Stability of microencapsulated B. lactis (BI 01) and L. acidophilus (LAC 4) by complex coacervation followed by spray drying

Microcapsules containing Bifidobacterium lactis (BI 01) and Lactobacillus acidophilus (LAC 4) were produced by complex coacervation using a casein/pectin complex as the wall material, followed by spray drying. The aim of this study was to evaluate the resistance of these microorganisms when submitted to the spray drying process, a shelf-life of 120 days at 7–37°C and the in vitro tolerance after being submitted to acid pH (pH 1.0 and 3.0) solutions besides morphology of microcapsules. Microencapsulated microorganisms were shown to be more resistant to acid conditions than free ones. Microencapsulated L. acidophilus maintained its viability for a longer storage period at both temperatures. The microcapsules presented a spherical shape with no fissures. The process used and the wall material were efficient in protecting the microorganisms under study against the spray drying process and simulated gastric juice; however, microencapsulated B. lactis lost its viability before the end of the storage time.     

Application of whey protein micro-bead coatings for enhanced strength and probiotic protection during fruit juice storage and gastric incubation

Context: Coated whey protein micro-beads may improve probiotic protection and provide delayed cell-release mechanisms.

Objective: Lactobacillus rhamnosus GG was encapsulated in whey protein micro-beads by droplet extrusion with coating via electrostatic deposition: primary-polysaccharide and secondary-whey protein.

Materials and methods: Storage studies were performed in cranberry and pomegranate juice (pH 2.4; 28 days; 4 and 25°C) followed by simulated ex vivo porcine gastric (pH 1.6) and intestinal (pH 6.6) digestion.

Results and discussion: After storage and simulated gastro-intestinal digestion, free cells, cells suspended in protein and cells encapsulated in alginate micro-beads, illustrated complete probiotic mortality, while coated micro-beads enhanced probiotic viability after juice storage (8.6?±?0.1 log₁₀CFUmL^?1). Beads also showed significant binding of hydrophobic molecules. Coated micro-beads illustrated high gastric survival (9.5?±?0.1 log₁₀CFUmL^?1) with 30?min delayed intestinal release relative to non-coated micro-beads.

Conclusions: Micro-bead coatings could be applied in delayed cell-release for targeted intestinal probiotic delivery.     

Microencapsulation in genipin cross-linked gelatine-maltodextrin improves survival of Bifidobacterium adolescentis during exposure to in vitro gastrointestinal conditions

To improve survival during exposure to adverse conditions, probiotic Bifidobacterium adolescentis 15703T cells were encapsulated in novel mono-core and multi-core phase-separated gelatine-maltodextrin (GMD) microspheres where the gelatine (G) phase was cross-linked with genipin (GP). Microscopy showed that encapsulated cells were exclusively associated with maltodextrin (MD) core(s). Small (average diameter 37 µm) and large (70 µm) GMD and G microspheres were produced by modulating factors (e.g. mixing speed, surfactant, GP and G concentrations) affecting the size, structural stability and phase-separation. In vitro sequential gastro-intestinal (GI) juice challenge experiments revealed increased survival of cells encapsulated in GMD (～10^6–7 cfu mL^?1) and G (～10⁵ cfu mL^?1) microspheres as compared to free cells (～10⁴ cfu mL^?1). In GMD microspheres, the bacteria derive energy from MD to survive during exposure to acid and bile salts. In conclusion, the novel food grade GMD microencapsulation formulation was shown to protect probiotic bifidobacteria from adverse conditions.     

