D-4F-mediated reduction in metabolites of arachidonic and linoleic acids in the small intestine is associated with decreased inflammation in low-density lipoprotein receptor-null mice

To test the hypothesis that intestine is a major site of action for D-4F, LDLR(-/-) mice were fed a Western diet (WD) and administered the peptide subcutaneously (SQ) or orally. Plasma and liver D-4F levels were 298-fold and 96-fold higher, respectively, after SQ administration, whereas peptide levels in small intestine only varied by 1.66 ± 0.33-fold. Levels of metabolites of arachidonic and linoleic acids known to bind with high affinity to D-4F were significantly reduced in intestine, liver and hepatic bile to a similar degree whether administered SQ or orally. However, levels of 20-HETE, which is known to bind the peptide with low affinity, were unchanged. D-4F treatment reduced plasma serum amyloid A (SAA) and triglyceride levels (P < 0.03) and increased HDL-cholesterol levels (P < 0.04) similarly after SQ or oral administration. Plasma levels of metabolites of arachidonic and linoleic acids significantly correlated with SAA levels (P < 0.0001). Feeding 15-HETE in chow (without WD) significantly increased plasma SAA and triglyceride levels and decreased HDL-cholesterol and paraoxonase activity (P < 0.05), all of which were significantly ameliorated by SQ D-4F (P < 0.05). We conclude that D-4F administration reduces levels of free metabolites of arachidonic and linoleic acids in the small intestine and this is associated with decreased inflammation in LDL receptor deficient mice.     

Anticoagulant activity of a peptide boronic acid thrombin inhibitor by various routes of administration in rats.

The peptide boronic acid analog Ac-(D)Phe-Pro-boroArg-OH (I) is a potent and selective inhibitor of thrombin. The objective of this study was to determine whether I is active orally or when administered by alternative transmucosal routes. The measured effect was the time for clotting of plasma after initiation with thrombin. With this assay there was a narrow window from no measurable effect to the maximal effect, a clotting time greater than 300 seconds. Intravenous I at a 0.15 mg/kg dose in rats, a nasal 0.45 mg/kg dose, and 3 mg/kg doses administered orally, colonically, or rectally all produced maximal effects. Therefore, although bioavailability cannot be estimated, it is demonstrated that this peptide analog was absorbed by each of these routes.     

L-4F treatment reduces adiposity, increases adiponectin levels, and improves insulin sensitivity in obese mice

We hypothesized that the apolipoprotein mimetic peptide L-4F, which induces arterial anti-oxidative enzymes and is vasoprotective in a rat model of diabetes, would ameliorate insulin resistance and diabetes in obese mice. L-4F (2 mg/kg/d) administered to ob/ob mice for 6 weeks limited weight gain without altering food intake, decreased visceral (P < 0.02) and subcutaneous (P < 0.045) fat content, decreased plasma IL-1beta and IL-6 levels (P < 0.05) and increased insulin sensitivity, resulting in decreased glucose (P < 0.001) and insulin (P < 0.036) levels. In addition, L-4F treatment increased aortic and bone marrow heme oxygenase (HO) activity and decreased aortic and bone marrow superoxide production (P < 0.001). L-4F treatment increased serum adiponectin levels (P < 0.037) and decreased adipogenesis in mouse bone marrow (P < 0.039) and in cultures of human bone marrow-derived mesenchymal stem cells (P < 0.022). This was manifested by reduced adiposity, improved insulin sensitivity, improved glucose tolerance, increased plasma adiponectin levels, and reduced IL-1beta and IL-6 levels in obese mice. This study highlights the existence of a temporal relationship between HO-1 and adiponectin that is positively affected by L-4F in the ob/ob mouse model of diabetes, resulting in the amelioration of the deleterious effects of diabetes.     

