Amphotericin-B-loaded polymersomes formulation (PAMBO) based on (PEG)₃-PLA copolymers: an in vivo evaluation in a murine model

This paper deals with in vivo evaluation of a new amphotericin-B-loaded polymersomes (PAMBO) formulation in terms of pharmacokinetics, toxicity, tissue distribution profile, and its efficacy in a murine model of disseminated candidiasis. Pharmacokinetic and tissue distribution studies of the PAMBO showed sustained levels of the drug in plasma as well as in target organs which harbor fungal and leishmanial infection. PAMBO was found to be much less toxic than Fungizone. It was observed that 700% increment in the dose is tolerated without observable toxicity which is supported by survival, biochemical, and histopathological results. PAMBO showed a significant improvement in the survival rate of immunosuppressed mice infected with Candida albicans as compared to control. It also showed better dose to dose (1 mg/kg) efficacy as compared to Fungizone and a significant improvement in the life expectancy at 3 and 5 mg/kg dose levels in the animals. Colony forming unit (CFU) counts in the target organs revealed significant reduction in Candida burden with PAMBO treatment. Kidney, spleen, and lung were cleared of infection, although liver was carrying a very low level of infection. Overall, PAMBO formulation is found to be more efficacious and less toxic in a fungal mice model.

Lipid analysis by thin-layer chromatography--a review of the current state

High-performance thin-layer chromatography (HPTLC) is a widely used, fast and relatively inexpensive method of separating complex mixtures. It is particularly useful for smaller, apolar compounds and offers some advantages over HPLC. This review gives an overview about the special features as well as the problems that have to be considered upon the HPTLC analysis of lipids. The term "lipids" is used here in a broad sense and comprises fatty acids and their derivatives as well as substances related biosynthetically or functionally to these compounds. After a short introduction regarding the stationary phases and the methods how lipids can be visualized on an HPTLC plate, the individual lipid classes will be discussed and the most suitable solvent systems for their separation indicated. The focus will be on lipids that are most abundant in biological systems, i.e. cholesterol and its derivates, glycerides, sphingo- and glycolipids as well as phospholipids. Finally, a nowadays very important topic, the combination between HPTLC and mass spectrometric (MS) detection methods will be discussed. It will be shown that this is a very powerful method to investigate the identities of the HPTLC spots in more detail than by the use of common staining methods. Future aspects of HPTLC in the lipid field will be also discussed.

Aceclofenac topical dosage forms: in vitro and in vivo characterization

Aceclofenac is a new generation non-steroidal anti-inflammatory drug showing effective anti-inflammatory and analgesic properties. It is available in the form of tablets of 100 mg. Importance of aceclofenac as a NSAID has inspired development of topical dosage forms. This mode of administration may help avoid typical side effects associated with oral administration of NSAIDs, which have led to its withdrawal. Furthermore, aceclofenac topical dosage forms can be used as a supplement to oral therapy for better treatment of conditions such as arthritis. Ointments, creams, and gels containing 1% (m/m) aceclofenac have been prepared. They were tested for physical appearance, pH, spreadability, extrudability, drug content uniformity, in vitro diffusion and in vitro permeation. Gels prepared using Carbopol 940 (AF2, AF3) and macrogol bases (AF7) were selected after the analysis of the results. They were evaluated for acute skin irritancy, anti-inflammatory and analgesic effects using the carrageenan-induced thermal hyperalgesia and paw edema method. AF2 was shown to be significantly (p < 0.05) more effective in inhibiting hyperalgesia associated with inflammation, compared to AF3 and AF7. Hence, AF2 may be suggested as an alternative to oral preparations.

Extraction and phytochemical investigation of Calotropis procera: effect of plant extracts on the activity of diverse muscles

CONTEXT

Calotropis procera (Ait.) R.Br. (Asclepiadaceae) is a shrub or small tree that grows wild in Egypt. Calotropis acts as a purgative, anthelmintic, anticoagulant, palliative (in problems with respiration, blood pressure), antipyretic, and analgesic, and induces neuromuscular blocking activity. Little research has been done to study the electrophysiological effects of this plant's extracts on cardiac, smooth, and skeletal muscle activities.