Microencapsulation of an indigenous isolate of Bacillus thuringiensis by spray drying

In this study, microencapsulation by spray drying was performed to protect spores and crystals of an indigenous isolate of Bacillus thuringiensis Se13 from environmental stress. The effects of wall material, inlet temperature, and outlet temperature on microencapsulation of Bt-Se13 were investigated using Taguchi’s orthogonal array. The most suitable wall material determined as maltodextrin DE10. The optimum inlet and outlet temperatures of spray drier were determined as 160?°C and 70?°C, respectively. The number of viable spores, mean particle size, wetting time, percentage of suspensibility and moisture content of the product produced under optimum conditions were determined as 8.1?×?10¹¹ cfu g^?1, 13.462?µm, 25.22?s, 77.66% and 7.29%, respectively. As a result of efficiency studies on Spodoptera exigua in the laboratory conditions, the LC₅₀ was determined as 1.6?×?10⁴ cfu mL^?1. Microencapsulated Bt-Se13 based bio-pesticide may be registered for the control of S. exigua and can be tested against other lepidopterans which share the same environment.     

Soy extract and maltodextrin as microencapsulating agents for Lactobacillus acidophilus: a model approach

Abstract

The present study aimed to optimise the microencapsulation of Lactobacillus acidophilus La-05 by spray drying, using soy extract and maltodextrin as encapsulants. Air inlet temperature, maltodextrin/soy extract ratio and feed flow rate were investigated through Central Composite Rotational Design (CCRD). Probiotic viability increased with increasing the proportion of soy extract. Temperature and feed flow rate had a negative effect. Particle diameter ranged from 4.97 to 8.82?μm, water activity from 0.25 to 0.52 and moisture from 2.30 to 7.01?g.100g^?1 Particles produced following the optimised conditions (air temperature of 87?°C, maltodextrin/soy extract ratio of 2:3 w.w^?1, feed flow rate of 0.54?L.h^?1) reached Encapsulation yield (EY) of 83%. Thermogravimetry and FTIR analysis suggested that microcapsules could protect L. acidophilus cells against dehydration and heating. During storage, microencapsulated probiotic had high cell viability (reductions ranged between 0.12 and 1.72 log cycles). Soy extract/maltodextrin presented well-encapsulating properties of Lactobacillus acidophilus La-05.     

Microentrapment of probiotic bacteria in a Ca2 +-induced whey protein gel and effects on their viability in a dynamic gastro-intestinal model

Entrapping probiotic bacteria in gels with ionic cross-linking is typically achieved with polysaccharides (alginate, pectin, carraghenan). In this study, whey proteins were used for this purpose by carrying out the Ca²⁺-induced gelation of pre-heated whey protein isolate (WPI). A Lactobacillus rhamnosus cell suspension was added in a denatured WPI solution in a 30?:?70 volume ratio. Gelation was carried out by extrusion of the cell suspension in a CaCl₂ solution. Beads of ～3?mm diameter were formed. The population in the beads was 8.0?×?10⁸?cells?g^?1. Entrapment efficiency in gel beads was 96%, with a survival level of 23%. Scanning electron microscopy of beads before freeze-drying showed a tight protein network containing encapsulated Lb. rhamnosus cells homogeneously distributed throughout the matrix. The survival to freeze-drying of the bead-entrapped cells was 41%. Viability of microentrapped cells in a dynamic gastro-intestinal (GI) model was studied and the results were compared to free cells freeze-dried in a milk-based cryoprotective solution, as well as in a pre-denatured WPI solution. Results showed that protein gelation provided protection against acidic conditions in the stomach after 90?min, as well as against bile after 30, 60 and 90?min in the duodenum. Moreover, the milk-based cryoprotective solution was equally effective after 90?min in the duodenum. It is concluded that the gelation of whey proteins induced by Ca²⁺ ions can protect the cells against adverse conditions of the GI system. However, certain stages in the entrapment process, particularly extrusion in the solution of CaCl₂, still need to be optimized in order to reduce the mortality of the cells during gelation.     

Mechanism of action of relaxant effect of Agastache mexicana ssp.mexicana essential oil in guinea-pig trachea smooth muscle

Context: Agastache mexicana ssp. mexicana (Kunth) Lint &; Epling (Lamiaceae), popularly known as ‘toronjil morado’, is used in Mexican traditional medicine for the treatment of several diseases such as hypertension, anxiety and respiratory disorders.