Basal insulin, glucagon, and growth hormone replacement

Conclusions drawn from the pancreatic (or islet) clamp technique (suppression of endogenous insulin, glucagon, and growth hormone secretion with somatostatin and replacement of basal hormone levels by intravenous infusion) are critically dependent on the biological appropriateness of the selected doses of the replaced hormones. To assess the appropriateness of representative doses we infused saline alone, insulin (initially 0.20 mU.kg(-1).min(-1)) alone, glucagon (1.0 ng.kg(-1).min(-1)) alone, and growth hormone (3.0 ng.kg(-1).min(-1)) alone intravenously for 4 h in 13 healthy individuals. That dose of insulin raised plasma insulin concentrations approximately threefold, suppressed glucose production, and drove plasma glucose concentrations down to subphysiological levels (65 +/- 3 mg/dl, P < 0.0001 vs. saline), resulting in nearly complete suppression of insulin secretion (P < 0.0001) and stimulation of glucagon (P = 0.0059) and epinephrine (P = 0.0009) secretion. An insulin dose of 0.15 mU.kg(-1).min(-1) caused similar effects, but a dose of 0.10 mU.kg(-1).min(-1) did not. The glucagon and growth hormone infusions did not alter plasma glucose levels or those of glucoregulatory factors. Thus, insulin "replacement" doses of 0.20 and even 0.15 mU.kg(-1).min(-1) are excessive, and conclusions drawn from the pancreatic clamp technique using such doses may need to be reassessed.     

Embryotoxicity studies of norfloxacin in cynomolgus monkeys: I. Teratology studies and norfloxacin plasma concentration in pregnant and nonpregnant monkeys

Norfloxacin, a new orally active antibiotic, was investigated in cynomolgus monkeys for potential developmental toxicity. Fifty-seven monkeys were administered a control vehicle or norfloxacin by nasogastric gavage during the major period of organogenesis on gestational days (GD) 21 through 50 at doses of 0, 50, 100, 150, or 200/300 mg/kg/day. There was no evidence of teratogenicity at any dose level. Maternotoxicity and a significant increase in embryolethality occurred following doses of 200/300 mg/kg/day. The maternotoxicity was not expected based on range-finding studies in nonpregnant female monkeys, which showed no signs of toxicity in doses up to 500 mg/kg/day. Additional studies were conducted to determine if norfloxacin caused similar toxicity later in gestation. Forty-six pregnant monkeys were dosed with a control vehicle or 200 mg/kg/day norfloxacin for one of three 10-day periods on GD 36-45, 71-80, or 111-120. There were no maternotoxic, embryotoxic, or fetotoxic effects observed. Plasma concentrations of norfloxacin in five cynomolgus monkeys following 50 and 200 mg/kg oral doses were not dose-proportionate. However, at a given dose, administered in cross-over fashion, plasma concentrations of norfloxacin were higher in nonpregnant females (approximately 20-40%) than during pregnancy when the same subject was compared. At the no-observed-effect dose for maternal and embryotoxicity (50 mg/kg), peak plasma concentrations of norfloxacin in pregnant cynomolgus monkeys are approximately threefold higher than those observed in human volunteers receiving norfloxacin at the maximum recommended therapeutic dose of 400 mg (5.7 mg/kg based on 70 kg body weight) twice per day.     

A novel method for oral delivery of apolipoprotein mimetic peptides synthesized from all L-amino acids

Administered subcutaneously, D-4F or L-4F are equally efficacious, but only D-4F is orally efficacious because of digestion of L-4F by gut proteases. Orally administering niclosamide (a chlorinated salicylanilide used as a molluscicide, antihelminthic, and lampricide) in temporal proximity to oral L-4F (but not niclosamide alone) in apoE null mice resulted in significant improvement (P < 0.001) in the HDL-inflammatory index (HII), which measures the ability of HDL to inhibit LDL-induced monocyte chemotactic activity in endothelial cell cultures. Oral administration of L-[113-122]apoJ with niclosamide also resulted in significant improvement (P < 0.001) in HII. Oral administration of niclosamide and L-4F together with pravastatin to female apoE null mice at 9.5 months of age for six months significantly reduced aortic sinus lesion area (P = 0.02), en face lesion area (P = 0.033), and macrophage lesion area (P = 0.02) compared with pretreatment, indicating lesion regression. In contrast, lesions were significantly larger in mice receiving only niclosamide and pravastatin or L-4F and pravastatin (P < 0.001). In vitro niclosamide and L-4F tightly associated rendering the peptide resistant to trypsin digestion. Niclosamide itself did not inhibit trypsin activity. The combination of niclosamide with apolipoprotein mimetic peptides appears to be a promising method for oral delivery of these peptides.     