OBJECTIVE

The present study was conducted to determine the phytochemical composition and the effect of the total alcohol extract of the shoot of the plant, which contains almost all of C. procera's cardiac glycosides, flavonoids, and saponins. Also, this study attempted to throw more light on the electrophysiological effects of the plant extracts on cardiac, smooth, and skeletal muscle activities and to clarify the mechanism(s) of their observed action(s).

MATERIALS AND METHODS

The aerial parts of the plant were air dried and their ethanol extracts partitioned with successive solvents. Cardiac, smooth, and skeletal muscles were used in this study to investigate the physiological and pharmacological effects of the plant extracts from different solvents. The data were analyzed by paired t-test.

RESULTS

The phytochemical investigation of Calotropis procera revealed the presence of cardenolides, flavonoids, and saponins. The effects of ethanol, n-butanol, and ethyl acetate (EtOAc) extracts were each evaluated on isolated toad heart and their mechanisms of action determined. Perfusion with 2 μg/mL ethanol, 0.2 μg/mL butanol, and 0.2 μg/mL EtOAc extracts caused a significant decrease in heart rate (bradycardia), significant increase in the force of ventricular contraction, and increase in T-wave amplitude. In addition, the effects of different extracts of the studied plant on smooth muscle and skeletal muscle were investigated in this study. The different extracts and latex of C. procera induced a negative chronotropic effect and decreased the heart rate (HR) of isolated toad heart. The different extracts increased the power of contraction of the duodenum (trace a). Pretreatment with atropine sulfate as a muscarinic receptor blocker abolished the stimulatory effect of the different plant extracts and latex of C. procera (trace b).

DISCUSSION

The present data suggest that ethanol, butanol, and EtOAc extracts of Calotropis procera have negative chronotropism and positive inotropism. Verapamil could abolish the inotropic effect of ethanol as well as that of butanol and EtOAc extracts. Meanwhile, atropine did not abolish the observed negative chronotropic effect. The ethanol extract increased the power of contraction of rabbit duodenum, but atropine abolished this effect. It also decreased the skeletal muscle contraction; this effect could be through blocking of the nicotinic receptors. Butanol and EtOAc extract data for smooth and skeletal muscles are very close to those for the corresponding ethanol extract of the studied plant. The present data for C. procera indicate its direct action on the myocardium, its increase of smooth muscle motility, and its relaxation of skeletal muscle contraction. The chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.

CONCLUSION

The present data on the extracts of C. procera indicate a direct action on the myocardium, stimulatory effect on smooth muscle motility, and relaxant action on skeletal muscle contraction. Chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.

Antimalarial drug targets in Plasmodium falciparum predicted by stage-specific metabolic network analysis

BACKGROUND

Despite enormous efforts to combat malaria the disease still afflicts up to half a billion people each year of which more than one million die. Currently no approved vaccine is available and resistances to antimalarials are widely spread. Hence, new antimalarial drugs are urgently needed.

RESULTS

Here, we present a computational analysis of the metabolism of Plasmodium falciparum, the deadliest malaria pathogen. We assembled a compartmentalized metabolic model and predicted life cycle stage specific metabolism with the help of a flux balance approach that integrates gene expression data. Predicted metabolite exchanges between parasite and host were found to be in good accordance with experimental findings when the parasite's metabolic network was embedded into that of its host (erythrocyte). Knock-out simulations identified 307 indispensable metabolic reactions within the parasite. 35 out of 57 experimentally demonstrated essential enzymes were recovered and another 16 enzymes, if additionally the assumption was made that nutrient uptake from the host cell is limited and all reactions catalyzed by the inhibited enzyme are blocked. This predicted set of putative drug targets, shown to be enriched with true targets by a factor of at least 2.75, was further analyzed with respect to homology to human enzymes, functional similarity to therapeutic targets in other organisms and their predicted potency for prophylaxis and disease treatment.

CONCLUSIONS

The results suggest that the set of essential enzymes predicted by our flux balance approach represents a promising starting point for further drug development.