Objective: This study investigates the relaxant action mechanism of A. mexicana ssp. mexicana essential oil (AMEO) in guinea-pig isolated trachea model.

Materials and method: AMEO was analyzed by GC/MS. The relaxant effect of AMEO (5–50?μg/mL) was tested in guinea-pig trachea pre-contracted with carbachol (3?×?10?^??⁶?M) or histamine (3?×?10?^??⁵?M) in the presence or absence of glibenclamide (10?^??⁵?M), propranolol (3?×?10?^??⁶?M) or 2′,5′-dideoxyadenosine (10?^??⁵?M). The antagonist effect of AMEO (10–300?μg/mL) against contractions elicited by carbachol (10?^??¹⁵–10?^??³?M), histamine (10?^??¹⁵–10?^??³?M) or calcium (10–300?μg/mL) was evaluated.

Results: Essential oil composition was estragole, d-limonene and linalyl anthranilate. AMEO relaxed the carbachol (EC_50?=_?18.25?±?1.03?μg/mL) and histamine (EC_50?=_?13.3?±?1.02?μg/mL)-induced contractions. The relaxant effect of AMEO was not modified by the presence of propranolol, glibenclamide or 2′,5′-dideoxyadenosine, suggesting that effect of AMEO is not related to β₂-adrenergic receptors, ATP-sensitive potassium channels or adenylate cyclase activation. AMEO was more potent to antagonize histamine (pA₂′?=??1.507?±?0.122) than carbachol (pA₂′?=??2.180?±?0.357). Also, AMEO antagonized the calcium chloride-induced contractions.

Conclusion: The results suggest that relaxant effect of AMEO might be due to blockade of calcium influx in guinea-pig trachea smooth muscle. It is possible that estragole and d-limonene could contribute majority in the relaxant effect of AMEO.     

Potentiation of pro-inflammatory cytokine suppression and survival by microencapsulated dexamethasone in the treatment of experimental sepsis

Cytokine inhibiting drugs are much more effective when delivered intracellularly to phagocytic cells in the microencapsulated form. Dexamethasone is a powerful inhibitor of TNF-α cytokine through inhibition of NF-κB which is a gene regulator of multiple pro-inflammatory cytokines. We have determined the effect of microencapsulated dexamethasone in pro-inflammatory cytokine release both in in vitro using whole blood model, and in vivo using peritonitis model of septic shock. Microspheres of 1–4 μm mean size were prepared by using albumin polymer matrix in a one-step spray drying method. Microencapsulated form of dexamethasone with concentration of 10^?1, 10^?2 and 10^?3 M was compared to an equivalent concentration of solution form of dexamethasone in the in vitro whole blood model. The results show microencapsulated dexamethasone inhibited tumor necrosis factor-alpha (TNF-α) and interleukin-beta (IL-1β) significantly in comparison with the solution form of dexamethasone. The in vivo peritonitis model also demonstrated significant inhibition of TNF-α and IL-1β cytokines in microencapsulated form in comparison with solution form of dexamethasone. In the in vivo study, the animal survival rate after 5 days was 90%, dexamethasone in solution with gentamicin was 40% and gentamicin alone was 30%. This study demonstrates significantly improved inhibition of TNF-α and IL-1β both in vivo and in vitro when dexamethasone was used in microencapsulated form.     

