Assessment of the genotoxic effects of antihypertensive drug active ingredient indapamide in human lymphocytes.

Hypertension is the most common cardiovascular disease and is also known as high blood pressure. The large majority of hypertensive patients need long-term administration of antihypertensive agents. Indapamide is an orally administered diuretic antihypertensive drug. The present work aimed to assess the possible genotoxic effects of indapamide using four different assays: chromosomal aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet. Lymphocytes from three different donors were exposed to 18.75, 37.50, 75.00, and 100.00 µg/ml indapamide. Additionally, a negative, a positive (mitomycin C = MMC, 0.20 µg/ml), and a solvent control (5.4 µl/ml methanol) were also applied. As a result, it was seen that indapamide did not cause a significant change in CAs and MN frequencies compared to the control. It caused significant damage only at the highest concentration in the comet assay. Similarly, while it did not affect the number of SCEs in the 24-h treatment, it increased the SCE frequency at the two highest concentrations in the 48-h. Mitotic index (MI) decreased at almost all concentrations. Considering all these results, this study revealed that indapamide did not have a significant genotoxic effect in these conditions. To the best of our knowledge, this is the first investigation about the genotoxic effect of indapamide in human lymphocytes in vitro.

A novel ophthalmic latanoprost 0.005% nanoemulsion: a cytotoxicity study.

BACKGROUND: Benzalkonium chloride (BAK), the most commonly used preservative in anti-glaucoma eye drops, inflicts damage to the ocular surface. A novel anti-glaucoma formulation that avoids the use of BAK has been developed. The aim of this study was to evaluate the cytotoxicity of this formulation and to compare it with an ophthalmic solution containing BAK. METHODS: Two different latanoprost eye drops were used: one ophthalmic solution (LSc) containing BAK 0.02% and one ophthalmic nanoemulsion (LNe) with a soft preservative (potassium sorbate 0.18%). Human epithelial conjunctival cells were incubated for 15, 30, and 60 min with either LSc or LNe. The cytotoxicity was determined by MTT assay. Cell death was measured by flow cytometry using annexin V-FITC and propidium iodide. RESULTS: The values of cell viability and proliferation obtained from cells exposed to LNe were between 80 and 90% relative to the control group, whereas values obtained from cells exposed to LSc were around 30% at all study times (p < 0.05 at 15 and 30 min; p < 0.01 at 60 min). The percentage of viable cells decreased significantly when cells were incubated with LSc compared with cells incubated with LNe at all the study times, while the percentage of cells in late apoptosis/necrosis increased significantly in cells exposed to LSc compared to LNe. CONCLUSIONS: The new latanoprost nanoemulsion is significantly less cytotoxic on human conjunctival cells than LSc. These results suggest that the new formulation might be gentler on the eye surface than currently available BAK-preserved latanoprost solutions.

Ecotoxicity of losartan potassium in aquatic organisms of different trophic levels.

The intensive use of the antihypertensive losartan potassium (LOS) has culminated in its high occurrence in aquatic environments. However, insufficient studies had investigated its effects in non-target organisms. In this study, ecotoxicity of LOS was assessed in aquatic organisms from distinct trophic levels (Desmodesmus subspicatus, Daphnia magna, and Astyanax altiparanae). Genotoxicity was assessed by the comet assay in D. magna and A. altiparanae, and biochemical biomarkers for the fish. LOS was more toxic to D. subspicatus (EC50(72h) = 27.93 mg L-1) than D. magna (EC50 = 303.69 mg L-1). Subsequently, this drug showed to induce more DNA damage in D. magna than A. altiparanae, when exposed to 2.5 mg L-1. No significant stress responses were observed by the fish biomarkers, suggesting that higher trophic levels organisms are more tolerant to LOS toxicity. LOS showed relatively low toxic potential for a short period of exposure, but with different patterns of toxicity for the organisms from distinct trophic levels, contributing to further risk assessment of LOS.