Hypoglycemic activity of Ziziphus mauritiana aqueous ethanol seed extract in alloxan-induced diabetic mice

Ziziphus mauritiana Lamk. (Rhamnaceae) is a fruit tree that has been used as folkloric medicine for many ailments and diseases. In the present study, the hypoglycemic effect of seed extract of Ziziphus mauritiana in alloxan-induced diabetic mice was assessed. Seed extract was administered orally at doses of 100, 400, and 800 mg/kg body weight (bw) and also in combination with glyburide (800 mg/kg seed extract and 10 mg/kg glyburide) to different groups of mice (normal and alloxan-treated diabetic mice). Their blood glucose level (in acute and sub-acute study), body weight, and mortality rate were monitored. Oral glucose tolerance test (OGTT) was also performed. Oral administration of extract alone or in combination with glyburide reduced the blood glucose level in all the diabetic mice after acute and sub-acute (28 days) administration. Administration of the extract reduced the weight loss and mortality rate during the sub-acute study. The results of blood glucose level, loss in body weight, and mortality rate were more pronounced in the group treated with combination (800 mg/kg seed extract and 10 mg/kg glyburide). The extract also augmented the glucose tolerance in both normal and diabetic mice. These results suggest that the extract possesses synergistic hypoglycemic activity.

Microparticulated anti-HIV vaginal gel: in vitro-in vivo drug release and vaginal irritation study

The aim of this study was to develop and evaluate a Zidovudine (AZT)-loaded microparticulated bioadhesive vaginal gel (MBVG) in order to obtain a controlled releasing, safe gel delivery system. AZT microparticles (ZMPs) were evaluated for encapsulation efficiency, drug loading, surface morphology and in vitro drug release profiles and drug release mechanism and optimized. The optimized ZMPs were then encompassed in bioadhesive gel using different bioadhesive polymers and evaluated for the drug encapsulation efficiency, drug loading, in vitro and in vivo drug release profiles, drug release mechanism and vaginal irritancy study. From the dissolution data of ZMP4 and MBVG4 showed a zero-order diffusion pattern and Fickian diffusion case I transport mechanism in 24 and 36 h, respectively. On the basis of a pharmacokinetic study of MBVG4 (containing ZMP: Carbopol 1:4), it was found to have better bioavailability, larger AUC and T(max) in comparison to an oral pure suspension of AZT.

Development of amphotericin B loaded polymersomes based on (PEG)(3)-PLA co-polymers: Factors affecting size and in vitro evaluation

Amphotericin B (AmB) is a broad spectrum antifungal and antileishmenial agent and its clinical use is limited due to substantial dose limiting toxicities such as nephrotoxicity. In this work, amphotericin B is formulated in polymersomes of branched (PEG)(3)-PLA co-polymer. Polymersomes were prepared by solvent injection method and the effects of various formulation and process parameters on size and size distribution were studied. The results showed that viscosity of biphasic solution during formulation has significant influence on the size and size distribution of the polymersomes. Further, drug-loaded polymersomes with size of 199.6+/-14.1nm, PDI of 0.258+/-0.18, zeta potential (zeta) of -18.07+/-4.91mV and loading of 16.26+/-2.50% were obtained. Drug was found to be intercalated in the wall of polymersomes as observed using FITC tagged drug and CLSM study. An in vitro release media containing sodium deoxycholate was developed and a significant amount of drug release was observed up to 24h there after a very slow release was obtained. Free drug was not found in the formulation and different molecular forms of the drug (AmB) were observed by UV-visible spectroscopy and circular dichroism. This was further supported by hemolysis experiments, where negligible hemolysis in the test formulation was observed as compared to 100% hemolysis in a marketed formulation (Fungizone).

