Alkaloids for cancer prevention and therapy: Current progress and future perspectives.

Alkaloids are important chemical compounds that serve as a rich source for drug discovery. Numerous alkaloids screened from medicinal plants and herbs showed antiproliferative and anticancer effects on wide category of cancers both in vitro and in vivo. Vinblastine, vinorelbine, vincristine, and vindesine have already been successfully developed as anticancer drugs. The available and up-to-date information on the ethnopharmacological uses in traditional medicine, phytochemistry, pharmacology and clinical utility of alkaloids were collected using various resources (PubMed, ScienceDirect, Google Scholar and Springerlink). In this article, we provide a comprehensive and critical overview on naturally-occurring alkaloids with anticancer activities and highlight the molecular mechanisms of action of these secondary metabolites. Furthermore, this review also presents a summary of synthetic derivatives and pharmacological profiles useful to researchers for the therapeutic development of alkaloids. Based on the literature survey compiled in this review, alkaloids represent an important group of anticancer drugs of plant origin with enormous potential for future development of drugs for cancer therapy and management.

Alginate Based Nanocarriers for Drug Delivery Applications.

BACKGROUND: Now a day's natural polymer based nanoparticulate system have been widely studied as particulate vehicles in the bio-medical and pharmaceutical area. Alginate, a natural biopolymer show good biodegradability, biocompatibility and non toxic, has received attention to utilise as a carrier for preparation of polymeric nanoparticles. Chemically and physically alginate can modified easily and obtained various structure having various properties, and versatile applications. Various properties and structure such as biodegradability, gelling property, mechanical strength and cell affinity can be obtained through combination of alginate with other biopolymers, immobilization of specific molecules such as sugar molecules and peptide through chemical or physical cross-linking. CONCLUSION: In this article, we report different method of preparation of alginate nanoparticles, and also focus on recent advances of nanoparticles made of alginate and its modified form in the field of drug delivery applications.

Metal ion-induced alginate-locust bean gum IPN microspheres for sustained oral delivery of aceclofenac.

The alginate microspheres represent a useful tool for sustained oral delivery of drugs but exhibit several problems associated with the stability and rapid release of drugs at higher pH values. To overcome these drawbacks, alginate-locust bean gum (LBG) interpenetrating microspheres were prepared by calcium ion (Ca(+2)) induced ionotropic gelation technique for prolonged release of aceclofenac. The drug entrapment efficiency of these microspheres was found to be 59-93%. The microspheres lied in the size range of 406-684µm. Scanning electron microscopy revealed spherical shape of the microspheres. No drug-polymer interaction was evident after infrared spectroscopy analysis. The microspheres provided sustained release of aceclofenac in phosphate buffer solution (pH 6.8) over a period of 8h. The drug release data were fitted into the Korsmeyer-Peppas model and the drug release was found to follow anomalous (non-Fickian) diffusion mechanism. Pharmacodynamic study of the microspheres showed a prolonged anti-inflammatory activity in carrageenan-induced rat paw model following oral administration.

Gellan gum microspheres containing a novel α-amylase from marine Nocardiopsis sp. strain B2 for immobilization.

A Nocardiopsis sp. stain B2 with an ability to produce stable α-amylase was isolated from marine sediments. The characterization of microorganism was done by biochemical tests and 16S rDNA sequencing. The α-amylase was purified by gel filtration chromatography by using sephadex G-75. The molecular mass of the amylase was found to be 45 kDa by SDS-PAGE and gel filtration chromatography. The isolated α-amylase was immobilized by ionotropic gelation technique using gellan gum (GG). These microspheres were spherical with average particle size of 375.62±21.76 to 492.54±32.18 µm. The entrapment efficiency of these α-amylase loaded GG microspheres was found 74.76±1.32 to 87.64±1.52%. Characterization of α-amylase-gellan gum microspheres was confirmed using FTIR and SEM analysis. The in vitro amylase release kinetic have been studied by various mathematical models that follow the Korsmeyer-Peppas model (R2=0.9804-0.9831) with anomalous (non-Fickian) diffusion release mechanism.

In-vitro release of acyclovir loaded Eudragit RLPO(®) nanoparticles for sustained drug delivery.

In this present study the possibility to develop Eudragit RLPO(®) based nanoparticles of acyclovir was investigated in order to increase its efficacy because acyclovir has oral bioavailability of only 10-20% thus showing erratic absorption and bioavailability behaviour. The nanoparticles were prepared by nanoprecipitation technique. Pluronic F68 was used as stabilizer. The nanoparticles were characterized by particle size, entrapment efficiency, DSC, SEM, FTIR and in-vitro drug release. It was found that as drug:polymer (Acyclovir:Eudragit RLPO(®)) ratio increased from 1:1.5 to 1:2, particle size was increased significantly and drug entrapment also increased but thereafter, further increase in drug: polymer ratio showed reduced or insignificant change in the drug entrapment efficiency. DSC results showed that in the prepared nanoaprticles, the drug was present in the amorphous phase and may have been homogeneously dispersed in the polymer matrix. In vitro drug release study of formulations showed release in 24h in the range 71.62±1.72 to 93.25±1.02%. The release was found to follow Higuchi model with non-Fickian diffusion mechanism for all batches. These preliminary results indicate that acyclovir loaded Eudragit RLPO(®) nanoparticles could be effective in sustaining drug release for a prolonged period.