Comparative analysis of drought-responsive transcriptomes of sugarcane genotypes with differential tolerance to drought

Water stress causes considerable yield losses in sugarcane. To investigate differentially expressed genes under water stress, two sugarcane genotypes were subjected to three water-deficit levels (mild, moderate, and severe) and subsequent recovery and leaf transcriptome was generated using Illumina NextSeq sequencing. Among the differentially expressed genes, the tolerant genotype Co 06022 generated 2970 unigenes (p ≤ 0.05, functionally known, non-redundant DEGs) at 2-day stress, and there was a progressive decrease in the expressed genes as the stress period increased with 2109 unigenes at 6-day stress and 2307 unigenes at 10-day stress. There was considerable reduction at recovery with 1334 unigenes expressed at 10 days after recovery. However, in the susceptible genotype Co 8021, the number of unigenes expressed at 2 days was lower (2025) than the tolerant genotype and a further reduction was seen at 6-day stress (1552). During recovery, more differentially expressed genes were observed in the susceptible cultivar indicating that the cultivar has to activate more functions/processes to recover from the damage caused by stress. Comparison of DEGs between all stages of stress and recovery in both genotypes revealed that, the commonly up- and down-regulated genes across different stages were approximately double in the tolerant genotype. The most enriched gene ontology classes were heme binding, peroxidase activity and metal ion binding in the biological process and response to oxidative stress, hydrogen peroxide catabolic process and response to stress in the molecular function category. The cellular component was enriched with DEGs involved in extracellular region followed by integral component of membrane. The KEGG pathway analysis revealed important metabolic activities and functionally important genes involved in mitigating water-deficit stress in both the varieties. In addition, several unannotated genes in important pathways were detected and together may provide novel insights into water-deficit tolerance mechanisms in sugarcane. The reliability of the observed expression patterns was confirmed by qRT-PCR. The results of this study will help to identify useful genes for improving drought tolerance in sugarcane.

Picosecond difference-frequency-generation in orientation-patterned gallium phosphide

We report the generation of tunable high-repetition-rate picosecond radiation in the mid-infrared using the new quasi-phase-matched nonlinear material of orientation-patterned gallium phosphide (OP-GaP). The source is realized by single-pass difference-frequency-generation (DFG) between the output signal of a picosecond optical parametric oscillator (OPO) tunable across 1609-1637 nm with input pump pulses at 1064 nm in OP-GaP, resulting in tunable radiation across 3040-3132 nm. Using a 40-mm-long crystal, we have generated up to 57 mW of DFG average power at ~80 MHz repetition rate for a pump power of 5 W and signal power of 0.9 W, with >30 mW over >50% of the tuning range. The DFG source exhibits a passive power stability better than 3.2% rms over 1 hour in good spatial beam quality. To the best of our knowledge, this is the first picosecond frequency conversion source based on OP-GaP.

Ti:sapphire-pumped deep-infrared femtosecond optical parametric oscillator based on CdSiP2

We report on a femtosecond optical parametric oscillator (OPO) for the deep-infrared (deep-IR) based on the Kerr-lens-mode-locked Ti:sapphire laser as the pump source. By deploying a novel cascaded intracavity arrangement, comprising a femtosecond OPO based on the nonlinear crystal, CdSiP2, synchronously pumped internal to a MgO:PPLN femtosecond OPO, we have generated broadly tunable radiation across 5958-8117 nm using rapid static cavity delay tuning, with a maximum power of 64 μW at 6791 nm, limited by the absorption in mirror substrates as well as polarization-dependent intracavity losses. The deep-IR idler power exhibits excellent passive stability of better than 1.1% rms over 2 h, with a spectral bandwidth as large as ∼650 nm at ∼6800 nm. The demonstrated concept is generic and can be similarly deployed in other operating time scales and wavelength regions, also using different laser pump sources and nonlinear materials.

A novel approach for lung delivery of rifampicin-loaded liposomes in dry powder form for the treatment of tuberculosis

Background:

Lung administration of antibiotics by nebulization is promising for improved treatment efficiency for pulmonary infections, as it increases drug concentration at sites of infection while minimizing systemic side effects. For poorly soluble molecules like rifampicin, lipid particulate system may improve lung delivery.

Materials and Methods:

We investigated rifampicin-loaded freeze-dried liposomes. Various formulations were prepared with different drug lipid ratios and one formulation was optimized. Optimized colloidal liposome formulation was freeze-dried and subsequently subjected for various evaluation and characterization parameters such as in-vitro dissolution, in-vitro antitubercular activity, aerodynamic characters, surface morphology, and thermal behavior. The optimized formulation of rifampicin-loaded freeze-dried liposome and free rifampicin was subjected for the in-vivo drug disposition study in Wister rat model by intra-tracheal instillation in comparison with an oral route of administration.