Microchannels created by sugar and metal microneedles: characterization by microscopy, macromolecular flux and other techniques

The objective of this study was to investigate the feasibility of using microneedle technology to enhance transcutaneous permeation of human immunoglobulin G (IgG) across hairless rat skin. Microchannels created by maltose and metal (DermaRoller) microneedles were characterized by techniques such as methylene blue staining, histological examination, and calcein imaging. Methylene blue staining and histological sections of treated skin showed that maltose microneedles and DermaRoller breached the skin barrier by creating microchannels in the skin with an average depth of approximately 150 microm, as imaged by confocal microscopy. Calcein imaging and pore permeability index values suggested the uniformity of the created pores in microneedle-treated skin. Transdermal studies with IgG indicated a flux rate of 45.96 ng/cm(2)/h, in vitro, and a C(max) of 7.27 ng/mL, in vivo, for maltose microneedles-treated skin while a flux rate of 353.17 ng/cm(2)/h, in vitro, and a C(max) of 9.33 ng/mL, in vivo, was achieved for DermaRoller-treated skin. Transepidermal water loss measurements and methylene blue staining, in vivo, indicated the presence of microchannels for upto 24 h, when occluded. In conclusion, the microchannels created by maltose microneedles and DermaRoller resulted in the percutaneous enhancement of a macromolecule, human IgG.

In vitro anti-aging activities of Terminalia chebula gall extract

CONTEXT

The Thai Lanna region has its own folklores and wisdoms in various fields such as traditional medicines. The galls of Terminalia chebula Retz. (Combretaceae) frequently appear in many Thai Lanna medicinal plant recipes for promoting longevity.

OBJECTIVES

To investigate the in vitro anti-aging activities of the extracts from 15 plants including T. chebula gall selected from the Thai medicinal plant recipes that have been traditionally used for longevity.

MATERIALS AND METHODS

The plant extracts were prepared by four extraction methods including hot (HW) and cold (CW) aqueous processes and hot (HM) and cold (CM) methanol processes. These extracts were tested for antioxidative and tyrosinase inhibition activity as well as the proliferative and MMP-2 inhibition activity on early aging human skin fibroblasts in order to evaluate their in vitro anti-aging activity.

RESULTS

At 0.1 mg/mL, the CW extract of T. chebula gall exhibited the highest DPPH radical scavenging activity with scavenging of 84.64% +/- 2.22%, whereas ascorbic acid, alpha-tocopherol and butylated hydroxyl toluene gave 96.50% +/- 0.1%, 35.74% +/- 0.2% and 27.43% +/- 0.1%, respectively. The CW extract of T. chebula gall indicated the highest stimulation index (SI) on normal human fibroblast proliferation of 1.441 which was more active than ascorbic acid (SI 1.21). This extract has also demonstrated MMP-2 inhibition on fibroblasts determined by zymography 1.37 times more potent than ascorbic acid.

DISCUSSION AND CONCLUSION

This study has confirmed the traditional use of T. chebula gall in many Thai medicinal plant recipes for longevity which will be beneficial for further development of anti-aging products.

Physicochemical characterization of gliclazide-macrogol solid dispersion and tablets based on optimized dispersion

BACKGROUND

This study investigated the physical interaction of gliclazide (GLC) with a hydrophilic carrier, that is, macrogol [polyethylene glycol (PEG)]. Different molecular weights of PEG (4000, 10,000, and 20,000) were used in different drug : carrier weight ratios (1 : 1, 1 : 2, 1 : 5, and 1 : 10).

METHOD

Preliminary screening was done by phase solubility studies to characterize the liquid state interaction between the drug and the carrier. Solid dispersions (SDs) of GLC and PEG in different ratios were prepared by fusion technique and by physical mixing. The solid-state interaction between the drug and the carrier was examined by performing differential scanning calorimetry and Fourier transform infrared spectroscopic studies. SD with satisfactory characteristics was selected for the formulation of tablets by wet granulation method and compared with the commercial brand for in vitro dissolution.

RESULTS

It was evident from phase solubility studies that the drug solubility increased linearly with increasing PEG concentrations. In vitro dissolution of GLC improved significantly in the SDs prepared by fusion method as compared with the original drug and physical mixtures. Scanning electron microscopy images showed well-defined changes in the surface topography of GLC, thus confirming the effective formation of a fused binary system. The SD tablets showed a significant improvement in the drug release profile than that of the commercial brand.

