New surface hydroxylated and internally quaternised poly(propylene imine) dendrimers as efficient biocompatible drug carriers of norfloxacin.

OBJECTIVES: This study intended to describe the development of two novel, biocompatible and potential surface hydroxylated quaternary ammonium chloride based poly(propylene imine) (PPI) dendrimers for effective delivery of the drug Norfloxacin (NFN). METHODS: The synthetic pathway involved the hydroxylation and methylation of generation 2 and 3 PPI dendrimers and thus produced surface hydroxylated and internally quaternised PPI dendrimers viz., QPPI-OH (G2) and QPPI-OH (G3), respectively. The potential of these dendrimers were examined as drug carrier for NFN, by carrying out solubility, in vitro release, cytotoxicity and anti-bacterial studies. RESULTS: It was observed that the QPPI-OH (G2)/QPPI-OH (G3) dendrimers have excellent solubilising potential/drug loading abilities of NFN in aqueous medium and can also sustain delivery of NFN. The effective complexation of NFN with QPPI-OH (G2) and QPPI-OH (G3) increased the solubility of NFN and thus elevates the NFN drug from Class 4 to Class 3 (according to BCS). These dendrimers increase the biocompatibility and increase the tolerance concentration during drug-dendrimer formulations. Anti-bacterial studies showed that the efficacy of the drug was increased in the presence of dendrimer carriers. CONCLUSIONS: These results indicate that the QPPI-OH (G2) and QPPI-OH (G3) dendrimers might be considered as potential biocompatible drug carriers of fluoroquinolines under suitable conditions.

Biosynthesis of silver nanoparticles using citrus sinensis peel extract and its antibacterial activity.

Biosynthesis of silver nanoparticles (AgNPs) was achieved by a novel, simple green chemistry procedure using citrus sinensis peel extract as a reducing and a capping agent. The effect of temperature on the synthesis of silver nanoparticles was carried out at room temperature (25°C) and 60°C. The successful formation of silver nanoparticles has been confirmed by UV-vis, FTIR, XRD, EDAX, FESEM and TEM analysis and their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa (gram-negative), and Staphylococcus aureus (gram-positive) has been studied. The results suggest that the synthesized AgNPs act as an effective antibacterial agent.

Anticancer activity of fungal taxol derived from Botryodiplodia theobromae Pat., an endophytic fungus, against 7, 12 dimethyl benz(a)anthracene (DMBA)-induced mammary gland carcinogenesis in Sprague Dawley rats.

Breast cancer is the second most prevalent cancer worldwide and their incidence increases gradually. Taxol (paclitaxel), a potent anticancer drug, is naturally isolated from the bark of the Pacific yew. Taxol is widely used in the treatment of ovarian, lung and breast cancer. The increased demand for taxol, coupled with its limited availability from the protected Pacific yew, has had researchers scrambling for alternate sources. The purpose of the present study is to investigate chemopreventive effect of fungal taxol derived from a novel endophytic fungus Botryodiplodia theobromae Pat., isolated from a medicinal plant Morinda citrifolia Linn. The fungal taxol is found to be active against the 7, 12 dimethyl benz(a)anthracene (DMBA)-induced mammary gland carcinogenesis in Sprague dawley rats. The enzymic and non-enzymic antioxidants i.e. superoxide dismutase (SOD), catalase (CAT), glutatione peroxidase (GPx), glutatione-S-transferase (GST), reduced glutathione (GSH), vitamin C and vitamin E were evaluated in control and experimental groups. Lipid peroxides levels (LPO) were also tested. Histological analysis of breast tissue was analyzed by haematoxylin and eosin staining to assess the cytoprotective role of fungal taxol active against breast cancer. Immunohistochemical analyses were also performed to evaluate the effect of fungal taxol on the inflammatory marker such as Cyclooxygenase-2 (COX-2) in control and experimental groups. The results showed that the fungal taxol significantly suppresses the DMBA-induced breast cancer in Sprague dawley rats.

A novel endophytic Taxol-producing fungus Chaetomella raphigera isolated from a medicinal plant, Terminalia arjuna.

Taxol is the most important member of the clinically useful natural anticancer drug. An endophytic fungus Chaetomella raphigera (strain TAC-15) was isolated from a medicinal plant Terminalia arjuna and screened for its potential in Taxol production. The fungus was identified based on the morphology of the fungal culture and the characteristics of the spores. This fungus was grown in MID liquid medium and analyzed by chromatographically and spectrometrically for the presence of Taxol. The amount of Taxol produced by this endophytic fungus was quantified by HPLC which showed that it produced 79.6 microg/L, and further confirmative analyses were done by using UV, IR, FAB mass spectroscopy, and NMR spectroscopy. Thus, the fungus can serve as a potential material for fungus engineering to improve the production of Taxol.

Taxol determination from Pestalotiopsis pauciseta, a fungal endophyte of a medicinal plant.

Taxol is the most effective antitumor agent developed in the past three decades. It has been used for effective treatment of a variety of cancers. A taxol-producing endophytic fungus Pestalotiopsis pauciseta (strain CHP-11) was isolated from the leaves of Cardiospermum helicacabum and screened for taxol production. The fungus was identified based on the morphology of the fungal culture and the characteristics of the spores and screened for taxol production. The amount of taxol produced by this endophytic fungus was quantified by HPLC and it produced 113.3 microg/L, thus the fungus can serve as a potential material for fungus engineering to improve taxol production. This fungal taxol also had strong anticancer activity against some cancer cells viz., BT 220, H116, Int 407, HL 251 and HLK 210 tested by Apoptotic assay and it is indicated that with the increase of taxol concentration from 0.005-0.05 micromol/L, taxol induced increased cell death through apoptosis.

A simple and rapid method for the determination of taxol produced by fungal endophytes from medicinal plants using high performance thin layer chromatography.

Taxol is an important anticancer drug used widely in the clinical field. In this study, some endophytic fungi were isolated from selected medicinal plants, and were screened for their potential in the production of taxol, using a rapid separation technique of high performance thin layer chromatography (HPTLC). Of the 20 screened fungi, only 13 fungal species produced taxol in the artificial culture medium. The results of HPTLC showed that the 13 fungal species had identical ultraviolet (UV) characteristics, positive reactivity with a spray reagent, yielding a blue spot, which turned to dark gray after 24 hours, and had Rf values identical to that of the authentic taxol. The amount of taxol was also quantified by comparing the peak area and the peak height of the fungal samples with those of authentic taxol.