Pharmacological characterization of mechanisms involved in the vasorelaxation produced by rosuvastatin in aortic rings from rats with a cafeteria‐style diet

The present study aimed to investigate the possible influence of several inhibitors and blockers on the vascular effect produced by the acute in vitro application of rosuvastatin to phenylephrine‐precontracted aortic rings from rats with a semi‐solid, cafeteria‐style (CAF) diet. It also aimed to examine the effects of rosuvastatin on the expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase in aortic rings from rats with a CAF diet. From comparisons of the effect on phenylephrine‐precontracted aortic rings extracted from rats with two different diets (a standard and a CAF diet), it was found that 10^?9–10^?5‐mol/L rosuvastatin produced lower concentration‐dependent vasorelaxation on rings from the CAF diet group. The vasorelaxant effect was unaffected by the vehicle, but it was significantly attenuated by 10^?5‐mol/L N^G‐nitro‐l ‐arginine methyl ester, 10^?2‐mol/L tetraethylammonium, 10^?3‐mol/L 4‐aminopyridine, 10^?7‐mol/L apamin plus 10^?7‐mol/L charybdotoxin, 10^?5‐mol/L indomethacin, or 10^?5‐mol/L cycloheximide. Moreover, in aortic rings from rats with a CAF diet, rosuvastatin enhanced the expression of eNOS, inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase. The acute in vitro application of rosuvastatin to phenylephrine‐precontracted aortic rings from rats with a CAF diet had a vasorelaxant effect. Overall, the present results suggest that the stimulation of eNOS, the opening of Ca²⁺‐activated and voltage‐activated K⁺ channels, the stimulation of prostaglandin synthesis and enhanced protein levels of eNOS, inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase are involved in this relaxant effect.     

Pharmacokinetics of reboxetine in healthy volunteers. Single oral doses,linearity and plasma protein binding

The pharmacokinetics of reboxetine, a new antidepressant agent, were found to be close to linear in a crossover study comparing administration of single 2, 3, 4 and 5 mg capsule doses in 15 healthy male volunteers, and in the same study the capsules were bioequivalent to the proposed therapeutic tablet formulation (4mg). Kinetic analysis was based on HPLC assay of reboxetine in plasma and urine collected up to 72 h after each administration. Plasma levels indicated a rapid absorption (t_max?2h) and an elimination half-life of about 13 h. Clearance and volume of distribution were modest (ratios to bioavailability: CL/F?29 mL min^?1; V_z/F?32L); urinary excretion was ～9% of dose, corresponding to a renal clearance of only 3 mL min^?1 (a value consistent with the rate of glomerular filtration of unbound drug). In vitro, binding to plasma proteins, estimated from radioactivity levels following dialysis of ¹⁴C-labelled reboxetine, appeared to be dominated by α₁-acid glycoprotein without marked saturation up to plasma concentrations of over 500 ng mL^?1 (2.8–3.1% unbound with human plasma from three additional volunteers; 1.8–2.0% for 2gL^?1 orosomucoid α₁-acid glycoprotein, and 46.4–47.4% for 40 gL^?1 albumin), whilst the mean C_max in the current study was much lower (164 ng mL^?1 after a 5 mg dose).     

EFFECTS OF NITRO-l-ARGININE ON ENDOTHELIUM-DEPENDENT RELAXATION OF CANINE CEREBRAL ARTERIES

1. The effect of N^G-nitro-l-arginine (NO₂Arg) on the relaxation of canine basilar artery was investigated and compared with those of middle cerebral and femoral arteries. 2. NO₂Arg (10^?7-3 × 10^?5 mol/L) inhibited the substance-P (Sub-P; 10^?12-10^?8 mol/L) induced relaxation in the basilar artery precontracted with prostaglandin F_2α (PGF_2α; 10^?5 mol/L) or KCl (10^?2 mol/L) in a concentration-dependent manner and a ratio of the maximum inhibition by NO₂Arg (3 × 10^?5 mol/L) was more than 90%. 3. The relaxation induced by A23187 (10^?9-3 × 10^?6) was also abolished by NO₂Arg (3 × 10^?5 mol/L), but that by glyceryl trinitrate (GTN; 10^?9-3 × 10^?5 mol/L) was not, in the basilar artery precontracted with PGF_2α (10^?5 mol/L). N^G-nitro-d-arginine (NO₂ArgD; 3 × 10^?5 mol/L) did not affect the relaxation induced by Sub-P (10^?12-10^?8 mol/L). 4. l-arginine (l-Arg; 3 × 10^?5-10^?4 mol/L) did not inhibit Sub-P (10^?12-10^?8 mol/L) induced relaxation in the basilar artery. Pretreatment of l-Arg (10^?4 mol/L) reversed the relaxation inhibited by NO₂Arg (3 × 10^?6 mol/L) in the arteries. 5. NO₂Arg (3 × 10^?5 mol/L) inhibited the Sub-P (10^?12-10^?8 mol/L) induced relaxation in the canine middle cerebral artery as much as in the basilar artery. NO₂Arg (3 × 10^?5 mol/L) also inhibited Sub-P (10^?12-10^?8 mol/L) induced relaxation in the femoral artery, but the degree of the inhibition was less than that in the basilar artery. 6. These results suggest that the endothelium-derived relaxing factor (EDRF) of canine basilar artery is mainly l-Arg derived nitric oxide which may play a more important role in the basilar artery than the femoral artery.     