Cardioprotective, hypotensive and toxicological studies of Populus ciliata (Wall. ex Royle).

Populus ciliata Wall ex. Royle has folkloric repute to treat various cardiovascular ailments and related disorders. The current study was designed to evaluate the toxic profile, cardioprotective and hypotensive effects of Populus ciliata (Wall. ex Royle). Populus ciliata crude ethanolic extract (Pc. Cr) and its aqueous (Pc. Aq) & organic (Pc. Dcm) fractions were tested on isolated aorta of rat and rabbit having intact and non-intact endothelium respectively. Pc. Cr & Pc. Aq relaxed the contractions induced by PE (1 µM)-induced and K+ (80 mM)-induced on aorta, possibly by mediating endothelium derived relaxing factor (EDRF) in intact endothelium and voltage dependent L-type calcium channels blocking (CCB) mechanism in non-intact endothelium. Pc. Cr showed anti-hypertensive & cardioprotective activity by decreasing force of contraction & heart rate on isolated rabbit paired atria and reduced blood pressure in anesthetized rat. Cardioprotective effect of Pc. Cr was assessed in isoproterenol induced acute myocardial infarction (AMI) and left ventricular hypertrophy (LVH) in Sprague Dawley rats. In LVH, Pc. Cr exerted positive effects by decreasing angiotensin II & renin and increasing cGMP & nitric oxide (NO) with reduced cardiac fibrosis, necrosis and cardiac cell size. In AMI, Pc. Cr responded effectively by decreasing cardiac markers creatinine kinase (CK), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LD) in blood associated with less edema and necrosis. Presence of catechin, vinallic acid, P-coumeric acid and quercitin identified through HPLC support the effectiveness of Pc. Cr in hypertension, AMI and LVH. Pc. Cr showed no significant adverse effects in Sprague Dawley albino rats after acute & sub-acute treatment in histopathological investigation. Extract of Populus ciliata showed vasorelaxant, hypotensive and cardioprotective effect in Sprague Dawley albino rats and white albino rabbit by mediating EDRF and voltage dependent L-type CCB mechanism respectively.

Polygalacto-fucopyranose from marine alga as a prospective antihypertensive lead.

Consumption of marine alga-based polysaccharides as additional functional foods can endow with health benefits by diminishing the risk of chronic diseases. A polygalacto-fucopyranose characterized as [→1)-2, 4-SO3-α-Fucp-(3 → 1)-{2-SO3-α-Fucp-(3→}] with [(4 → 1)-6-OAc-ß-Galp-(4→] side chain isolated from marine alga Sargassum wightii exhibited potential antihypertensive activity. Upon treatment with studied polygalactofucan (50 mg/kg BW), serum hypertension biomarkers troponin-T (1.3 pg/mL), troponin-I (1.2 µg/dL) and angiotensin-II converting enzyme (0.18 pg/mL) were significantly recovered in hypertensive rats compared to disease control. Serum cardiovascular risk indices of diseased rats were significantly decreased (< 10%, p < 0.05) after administration of the studied galactofucan (50 mg/kg BW) related to hypertension group (> 17%), and were comparable with standard antihypertensive agent telmisartan (8.3-10.2% at 2 mg/kg BW). The studied compound was safe for consumption as obvious from the high LD50 value (>5 g/kg), and could be developed as a prospective functional food ingredient attenuating the pathophysiological attributes causing hypertension-related conditions.

Stimulation of mTOR-independent autophagy and mitophagy by rilmenidine exacerbates the phenotype of transgenic TDP-43 mice.

