S. Arulmozhi

Design and statistical optimization of glipizide loaded lipospheres using response surface methodology

Design and statistical optimization of glipizide loaded lipospheres using response surface methodology A 32 factorial design was employed to produce glipizide lipospheres by the emulsification phase separation technique using paraffin wax and stearic acid as retardants. The effect of critical formulation variables, namely levels of paraffin wax (X1) and proportion of stearic acid in the wax (X2) on geometric mean diameter (dg), percent encapsulation efficiency (% EE), release at the end of 12 h (rel12) and time taken for 50% of drug release (t50), were evaluated using the F-test. Mathematical models containing only the significant terms were generated for each response parameter using the multiple linear regression analysis (MLRA) and analysis of variance (ANOVA). Both formulation variables studied exerted a significant influence (p < 0.05) on the response parameters. Numerical optimization using the desirability approach was employed to develop an optimized formulation by setting constraints on the dependent and independent variables. The experimental values of dg, % EE, rel12 and t50 values for the optimized formulation were found to be 57.54 ± 1.38 μm, 86.28 ± 1.32%, 77.23 ± 2.78% and 5.60 ± 0.32 h, respectively, which were in close agreement with those predicted by the mathematical models. The drug release from lipospheres followed first-order kinetics and was characterized by the Higuchi diffusion model. The optimized liposphere formulation developed was found to produce sustained anti-diabetic activity following oral administration in rats. Dizaj i statistička optimizacija liposfera s glipizidom pomoću metodologije odgovora površine 32 faktorijalni dizajn je primijenjen za pripravu liposfera s glipizidom metodom separacije pomoću emulzija koristeći parafinski vosak i stearinsku kiselinu kao tvari za usporavanje. Pomoću F-testa praćen je učinak kritičnih varijabli tijekom formuliranja, tj. količina parafinskog voska (X1) i udio stearinske kiseline (X2) na srednji promjer liposfera (dg), postotak inkapsulirane ljekovite tvari (% EE), oslobađanje ljekovite tvari nakon 12 h (rel12) te vrijeme potrebno za oslobađanje 50% ljekovite tvari (t50). Za svaki parametar su pomoću multiple linearne regresijske analize (MLRA) i analize varijabli (ANOVA) načinjeni matematički modeli koji sadrže samo značajne varijable. Proučavanje varijabli na oba načina ukazalo je na njihov značajan utjecaj (p < 0,05) na parametre liposfera. Postavljanjem ograničenja na zavisne i nezavisne varijable provedena je numerička optimizacija na principu poželjnosti. Eksperimentalne vrijednosti dg, % EE, rel12 i t50 optimiziranih formulacija bile su 57,54 ± 1,38 μm, 86,28 ± 1,32%, 77,23 ± 2,78% i 5,60 ± 0,32 h. Dobivene eksperimentalne vrijednosti bile su vrlo slične vrijednostima predviđenim matematič kim modelima. Oslobađanje glipizida iz liposfera slijedio je kinetiku prvog reda i karakteriziran je Higuchijevim difuzijskim modelom. Optimizirane liposfere su nakon peroralne primjene na štakorima pokazale produljeni antidijabetički učinak.

Validation of ethnopharmacology of ayurvedic sarasvata ghrita and comparative evaluation of its neuroprotective effect with modern alcoholic and lipid based extracts in β-amyloid induced memory impairment

ETHNOPHARMACOLOGICAL RELEVANCE Sarasvata ghrita (SG), a polyherbal formulation from ayurveda, an ancient medicinal system of India, has been used to improve intelligence and memory, treat speech delay, speaking difficulties and low digestion power in children. AIM OF THE STUDY Study aimed to validate the ethno use of SG in memory enhancement through systematic scientific protocol. The effect of SG and modern extracts of ingredients of SG was compared on cognitive function and neuroprotection in amyloid-β peptide 25-35(Aβ25-35) induced memory impairment in wistar rats. Further the underlying mechanism for neuroprotective activity was investigated. MATERIALS AND METHODS SG was prepared as per traditional method, ethanolic extract (EE) was prepared by conventional method and lipid based extract was prepared by modern extraction method. All extracts were standardised by newly developed HPLC method with respect to marker compounds. SG, EE and LE were administered orally to male Wistar rats at doses of 100,200 and 400 mg/kg Body Weight by feeding needle for a period of 21 days after the intracerebroventricular administration of Aβ25-35 bilaterally. Spatial memory of rats was tested using Morris water maze (MWM) and Radial arm maze (RAM) test. The possible underlying mechanisms for the cognitive improvement exhibited by SG, EE and LE was investigated through ex-vivo brain antioxidant effect, monoamine level estimation, acetylcholine esterase (AchE) inhibitory effect and Brain-derived neurotropic factor (BDNF) levels estimation. RESULTS SG, EE and LE were analyzed by HPLC method, results showed that EE extract has high percent of selected phytoconstituents as compared with SG and LE. SG and LE decrease escape latency and searching distance in a dose dependant manner during MWM test. In case of RAM significant decrease in number of errors and increase in number of correct choices indicate an elevation in retention and recall aspects of learning and memory after administration of SG an LE. SG and LE extract can efficiently prevent accumulation of β-amyloid plaque in hippocampus region. There was increase in SOD, GSH, CAT and NO level and decrease in MDA levels in SG and LE administered animals. SG and LE have found to exhibit AchE inhibitiory activity and significant dose-dependant increase in BDNF level in the plasma. SG and LE significantly increased the levels of noradrenaline, dopamine and 5-hydroxytryptamine in the brain. CONCLUSION The study validated the neuroprotective activity of SG. The study concludes the extraction efficiency of SG for selected phytoconstituents is less than modern methods. However the neuroprotective activity of SG and LE was found to be greater than EE.

Investigation of anti-arthritic, antioxidant properties of dichloromethane fraction of Alstonia scholaris Linn. in Freund’s complete adjuvant induced rats and identification of biomarker

Alstonia scholaris (Family: Apocynaceae) is a medicinal plant which has been indicated for the treatment of various diseases including arthritis in folklore medicine. The antiarthritic activity of the ethanolic extract of Alstonia scholaris leaves is reported. The present study was performed to establish the antiarthritic activity of the dichloromethane fraction (DCM) and to identify the constituent(s) responsible for the activity. DCM was tested for antiarthritic activity against Freund’s Complete Adjuvant (FCA) induced arthritic rats. Arthritis assessment, nociceptive threshold and body weight were measured. On day 28, plasma tumor necrosis factor α, synovial leukocyte concentration, synovial tissue myeloperoxide, malonaldehyde, glutathione, glutathione peroxidase and superoxide dismutase were determined. Effect of DCM on ethanol and sodium salicylate induced gastropathy was also studied. DCM was subjected to HPTLC analysis and the phytoconstituent was identified using marker. DCM significantly decreased the signs of arthritis evident with decreased arthritis index, body weight, TNF-α and leukocyte infiltration. DCM significantly reduced gastric lesion indices and gastric juice secretion. It also significantly decreased the levels of lipid peroxidation and myeloperoxide in the articular tissue, whereas significantly increased the antioxidant enzymes glutathione, glutathione peroxidase and superoxide dismutase. Moreover DCM was found to contain ursolic acid, which is one of the biomarkers indicated to have anti-inflammatory activity. The present study is suggestive that DCM has prominent antiarthritic activity which may be attributed to its analgesic, anti-inflammatory, and antioxidant activities. The Ursolic acid may contribute the found antiarthritic activity in part or whole.