Results:

The results of pharmacokinetic study for both free drug and the formulation suggested that liposomes released the drug in a controlled manner for a longer period of time. The enhanced efficiency of drug incorporated into liposomes suggested that the delivery of encapsulated drugs to macrophages was more rapid than that of free drug.

Conclusion:

Therefore, the pharmacokinetic and drug disposition studies provided a sound basis for predicting the successful treatment for tuberculosis.

Yb-fiber-laser-based, 1.8 W average power, picosecond ultraviolet source at 266 nm

We report a compact, stable, high-power, picosecond ultraviolet (UV) source at 266 nm based on simple single-pass two-step fourth-harmonic generation (FHG) of a mode-locked Yb-fiber laser at 79.5 MHz in LiB3O5 (LBO) and β-BaB2O4. Using a 30-mm-long LBO crystal for single-pass second-harmonic generation, we achieve up to 9.1 W of average green power at 532 nm for 16.8 W of Yb-fiber power at a conversion efficiency of 54% in 16.2 ps pulses with a TEM00 spatial profile and passive power stability better than 0.5% rms over 16 h. The generated green radiation is then used for single-pass FHG into the UV, providing as much as 1.8 W of average power at 266 nm under the optimum focusing condition in the presence of spatial walk-off, at an overall FHG conversion efficiency of ∼11%. The generated UV output exhibits passive power stability better than 4.6% rms over 1.5 h and beam pointing stability better than 84 μrad over 1 h. The UV output beam has a circularity of >80% in high beam quality with the TEM00 mode profile. To the best of our knowledge, this is the first report of picosecond UV generation at 266 nm at megahertz repetition rates.

Preparation and characterization of pioglitazone cyclodextrin inclusion complexes

Pioglitazone, a class II Biopharmaceutical Classification System drug having poor water solubility and slow dissolution rate may have a negative impact on its subtherapeutic plasma drug levels leading to therapeutic failure. In order to improve its water solubility and thus dissolution, cyclodextrin complexation technique was followed. The phase solubility studies were carried using three different types of cyclodextrins viz., β, methyl-β and γ-cyclodextrins. The Gibbs free energy was calculated in order to determine ease of the complexation. Binary systems of pioglitazone with cyclodextrins were prepared by kneading method and spray drying method. The phase solubility profiles with all the three cyclodextrins were classified as A_L-type, indicating the formation of 1:1 stoichiometric inclusion complexes. The complexation capability of cyclodextrins with pioglitazone increased in the order of methyl-β > β > γ-cyclodextrin. The Gibbs free energy was found to be in the order γ > methyl-β > β cyclodextrin. Characterization of inclusion complexes was done by solubility studies, in vitro dissolution studies, Fourier transformation-infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and X-ray powder diffractometry studies. Inclusion complexes exhibited higher rates of dissolution than the corresponding physical mixtures and pure drug. Greater solubility was observed with spray-dried methyl-β cyclodextrin complexes (2.29 ± 0.001 mg/ml) in comparison to the kneaded methyl-β cyclodextrin complexes (1.584 ± 0.053 mg/ml) and pure drug (0.0714 ± 0.0018 mg/ml).

Development and validation of the liquid chromatographic method for simultaneous estimation of metformin, pioglitazone, and glimepiride in pharmaceutical dosage forms

Introduction:

A simple, precise, and accurate HPLC method for simultaneous estimation of metformin hydrochloride (MET), pioglitazone hydrochloride (PIO), and glimepiride (GLIMP) was developed and validated.

Materials and Methods:

Chromatographic separation of the drugs was performed by using a Phenomenex-ODS-3 (C-18) column (250 × 4.60 mm, 5 μm) with a mobile phase consisting of methanol:acetonitrile:15 mM potassium dihydrogen phosphate (pH 4) in the proportion of 40:35:25 (v/v) at a flow rate of 1 ml/min. Detection was carried out using a UV-SPD-10AVP detector at 240 nm.

Results:

The retention time for MET, PIO, and GLIMP were 2.85 ± 0.03 min, 4.52 ± 0.03 min, and 7.08 ± 0.02min, respectively. Parameters such as linearity (0.2–50 μg/ ml for MET, 0.2–30 μg/ml for PIO, and GLIMP, respectively), precision (intra-day % RSD was 1.01–3.24 and inter-day % RSD was 1.54–4.09 for MET; intra-day % RSD was 1.03–2.09 and inter-day % RSD was 2.26–3.10 for PIO; and intra-day% RSD was 1.00–3.15 and inter-day % RSD was 1.58–3.07 for GLIMP), accuracy (99.66 ± 0.14 for MET, 98.46 ± 0.40 for PIO, and 98.62 ± 0.39 for GLIMP), specificity and robustness were calculated in accordance with ICH guidelines.

Conclusions:

The method was proved to be simple, rapid, precise, accurate, and cost effective.