Autophagy, which mediates the delivery of cytoplasmic substrates to the lysosome for degradation, is essential for maintaining proper cell homeostasis in physiology, ageing, and disease. There is increasing evidence that autophagy is defective in neurodegenerative disorders, including motor neurons affected in amyotrophic lateral sclerosis (ALS). Restoring impaired autophagy in motor neurons may therefore represent a rational approach for ALS. Here, we demonstrate autophagy impairment in spinal cords of mice expressing mutant TDP-43Q331K or co-expressing TDP-43WTxQ331K transgenes. The clinically approved anti-hypertensive drug rilmenidine was used to stimulate mTOR-independent autophagy in double transgenic TDP-43WTxQ331K mice to alleviate impaired autophagy. Although rilmenidine treatment induced robust autophagy in spinal cords, this exacerbated the phenotype of TDP-43WTxQ331K mice, shown by truncated lifespan, accelerated motor neuron loss, and pronounced nuclear TDP-43 clearance. Importantly, rilmenidine significantly promoted mitophagy in spinal cords TDP-43WTxQ331K mice, evidenced by reduced mitochondrial markers and load in spinal motor neurons. These results suggest that autophagy induction accelerates the phenotype of this TDP-43 mouse model of ALS, most likely through excessive mitochondrial clearance in motor neurons. These findings also emphasise the importance of balancing autophagy stimulation with the potential negative consequences of hyperactive mitophagy in ALS and other neurodegenerative diseases.

Ethnopharmacological investigation of the cardiovascular effects of the ethanol-soluble fraction of Aloysia polystachya (Griseb.) Moldenke leaves in spontaneously hypertensive rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Aloysia polystachya (Griseb) Moldenke (Verbenaceae), popularly known as "burrito", is a South American species widely prescribed by local Brazilian healers for the treatment of cardiovascular diseases. However, its antihypertensive and cardioprotective effects are still unknown. AIM: To evaluate the role of the ethanol-soluble fraction of A. polystachya leaves (ESAP) against hypertension in spontaneously hypertensive rats (SHRs), as well as its safety, morphoanatomical and phytochemical aspects. MATERIALS AND METHODS: First, the leaves and stems of A. polystachya were analyzed by optical and scanning electron microscopy in order to provide anatomical data for quality control. Then, ESAP was obtained and its chemical profile was analyzed by LC-DAD-MS. In addition, the cytotoxic and acute toxicity potential of ESAP were evaluated in six cell lines and in female Wistar rats, respectively. Next, female spontaneously hypertensive rats (SHRs) received ESAP (30, 100, 300 mg/kg), hydrochlorothiazide (25 mg/kg), or vehicle once daily for 28 days. Weekly kidney function was monitored by analyzing urinary parameters. At the end of the 28-day treatment, the electrocardiographic profile, blood pressure, and renal and mesenteric vascular reactivity were evaluated. Relative organ (heart, kidney, and liver) weights and biochemical parameters were also evaluated. Finally, the heart, kidneys, and aorta were collected for determination of the tissue redox state, cardiac morphometry, and histopathological analysis. RESULTS: The chemical profile of ESAP was composed by organic acids, a nucleoside, methoxylated flavones and glycosylated compounds including phenolic acids, phenylpropanoids, iridoids and monoterpenes. No signs of toxicity were observed in all cell's lines nor in female Wistar rats submitted to this trial. All SHRs from the negative control group presented a reduction in renal function, alterations in the renal and mesenteric vascular reactivity, and electrocardiographic and morphometric changes typical of ventricular hypertrophy. Oral prolonged ESAP-administration in SHRs was able to reverse renal, electrocardiographic and hemodynamic changes induced by hypertension. Moreover, ESAP-treatment was able to modulate the vascular and renal arterial reactivity and tissue redox state. The aforementioned data were accompanied by reduction of cardiac hypertrophy. CONCLUSION: In this study, we present important anatomical and phytochemical data that contributed to the correct identification and quality control of A. polystachya. In addition, we have shown that ESAP is safe after acute administration and present significant cardioprotective effects (at 30, 100, and 300 mg/kg doses) in SHRs after prolonged treatment.

Chronic cannabidiol treatment reduces the carbachol-induced coronary constriction and left ventricular cardiomyocyte width of the isolated hypertensive rat heart.