Cardiovascular and behavioral responses of gray wolves to ketamine-xylazine immobilization and antagonism by yohimbine

Adult wolves (Canis lupus) were immobilized with 6.6 mg/kg ketamine hydrochloride (KET) and 2.2 mg/kg xylazine hydrochloride (XYL) administered intramuscularly. Induction time was 4.6 +/- 0.3 min (mean +/- SE). Immobilization resulted in significant bradycardia and hypertension (P less than 0.05). Twenty min after induction, the wolves were given 0.05-0.60 mg/kg yohimbine hydrochloride (YOH). Yohimbine given intravenously produced dose-related increases in heart rate (HR) with doses greater than 0.15 mg/kg resulting in extreme tachycardia (greater than 300 bpm). All doses of YOH caused a temporary decrease in mean arterial blood pressure (MABP) with some individual animals manifesting profound hypotension (less than 30 torr) at doses greater than 0.15 mg/kg. Increasing the dose of YOH above 0.15 mg/kg did not significantly decrease either arousal or ambulation times. Administering YOH at 40 or 60 min after induction resulted in decreased arousal and ambulation times. Stimulation by weighing and taking repeated blood samples during anesthesia did not shorten arousal times. We recommend that wolves immobilized with XYL-KET be antagonized with doses of YOH less than 0.15 mg/kg.     

Lipoprotein inflammatory properties and serum amyloid A levels but not cholesterol levels predict lesion area in cholesterol-fed rabbits

Rabbits on a 1% cholesterol diet received injections of vehicle with or without D-4F or L-4F. After 1 month, the percent of aorta with atherosclerotic lesions was 24 +/- 15% (vehicle), 10 +/- 6% (D-4F) (P < 0.01 vs. vehicle), and 13 +/- 9% (L-4F) (P < 0.05 vs. vehicle). Inflammatory indexes for HDL and LDL were determined by measuring monocyte chemotactic activity after adding rabbit lipoproteins to human endothelial cells. HDL-inflammatory index (HII) and LDL-inflammatory index (LII), respectively, were 1.39 +/- 0.24; 1.35 +/- 0.29 (vehicle), 0.67 +/- 0.26; 0.63 +/- 0.38 (D-4F) (P < 0.001 vs. vehicle), and 0.67 +/- 0.2; 0.68 +/- 0.32 (L-4F) (P < 0.01 vs. vehicle). Serum amyloid A (SAA) levels were 95 +/- 39, 8 +/- 22, and 7 +/- 19 mug/ml, respectively, for vehicle, D-4F, and L-4F (P < 0.001 vs. vehicle). There was no correlation between lesion area and total plasma or HDL-cholesterol levels. In contrast, there was a positive correlation with HII, LII, and SAA (P = 0.002, P = 0.0026, P = 0.0079, respectively). HII correlated closely with SAA levels (r = 0.6616; r(2) = 0.4377, P < 0.0001). Thus, HII, LII, and SAA are better predictors of lesion area than are total plasma or HDL-cholesterol levels in cholesterol-fed rabbits.     

In vivo efficacy of HDL-like nanolipid particles containing multivalent peptide mimetics of apolipoprotein A-I

