Rajarshi Biswas

Enhanced permeability of ferulic acid loaded nanoemulsion based gel through skin against UVA mediated oxidative stress.

AIMS The study was aimed to develop a ferulic acid (FA) loaded nanoemulsion based gel in order to ensure the enhanced permeability and maximum antioxidant activity against UVA induced oxidative stress in rat. MAIN METHODS The optimized ferulic acid loaded nanoemulsion 3 (FA-NE3) was prepared by spontaneous nano-emulsification method with an appropriate ratio (20:30:50% w/w) of the oil (isostearyl isostearate), aqueous system and Smix [surfactant (labrasol) and co-surfactant (plurol isostearique)] respectively. FA-NE3 was characterized by measuring their droplet size, zeta potential, refractive index, transmission electron microscopy (TEM), ultraviolet (UV), fourier transform infrared spectroscopy (FTIR) and rheological characteristics. Ex vivo skin permeation and in vivo UVA protection activity of FA-NE3 based nano-gels (FA-NG3) along with placebo were studied through the rat skin. KEY FINDINGS FA-NE3 exhibited sustained-release profile, better permeability and ultraviolet A (UVA) protection activity as compared to conventional dosage form. This phenomenon may be attributed towards increased solubility of the drug and enhanced permeability from nanoemulsion. FA-NE3 based nanogel (FA-NG3) could elevate the level of skin marker enzymes against oxidative stress mediated by UVA. SIGNIFICANCE The gel formulation exhibited significant (P<0.01) skin permeability and antioxidant activity in the current investigations. The nanogel could be promising nanocarriers for topical delivery of FA in response to better skin protection activity against UVA rays in a sustained manner.

Tyrosinase inhibitory mechanism of betulinic acid from Dillenia indica

The fruit of Dillenia indica L. is extensively used as a food additive. Betulinic acid (BA) is the most prominent secondary metabolite present in D. indica. This study screened the bioassay guided isolation of BA from D. indica and explored its tyrosinase inhibitory mechanism. Half maximal inhibitory concentration (IC50) of BA were calculated as 13.93µM and 25.66µM for diphenolase and monophenolase. Enzyme kinetic analysis revealed that BA inhibited tyrosinase activity non-competitively. Further, conformational analysis of tyrosinase with BA was measured by fluorescence and circular dichroism spectroscopy. These results implied that diminish rigidity of enzyme might disturb the catalytic conformation of tyrosinase. Moreover, In-silico analysis confirmed probable binding polar and non-polar region on the active site of tyrosinase. Based on these findings, we suggest that BA from D. indica may be useful in preventing enzymatic browning reactions in food products.

Tyrosinase inhibition kinetic studies of standardized extract of Berberis aristata.

Abstract The stem bark and wood of Berberis aristata DC (Daruharidra) are one of the principal ingredients of traditional skin lighting and exfoliating scrub preparation in India. The standardised extract of B. aristata was screened to evaluate their in vitro antityrosinase activity and inhibition kinetics. Phytochemical and pharmacological studies were carried out with different solvent fractions of the methanol extract of B. aristata (MEBA). RP-HPLC analysis was used to determine the berberine content in extract and fractions of B. aristata. MEBA showed maximum berberine content. Extract and fractions of B. aristata contain the maximum amount of alkaloids than other constituents. In tyrosinase inhibition assay, MEBA was found to possess highest dose-dependent monophenolase and moderate diphenolase activity. The enzyme kinetic study revealed that MEBA possessed mixed type inhibition of monophenolase activity of tyrosinase. These bioactivities indicate that the MEBA has antihyperpigmentation potential in human skin. Graphical abstract

Botanicals as Medicinal Food and Their Effects against Obesity

Obesity is one type of metabolic syndrome, causes excess fat accumulation in the torso, resulting health problems like diabetes, hypertension, and dyslipidemia. As per World Health Organization, large population of the world is suffering from obesity and obesity associated disorders. R&D sectors of pharmaceutical companies around the globe are making several efforts to find effective antiobesity drugs. Despite that not many of the drug candidates pass all phases of clinical trials. Researchers in this field are instantly concerned to hunt nonconventional approach to the prevention and treatment of obesity. Herbs as food have a promising future in this regard. It has a beneficial effect over conventional food because it has provided therapeutic value in addition to nutritional supplement, in a way relevant to improved state of wellness and well-being which in turn reduce the risk of disease. Many plants and plant-derived products have been discussed in this chapter, which have potential activity against metabolic disorder such as obesity, hyperlipidemia, fatty liver, insulin resistance, and hyperglycemia and they exert their effect through multiple mechanisms.