Cannabidiol (CBD) is suggested to possess cardioprotective properties. We examined the influence of chronic (10 mg/kg once daily for 2 weeks) CBD administration on heart structure (e.g. cardiomyocyte width) and function (e.g. stimulatory and inhibitory responses induced by ß-adrenoceptor (isoprenaline) and muscarinic receptor (carbachol) activation, respectively). Experiments were performed on hearts and/or left atria isolated from spontaneously (SHR) and deoxycorticosterone (DOCA-salt) hypertensive rats; Wistar-Kyoto (WKY) and sham-operated rats (SHAM) served as the respective normotensive controls. CBD diminished the width of cardiomyocytes in left ventricle and reduced the carbachol-induced vasoconstriction of coronary arteries both in DOCA-salt and SHR. However, it failed to affect left ventricular hypertrophy and even aggravated the impaired positive and negative lusitropic effects elicited by isoprenaline and carbachol, respectively. In normotensive hearts CBD led to untoward structural and functional effects, which occurred only in WKY or SHAM or, like the decrease in ß1-adrenoceptor density, in either control strain. In conclusion, due to its modest beneficial effect in hypertension and its adverse effects in normotensive hearts, caution should be taken when using CBD as a drug in therapy.

Lipid emulsion attenuates extrinsic apoptosis induced by amlodipine toxicity in rat cardiomyoblasts.

Amlodipine-induced toxicity has detrimental effects on cardiac cells. The aim of this study was to examine the effect of lipid emulsion on decreased H9c2 rat cardiomyoblast viability induced by amlodipine toxicity. The effects of amlodipine, lipid emulsion, LY 294002, and glibenclamide, either alone or in combination, on cell viability and count, apoptosis, and expression of cleaved caspase-3 and -8, and Bax were examined. LY 294002 and glibenclamide partially reversed lipid emulsion-mediated attenuation of decreased cell viability and count induced by amlodipine. Amlodipine increased caspase-3 and -8 expression, but it did not alter Bax expression. LY 294002 and glibenclamide reversed lipid emulsion-mediated inhibition of cleaved caspase-3 and -8 expression induced by amlodipine. Lipid emulsion inhibited early and late apoptosis induced by amlodipine. LY 294002 and glibenclamide inhibited lipid emulsion-mediated inhibition of late apoptosis induced by amlodipine, but they did not significantly alter lipid emulsion-mediated inhibition of early apoptosis induced by amlodipine. Lipid emulsion decreased amlodipine-induced TUNEL-positive cells. These results suggest that lipid emulsion inhibits late apoptosis induced by amlodipine at toxic dose via the activation of phosphoinositide-3 kinase and ATP-sensitive potassium channels in the extrinsic apoptotic pathway.

Chronic Pregabalin Treatment Ameliorates Pain, but not Depressive-Like Behaviors, in a Reserpine-Induced Myalgia Model in Rats.

BACKGROUND: Anticonvulsants are often prescribed as coanalgesics for pathologies presenting chronic pain, such as chronic neuropathic pain and fibromyalgia. These pathologies are associated with a wide range of comorbidities: chronic fatigue, cognitive impairment, sleep disturbances, and mood disorders. Pregabalin, an anticonvulsant used to treat fibromyalgia syndrome, has been proven to improve pain and fatigue symptoms. However, most studies have not considered the analytic effect of this drug on comorbid depressive-like symptoms in this syndrome. OBJECTIVES: The main study objective was to examine the role of pregabalin in depressive symptomatology comorbid to chronic widespread pain using a reserpine-induced myalgia model. STUDY DESIGN: A randomized, controlled, animal study. SETTING: Research and data analyses were performed at the GESADA laboratory, Department of Human Anatomy and Embryology, University of Valencia, Spain. METHODS: Forty-six Sprague-Dawley male rats were used. Acute chronic pregabalin administration was tested for depressive-like behaviors (Forced Swimming and Novelty-Suppressed Feeding Tests) and for alteration of pain thresholds (tactile allodynia, Electronic Von Frey test; and mechanical hyperalgesia, Randall and Selitto test). The same procedures were followed with duloxetine as a positive control. RESULTS: Pregabalin significantly improved depressive-like behaviors in acute, but not chronic treatment, and significantly ameliorated pain thresholds. LIMITATIONS: Lack of histological and electrophysiological tests. CONCLUSIONS: Pregabalin is not effective in depressive-like symptoms associated with chronic pain but might play an acute antidepressive-like role given its antinociceptive effect.