We have observed that molecular constructs based on multiple apoA-I mimetic peptides attached to a branched scaffold display promising anti-atherosclerosis functions in vitro. Building on these promising results, we now describe chronic in vivo studies to assess anti-atherosclerotic efficacy of HDL-like nanoparticles assembled from a trimeric construct, administered over 10 weeks either ip or orally to LDL receptor-null mice. When dosed ip, the trimer-based nanolipids markedly reduced plasma LDL-cholesterol levels by 40%, unlike many other apoA-I mimetic peptides, and were substantially atheroprotective. Surprisingly, these nanoparticles were also effective when administered orally at a dose of 75 mg/kg, despite the peptide construct being composed of l-amino acids and being undetectable in the plasma. The orally administered nanoparticles reduced whole aorta lesion areas by 55% and aortic sinus lesion volumes by 71%. Reductions in plasma cholesterol were due to the loss of non-HDL lipoproteins, while plasma HDL-cholesterol levels were increased. At a 10-fold lower oral dose, the nanoparticles were marginally effective in reducing atherosclerotic lesions. Intriguingly, analogous results were obtained with nanolipids of the corresponding monomeric peptide. These nanolipid formulations provide an avenue for developing orally efficacious therapeutic agents to manage atherosclerosis.     

The use of ginger (Zingiber officinale Rosc.) as a potential anti-inflammatory and antithrombotic agent

The effect of an aqueous extract of ginger (Zingiber officinale) on serum cholesterol and triglyceride levels as well as platelet thromboxane-B(2) and prostaglandin-E(2) production was examined. A raw aqueous extract of ginger was administered daily for a period of 4 weeks, either orally or intraperitoneally (IP) to rats. Fasting blood serum was investigated for thromboxane-B(2), prostaglandin-E(2), cholesterol and triglycerides. A low dose of ginger (50 mg/kg) administered either orally or IP did not produce any significant reduction in the serum thromboxane-B(2) levels when compared to saline-treated animals. However, ginger administered orally caused significant changes in the serum PGE(2) at this dose. High doses of ginger (500 mg/kg) were significantly effective in lowering serum PGE(2) when given either orally or IP. However, TXB(2) levels were significantly lower in rats given 500 mg/kg ginger orally but not IP. A significant reduction in serum cholesterol was observed when a higher dose of ginger (500 mg/kg) was administered. At a low dose of ginger (50 mg/kg), a significant reduction in the serum cholesterol was observed only when ginger was administered IP. No significant changes in serum triglyceride levels were observed upon administration of either the low or high dose of ginger. These results suggest that ginger could be used as an cholesterol-lowering, antithrombotic and anti-inflammatory agent.     

Oral activity of the growth hormone releasing peptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 in rats, dogs and monkeys

The purpose of this study was to evaluate the growth hormone (GH) releasing activity of orally administered His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6, SK&F 110679) in rats, dogs and monkeys. Rats were administered GHRP-6 orally by gavage or parenterally through femoral artery catheters. Blood was collected before and after GHRP-6 administration for estimation of plasma GH and comparison of GH changes resulting from enteral and parenteral administration of the peptide. GHRP-6 was administered to dogs intravenously (i.v.) through cephalic vein catheters, intragastrically (i.g.) through esophagostomy tubes or intraduodenally (i.d.) through vascular access ports, and blood was collected before and after peptide administration for estimation of plasma GH. Cynomolgus monkeys were administered GHRP-6 i.g., and blood was collected from abdominal aorta for estimation of changes in plasma GH. Enteral activity of GHRP-6 was observed in all 3 species tested. In rats, ED50's for enteral and parenteral administration of GHRP-6 were 4 mg/kg and 28 micrograms/kg, respectively. Thus in rats, enterally administered GHRP-6 was 0.7% as bioactive as the parenterally administered peptide. In dogs GHRP-6 was slightly less potent than in rats, with ED50's for i.g. and i.v. administration approximately 15 mg/kg and 125 micrograms/kg, respectively. However, enteral potency of GHRP-6 in dogs was 0.8% of parenteral potency, and thus, comparable to that in rats. Additionally, comparison of plasma GH levels following i.g. vs i.d. administration in dogs suggested greater activity by the i.d. route. Monkeys were the species most sensitive to enterally administered GHRP-6, with plasma GH increased in those receiving i.g. doses as low as 0.3 mg/kg and an ED50 of 0.75 mg/kg compared to 4 and 15 mg/kg in rats and dogs, respectively. The results of this study demonstrate that GHRP-6 releases GH when administered directly into the gastrointestinal tract. Although enteral activity is approximately 1% of parenteral activity, GHRP-6 is potent, especially in primates which require relatively low doses to provoke GH release. These data suggest that orally active GHRP-6 may provide a practical therapeutic alternative to parenterally administered peptides such as GHRH, especially if enteral activity is enhanced with appropriate formulation.     