Effects of statins and cholesterol on memory functions in mice

Studies on influence of lipid lowering therapies have generated wide controversial results on the role of cholesterol on memory function. However recent studies revealed that cholesterol lowering treatment substantially reduce the risk of dementia. The objectives of this study were to analyze the effect of statins on memory function and to establish the relationship between increase/decrease in cholesterol synthesis, total cholesterol level and memory function in animals. We examined the relationship between biosynthesis of cholesterol and memory function using two statins (lipophilic simvastatin and hydrophilic pravastatin) and high cholesterol diet in mice for 15 days and 4 months. Memory performance was evaluated with two different behavioral tests and various biochemical parameters such as serum cholesterol, whole brain cholesterol, brain 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) activity and brain acetylcholine esterase (AChE) activity. We found that statin treatment for 4 months, but not for 15 days, showed significant improvement in memory function whereas high cholesterol diet showed significant impairment of memory. However long-term statin treatment showed significant decrease in serum cholesterol level as well as brain AChE level. Moreover high cholesterol diet showed significant decrease in memory function with an increase in serum cholesterol level as well as brain AChE level. There is no direct correlation between brain cholesterol level, as well as HMG-CoA activity with memory function regulation. However there is definite link between plasma cholesterol level and AChE level. A long-standing plasma cholesterol alteration may be essential to regulate memory function which in turn might be mediated through AChE modulated pathway.

Influence of pioglitazone on experimental heart failure and hyperlipidemia in rats

Objectives:

To investigate the effect of pioglitazone on isoproterenol-induced heart failure and high-fructose diet-induced metabolic changes in rats.

Materials and Methods:

Three doses of pioglitazone (Pio – 3, 10, 30 mg/kg, po) were tested in male Wistar rats. In the Heart Failure (HF) group, treatment was followed by Isoproterenol (ISO) injection. The markers for HF, such as enzyme estimation, relative heart weight, and antioxidant status, were evaluated. In another group, metabolic disturbances were induced by High Fructose Diet (HFD). The influence of Pio treatment on Systolic Blood Pressure (SBP), serum glucose, Triglycerides (TG), Total Cholesterol (TC), and High-Density Lipoprotein (HDL)-cholesterol (HDL-c) were determined.

Results:

The results indicated that Pio at 10 mg increased significantly (P<0.05) the Lactate Dehydrogenase (LDH), Creatinine Kinase-MB (CK-MB), and antioxidant enzyme levels as compared to ISO. The high dose of Pio (30 mg) enhanced (P<0.05) Aspartate Transaminase (AST), Alanine Transaminase (ALT), Lipid Peroxidation (LPO),and relative heart weight in addition to increased LDH, CK-MB, and antioxidant enzyme activity. In the HFD group, a dose-dependent inhibitory effect was observed. Pio at 3 mg significantly reduced (P<0.05) elevated glycemia, TG, and SBP as compared to HFD rats. Further, the higher doses of Pio (10 and 30 mg) enhanced the inhibitory effect on glucose, TG, and SBP besides elevating the HDL-c levels. However, none of the tested doses of Pio significantly altered the TC level in HFD rats.

Conclusion:

The observations suggest that Pio exhibits anti-diabetic and anti-hypertensive effects and also partially corrected the hyperlipidemia, but the treatment augmented the cardiac damage associated with ISO. The antioxidant property of Pio appears to have a limited role in protecting the ISO-mediated heart damage.

Evaluation of the anti-depressant activity of Myristica fragrans (Nutmeg) in male rats

OBJECTIVE

The present study was undertaken to evaluate anti-depressant activity of Myristica fragrans (MS).

MATERIALS AND METHODS

Male Wistar rats were subjected to imipramine and herbal extract of MS for their antidepressant activity using Forced Swimming Test (FST), Reserpine Reversal Test (RRT), Haloperidol-Induced Catalepsy (HIC), and Pentobarbitone Sleeping Time (PST).

RESULTS

Administration of MS and imipramine revealed a statistically significant reduction in immobility time in FST, RRT, and protection against HIC, compared to the control group. However, there was no significant potentiation of PST.

CONCLUSION

Our study demonstrated the potential antidepressant activity of MS.

Protective role of glibenclamide against nicotinamide-streptozotocin induced nuclear damage in diabetic Wistar rats

Objective:

To evaluate the protective effect of glibenclamide against the experimental diabetes-induced nuclear damage in Wistar rats.

Materials and Methods:

The anti-mutagenic effect of glibenclamide (0.5, 5 and 50 mg/kg, p.o daily for 4 weeks) was evaluated against the nicotinamide (NA)-streptozotocin (STZ) induced type-2 diabetes mellitus using bone marrow micronucleus and sperm abnormalities tests. The antioxidant status was tested by estimating the serum levels of lipid peroxidation (LPO), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx).