Early antihypertensive treatment and ischemia-induced acute kidney injury.

Acute kidney injury (AKI) frequently complicates major surgery and can be associated with hypertension and progress to chronic kidney disease, but reports on blood pressure normalization in AKI are conflicting. In the present study, we investigated the effects of an angiotensin-converting enzyme inhibitor, enalapril, and a soluble epoxide hydrolase inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl)urea (TPPU), on renal inflammation, fibrosis, and glomerulosclerosis in a mouse model of ischemia-reperfusion injury (IRI)-induced AKI. Male CD1 mice underwent unilateral IRI for 35 min. Blood pressure was measured by tail cuff, and mesangial matrix expansion was quantified on methenamine silver-stained sections. Renal perfusion was assessed by functional MRI in vehicle- and TPPU-treated mice. Immunohistochemistry was performed to study the severity of AKI and inflammation. Leukocyte subsets were analyzed by flow cytometry, and proinflammatory cytokines were analyzed by quantitative PCR. Plasma and tissue levels of TPPU and lipid mediators were analyzed by liquid chromatography mass spectrometry. IRI resulted in a blood pressure increase of 20 mmHg in the vehicle-treated group. TPPU and enalapril normalized blood pressure and reduced mesangial matrix expansion. However, inflammation and progressive renal fibrosis were severe in all groups. TPPU further reduced renal perfusion on days 1 and 14. In conclusion, early antihypertensive treatment worsened renal outcome after AKI by further reducing renal perfusion despite reduced glomerulosclerosis.

Novel Toxicology Program to Support the Development of Inhaled VentaProst.

Currently, off-label continuous administration of inhaled epoprostenol is used to manage hemodynamics during mitral valve surgery. A toxicology program was developed to support the use of inhaled epoprostenol during mechanical ventilation as well as pre- and postsurgery via nasal prongs. To support use in patients using nasal prongs, a Good Laboratory Practice (GLP), 14-day rat, nose-only inhalation study was performed. No adverse findings were observed at ∼50× the dose rate received by patient during off-label use. To simulate up to 48 hours continuous aerosol exposure during mechanical ventilation, a GLP toxicology study was performed using anesthetized, intubated, mechanically ventilated dogs. Dogs inhaled epoprostenol at approximately 6× and 13× the dose rate reported in off-label human studies. This novel animal model required establishment of a dog intensive care unit providing sedation, multisystem support, partial parenteral nutrition, and management of the intubated mechanically ventilated dogs for the 48-hour duration of study. Aerosol was generated by a vibrating mesh nebulizer with novel methods required to determine dose and particle size in-vitro. Continuous pH 10.5 epoprostenol was anticipated to be associated with lung injury; however, no adverse findings were observed. As no toxicity at pH 10.5 was observed with a formulation that required refrigeration, a room temperature stable formulation at pH 12 was evaluated in the same ventilated dog model. Again, there were no adverse findings. In conclusion, current toxicology findings support the evaluation of inhaled epoprostenol at pH 12 in surgical patients with pulmonary hypertension for up to 48 hours continuous exposure.