Nascent HDL formation by hepatocytes is reduced by the concerted action of serum amyloid A and endothelial lipase

Inflammation is associated with significant decreases in plasma HDL-cholesterol (HDL-C) and apoA-I levels. Endothelial lipase (EL) is known to be an important determinant of HDL-C in mice and in humans and is upregulated during inflammation. In this study, we investigated whether serum amyloid A (SAA), an HDL apolipoprotein highly induced during inflammation, alters the ability of EL to metabolize HDL. We determined that EL hydrolyzes SAA-enriched HDL in vitro without liberating lipid-free apoA-I. Coexpression of SAA and EL in mice by adenoviral vector produced a significantly greater reduction in HDL-C and apoA-I than a corresponding level of expression of either SAA or EL alone. The loss of HDL occurred without any evidence of HDL remodeling to smaller particles that would be expected to have more rapid turnover. Studies with primary hepatocytes demonstrated that coexpression of SAA and EL markedly impeded ABCA1-mediated lipidation of apoA-I to form nascent HDL. Our findings suggest that a reduction in nascent HDL formation may be partly responsible for reduced HDL-C during inflammation when both EL and SAA are known to be upregulated.     

Optimization of dose of collagen hydrolysate to prevent UVB-irradiated skin damage

Collagen hydrolysate (CH) was orally administered to UVB-irradiated hairless mice at doses of 20, 200–2000 mg/kg BW/day. The low dose of CH increased the skin hydration and reduced the transepidermal water loss on damaged skin. These results suggested the optimal dose of collagen to improve the UV-damaged skin condition.     

Pregnancy outcomes after weekly oral administration of ethanol during gestation in the pig-tailed macaque (Macaca nemestrina)

Ethanol was orally administered once per week to gravid pig-tailed macaques (Macaca nemestrina) in doses of 0.3, 0.6, 1.2, 1.8, 2.5, 3.3, or 4.1 g/kg. A control group received a sucrose solution, isocaloric and isovolemic to the highest ethanol dose. Pregnancy was followed after 116 possible conceptions in 54 females. Peak plasma ethanol concentrations (PPECs) ranged from 24 +/- 6 mg/dl at the 0.3 g/kg dose to 549 +/- 71 mg/dl at the 4.1 g/kg dose. An increased rate of spontaneous abortion was related to ethanol exposure at and above 1.8 g/kg (mean PPEC = 205 mg/dl). Pregnancy failure in the first 30 days of gestation increased at doses above 2.5 g/kg. The effect on pregnancy outcome of weekly exposure to ethanol in this nonhuman primate is comparable to available data on humans. The methodology of this study represents an effective model for studying ethanol teratogenesis in a nonhuman primate.     

Comparative effects of Pro-Leu-Gly-NH2 and cyclo(Leu-Gly) administered orally on the development of tolerance to the analgesic effect of morphine in the rat

Comparative effects of Pro-Leu-Gly-NH2 (MIF) and cyclo(Leu-Gly) (CLG) administered orally at different stages of chronic morphine treatment on the development of tolerance to the analgesic effect of morphine in the rat were determined. Male Sprague-Dawley rats were implanted with either 6 placebo or morphine pellets during a 7-day period. Implantation of morphine pellets resulted in the development of a high degree of tolerance as evidenced by a decrease in the analgesic response to morphine. Administration of CLG (8 and 16 mg/kg/day) on day 5, 6 and 7 of implantation inhibited the development of tolerance to morphine but 4 and 32 mg/kg doses had no effect. Further, CLG (2 mg/kg/day for 7 days) inhibited the development of tolerance but higher doses (4 and 8 mg/kg) had no effect. MIF (26 and 52 mg/kg) administered orally on the last three days of the implantation schedule inhibited the development of tolerance to morphine. MIF (6.5 mg/kg/day for 7 days) inhibited the development of tolerance but the higher doses had no effect. Concurrent administration of MIF (6.5 mg/kg) and CLG (2 mg/kg) for seven days failed to inhibit the development of tolerance. A single dose of MIF or CLG administered a day before the assessment of tolerance did not affect the morphine tolerance. Thus, even after a significant degree of tolerance to morphine had developed, neuropeptides like MIF and CLG given orally, in appropriate doses, can inhibit development of tolerance to morphine and restore the analgesic effect of morphine.     