CONCLUSION

It was thus concluded that SD formulations of GLC can be successfully used to design a solid dosage form of the drug, which would have significant advantages over the current marketed tablets.

Self-Assembled Hydrogel Nanoparticles for Drug Delivery Applications

Hydrogel nanoparticles—also referred to as polymeric nanogels or macromolecular micelles—are emerging as promising drug carriers for therapeutic applications. These nanostructures hold versatility and properties suitable for the delivery of bioactive molecules, namely of biopharmaceuticals. This article reviews the latest developments in the use of self-assembled polymeric nanogels for drug delivery applications, including small molecular weight drugs, proteins, peptides, oligosaccharides, vaccines and nucleic acids. The materials and techniques used in the development of self-assembling nanogels are also described.

Augmentation of expression of immunocytes' functions by seed extract of Ziziphus mauritiana (Lamk.)

AIM OF THE STUDY

The present study was carried out to evaluate the immunomodulatory potential of Ziziphus mauritiana (Lamk.) seed extract to ascertain the folkloric claim as immunomodulator.

MATERIALS AND METHODS

The aqueous-ethanolic seed extract (100-400 mg kg(-1)) of Z. mauritiana was investigated for immunomodulatory potential in mice. The extract was standardized with HPLC using betulinic acid as a marker. Functions of various immunocytes in the form of humoral (development of anti-SRBC (sheep red blood cells) antibody titers) and cell-mediated immune response (delayed type hypersensitivity, nitroblue tetrazolium reduction, inducible nitric oxide synthase activity and bactericidal activity) was studied in SRBC immunized mice. The cytokine, IFN-gamma (interferon-gamma) and IL-4 (interleukin-4) secretion was also measured quantitatively by ELISA as the expression of functions of Th-1 and Th-2 respectively. Levamisole (2.5 mg kg(-1)) was used as standard drug.

RESULTS

The seed extract demonstrated significant (P<0.05-0.001) up-regulation of cell-mediated, humoral immune response and Th-1 mediated cytokine IFN-gamma and decline in Th-2 mediated cytokine IL-4. At higher dose of extract the results were comparable to that of the levamisole.

CONCLUSION

The immunostimulatory potential of this seed extract is likely to be mediated through its effect on macrophage function and Th-1 mediated immunity confirming the folkloric use of this plant.

Antifungal constituents isolated from the seeds of Aegle marmelos

Antifungal constituents, 2-isopropenyl-4-methyl-1-oxa-cyclopenta[b]anthracene-5,10-dione and (+)-4-(2'-hydroxy-3'-methylbut-3'-enyloxy)-8H-[1,3]dioxolo[4,5-h]chromen-8-one in addition to known compounds imperatorin, beta-sitosterol, plumbagin, 1-methyl-2-(3'-methyl-but-2'-enyloxy)-anthraquinone, beta-sitosterol glucoside, stigmasterol, vanillin and salicin were isolated during phytochemical investigation on seeds of Aegle marmelos Correa.

Solvatochromic behaviours and structure-spectra relationships of 4-carboxyl-2,6-dinitrophenylazohydroxynaphthalenes

Comprehensive electronic absorption spectra of a new dye series, 4-carboxyl-2,6-dinitrophenylazohydroxynaphthalenes have been investigated in solvents of varying polarities. The solvent dependent UV-vis spectral shifts were analysed using some solvent physical parameters such as refractive index, dielectric function, hydrogen bonding acceptor ability, orientation of polarization and others. The observed spectral shifts were correlated with different solute-solvent interaction mechanisms using simple and multiple linear regression analyses. The results of the curve fitting coefficients enabled us to classify the various interactions of solvents with the dyes and relate the solvatochromic behaviours to the substituent effects on the dye molecules. Charge-transfer complexation occurring between one of the congeners and N,N'-dimethylformamide was extensively studied and discovered to be both concentration- and temperature-dependent. The electronic character and the chemical nature of the solvents as well as the chemical nature of the other substituents, apart from the common hydroxyl group, are important factors for the observed solvatochromic properties of the 4-carboxyl-2, 6-dinitrophenylazohydroxynaphthalenes.

