Profiling of insulin and resveratrol interaction using multi-spectroscopy and molecular docking study

Phytochemical profiling, human insulin stability and alpha glucosidase inhibition of Gymnema latifolium leaves aqueous extract: Exploring through experimental and in silico approach

Diabetes mellitus Type 2 (DM2T) is a rapidly expanding metabolic endocrine disorder worldwide. It is caused due to inadequate insulin secretion by pancreatic beta cells as well as development of insulin resistance. This study aimed to investigate the anti-α-glucosidase, insulin stabilization effect, and non-cytotoxic nature of Gymnema latifolium leaf aqueous extract (GLAE). FTIR analysis revealed the functional groups of compounds present in GLAE. Through LC/ESI-MS/MS analysis, about 12 compounds which belongs to different classes, triterpene glycosides, flavonoids, phenolics, stilbene glycosides and chlorophenolic glycosides were identified. GLAE showed in vitro antioxidant activity. GLAE stabilized insulin by increasing its α-helical content. GLAE inhibited the mammalian α-glucosidase (IC50 = 144 μg/mL) activity through competitive mode (Ki = 61.30 µg/mL). GLAE did not affect the viability of normal cell line (Vero cell line) which shows its non-toxic nature. Molecular docking of phytocompounds identified in GLAE was done with human α-glucosidase and insulin. The top 2 compounds [Gymnema saponin V (GSV) and quercetin 3-(2-galloylglucoside) (QGG) with α-glucosidase; GSV and Z)-resveratrol 3,4'-diglucoside (RDG) with human insulin] with low binding free energy were subjected to 100 ns molecular dynamics simulation to ascertain the stable binding of ligand with protein. The MM/GBSA analysis revealed binding free energy of GSV/α-glucosidase and QGG /α-glucosidase to be - 20.9935 and, - 30.9461 kcal/mol, respectively. Altogether GLAE is valuable source of anti-α-glucosidase inhibitors and insulin stabilizing compounds, suggesting potential lead for further exploration as complementary medicine against DM2T.

Gelled Liquid Crystal Nanocarriers for Improved Antioxidant Activity of Resveratrol

As many natural origin antioxidants, resveratrol is characterized by non-suitable physicochemical properties for its topical application. To allow its benefits to manifest on human skin, resveratrol has been entrapped within liquid crystal nanocarriers (LCNs) made up of glyceryl monooleate, a penetration enhancer, and DSPE-PEG 750. The nanosystems have been more deeply characterized by using dynamic light scattering and Turbiscan Lab® Expert optical analyzer, and they have been tested in vitro on NCTC 2544. The improved antioxidant activity of entrapped resveratrol was evaluated on keratinocyte cells as a function of its concentration. Finally, to really propose the resveratrol-loaded LCNs for topical use, the systems were gelled by using two different gelling agents, poloxamer P407 and carboxymethyl cellulose, to improve the contact time between skin and formulation. The rheological features of obtained gels were evaluated using two important methods (microrheology at rest and dynamic rheology), before testing their safety profile on human healthy volunteers. The obtained results showed the ability of LCNs to improve antioxidant activity of RSV and the gelled LCNs showed good rheological profiles. In conclusion, the results confirmed the potentiality of gelled resveratrol-loaded nanosystems for skin disease, mainly related to their antioxidant effects.

Nutritional Comparison of Sacha Inchi (Plukenetia volubilis) Residue with Edible Seeds and Nuts in Taiwan: A Chromatographic and Spectroscopic Study

Sacha inchi is a source of quality commercial oil in Taiwan. Oil extraction results in sacha inchi residue have not been utilized and not much investigated. Different edible seeds and nuts have different levels of nutrients. This study aims (a) to determine the oil, moisture, ash, protein, carbohydrate, type of fatty acid, resveratrol, and type of sugar in edible seeds and nuts, including sacha inchi residue, and (b) to determine the model to predict the five macronutrients using NIR spectroscopy. The samples used were candlenut, peanut, sesame, sunflower, sacha inchi residue, and black bean. Determination was conducted using NIR spectroscopy, NMR spectroscopy, LC-MS/MS, and HPLC-ELSD. NIR spectroscopy prediction results show that candlenut is rich in oil, and sacha inchi residue is rich in minerals, protein, and moisture. The correct prediction model for oil and moisture is principal component regression, while partial least squares are for ash, protein, and carbohydrates. NMR spectroscopy results showed that all samples were rich in polyunsaturated fatty acids. Sacha inchi residue is rich in omega 3. LC-MS/MS results showed that all samples contained resveratrol, and its highest level was found in sesame. HPLC-ELSD results showed eight types of sugars in the samples. High sucrose was found in sacha inchi residue, sunflower, sesame, and candlenut. The results are expected to provide information on nutrient levels in seeds and nuts to consumers and people who deal with nutrition. Also, results are expected to increase the economic value of sacha inchi residue as a source of diversification of food products in Taiwan.