A novel approach to oral apoA-I mimetic therapy

Transgenic tomato plants were constructed with an empty vector (EV) or a vector expressing an apoA-I mimetic peptide, 6F. EV or 6F tomatoes were harvested, lyophilized, ground into powder, added to Western diet (WD) at 2.2% by weight, and fed to LDL receptor-null (LDLR^−/−) mice at 45 mg/kg/day 6F. After 13 weeks, the percent of the aorta with lesions was 4.1 ± 4%, 3.3 ± 2.4%, and 1.9 ± 1.4% for WD, WD + EV, and WD + 6F, respectively (WD + 6F vs. WD, P = 0.0134; WD + 6F vs. WD + EV, P = 0.0386; WD + EV vs. WD, not significant). While body weight did not differ, plasma serum amyloid A (SAA), total cholesterol, triglycerides, and lysophosphatidic acid (LPA) levels were less in WD + 6F mice; P < 0.0295. HDL cholesterol and paroxonase-1 activity (PON) were higher in WD + 6F mice (P = 0.0055 and P = 0.0254, respectively), but not in WD + EV mice. Plasma SAA, total cholesterol, triglycerides, LPA, and 15-hydroxyeicosatetraenoic acid (HETE) levels positively correlated with lesions (P < 0.0001); HDL cholesterol and PON were inversely correlated (P < 0.0001). After feeding WD + 6F: i) intact 6F was detected in small intestine (but not in plasma); ii) small intestine LPA was decreased compared with WD + EV (P < 0.0469); and iii) small intestine LPA 18:2 positively correlated with the percent of the aorta with lesions (P < 0.0179). These data suggest that 6F acts in the small intestine and provides a novel approach to oral apoA-I mimetic therapy.     

Plasmodium yoelii nigeriensis (MDR)-efficacy of oral pyronaridine against multidrug-resistant malaria in Swiss mice

A multidrug-resistant strain of Plasmodium yoelii nigeriensis (MDR) showing a wide spectrum of resistance to chloroquine, amodiaquine, mepacrine, mefloquine, halofantrine, quinine, and quinidine was used in this study for in vivo evaluation of the blood schizontocidal activity of pyronaridine, a topoisomerase II inhibitor, in Swiss mice. The parasite produces 100% lethal infection in mice. The drug was administered orally once a day from day 0 onward. The initial studies showed that low doses of pyronaridine (0.625 to 5.0 mg base/kg x9 days) did not completely control blood-induced P. yoelii nigeriensis infection. Finally a series of doses of pyronaridine ranging from 1.25 to 30.0 mg/kg administered orally for 7 consecutive days were evaluated and in spite of high level of resistance to standard antimalarials, the parasite P. yoelii nigeriensis has shown complete susceptibility to pyronaridine (15 mg/kg dose x7 days). The present paper also compares the merits of a single MDR strain vs a battery of different resistant lines for quick antimalarials screening.     

The anti-inflammatory and analgesic effects of a crude extract of Petiveria alliacea L. (Phytolaccaceae).

