Quercetin

Alike many allopathic lipophilic drug molecules, these natural phyto-constituents are potent, lipophilic, but pose problems like poor aqueous solubility, slower drug release profile, and, reduced bioavailability leading to inferior therapeutic efficacy. This creates scope as well as a challenge for researchers to overcome the above-mentioned problems while developing a formulation for poorly aqueous soluble phytoconstituents. Herbosome is one of the efficient techniques to improve these problems. Herbosome /Phytosome is nothing but the combination of liposome with phytoconstituents forming H-bond anchored amphiphilic drug-phospholipids complexes. Quercetin i.e. 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4H-1-benzopyran-4-one is a polyphenolic flavonoid with potent and diverse biological effects like anti-inflammatory, anti-proliferative, and anti-mutagenic. However, like many other potent drugs, its usage is limited due to its poor aqueous solubility. To overcome this problem, an ameliorated complex of phospholipids loaded with quercetin was developed to improve its aqueous solubility for better absorption. Thus quercetin encapsulated in herbosomes/phytosomes was assessed for the phospholipid complex formation, appearance, surface, and porosity evaluation using different physicochemical tests like FT­IR, DSC, XRPD, 1H-NMR, SEM, and solubility studies. Apart from this anti-oxidant activity of quercetin was evaluated in vitro. The surface characteristics of herbosomes appeared to be flocculent and permeable with a coarse surface in SEM studies whereas FTIR, DSC, 1H-NMR, and XRPD data, confirmed the formation of the phospholipids complex. There were 12 folds improvement in aqueous solubility of per se quercetin and quercetin encapsulated in herbosome (i.e. from 3.44 µg/ml to 36.81 µg/ ml). On the other hand, the results of in vitro anti­oxidant activity of phytosomic quercetin showed no significant statistical difference compared to per se quercetin thus indicating no adverse effects of complexation on quercetin’s availability for anti­oxidant activity. Further, we prepared tard-gelatin capsules containing phytosomic quercetin and evaluated them for drug release, drug content, and solubility studies like dissolution, disintegration, drug content, and stability studies. The results for the evaluation of the kinetics of drug release were in line with the Korsmeyer Peppas model. The drug stability studies did not affect the drug's organoleptic properties, disintegration time, drug content, and in-vitro drug release of the formulation.

The study was undertaken with an aim to improve the efficacy and reduce the adverse effect of drug, by combination therapy of  Diltiazem HCL and Quercetin dihydrate. In the present research 22 formulations were developed using design expert software with response surface methodology. In which the effect of superdisintegrant, type of superdisintegrant, effect of diluents, formation of solid dispersion studied for their in vitro release  from pellets. The result depicted that the formulation containing superdisintegrant crospovidone, diluent lactose and presence of surfactant  showed good disintegration time and in vitro drug release. Key words: Diltiazem HCL, Quercetin, Pellets, Immediate release

Clitora ternatea is a disease resistant plant used in ethno-pharmacological preparations for its high therapeutic value of primary and secondary metabolites. The aim of this study was to investigate the amount of quercetin in plant parts of Clitoria ternatea and its antifungal activity on dermatophytes. To obtain chemical pattern of flavonoids and quercetin in different plant parts, the extraction solvent was standardized and a finger printing profile of flavonoid was established by means of high performance liquid chromatography (HPLC). The greatest amount of flavonoid was observed in methanolic extracts of C.ternatea flowers while the lowest level was found in the C.ternatea stem extracts, whereas HPLC fingerprinting of flavonoids in flowers was significantly different from stem and leaf extracts. These extracts also differ in their fungicidal capacity against dermatophytes tested, although they all showed significant antifungal activity against Candida sp.. and Aspergillus sp.. flower extracts showed concentration dependent strong inhibition on growth of Microsporum gypseum and Epidermophyton floccosum, and weak inhibition on Trichophyton metagraphytes. The results of this study will be used to promote application of C.ternatea for improving human health by providing antidermatophytic effect on skin infections.

In the present investigations, methanolic extracts of four marketed Aegle marmelos formulations (F1, F2, F3, and F4) were prepared and subjected to simultaneous quantitative determination of two biologically active compounds; umbelliferone and quercetin. Analysis of umbelliferone and quercetin was performed on TLC aluminum plates pre-coated with silica gel 60F-254 as stationary phase. Linear ascending development was carried out in twin trough glass chamber saturated with mobile phase consisting of toluene: ethyl acetate: formic acid (6:4:1, v/v/v), and densitometric determination of these compounds was carried out at 300nm in reflectance/absorbance mode. The system was found to give compact spots for umbelliferone and quercetin with Rf value of 0.66 and 0.68, respectively. The present method was validated for precision, recovery, repeatability, and accuracy in accordance with International Conference on Harmonisation (ICH Q2) guidelines. Statistical analysis of the data showed that the method is reproducible and selective for estimation of umbelliferone and quercetin. This method may be used for routine quality control and standardization of the herbal drugs and there formulations. Key words: Aegle marmelos, Quercetin, Umbelliferone, HPTLC  

Oxidative stress caused by free radicals is implicated in the pathogenesis of many diseases.  In order to continue the other plants with potential benefits with free radical scavenging properties, researchers start looking forward for exploring new plants with rich in flavonoids and polyphenolics. These constituents possess not only free radical scavenging properties but also they are highly safe in the treatment of many diseases/disorders. In one of the field survey, it was identified that Sesbania grandiflora(Linn) was extensively used by folklore practitioner for treating many human ailments such as flatulent-colic, astringent, cooling, bitter, tonic, anthelmintic, febrifuge, dyspepsia, diarrhea and gastralgia, pain, nyctalopia, anaemia, emaciation. Even the plant is a rich source of antioxidants such as phenolics and flavonoids. However, scientific information about the plant and concentration of these constituents was not updated. Hence it was planned to undertake the plant of the present study for its spectrophotometric determination of total phenolic and flavonoid contents from 70% alcoholic extract of flowers of Sesbania grandiflora using Catechol and Quercetin as reference standard. It was observed that, 70% alcoholic extract of flowers of Sesbania grandiflora(Linn) showed 64.0mg/G of total phenol equivalent to catechol and 28.80mg/G of flavonoidal content equivalent to quarcetin standard.  Hence it may be concluded that the plant many be potential source of antioxidant principles such as phenolic and flavonoid. Furthermore, the plants possessing these antioxidants can be highly beneficial for the treatment of many common human ailments. Key-Words: Catechol, Flavonoid, Phenolic, Quercetin, Sesbania grandiflora(Linn).