Traditional Chinese medicine practices used in COVID-19 (Sars-cov 2/Coronavirus-19) treatment in clinic and their effects on the cardiovascular system.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of plants used in the formulations of traditional Chinese medicine (TCM), which were also used in clinical trials to treat patients with the novel coronavirus COVID-19, and to assess their effects on the cardiovascular system. METHODS: A literature review of PubMed, ResearchGate, ScienceDirect, the Cochrane Library, and TCM monographs was conducted and the effects of the plants on the cardiovascular system and the mechanisms of action in COVID-19 treatment were evaluated. RESULTS: The mechanism of action, cardiovascular effects, and possible toxicity of 10 plants frequently found in TCM formulations that were used in the clinical treatment of COVID-19 were examined. CONCLUSION: TCM formulations that had been originally developed for earlier viral diseases have been used in COVID-19 treatment. Despite the effectiveness seen in laboratory and animal studies with the most commonly used plants in these formulations, the clinical studies are currently insufficient according to standard operating procedures. More clinical studies are needed to understand the safe clinical use of traditional plants.

Pharmacological characterization of the cardiovascular effect of Nibethione: ex vivo, in vivo and in silico studies.

OBJECTIVE: This work describes the vasorelaxant and antihypertensive effects and the mechanism of action on vascular smooth muscle cells of Nibethione, a synthetic thiazolidinedione derivative. Additionally, evidence of its cytotoxicity is assessed. METHODS: Nibethione (NB) was synthesized, and its vasorelaxant effect and mechanism of action were assessed through ex vivo experiments. Molecular docking studies were used to predict the mode of interaction with L-type Ca2+ channel, and in vivo antihypertensive activity was assayed on spontaneously hypertensive rats (SHR). The cytotoxicity potential was evaluated in porcine aortic endothelial cells (PAECs) from primary explants. KEY FINDINGS: Nibethione vasorelaxant effect was efficient on KCl (80 mm) and NE-contraction. This effect was deleteriously modified in the presence of potassium channel block drugs, while the maximal contraction induced with NE was significantly decreased by NB; the CaCl2 -induced contraction was abolished entirely. In vivo experiments showed that NB decreased diastolic blood pressure in 20.3 % after its administration on SHR. The molecular docking showed that NB blocks L-type Ca2+ channel, and in vitro tests showed that NB did not produce cytotoxic activity on PAECs (IC50 >1000 µm). CONCLUSIONS: Nibethione showed in vivo antihypertensive and ex vivo vasorelaxant effects with implication of voltage-dependent L-type Ca2+ channel blocking, and this may contribute to the research of novel antihypertensive drugs.

Modification of the Microtox® Basic Solid Phase Test: A new application for the ecotoxicological studies on poorly soluble antihypertensive drugs.

Increasing consumption of angiotensin II receptor blockers (ARBs: valsartan, losartan potassium, telmisartan) is inevitably associated with their appearance in the environment and impact on aquatic and terrestrial organisms. Since the pharmaceuticals do not occur as pure substances in the environment, but as complex mixtures with other active pharmaceutical ingredients (APIs) and excipients used in pharmaceutical formulations, we compared the ecotoxicity of ARBs in various forms: as pure APIs, in pharmaceutical formulations and in mixtures with hydrochlorothiazide (HCT). Because the studied APIs are poorly water-soluble, the Microtox® Basic Solid Phase Test, utilizing bacteria Aliivibrio fischeri, has been modified by using a neutral matrix. Thus, this test, which is correlated with other tests for higher aquatic organisms, may be applied for the ecotoxicological evaluation of poorly soluble APIs. This is the first study reflecting the real situation in the environment, where non-target species are exposed to the pharmaceuticals, which can be dissolved/suspended in the liquid medium or adsorbed on the solid matrix. The results obtained indicate that the excipients are not inert substances and their presence in the environment may cause an increased risk to non-target organisms. Moreover, antagonistic effects were observed for two-component drug-drug (ARBs-HCT) mixtures.

The Antiglaucoma Agent and EP2 Receptor Agonist Omidenepag Does Not Affect Eyelash Growth in Mice.