Survival and stability of bifidobacteria loaded in alginate poly-l-lysine microparticles

Bifidobacteria-loaded alginate microparticles were prepared by spraying a mixture of alginate and bifidobacteria culture using an air atomization method. Survival and stability of bifidobacteria loaded in microparticles were then evaluated. Survival of bifidobacteria from alginate poly-l-lysine microparticles was significantly increased when MRS broth or yeast extract was added in simulated intestinal fluid (pH 6.8). The number of bifidobacteria gradually increased for 8 h (10⁸ cfu/g) and then reached about 10⁹–10¹⁰ cfu/g when incubated over 12 h in intestinal fluid containing 0.5% yeast extract and 0.05% -cysteine. The survival of bifidobacteria was highly dependent on the pH of the exposing media. When the bifidobacteria was immobilized with alginate or even poly-l-lysine treatment, the survival of bifidobacteria was highly enhanced in the low pH conditions (ca. >10⁸ vs. <10³ cfu/g). The stability of free flowing bifidobacteria-loaded alginate poly-l-lysine microparticles was significantly improved during storage at 4°C in a refrigerator when compared to bifidobacteria cultures. The bifidobacteria-loaded alginate poly-l-lysine microparticles could be applied to various dairy products.     

Peptides extracted from edible mushroom: Lentinus squarrosulus induces apoptosis in human lung cancer cells

Context: Lentinus squarrosulus Mont. (Polyporaceae) is an interesting source of diverse bioactive compounds.

Objective: This is the first study of the anticancer activity and underlying mechanism of peptides extracted from Lentinus squarrosuls.

Materials and methods: Peptides were isolated from the aqueous extract of L. squarrosulus by employing solid ammonium sulphate precipitation. They were further purified by ion-exchange chromatography on diethylaminoethanol (DEAE)-cellulose and gel filtration chromatography on Sephadex G25. Anticancer activity was investigated in human lung cancer H460, H292 and H23 cells cultured with 0–40?μg/mL of peptide extracts for 24?h. Cell viability and mode of cell death were evaluated by MTT and nuclear staining assay, respectively. Western blotting was used to investigate the alteration of apoptosis-regulating proteins in lung cancer cells treated with peptide extracts (0–20?μg/mL) for 24?h.

Results: The cytotoxicity of partially-purified peptide extracts from L. squarrosulus was indicated with IC₅₀ of ～26.84?±?2.84, 2.80?±?2.14 and 18.84?±?0.30?μg/mL in lung cancer H460, H292 and H23 cells, respectively. The extracts at 20?μg/mL induced apoptosis through the reduction of anti-apoptotic Bcl-2 protein (～0.5-fold reduction) and up-regulation of BAX (～4.5-fold induction), a pro-apoptotic protein. Furthermore, L. squarrosulus peptide extracts (20?μg/mL) also decreased the cellular level of death receptor inhibitor c-FLIP (～0.6-fold reduction).

