Quercetin-loaded nanoemulsions prevent Scopolamine-induced neurotoxicity in male rats

Quercetin (QCT) is well-known as a neuroprotective agent due to its antioxidant capacities and reinstating mitochondrial functions. Scopolamine is commonly used as a model to induce Alzheimer's disease (AD-like) symptoms. The current study develops QCT-loaded nanoemulsion (QCT-NE) accompanied by evaluating its neuro-therapeutic effectiveness against SCO-induced neurotoxicity in male rats. The QCT-NE was prepared by the spontaneous emulsification technique and characterized by using particle size, zeta potential, drug loading, in vitro drug release behavior, and stability studies. In vivo studies were done on adult Wistar rats by applying the Morris water maze (MWM) test to study spatial memory and learning. The levels of lipid peroxidation and reduced glutathione were quantitatively determined to reveal the potential mechanism of SCO-induced oxidative stress. Finally, histological studies were performed using staining techniques. The QCT-NE particle size, zeta potential, polydispersity index (PDI), and DL were obtained at 172.4 ± 16.8 nm, -29 ± 0.26 mV, 0.3 ± 0.07, and 81.42 ± 9.14 %, respectively. The QCT and more effectively QCT-NE reduced the elevation of neurobehavioral abnormalities in the MWM test in SCO-exposed rats. The results of oxidative status showed that SCO significantly could increase the LPO and decrease the GSH levels in the rat's brain. However, QCT-NE treatment was more effective than free QCT to inhibit oxidative damage and was well correlated with histopathological findings. Taken together, QCT-NE, compared to QCT, was superior in ameliorating SCO-induced AD-like symptoms due to its better neuroprotective activity and can be considered a novel supplementary therapeutic agent in AD management.

Quality control and standardization of Quercetin in herbal medicines by spectroscopic and chromatographic techniques

Background

Herbal medicines and their preparations have been mostly used since from thousands of years in all developing and developed countries in the primary health care of society and community. Flavonoids are the class of polyphenolic compounds, which are mainly distributed throughout the plant kingdom. Quercetin is a flavonoid which shows major pharmacological activities and effectively used for the management and treatment of various diseases and disorders. Many herbal medicines and their formulations containing Quercetin are available in market and hence quality control of Quercetin in is very important and essential in manufacturing industries

Main body of the abstract

We have reviewed various scientific research published on quality control analysis and standardization of Quercetin in its isolated form, extract or any other herbal or polyherbal preparation. We have mainly focused on the spectroscopic and chromatographic methods for qualitative and quantitative analysis of Quercetin and they were comprehensively presented in the present review work.

Short conclusion

The present review concludes that the spectroscopic and chromatographic methods play great role in the quality control and standardization of Quercetin in its isolated form, extract and in its herbal and polyherbal preparation.

Development and validation of a rapid RP-HPLC-DAD analysis method for the quantification of pilocarpine in Pilocarpus microphyllus (Rutaceae)

A method using high performance liquid chromatography with diode array detector (HPLC-DAD) for identification and quantification of pilocarpine in the extract of Pilocarpus microphyllus, popularly known as jaborandi. The analysis was conducted using RP-18 column (250 mm × 4.6 mm x 5 μm id) and a buffer solution composed of acidified water, phosphoric acid and triethylamine and methanol as a mobile phase in a flow rate of 1.0 mL/min and detection at 215  nm at 25 °C. Excellent linearity with r² equal to 0.9999 was obtained. The recovery percentage was very satisfactory with values within the specifications. It is correct to affirm that the method has optimal intracurrent and intercurrent precision values with relative standard deviations of 0.1852% and 0.1932%, respectively. The robustness of the method, assessed through the Youden test, showed no significant influence of any of the evaluated parameters. In general, the method proved to be suitable for the intended purpose.

Topical antiedematogenic and anti-inflammatory effect of Scutia buxifolia Reissek gel and stability study

Scutia buxifolia Reissek (Rhamnaceae), popularly known in Brazil as "coronilha", is a plant species used in folk medicine for several disorders, including inflammation. However, no studies have been done with this species to confirm its topical anti-inflammatory action. In this study we evaluate the topical antiedematogenic and anti-inflammatory effects of the gel containing crude extract (CE) and the gel containing ethyl acetate (EtOAc) fraction of S. buxifolia on croton oil or UVB radiation-induced ear edema in mice, and perform gel stability study. Antiedematogenic and anti-inflammatory effects were evaluated through ear edema induced by irritant agent croton oil, UVB irradiation-induced skin injury model and neutrophil infiltration. The gel stability study was performed by analyzing organoleptical aspects, pH, viscosity, and quantification of quercetin and rutin by HPLC. The topical treatment with S. buxifolia gel reduced the ear edema and myeloperoxidase activity. Antiedematogenic and anti-inflammatory effects of S. buxifolia were obtained with concentrations of 0.3, 1 and 3%, with maximal inhibition in the concentration of 1% for gel containing CE (inhibitions of 100, 73±0.05 and 97±0.08% for croton oil- or UVB irradiation-induced ear edema and myeloperoxidase activity, respectively) and EtOAc fraction (inhibitions of 79±0.05, 73±0.05 and 89±0.04% for croton oil- or UVB irradiation-induced ear edema and myeloperoxidase activity, respectively). Such effects may be attributed, at least in part, to rutin and quercetin, as well as other compounds found in this species. No important changes were detected in the stability study, in all aspects analyzed in temperature below 25°C. Our results demonstrate that topically applied S. buxifolia gel presented anti-inflammatory effects, provided that it was maintained at a temperature below 25°C.