Purpose: The present study investigated the effects of the antiglaucoma agent and selective E2 receptor agonist omidenepag isopropyl (OMDI) on eyelash growth in comparison with a prostaglandin analog (prostamide receptor agonist) in mice. Methods: Four-week-old female mice (C57BL/6J) were divided into 3 groups of n = 10 each. The groups were administered 3 µL of 0.003% OMDI solution, the vehicle (negative control), or a 0.03% bimatoprost solution (positive control) on the upper eyelids of the right eyes once daily for 14 days. On the 15th day, all animals were euthanized, and the upper eyelids with eyelashes were fixed with 10% neutral formalin. Eyelashes were evaluated for number, length, and thickness using a stereomicroscope. Specimens were then paraffin-embedded and stained with hematoxylin and eosin, followed by microscopic examination to assess eyelash morphology and growth cycle. Results: Eyelash number (143.5 ± 6.7/eyelid), thickness, and percentage of dermal papilla in the anagen phase in the OMDI group were similar to those observed in the vehicle group (eyelash number, 144.2 ± 5.7/eyelid). In contrast, eyelash number (166.7 ± 7.0/eyelid), thickness, and the percentage of dermal papilla in the anagen phase were significantly greater in the bimatoprost group compared with those of the vehicle group. Conclusions: Unlike existing prostaglandin analogs, our findings indicate that OMDI has no effect on eyelash growth in mice, suggesting that it may be a promising antiglaucoma agent with a reduced number of adverse effects.

Nanoemulsion as a feasible and biocompatible carrier for ocular delivery of travoprost: Improved pharmacokinetic/pharmacodynamic properties.

Travoprost is a synthetic prostaglandin F2α analogue used in treatment of glaucoma. Due to its water insolubility and oily nature, novel delivery systems need to be developed to enhance its bioavailability, and sustain its release. In the current work, travoprost nanoemulsion was explored as a novel carrier prepared using low energy technique. Results showed that travoprost nanoemulsions exhibited suitable nanodroplet size, zeta potential, pH, refractive index, controlled release, as well as sufficient stability under accelerated conditions. In vivo studies delineated the enhanced absorption of travoprost nanoemulsion compared to the marketed eye drops Travatan®, as proven by the higher Cmax and AUC of the former, and its prolonged intraocular pressure reduction time. Moreover, the nanoemulsion formulation was proven safe and non-irritant to ocular surfaces. Therefore, it can be suggested that travoprost nanoemulsion is a promising ocular delivery system for glaucoma treatment.

Corneal damage and its recovery after instillation of preservative-free versus preserved latanoprost eye drops.

Purpose: Latanoprost ophthalmic solution is highly effective as a therapeutic agent for glaucoma and is applied worldwide. However, harmful effects on the corneal surface have been reported regarding the commercially available latanoprost ophthalmic solution. Corneal surface toxicity may be caused by the added preservative of the ophthalmic solution. In order to ascertain whether latanoprost itself can damage the cornea or if this is solely due to the added preservatives, this study attempted to determine the corneal changes that occur at different time periods following usage of preservative-free versus preserved latanoprost eye drops.Materials and methods: Preservative-free latanoprost eye drops (Monoprost®) or preserved latanoprost eye drops (Xalatan®) containing 0.02% benzalkonium chloride (BAC) were instilled in the corneas of rabbits. For each of the two different eye drop solutions, the rabbits used in this experiment were divided into three exposure groups: 1 minute, 24 hour, and 1 week groups. Corneal transepithelial electrical resistance (TER) and scanning electron microscopy (SEM) were examined immediately (1 minute) after instillation, at 24 hours after instillation, and at 24 hours after 1 week of daily instillations of latanoprost. Hank's balanced salt solution was used in the control group.Results: The mean corneal TER of the control group was 933.8 ± 279.0 Ω cm2. In preservative-free latanoprost instilled corneas, there was no significant decrease in the TER or morphological changes at any of the time points, with the relative TER values of 117 ± 38%, 100 ± 34%, and 93 ± 21% for 1 minute, 1 day, and 1 week time points, respectively. In preserved latanoprost instilled corneas, SEM showed that only the immediate group exhibited superficial cell damage and a significant decrease in the corneal TER compared to the controls and other time points and to the immediate preservative-free latanoprost corneas. In the preserved latanoprost groups, the relative TER values were 18 ± 5%, 110 ± 28%, and 92 ± 10%, for the three respective observation time points.Conclusions: Preservative-free latanoprost can be safely instilled to the corneal epithelium. Latanoprost with 0.02% BAC has an immediate deleterious impact on the corneal epithelium; however, it disappears within 24 hours after instillation.