Conclusions and discussion: This study provides the novel anticancer activity and mechanism of L. squarrosulus peptide extracts, which encourage further investigation and development of the extracts for anticancer use.     

Effect of matrix composition,sphere size and hormone concentration on diffusion coefficient of insulin for controlled gastrointestinal delivery for diabetes treatment

Oral insulin administration is limited due to its degradation by proteases. The hormone was encapsulated in spheres made of either pure calcium alginate (ALG) or its association with whey protein isolate (WPI-ALG) in order to minimise loss in the stomach region while allowing liberation in the maximum absorption area, located in the intestine. Diffusion coefficients for both matrix compositions were determined in vitro for gastric pH (5.88 and 10.26?×?10^?12?m²?s^?1) and intestinal pH (21.11 and 79.29?×?10^?12?m²?s^?1). Higher initial insulin concentrations and lower diameters accelerated its release, confirming Fickian behaviour. The analytic model exhibited a good fit in most cases. Computer simulations revealed that ALG spheres are more convenient for oral administration because they release more insulin in the intestine than the WPI-ALG ones, thus supporting its therapeutic viability for the purpose of reducing stress in those who depend on insulin.     

Epidural Metabolism of Articaine to its Metabolite Articainic Acid in Five Patients after Epidural Administration of 600 mg Articaine

The clinical pharmacokinetics, metabolism and renal excretion of articaine and its metabolite articainic acid have been investigated in man after epidural administration. (±)-Articaine and its metabolite (±)-articainic acid have different pharmacokinetic constants (P = 00079) except for lag-time (t_lag; 0.06 min), first phase distribution of elimination (t½_α; 0.49 ± 0.21 h), and elimination half life (t½_α; 2.19 ± 0.98 h), which are all the same for both compounds. The total body clearance of articaine (103 ± 57 L h^?1) is 10 times higher than that of the metabolite articainic acid (10.7 ± 1.80 L h^?1, P = 0.0079). With similar half-life (t½β) values (2 h), the volumes of distribution (V_β) are 10 times higher for the parent drug than for the metabolite ((329 ± 212 L compared with 38.4 ± 7.5 L, respectively; P = 0.0079). The difference between the areas under the curves for total plasma articainic acid and that formed in the plasma gives an indication of the percentage metabolism during epidural transfer (5.38 ± 1.51%). This percentage of metabolism corresponds to a mean epidural transfer time of 5 min. The main compound in the urine is articainic acid (64.2 ± 14.4%), followed by articainic acid glucuronide (13.4 ± 4.97%) and the parent drug (1.45 ± 0.77%). In total, 79.0 ± 18.5% of the dose is recovered in the urine. The renal clearance of articaine is 22.5 ± 13.9 mL min^?1, whereas that of articainic acid is 119.6 ± 30.1 mL min^?1 (P < 0.0001). The apparent renal clearance of articainic acid glucuronide was 25.4 ± 12.0 mL min^?1. This value does not differ from that of the parent drug (P > 0.8). Articainic acid glucuronide is not present in plasma, but has an apparent renal clearance of 25 mL min^?1. These results suggest that articainic acid is glucuronidated by the tubular cells and then excreted.     

Effect of 17β-oestradiol replacement on vascular responsiveness in ovariectomized diabetic rats

