Drug-fortified liposomes as carriers for sustained release of NSAIDs: The concept and its validation in the animal model for the treatment of arthritis.

Drug-fortified cationic liposomes of 6­methoxy­2­naphthylacetic acid (6­MNA) were prepared and characterized by various techniques. The residence time of drug-fortified liposomes in joint cavity was evaluated by intra-articular (IA) administration of the radio-labeled (99mTc) liposomal formulation in the inflamed joints in rats. The cationic liposomal formulation composed of 6­MNA (3) as an active agent, its double salt (4) with the lipid 1,2­distearoyl­sn­glycero­3­phosphoethanolamine (DSPE), and pharmaceutically acceptable excipients such as hydrogenated soyabean phospatidylcholine (HSPC) and 1,2­dioleyloxy­3­trimethylammoniumpropane chloride (DOTAP) were developed using thin film hydration technique. The cryo-TEM analysis confirmed that the prepared optimized liposomal formulation (DFL-2) was a mixture of small unilamellar vesicles (SUVs), large unilamellar vesicles (LUVs) and multilamellar vesicles (MLVs). In addition, the TEM analysis confirmed that the prepared liposomes were of spherical in shape having liposome size in the range of 500-900 nm and zeta potential of about +30 mV. The developed cationic liposomes exhibited sustained release profile of payload of 6­MNA for over >12 h and about five times higher retention in the inflamed animal joints after 24 h (by scintigraphy of the joints) as compared to the plain 6­MNA solution when administered by IA route. The anti-inflammatory activity of prepared liposomal composition is evaluated by Freund's adjuvant induced arthritic model in rats. The liposomal formulation was well tolerated by all animals indicating good biocompatibility. Further, the cationic liposomal formulation treated group showed decreased erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) level in comparison to the control and the standard groups in the in vivo study. The improved efficacy of the drug-fortified liposomal formulation was due to the coupled effect of longer retention and sustained release of the active drug 6­MNA in the joints. From the obtained results it could be concluded that the combined effect of the cationic charge on the drug-fortified liposomes and the inherent affinity of the active agent towards the synovial joint tissues, coupled with slow release of the active drug due to double salt approach at the site of administration could potentially decrease the frequency of IA drug administration. Hence such a formulation could prove to be a therapeutic boon for the management of late stage arthritis.

Clerodendron glandulosum.Coleb leaf extract attenuates in vitro macrophage differentiation and expression of VCAM-1 and P-selectin in thoracic aorta of atherogenic diet fed rats.

Present inventory evaluates the anti-atherogenic potential of C. glandulosum.Coleb leaf extract (CG) using in vivo and in vitro experimental models. Serum markers of low density lipoprotein (LDL-C) oxidation, cholesterol, triglycerides, lipoproteins, auto-antibody titer, ex vivo LDL-C oxidation, LDL-C aggregation, aortic lipids, histopathological evaluations and immunolocalization of macrophage surface marker (F4/80), vascular cell adhesion molecule-1 (VCAM-1) and P-selectin were performed in CON [rats treated with single dose of saline (i.p.) and fed with laboratory chow], ATH [rats treated with single dose of vitamin D3 (600,000 IU, i.p) and fed with atherogenic diet] and ATH+CG [rats treated with single dose of vitamin D3 (600,000 IU, i.p.) and fed with atherogenic diet and simultaneously treated with 200 mg/kg CG extract, p.o.] for 8 weeks. CG extract supplementation to atherogenic diet fed rats significantly prevented increment in serum cholesterol, triglycerides, and lipoproteins, markers of LDL-C oxidation, auto-antibody titer and aortic lipids. Also, LDL-C isolated from ATH+CG rats recorded mimimal aggregation and susceptibility to undergo ex vivo LDL-C oxidation. Microscopic evaluation of thoracic aorta of ATH+CG rats reveled prevention of atheromatous plaque formation, accumulation of lipid laden macrophages, calcium deposition, distortion/defragmentation of elastin, accumulation of macrophages and, down regulation of cell adhesion molecules (VCAM-1 and P-selectin) expression. Further, in vitro monocyte to macrophage differentiation was significantly attenuated in presence of CG extract (200 µg/mL). It can be concluded from the present study that, CG extract is capable of controlling induction of experimental atherosclerosis and warrants further scrutiny at the clinical level as a possible therapeutic agent.

Clerodendron glandulosum.Coleb extract prevents in vitro human LDL oxidation and oxidized LDL induced apoptosis in human monocyte derived macrophages.

This study reports the protective role of Clerodendron glandulosum (CG) extract against in vitro LDL oxidation and Ox-LDL induced macrophage apoptosis using various experimental models. Effect of CG extract on Cu(2+) mediated LDL oxidation kinetics and formation of various intermediary products and its ability to prevent human monocyte derived macrophage mediated LDL oxidation have been investigated. Ox-LDL induced macrophage apoptosis was evaluated by nuclear condensation, cell cycle analysis, and annexin V-FITC/PI staining in presence or absence of CG extract. Results recorded in the present study clearly suggest the protective role of CG extract against LDL oxidation and Ox-LDL induced macrophage oxidative stress, mitochondrial dysfunction, and apoptosis. This is the first report on the protective role of CG extract on two key events of atherosclerosis portending its possible therapeutic use as an anti-atherogenic herbal medicine.

In vitro evidence for the protective role of Sida rhomboidea. Roxb extract against LDL oxidation and oxidized LDL-induced apoptosis in human monocyte-derived macrophages.

The present study was undertaken to evaluate protective role of S. rhomboidea. Roxb (SR) leaf extract against in vitro low-density lipoprotein (LDL) oxidation and oxidized LDL (Ox-LDL) induced macrophage apoptosis. Copper and cell-mediated LDL oxidation, Ox-LDL-induced peroxyl radical generation, mitochondrial activity, and apoptosis in human monocyte-derived macrophages (HMDMs) were assessed in presence of SR extract. Results clearly indicated that SR was capable of reducing LDL oxidation and formation of intermediary oxidation products. Also, SR successfully attenuated peroxyl radical formation, mitochondrial dysfunction, nuclear condensation, and apoptosis in Ox-LDL-exposed HMDMs. This scientific report is the first detailed investigation that establishes anti-atherosclerotic potential of SR extract.