Results:

The results indicated that glibenclamide at 50 mg/kg decreased the frequency of micronuclei in erythrocytes (P < 0.05) and sperm shape abnormality (P < 0.01) besides enhancing the antioxidant status (P < 0.05) in the diabetic rats. However, glibenclamide treatment did not enhance the polychromatic and normochromatic erythrocytes (P/N) ratio and sperm count in the diabetic condition.

Conclusion:

The observations indicate that the glibenclamide has anti-mutagenic potential which could be related to the antioxidant effect and might also possess anti-proliferative property.

Effect of saturated fatty acid-rich dietary vegetable oils on lipid profile, antioxidant enzymes and glucose tolerance in diabetic rats

OBJECTIVE

To study the effect of saturated fatty acid (SFA)-rich dietary vegetable oils on the lipid profile, endogenous antioxidant enzymes and glucose tolerance in type 2 diabetic rats.

MATERIALS AND METHODS

Type 2 diabetes was induced by administering streptozotocin (90 mg/kg, i.p.) in neonatal rats. Twenty-eight-day-old normal (N) and diabetic (D) male Wistar rats were fed for 45 days with a fat-enriched special diet (10%) prepared with coconut oil (CO) - lauric acid-rich SFA, palm oil (PO) - palmitic acid-rich SFA and groundnut oil (GNO) - control (N and D). Lipid profile, endogenous antioxidant enzymes and oral glucose tolerance tests were monitored.

RESULTS

D rats fed with CO (D + CO) exhibited a significant decrease in the total cholesterol and non-high-density lipoprotein cholesterol. Besides, they also showed a trend toward improving antioxidant enzymes and glucose tolerance as compared to the D + GNO group, whereas D + PO treatment aggravated the dyslipidemic condition while causing a significant decrease in the superoxide dismutase levels when compared to N rats fed with GNO (N + GNO). D + PO treatment also impaired the glucose tolerance when compared to N + GNO and D + GNO.

CONCLUSION

The type of FA in the dietary oil determines its deleterious or beneficial effects. Lauric acid present in CO may protect against diabetes-induced dyslipidemia.

Pioglitazone, a PPAR-gamma ligand inhibited the nicotinamide-streptozotocin induced sperm abnormalities in type-2 diabetic Wistar rats

Oxidative stress due to chronic hyperglycemia is known to cause infertility in diabetic patients. Pioglitazone (PIO), a PPAR-gamma ligand is known to possess the antioxidant property however, its role on the oxidative stress mediated germinal damage in Type-2 diabetes mellitus (T2DM) is poorly studies in the literature. In this study, the effect of PIO (1 and 10 mg/kg, p.o. daily for 4 weeks) was evaluated against the nicotinamide (NA- 230 mg/kg, ip) and streptozotocin (STZ-65 mg/kg, ip) induced changes in sperm abnormality and antioxidant status in Wistar rats. The effect of PIO on the male reproductive cells was studied by determining the sperm shape abnormality and sperm count in the experimental T2DM. The antioxidant profile was studied by estimating the serum lipid peroxidation (LPO), glutathione (GSH) and glutathione peroxidase (GPx) levels. The higher dose of PIO (10 mg/kg) significantly (p<0.001) reduced the sperm shape abnormality and increased the sperm count (p<0.001), besides decreasing (p<0.05) the LPO and enhancing the GSH and GPx levels in the diabetic rats. However, the lower dose of PIO (1 mg/kg) produced inhibitory (p<0.05) effect against the changes induced by T2DM in the sperm shape abnormality and GSH levels. alpha-tocopherol tested as an standard antioxidant agent prevented (p<0.001) the NA-STZ mediated alterations in sperm abnormalities and antioxidant enzyme levels. The results suggest that the inhibitory effect of PIO against the T2DM induced sperm abnormality could be related to its antioxidant property.

Novel formulation of solid lipid microparticles of curcumin for anti-angiogenic and anti-inflammatory activity for optimization of therapy of inflammatory bowel disease

Objectives

This project was undertaken with a view to optimize the treatment of inflammatory bowel disease through a novel drug delivery approach for localized treatment in the colon. Curcumin has poor aqueous solubility, poor stability in the gastrointestinal tract and poor bioavailability. The purpose of the study was to prepare and evaluate the anti-inflammatory activity of solid lipid microparticles (SLMs) of curcumin for the treatment of inflammatory bowel disease in a colitis-induced rat model by a colon-specific delivery approach.

Methods

We have developed a novel formulation approach for treating experimental colitis in the rat model. SLMs of curcumin were prepared with various lipids, such as palmitic acid, stearic acid and soya lecithin, with an optimized percentage of poloxamer 188. The SLMs of curcumin were characterized for particle size, drug content, drug entrapment, in-vitro release, surface morphology and infrared, differential scanning calorimetry and X-ray studies. The colonic delivery system of SLM formulations of curcumin were further investigated for their anti-angiogenic and anti-inflammatory activity using chick embryo and rat colitis models.