Urine kidney safety biomarkers improve understanding of indirect intra-renal injury potential in dogs with a drug-induced prerenal azotemia.

Drug-induced kidney injury (DIKI) is a frequent occurrence in nonclinical drug development. It is well established that novel urine kidney safety biomarkers will outperform urea nitrogen (BUN) and serum creatinine (sCr) for monitoring direct drug injury to the kidney across numerous compounds spanning diverse mechanisms and efforts are underway for a formal regulatory clinical qualification. However, it remains unclear how these novel biomarkers will perform under prerenal azotemia when BUN and sCr are elevated but no intra-renal injury is suspected. This lack of knowledge is largely due to the dearth of such nonclinical animal models. We report here that treatment of dogs with a potent antihypertensive compound MK-5478 at a suprapharmacologic dose for up to 9 days results in the development of prerenal azotemia and, in some dogs, kidney toxicity through the dual sustained effects of MK-5478 as a nitric oxide donor and an angiotensin II receptor blocker (ARB). While conventional serum biomarkers BUN, and often sCr as well, were highly elevated in these dogs with or without kidney damage, urine kidney biomarkers clusterin (CLU) and neutrophil gelatinase-associated lipocalin (NGAL) showed increases only in dogs with kidney histopathologic changes following the sustained period of prerenal azotemia. Urine albumin (ALB) and total protein also tracked with kidney lesions but with less sensitivity. Thus, we present evidence for the first time that urine kidney safety biomarkers used together with BUN and sCr can distinguish intra-renal injury among dogs with prerenal azotemia while the conventional serum biomarkers alone are ambiguous, either being interpreted as false positives of kidney injury, or dismissed under circumstances as benign without appreciation for a threshold of impending injury.

Toxicity profiles of fixed-combination eye drops for glaucoma therapy using cultivated human corneal epithelial sheets.

PURPOSE: We aimed to investigate the toxicity of 6 fixed-combination drugs for glaucoma therapy using human corneal epithelial sheets (HCES). STUDY DESIGN: Experimental. MATERIALS AND METHODS: We used 6 kinds of commercially available fixed-combination drugs: latanoprost/carteolol (LAT/CAR), latanoprost/timolol (LAT/TIM), tafluprost/timolol (TAF/TIM), travoprost/timolol (TRA/TIM), brinzolamide/timolol (BRZ/TIM), and dorzolamide/timolol (DRZ/TIM) including different preservatives. The cell viability and barrier function of the HCES after exposure to the eye drops for 10 or 30 minutes were assessed using the WST-1 assay and transepithelial electrical resistance (TEER) measurements, respectively. The HCES were also evaluated using hematoxylin and eosin (HE) staining and transmission electron microscopy. RESULTS: The cell viability significantly decreased in the HCES treated with LAT/TIM or DRZ/TIM after 10 and 30 minutes and in those treated with BRZ/TIM after 30 minutes. The barrier function increased significantly in the HCES treated with LAT/CAR. Histologically, the HCES were damaged after treatment with LAT/TIM, BRZ/TIM, or DRZ/TIM for 30 minutes. Transmission electron microscopy indicated narrow intercellular spaces and multiple intercellular junctions in the HCES treated with LAT/CAR, TAF/TIM, or TRA/TIM. The HCES treated with DRZ/TIM, BRZ/TIM, or LAT/TIM contained cytoplasmic vacuoles and collapsed cellular structures. CONCLUSION: Glaucoma fixed-combination eye drops demonstrated a different toxic effect on the cell viability, barrier function, and morphologic changes of HCES.