Niosomes in sustained and targeted drug delivery: some recent advances

Niosomes represent an emerging class of novel vesicular systems. They are composed of nonionic surfactants which are biodegradable and relatively nontoxic. They were developed as stable and inexpensive alternatives to liposomes. Since their early introduction to cosmetic industry their role has diversified to other application areas. They are now being ardently explored as potential carriers for sustained and targeted drug delivery. In addition to conventional, oral, and parenteral routes, they are amenable to be delivered by ocular, transdermal, vaginal, and inhalation routes. Delivery of biotechnological products including vaccine delivery with niosomes is also an interesting and promising research area. The introduction of provesicular approach in the form of proniosomes has further increased the relevance of these systems. More concerted research efforts, however, are still required to realize the full potential of these novel systems. This review considers the current status and explores the potential of niosomes in drug delivery with special attention to their role in drug targeting. Their methods of preparation, formulation aspects, advantages, limitations, and applications are also discussed.

In vivo genotoxicity evaluation of a plant based antiarthritic and anticancer therapeutic agent Boswelic acids in rodents

The genotoxic potential of anti-inflammatory/anti-arthritic and anticancer plant based drug molecule Boswelic acids (BA) was studied by in vivo system. Systematic literature survey revealed that studies on the genotoxicity of BA are not available. Although reports on genotoxicity of Boswellia serrata dry extract and modified 3-O-acetyl-11-keto-beta-boswelic acid are available and these studies were conducted in in vitro systems. The earlier general toxicity study of BA has been conducted by us, revealed it to be non toxic. The genotoxicity was carried out in Wistar rats using different cytogenetic assay system-abnormalities viz. chromosomal aberrations; sperm morphology, micronuclei and comet assays. Six groups of animals, each comprised of five rats, were taken for each study. Group1-4 received BA at 125, 250, 500 and 1000 mg/kg p.o., respectively prepared as 2% gum acacia suspension, fifth group received a positive control cyclophosphamide (CP) 40 mg/kg p.o. or metronedazole (MTZ) 130 mg/kg p.o. or mercuric chloride (HgCl(2)) 0.864 mg/kg p.o. (as per the experiment requirement) whereas the sixth group kept as vehicle control. The results on the bases of the data obtained revealed that BA is quite safe as it did not show any genotoxicity at any dose level up to 1000 mg/kg. The positive controls used in different experiments showed highly significant abnormal cytogenetic changes in comparison to the control group.

A review of phytotherapy of Acne vulgaris

Acne vulgaris (acne) is a cutaneous pleomorphic disorder of the pilosebaceous unit involving abnormalities in sebum production and is characterized by both inflammatory (papules, pustules and nodules) and non-inflammatory (comedones, open and closed) lesions. Propionibacterium acnes and Staphylococcus epidermidis are common pus-forming microbes responsible for the development of various forms of acne. This disease remains a common condition in industrialized societies, with many mainstream treatment options available. There are many acne products on the market, and making an appropriate selection can be daunting. Common therapies that are used for the treatment of acne include topical, systemic, hormonal, herbal and combination therapy. Topically used agents are benzoyl peroxide, antibiotics and retinoid. Systemically used agents are antibiotics and isotretinoin. However, all such treatments carry risks and none is completely satisfactory. Natural alternatives are gaining greater research support, and have much to offer clinically in this disorder. This review focuses primarily on herbal treatments for acne that show scientific evidence of clinical efficacy, as well as the more common herbs shown to be useful in the treatment of this dermatologic disorder.