Key findings

Particle size, drug content, drug entrapment and in-vitro release studies showed that formulation F4 containing one part stearic acid and 0.5% surfactant had the smallest diameter of 108 μm, 79.24% entrapment and exhibited excellent in-vitro release characteristics when compared with other formulations and pure curcumin. SLMs of curcumin (F4) proved to be a potent angio-inhibitory compound, as demonstrated by inhibition of angiogenesis in the chorioallantoic membrane assay. Rats treated with curcumin and its SLM complex showed a faster weight gain compared with dextran sulfate solution (DSS) control rats. The increase in whole colon length appeared to be significantly greater in SLM-treated rats when compared with pure curcumin and DSS control rats. An additional finding in the DSS-treated rats was chronic cell infiltration with predominance of eosinophils. Decreased mast cell numbers in the mucosa of the colon of SLMs of curcumin and pure curcumin-treated rats was observed.

Conclusions

The degree of colitis caused by administration of DSS was significantly attenuated by colonic delivery of SLMs of curcumin. Being a nontoxic natural dietary product, curcumin could be useful in the therapeutic strategy for inflammatory bowel disease patients.

Role of Pioglitazone with Metformin or Glimepiride on Oxidative Stress-induced Nuclear Damage and Reproductive Toxicity in Diabetic Rats

BACKGROUND

Oxidative stress due to improper control of blood glucose in chronic diabetes plays a major role in the development of secondary complications including cancer and birth defect. The aim of this study is to evaluate the protective effect of combination of pioglitazone with metformin or glimepiride against the experimental type-2 diabetes induced nuclear damage and reproductive toxicity in rats.

METHODS

The combinations of Pioglitazone (Pio-1 mg/kg) with metformin (Met-50 mg/kg) or glimepiride (Gmp-0.2 mg/kg) given orally daily for 4 weeks were tested against nicotinamide (NA-230 mg/kg, ip)-streptozotocin (STZ-65 mg/kg, ip)-induced micronuclei (MN) formation and sperm abnormalities in male Wistar rats. The antioxidant status was evaluated by measuring the levels of serum lipid peroxidation (LPO), catalase (CAT) and superoxide dismutase (SOD).

RESULTS

The administration of Pio+Met significantly (P<0.01) reduced the number of micronucleated erythrocytes, increased the polychromatic: normochromatic erythrocytes (P/N ratio), reduced (P<0.001) sperm morphology defects and increased (P<0.05) the caudal sperm count compared to the untreated diabetic condition. Furthermore, the Pio+Met combination enhanced the antioxidant status in diabetic animals. However, Pio+Gmp did not attenuate the nuclear and sperm defects or oxidative stress.

CONCLUSIONS

The observations suggest that Pio+Met combination reduced nuclear damage and sperm abnormalities by enhancing the antioxidant status in the diabetic animals.

Inhibitory effect of glimepiride on nicotinamide-streptozotocin induced nuclear damages and sperm abnormality in diabetic Wistar rats

The generation of reactive oxygen species in diabetes is considered to be the major cause for the mutation related defects such as cancer, infertility etc. Glimepiride (Gmp) is a third generation antidiabetic sulphonylurea known to possess the antioxidant effect in streptozotocin (STZ) induced diabetes. In this study, the anti-mutagenic activity of Gmp (0.175, 17.5 and 175 mg/kg, po daily for 4 weeks) was evaluated against the nicotinamide (NA-230 mg/kg) and STZ (65 mg/kg) induced somatic and germinal cells defect using bone marrow micronucleus (MN) test and sperm abnormality test respectively in male Wistar rats. Administration of Gmp at 175 mg prevented the NA-STZ induced increased frequency of MN in polychromatic and normochromatic erythrocytes. The treatment with Gmp also decreased the sperm shape abnormality and enhanced the sperm count besides improving the antioxidant status in the diabetic rats. However, the other doses of Gmp (0.175 and 17.5 mg) did not produce significant change in the MN frequency and sperm abnormality although Gmp at 17.5 mg showed significant antidiabetic effect in the hyperglycemic animals. The results indicated that Gmp inhibited the NA-STZ mediated changes in the MN frequency and sperm abnormality and enhanced the antioxidant defense. The observations suggest that the antioxidant property of Gmp could have contributed for its ability to decrease the NA-STZ mediated defects in somatic and germinal cells.

