ABSTRACT
Objective: To investigate Schima wallichii (S. wallichii) Choisy (Ternstroemiaceae) which is a well known plant of Sikkim in the Himalayan region, India. Methods: Therefore three major flavonoid enriched fractions (FPet.Ether, FChloroform and FEthylacetate) were isolated by petroleum ether chloroform and ethyl acetate successively. The reactive nitrogen species scavenging activity of the flavonoid fractions was established using biochemical assay to measure scavenging of 2, 2 diphenyl picrylhydrazyl (DPPH), nitric oxide (NO) and peroxinitrite. Results: FEthylacetate showed maximum scavenging activity: their IC50 being (7.33 ± 3.32), (7.11 ± 2.21), and (6.67 ± 2.23)μg/mL in DPPH, NO, peroxinitrite radical respectively. Presence of (57.32 ± 2.31) and (163.4 ±2.22) μg of flavonoids and phenolic compound in 1 mg of extract is assumed to be responsible for free radical scavenging activity. Conclusion: Taken together S. wallichii has potent free radical scavenging property indicating its importance in food supplement as a rich source of active flavonoid and phenolic compounds in ethyl acetate fraction which is responsible for its free radical scavenging as well as antioxidant activity.
ABSTRACT
The objectives of our study were to prepare and evaluate a biodegradable nanoparticulate system of Letrozole (LTZ) intended for breast cancer therapy. LTZ loaded poly(lactide-co-glycolide) nanoparticles (LTZ-PLGA-NPs) were prepared by emulsion-solvent evaporation method using methylene chloride and polyvinyl alcohol. Percentage of drug (with respect to polymer) was selected as formulation variable. LTZ-PLGA-NPs were characterized by particle size, zeta potential, infrared spectra, drug entrapment efficiency and in vitro release. Sonication was done with an ultrasound pulse sonicator at 70 W, 30 kHz for 90 sec to produce stable NPs of mean size range from 64 nm to 255 nm with high entrapment efficiency (68 percent to 82 percent). Percentage of drug significantly influenced particle size, entrapment efficiency and release (p <0.05). The system sustained release of LTZ significantly and further investigation could exhibit its potential usefulness in breast cancer therapy.
Os objetivos de nosso estudo foram preparar e avaliar o sistema de nanopartícula biodegradável de letrozol na terapia de câncer mamário. Nanopartículas de poli(lactídeo-co-glicolídeo) carregadas com LTZ (LTZ-PLGA-NPs) foram preparadas pelo método de emulsão-evaporação de solvente, utilizando dicloro metano e álcool polivinílico. A porcentagem do fármaco (com relação ao polímero) foi selecionada como variável da formulação. LTZ-PLGA-NPs foram caracterizadas pelo tamanho da partícula, potencial zeta, espectros no infravermelho, eficiência de inclusão e liberação in vitro. A sonicação foi realizada com sonicador de ultrassom, de pulso a 70W e 30 kHz por 90 segundos para produzir NPs estáveis, de faixa de tamanho médio de 64 nm a 266 nm, com alta eficiência de inclusão (68 por cento a 82 por cento). A porcentagem do fármaco foi significativamente influenciada pelo tamanho da partícula, eficiência de inclusão e liberação (p<0,05). O sistema controlou significativamente a liberação de LTZ e estudos posteriores poderiam mostrar sua utilidade potencial na terapia de câncer de mama.