Petiveria alliacea L (Phytolaccaceae) is a perennial bush plant that grows widely in Brazil. The roots and leaves of P. alliacea have been used in folk medicine for their antispasmodic, sedative, diuretic and antihelminthic actions. We recently described the anti-inflammatory properties of P. alliacea administered topically and orally in different animal models. In the present study, we investigated the anti-inflammatory activity of a crude lyophilized extract of P. alliacea roots administered to rats with pleurisy. The oral administration of P. alliacea root extract did not significantly reduce the total number of leukocytes at the doses tested. By contrast, the highest dose of extract tested (43.9 mg/kg body wt.) significantly reduced the number of migrating neutrophils, mononuclear cells and eosinophils; the dose of 31.4 mg/kg body wt. also reduced mononuclear cell migration. The P. alliacea root extract also showed a significant analgesic effect in the experimental model used. The results of this study provide a basis for the use of P. alliacea extracts in popular folk medicine, but further studies are necessary to elucidate the mechanism of its anti-inflammatory and analgesic actions.     

Antisense inhibition of apoB synthesis with mipomersen reduces plasma apoC-III and apoC-III-containing lipoproteins

Mipomersen, an antisense oligonucleotide that reduces hepatic production of apoB, has been shown in phase 2 studies to decrease plasma apoB, LDL cholesterol (LDL-C), and triglycerides. ApoC-III inhibits VLDL and LDL clearance, and it stimulates inflammatory responses in vascular cells. Concentrations of VLDL or LDL with apoC-III independently predict cardiovascular disease. We performed an exploratory posthoc analysis on a subset of hypercholesterolemic subjects obtained from a randomized controlled dose-ranging phase 2 study of mipomersen receiving 100, 200, or 300 mg/wk, or placebo for 13 wk (n = 8 each). ApoC-III-containing lipoproteins were isolated by immuno-affinity chromatography and ultracentrifugation. Mipomersen 200 and 300 mg/wk reduced total apoC-III from baseline by 6 mg/dl (38-42%) compared with placebo group (P < 0.01), and it reduced apoC-III in both apoB lipoproteins and HDL. Mipomersen 100, 200, and 300 mg doses reduced apoB concentration of LDL with apoC-III (27%, 38%, and 46%; P < 0.05). Mipomersen reduced apoC-III concentration in HDL. The drug had no effect on apoE concentration in total plasma and in apoB lipoproteins. In summary, antisense inhibition of apoB synthesis reduced plasma concentrations of apoC-III and apoC-III-containing lipoproteins. Lower concentrations of apoC-III and LDL with apoC-III are associated with reduced risk of coronary heart disease (CHD) in epidemiologic studies independent of traditional risk factors.     

Cysteamine in combination with N-acetylcysteine prevents acetaminophen-induced hepatotoxicity.

N-Acetylcysteine (NAC) is protective against acetaminophen-induced hepatotoxicity primarily by providing precursor for the glutathione synthetase pathway, while cysteamine has been demonstrated to alter the cytochrome P-450 dependent formation of toxic acetaminophen metabolite. Mice administered acetaminophen (500 mg/kg) had elevations of serum alanine aminotransferase (ALT) to 273.0 +/- 37.5 and 555.8 +/- 193.4 U/mL at 12 and 24 h, respectively, after injection. Administration of cysteamine (100 mg/kg) or NAC (500 mg/kg) significantly reduced serum ALT activity (p less than 0.001). Reducing the dose of NAC or cysteamine by 50% greatly reduced their hepatoprotective effect while the co-administration of the reduced doses of NAC (250 mg/kg) and cysteamine (50 mg/kg) following acetaminophen overdose prevented elevation of serum ALT activity (39.2 +/- 1.17 and 32.5 +/- 5.63 U/mL at 12 and 24 h post-injection, p less than 0.001) and preserved normal mouse hepatic histology. Neither NAC (500 mg/kg), cysteamine (100 mg/kg), or the lower doses in combination of both agents were found to alter the half-life or peak levels of acetaminophen. Liver microsomal aryl hydrocarbon hydroxylase activity measured 24 h after drug administration was not significantly different between treatment groups and controls receiving only saline. These results indicate a possible role for the concomitant use of NAC and cysteamine in the prevention of hepatic necrosis following toxic doses of acetaminophen. Neither decrease in plasma acetaminophen levels nor depression of cytochrome P-450 enzyme activity appears to be the mechanism of protection when these doses of NAC, cysteamine, or both drugs together are administered with a toxic dose of acetaminophen in mice.