1. Women with functional ovaries exhibit a gender advantage in terms of the prevalence of cardiovascular diseases. However, whether this gender bias pertains in diabetes is unknown. 2. The aim of the present study was to examine the effects of 17β‐oestradiol (E2) on vascular responsiveness in normal and diabetic ovariectomized (OVX) rats. Aged‐matched female rats were divided into four groups as follows: (i) OVX; (ii) OVX + E2 treated; (iii) diabetic OVX; and (iv) diabetic OVX + E2 treated. Bilateral ovariectomy was performed and streptozotocin was used to induce experimental diabetes. Rats were treated with 1 mg/kg per day, p.o., E2 for 8 weeks. 3. Although E2 treatment had no effect on blood glucose levels in normal and diabetic OVX rats, it significantly reduced systolic blood pressure and prevented diabetes‐induced loss of bodyweight gain. 4. In segments of the thoracic aorta, concentration‐dependent vasoconstrictor responses to KCl and phenylephrine were significantly attenuated following E2 treatment in both the normal and diabetic groups. The sarcoplasmic/endoplasmic reticulum calcium ATPase inhibitor thapsigargin (10^?6 mol/L) and the Ca²⁺ channel blocker nifedipine (10^?6 mol/L) inhibited the transient vasoconstriction to PE in all groups. The constrictor effect of PE was increased by the nitric oxide synthase inhibitor N^G‐nitro‐l‐ arginine methyl ester (l ‐NAME; 10^?6 mol/L), but was reduced by superoxide dismutase (SOD; 100 U/mL) and the cyclo‐oxygenase inhibitor indomethacin (10^?6 mol/L) in all groups. Responses to acetylcholine (ACh; 10^?6 mol/L) demonstrated reduced endothelium‐dependent relaxation in non‐E2‐treated groups. Relaxation responses to ACh were increased by 100 U/mL SOD and 10^?6 mol/L indomethacin, but were reduced by 10^?6 mol/L l ‐NAME in all groups. There were no differences among the four groups in terms of relaxation responses to sodium nitroprusside (10^?11 to 10^?6 mol/L). 5. In conclusion, the results of the present study suggest that oestrogen treatment has beneficial effects on vascular function in both diabetic and non‐diabetic OVX rats due to Ca²⁺ regulation and anti‐oxidation.     

Preclinical assessment of the ADME,efficacy and drug-drug interaction potential of a novel NAMPT inhibitor

1. GNE-617 (N-(4-((3,5-difluorophenyl)sulfonyl)benzyl)imidazo[1,2-a]pyridine-6-carboxamide) is a potent, selective nicotinamide phosphoribosyltransferase (NAMPT) inhibitor being explored as a potential treatment for human cancers.

2. Plasma clearance was low in monkeys and dogs (9.14?mL min^?1?kg^?1 and 4.62?mL min^?1?kg^?1, respectively) and moderate in mice and rats (36.4?mL min^?1?kg^?1 and 19.3?mL min^?1?kg^?1, respectively). Oral bioavailability in mice, rats, monkeys and dogs was 29.7, 33.9, 29.4 and 65.2%, respectively.

3. Allometric scaling predicted a low clearance of 3.3?mL min^?1?kg^?1 and a volume of distribution of 1.3?L kg^?1 in human.

4. Efficacy (57% tumor growth inhibition) in Colo-205 CRC tumor xenograft mice was observed at an oral dose of 15?mg/kg BID (AUC?=?10.4?µM h).

5. Plasma protein binding was moderately high. GNE-617 was stable to moderately stable in vitro. Main human metabolites identified in human hepatocytes were formed primarily by CYP3A4/5. Transporter studies suggested that GNE-617 is likely a substrate for MDR1 but not for BCRP.

6. Simcyp^® simulations suggested a low (CYP2C9 and CYP2C8) or moderate (CYP3A4/5) potential for drug-drug interactions. The potential for autoinhibition was low.

7. Overall, GNE-617 exhibited acceptable preclinical properties and projected human PK and dose estimates.

     

Spasmolytic effect of Alternanthera repens on isolated rat ileum

Context: Alternanthera repens (L.) Kuntze (Amaranthaceae) is widely used in Mexican traditional medicine for the treatment of gastrointestinal disorders that are mainly related to diarrhea.

Objective: The aim of the present study was to investigate the spasmolytic effect of hexane (Hx), methanol (Me) and aqueous (Aq) extracts as well as chromatographic Me fractions (F1–F6) of A. repens in rat ileum.