Effect of cyclodextrin complexation of curcumin on its solubility and antiangiogenic and anti-inflammatory activity in rat colitis model

The purpose of the study was to prepare and evaluate the anti-inflammatory activity of cyclodextrin (CD) complex of curcumin for the treatment of inflammatory bowel disease (IBD) in colitis-induced rat model. Inclusion complexes of curcumin were prepared by common solvent and kneading methods. These complexes were further evaluated for increase in solubility of poorly soluble curcumin. The inclusion complexes were characterized for enhancement in solubility, in vitro dissolution, surface morphology, infrared, differential scanning calorimetry, and X-ray studies. Solubility, phase solubility, and in vitro dissolution studies showed that curcumin has higher affinity for hydroxypropyl-beta-CD (HPbetaCD) than other CDs. HPbetaCD complex of curcumin was further investigated for its antiangiogenic and anti-inflammatory activity using chick embryo and rat colitis model. HPbetaCD complex of curcumin proved to be a potent angioinhibitory compound, as demonstrated by inhibition of angiogenesis in chorioallantoic membrane assay. Curcumin- and HPbetaCD-treated rats showed a faster weight gain compared to dextran sulfate solution (DSS) controls. Whole colon length appeared to be significantly longer in HPbetaCD-treated rats than pure curcumin and DSS controls. An additional finding in the DSS-treated rats was the predominance of eosinophils in the chronic cell infiltrate. Decreased mast cell numbers in the mucosa of the colon of CD of curcumin- and pure-curcumin-treated rats was observed. This study concluded that the degree of colitis caused by administration of DSS was significantly attenuated by CD of curcumin. Being a nontoxic natural dietary product, curcumin could be useful in the therapeutic strategy for IBD patients.

Novel formulation of solid lipid microparticles of curcumin for anti-angiogenic and anti-inflammatory activity for optimization of therapy of inflammatory bowel disease

OBJECTIVES

This project was undertaken with a view to optimize the treatment of inflammatory bowel disease through a novel drug delivery approach for localized treatment in the colon. Curcumin has poor aqueous solubility, poor stability in the gastrointestinal tract and poor bioavailability. The purpose of the study was to prepare and evaluate the anti-inflammatory activity of solid lipid microparticles (SLMs) of curcumin for the treatment of inflammatory bowel disease in a colitis-induced rat model by a colon-specific delivery approach.

METHODS

We have developed a novel formulation approach for treating experimental colitis in the rat model. SLMs of curcumin were prepared with various lipids, such as palmitic acid, stearic acid and soya lecithin, with an optimized percentage of poloxamer 188. The SLMs of curcumin were characterized for particle size, drug content, drug entrapment, in-vitro release, surface morphology and infrared, differential scanning calorimetry and X-ray studies. The colonic delivery system of SLM formulations of curcumin were further investigated for their anti-angiogenic and anti-inflammatory activity using chick embryo and rat colitis models.

KEY FINDINGS

Particle size, drug content, drug entrapment and in-vitro release studies showed that formulation F4 containing one part stearic acid and 0.5% surfactant had the smallest diameter of 108 microm, 79.24% entrapment and exhibited excellent in-vitro release characteristics when compared with other formulations and pure curcumin. SLMs of curcumin (F4) proved to be a potent angio-inhibitory compound, as demonstrated by inhibition of angiogenesis in the chorioallantoic membrane assay. Rats treated with curcumin and its SLM complex showed a faster weight gain compared with dextran sulfate solution (DSS) control rats. The increase in whole colon length appeared to be significantly greater in SLM-treated rats when compared with pure curcumin and DSS control rats. An additional finding in the DSS-treated rats was chronic cell infiltration with predominance of eosinophils. Decreased mast cell numbers in the mucosa of the colon of SLMs of curcumin and pure curcumin-treated rats was observed.

CONCLUSIONS

The degree of colitis caused by administration of DSS was significantly attenuated by colonic delivery of SLMs of curcumin. Being a nontoxic natural dietary product, curcumin could be useful in the therapeutic strategy for inflammatory bowel disease patients.

Influence of omega-6/omega-3 rich dietary oils on lipid profile and antioxidant enzymes in normal and stressed rats

To evaluate the influence of omega-6/omega-3 poly unsaturated fatty acid (PUFA) containing oils on lipid profile and endogenous antioxidant enzymes in normal and stressed (immobilization) rats, 28 day old male Wistar rats were fed for 45 days with fat enriched special diet (10% fat) prepared with sunflower oil (SO)--omega-6 rich, mustard oil (MO)--omega-3 rich and groundnut oil--control respectively. SO treated normal rats have significantly reduced total cholesterol, high density lipoprotein-cholesterol (HDL-C) and catalase thereby significantly increased the atherogenic index (AI) and lipid peroxidation (LPO). However, treatment with MO increased superoxide dismutase; decreased LPO significantly. Under stress conditions AI and LPO were significantly high with SO and significantly less with MO. In addition, SO decreased HDL-C whereas MO decreased non-HDL-C significantly. Results suggest a protective role against AI and LPO in normal and stress conditions in MO. The quantity of omega-3 fatty acids in dietary oil may play a crucial role in the body against atherogenicity. The findings signify that not just PUFA, but type of PUFA present in dietary oil used is important.