Antibacterial, antifungal, and antiviral activities of some flavonoids

Antibacterial and antifungal activities of six plant-derived flavonoids representing two different structural groups were evaluated against standard strains of Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and their drug-resistant isolates, as well as fungi (Candida albicans, C. krusei) using the microdilution broth method. Herpes simplex virus Type-1 and Parainfluenza-3 virus were employed for antiviral assessment of the flavonoids using Madin-Darby bovine kidney and Vero cell lines. Ampicillin, gentamycin, ofloxacin, levofloxacin, fluconazole, ketoconazole, acyclovir, and oseltamivir were used as the control agents. All tested compounds (32-128 microg/ml) showed strong antimicrobial and antifungal activities against isolated strains of P. aeruginosa, A. baumanni, S. aureus, and C. krusei. Rutin, 5,7-dimethoxyflavanone-4'-O-beta-D-glucopyranoside and 5,7,3'-trihydroxy-flavanone-4'-O-beta-D-glucopyranoside (0.2-0.05 microg/ml) were active against PI-3, while 5,7-dimethoxyflavanone-4'-O-[2''-O-(5'''-O-trans-cinnamoyl)-beta-D-apiofuranosyl]-beta-D-glucopyranoside (0.16-0.2 microg/ml) inhibited potently HSV-1.

Cassia occidentalis L.: a review on its ethnobotany, phytochemical and pharmacological profile

Cassia occidentalis L. is an annual or perennial Ayurvedic plant which is used in several traditional medicines to cure various diseases. This weed has been known to possess antibacterial, antifungal, antidiabetic, anti-inflammatory, anticancerous, antimutagenic and hepatoprotective activity. A wide range of chemical compounds including achrosin, aloe-emodin, emodin, anthraquinones, anthrones, apigenin, aurantiobtusin, campesterol, cassiollin, chryso-obtusin, chrysophanic acid, chrysarobin, chrysophanol, chrysoeriol etc. have been isolated from this plant. The presented review summarizes the information concerning the botany, ethnopharmacologyquery, phytochemistry, biological activity and toxicity of the C.occidentalis plant.

Chemical constituents from Swietenia macrophylla bark and their antioxidant activity

Chemical constituents of the bark of Swietenia macrophylla King (Meliaceae) was investigated not only to develop further bark utilization but also to understand the biochemical function of the bark in the forest environment. A new phenylpropanoid-substituted catechin, namely, swietemacrophyllanin [(2R*,3S*,7"R*)-catechin-8,7"-7,2"-epoxy-(methyl 4",5"-dihydroxyphenylpropanoate)] (1) was isolated from the bark of S. macrophylla together with two known compounds, catechin (2) and epicatechin (3). The structure of 1 was elucidated by spectroscopic data and by comparison of the NMR data with those of catiguanins A and B, phenylpropanoid-substituted epicatechins. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the isolated compounds indicated that all of the three compounds have strong activity compared with trolox as a reference. Swietemacrophyllanin (1) had the strongest activity with a 50% inhibitory concentration (IC50) value of 56 microg mL(-1).

Fabrication of polymer microneedles using a two-photon polymerization and micromolding process

BACKGROUND

Microneedle-mediated drug delivery is a promising method for transdermal delivery of insulin, incretin mimetics, and other protein-based pharmacologic agents for treatment of diabetes mellitus. One factor that has limited clinical application of conventional microneedle technology is the poor fracture behavior of microneedles that are created using conventional materials and methods. In this study polymer microneedles for transdermal delivery were created using a two-photon polymerization (2PP) microfabrication and subsequent polydimethylsiloxane (PDMS) micromolding process.

METHODS

Solid microneedle arrays, fabricated by means of 2PP, were used to create negative molds from PDMS. Using these molds microneedle arrays were subsequently prepared by molding eShell 200, a photo-reactive acrylate-based polymer that exhibits water and perspiration resistance.

RESULTS

The eShell 200 microneedle array demonstrated suitable compressive strength for use in transdermal drug delivery applications. Human epidermal keratinocyte viability on the eShell 200 polymer surfaces was similar to that on polystyrene control surfaces. In vitro studies demonstrated that eShell 200 microneedle arrays fabricated using the 2PP microfabrication and PDMS micromolding process technique successfully penetrated human stratum corneum and epidermis.

CONCLUSIONS

Our results suggest that a 2PP microfabrication and subsequent PDMS micromolding process may be used to create microneedle structures with appropriate structural, mechanical, and biological properties for transdermal drug delivery of insulin and other protein-based pharmacologic agents for treatment of diabetes mellitus.