Materials and methods: Dried and powdered aerial parts were used to obtain the extracts. The rat ileum preparations were incubated in Tyrode’s solution gassed (95% O₂–5% CO₂) at 37?°C. The effect on the contractile response of isolated ileum was evaluated by obtaining cumulative concentration–response curves to CaCl₂, KCl, 5-HT and acetylcholine in the absence and presence of different doses of Aq (0.56–2.09?mg/mL), Me (0.24–0.91?mg/mL) and Hx (0.24–0.91?mg/mL) extracts, as well as six Me fractions of 0.66?mg/mL (F1 to F6).

Results: The A. repens Me (0.24?mg/mL) caused an inhibitory response of the Ca²⁺-induced contractions, with IC₅₀ values of 0.18?±?0.061 and 0.67?±?0.061?mM in the presence and absence of the Me, respectively. Me fractions F2 to F4 presented a significant inhibitory effect (F_(3,8)?=?60.17, p?=?0.0001), causing a reduction in the CaCl₂-induced contractions and shifting the Ca²⁺ (0.39 to 1.81?mM) concentration–response curves to the right. With respect to the effect on 5-HT-induced contractions, IC₅₀ values Hx extract (0.24?mg/mL) were 5.44?±?0.08?×?10^?6?M and 3.38?±?0.07?×?10^?6?M in the presence and absence of the Hx, respectively.

Discussion and conclusion: The spasmolytic effects induced by Me and Me fractions of A. repens may involve a serotonergic and Ca²⁺ influx blockade mechanisms, which may justify the use of A. repens extracts as an effective traditional treatment against diarrhea.     

Effects of the antifouling agent tributyltin on the sinking behavior,photosynthetic rate and biochemical composition of the marine planktonic diatom Thalassiosira pseudonana

This study investigated the changes in the sinking rates and physiochemical characteristics of the planktonic marine diatom, Thalassiosira pseudonana, caused by 72?h exposure to antifouling agent tributyltin (TBT) at 1.0?µg?L^?1 (72-h 10% effective concentration for growth rate, EC10), and 1.7?µg?L^?1 (EC50). After 72?h of exposure, the sinking rates of T. pseudonana cells were changed from 0.13–0.08?m day^?1 in the control, 0.08–0.05?m day^?1 in the EC10 treatment, and 0.04–0.006?m day^?1 in the EC50 treatment. The results revealed that the sinking rate of T. pseudonana decreased significantly compared with the control at 48?h in the EC10 treatment group and at 24, 48, and 72?h in the EC50 treatment group. The photosynthetic performance index on an absorption basis and the maximum quantum yields of photosystem II also decreased significantly (P?<?0.05) in the TBT treatments compared with the control. There was a significant (P?<?0.05) positive correlation between sinking rates and cellular protein contents (ng cell^?1). Changes in the biochemical and physiochemical composition of the cells suggest that interference with photosynthetic processes by TBT may have reduced their specific gravity and thereby caused a decrease in the sinking rates of T. pseudonana. The results of this investigation suggest the importance of considering the effects of pollutants on the sinking behaviors of diatoms when evaluating the adverse effects of pollutants on marine primary production.

     

Multiplication of entomopathogenic fungus (Lecanicillium lecanii) on apple pomace and its toxicity against aphid (Aphis craccivora)

Abstract

The apple pomace (AP) was standardized for the multiplication of Lecanicillium lecanii and evaluated against Aphis craccivora. Results showed that AP medium at 2% recorded more mycelial growth and were at par with AP 3%, 4%, and 5% as compared to other concentrations. The spore yield of L. lecanii also significantly higher in AP 5% (16?×?10⁶ spores ml^?1) and was at par with AP 0.5%. L. lecanii at 1?×?10⁹ spores ml^?1 showed maximum mortality (43.33–93.33% mortality) against A. craccivora and was followed by 1?×?10⁸ spores ml^-1 (36.67–86.67% mortality).