Effect of thiazolidinediones on the erythropoeitic and germinal cells in the male wistar rats

Hyperglycemia is the main determinant of long term diabetic complications mainly through induction of oxidative stress responsible for secondary defects including cancer, infertility etc. Thiazolidinediones (TZDs) are known to posses the antioxidant potential against the reactive oxygen species. The ability of clinically used TZDs like Rosiglitazone (RSG) and Pioglitazone (PIO) in diabetic complications is still need to be studied extensively in the literature. In this study, the role of RSG and PIO on the frequency of nuclear and germinal cell damage was studied using bone marrow micronucleus (MN) test, sperm shape abnormality and sperm count in normal animals. The drugs were tested in the three doses (1, 10 and 100 mg/kg) after acute (48 hrs and 72 hrs) and chronic (4 weeks) treatment. The results indicated that RSG has produced significant (p < 0.01) decrease in P/N (polychromatic and normochromatic erythrocytes) ratio at 10 and 100 mg/kg without affecting the frequency of micronucleated erythrocytes, sperm shape morphology and sperm count. PIO in the tested doses did not induce any change in P/N ratio and sperm count but the higher dose (100 mg/kg) showed suppression of MN in normochromatic erythrocytes and % sperm shape abnormality compared to the control group.

Isolation and characterisation of bioactive isoflavonoids from the roots ofDalbergia horrida

The roots of Dalbergia horrida yielded two new isoflavanones, Dalhorridin (I) - 5,5'-dihydroxy-3',4'-methylenedioxy-5''-prenyl-6'',6''-dimethyl-dihydropyrano(2'',3'' : 7,8)-isoflavanone and Dalhorridinin (II) - 5,7,5'-trihydroxy-3',4'-methylenedioxy-8-[5-methyl-2-(2-hydroxyisopropyl)-1,4-hexadienyl]isoflavanone along with two known isoflavones, Dalspinin and Dalspinosin. Preliminary biological screening of the enriched extract revealed that it showed analgesic, anti-inflammatory, CNS depressant and mild anti-bacterial properties.

Intrastrain variations in anxiolytic effect of nitrazepam in mice

This study investigated the individual differences in the baseline anxiety and anxiolytic effect of nitrazepam in Balb/c mice. Initially mice were sorted according into low, intermediate and high anxiety groups (LA, IA and HA) based on the number of entries to and time spent in open arms in elevated plus maze. Later, anxiolytic effect of nitrazepam (2 mg/kg, p.o) in LA, IA and HA mice was evaluated using hole board and light/dark tests. In Hole board test, LA mice made more number of head dippings and spent more time during head dippings, while HA mice made less number of head dippings and spent less time during head dipping when compared to that of IA mice. In light/dark test LA mice made more reentries to and spent more time in bright compartment, while HA mice made few reentries to and spent less time in bright compartment. Results suggest that mice of a single strain differ in their baseline anxiety and anxiolytic effect of nitrazepam.

Citral, a component of lemongrass oil inhibits the clastogenic effect of nickel chloride in mouse micronucleus test system

Citral is a major component of Cymbopogon citratus (lemongrass oil). The aqueous suspension of citral (60 mg/kg body weight, per oral) treated for one week was tested for the anti-clastogenic effect using mouse micronucleus test system. A known mutagen nickel (Nickel chloride-10 mg/kg, b.w. intra-peritoneal) was used to induce the nuclear damage measured in polychromatic erythrocytes and normochromatic erythrocytes. The frequency of the micronucleated erythrocytes were studied in peripheral blood and bone marrow after 24, 48 and 72 hours of mutagenic exposure. The antioxidant activity of citral was tested in vitro by superoxide scavenging method. The results indicated that citral significantly (P<0.01) inhibited the formation of micronuclei induced by nickel. Further, a good superoxide scavenging activity (EC50=19 mcg/ml) was observed in citral treated groups, suggesting that the antioxidant action could be responsible for the anti-clastogenic effect of citral against nickel chloride.

Carbamazepine--the commonest cause of toxic epidermal necrolysis and Stevens-Johnson syndrome: a study of 7 years

BACKGROUND

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are a group of severe life threatening drug reactions. The drugs commonly implicated as the cause of these drug reactions vary depending on host factors and the prescription pattern of drugs in that particular area.

AIM

The aim of the study was to find the drugs implicated as the cause of SJS/TEN in the patients admitted in the dermatology ward at the Medical College, Thrissur and to find the clinical outcome.

METHODS

It was a retrospective study of 7 years from 1997 to 2004. The case records of all patients with a clinical diagnosis of TEN or SJS were studied in detail regarding the drugs implicated as the cause, the management and the clinical outcome.

RESULTS

During the study period, 41 patients in the age group ranging from 12 to 72 years were treated as inpatients, of which 20 were males and 21 were females. The commonest drug implicated as the cause of SJS/TEN was carbamazepine (44%). The indication for carbamazepine was control of pain in more than 50% of the cases. Presence of a major systemic disease before the onset of SJS/TEN was associated with a bad prognosis.

