentrations. Two hour pretreatment of these cultured cells with 1 mM melatonin provided approximately 26-44% decreases in lipid peroxidation, superoxide anion production and DNA fragmentation in cells treated with 400 and 500 microM naphthalene. Cellular viability decreased significantly when cells were incubated with concentrations of naphthalene greater than 100 microM, while preincubation with melatonin significantly increased the cellular viability. These results demonstrate that naphthalene may induce toxic manifestations by enhanced production of reactive oxygen free radicals, resulting in lipid peroxidation and DNA damage, while preincubation with melatonin significantly suppressed cytoxicity in J774A.1 macrophage cells.

Animals↗