CONCLUSION

The increased use of carbamazepine, especially for control of pain, may be the reason for the increased incidence of SJS/TEN due to the same drug. Awareness about the drugs implicated in life threatening drug reactions will help physicians in preventing them by judicious use of the drugs.

Role of emotionality on inter and intrastrain variations in imipramine response. a comparative study in Balb/c and Swiss mice

Association between emotionality and effect of imipramine on immobility time in forced swimming test was investigated in Swiss and Balb/c mice. Mice of both the strains were segregated into normal emotional (mean +/- 1SD), low emotional (> mean + 1SD) and high emotional (< mean - 1SD) based on their performance with respect to each indices of emotionality in novel arena and elevated plus maze. Baseline immobility and effect of imipramine (20 mg/kg, po) on immobility time was evaluated in these emotionally different groups of mice using forced swimming test model. Baseline immobility time of low emotional mice was found to be significantly less (P<0.01) and that of high emotional mice was found to be significantly more (P<0.01) when compared to normal emotional mice of both the strains. Immobility time after imipramine administration was found to be significantly less (P<0.05) with low emotional mice and significantly more (P<0.01) with high emotional mice when compared to normal emotional mice of both the strains.

Bone marrow necrosis in paediatric patients

Necrosis of bone marrow is a very rare condition with a prevalence ranging from 0.15 to 7 percent. It is mostly not compatible with life. We diagnosed four cases of necrotic marrow out of 830 bone marrow aspirations done in last five years of time. All were paediatric patients having peripheral pancytopenia. Three out of four patients expired within one month of diagnosis.

Pharmacokinetic profile of a new matrix-type transdermal delivery system: diclofenac diethyl ammonium patch

A transdermal delivery system containing the anti-inflammatory analgesic diclofenac diethyl ammonium in an ethyl hexyl acrylate and vinyl acetate pressure-sensitive adhesive system was developed for percutaneous absorption. These patches were subjected to in vitro permeation and permeation enhancement studies through rat skin using a specially designed diffusion cell. Further, the work deals with percutaneous absorption studies carried out on both animals and human volunteers. The pharmacokinetic parameters calculated from the blood levels of the drug reveal a profile typical of a sustained-release formulation, with the ability to maintain adequate plasma levels for 24 hr (i.e., up to the next application). (Area under the curve [AUC]: 4.356 +/- 1.3 mcg/ml.hr in animals and 0.442 +/- 0.053 mcg/ml.hr in humans; Tmax was 8 hr in both the cases, whereas Cmax was 0.288 +/- 0.088 mcg/ml in animals and 0.034 +/- .008 mcg/ml in human volunteers.) The amount of the drug bioavailable for targeting the sites of action is lower than via the oral route, but the absorbed dose appears to be adequate for therapeutic use, particularly because of the absence of side effects.

Pregnancy and congenital heart disease--maternal and fetal outcome

Two hundred and seventy five pregnancies in patients with congenital heart disease during 1980-1996 were analyzed retrospectively. Maternal and perinatal outcome was compared in 251 pregnancies of women with acyanotic and 24 pregnancies of women with cyanotic heart disease. Congenital heart disease was diagnosed during the index pregnancy in 26.1% of patients and the majority (88.4%) were in NYHA classes 1 and 2. Atrial septal defect (27.7%) was the most common lesion in women with acyanotic heart disease and the majority with cyanotic heart disease had Eisenmenger syndrome, 13 of 21 (61.9%). Sixty pregnancies occurred in patients with surgically corrected lesions (acyanotic, 56; cyanotic, 4). The incidences of abortions (8.3%), stillbirths (13.6%) and small for gestational age (SGA) (36.4%) were higher in cyanotic heart disease compared to acyanotic heart disease (stillbirth, 0.8%; SGA, 6.9%). There was a statistically significant difference in mean maternal age, mean gestational age and mean birth-weight in the surgically corrected and noncorrected lesions in both acyanotic and cyanotic heart disease. There was 1 maternal death in a woman with Eisenmenger syndrome.

Toxic epidermal necrolysis--a retrospective study

BACKGROUND

Toxic epidermal necrolysis (TEN) is a severe, idiosyncratic, exfoliative disease of the skin and mucous membranes. The treatment of this condition is controversial. High-dose corticosteroid therapy has been the most commonly advocated treatment, but, more recently, this has changed to a no-steroid protocol. These conflicting treatments prompted us to evaluate retrospectively our protocol.

METHODS

The patients admitted to the hospital from 1989 to 1995 with a clinical diagnosis of TEN were included in the study. These patients were given systemic steroids, prophylactic antibiotic, and supportive measures.

RESULTS

The patients belonged to both sexes with an average age of 34 years. The average area of involvement was 85.62%. All the patients made an uneventful recovery without any evidence of sepsis.

CONCLUSIONS

Treatment with systemic steroids is useful in the management of TEN, and there is no need for a burn care center.