Vilasinee Hirunpanich

Bio: Vilasinee Hirunpanich is an academic researcher from Mahasarakham University. The author has contributed to research in topics: Docosahexaenoic acid & Bioavailability. The author has an hindex of 7, co-authored 9 publications receiving 439 citations. Previous affiliations of Vilasinee Hirunpanich include Mahidol University & Showa University.

Antioxidant Effects of Aqueous Extracts from Dried Calyx of Hibiscus sabdariffa LINN. (Roselle) in Vitro Using Rat Low-Density Lipoprotein (LDL)

Abstract: The present study quantitatively investigated the antioxidant effects of the aqueous extracts from dried calyx of Hibiscus sabdariffa LINN. (roselle) in vitro using rat low-density lipoprotein (LDL). Formations of the conjugated dienes and thiobarbituric acid reactive substances (TBARs) were monitored as markers of the early and later stages of the oxidation of LDL, respectively. Thus, we demonstrated that the dried calyx extracts of roselle exhibits strong antioxidant activity in Cu(2+)-mediated oxidation of LDL (p<0.05) in vitro. The inhibitory effect of the extracts on LDL oxidation was dose-dependent at concentrations ranging from 0.1 to 5 mg/ml. Moreover, 5 mg/ml of roselle inhibited TBARs-formation with greater potency than 100 microM of vitamin E. In conclusion, this study provides a quantitative insight into the potent antioxidant effect of roselle in vitro.

Demonstration of docosahexaenoic acid as a bioavailability enhancer for CYP3A substrates: in vitro and in vivo evidence using cyclosporin in rats.

Abstract: To investigate the pharmacokinetic interaction between cyclosporin A (CsA) and docosahexaenoic acid (DHA) in vivo, 5 mg/kg CsA was orally or intravenously coadministered with DHA (50–200 μg/kg) to rats The effect of DHA on CYP3A activity was determined using rat liver microsomes in vitro Moreover, the effect of DHA on P-glycoprotein (P-gp) function was examined using cultured Caco-2 cells in vitro After oral coadministration of CsA with 100 μg/kg and 200 μg/kg DHA, bioavailability (BA) was significantly increased, compared with control rats In contrast, no pharmacokinetic interaction was observed when CsA was intravenously administered in rats dosed orally with DHA, suggesting that DHA did not affect hepatic metabolism The formation of 6β-hydroxytestosterone from testosterone in rat liver microsomes was competitively inhibited by DHA The Km, Vmax, and Ki values were 255 μM, 245 nmol/min/mg protein, and 552 μM, respectively Moreover, basal-to-apical transport of [3H]CsA in the Caco-2 cell monolayer was not affected by DHA but was decreased by valspodar (PSC 833), a P-gp inhibitor Our finding is the first to indicate that DHA inhibits intestinal CYP3A both in vitro and in vivo, but not P-gp It was thus demonstrated that DHA could be used as a BA enhancer for the drugs that are extensively metabolized by CYP3A in the gut

Strategies to Address Low Drug Solubility in Discovery and Development

Abstract: Drugs with low water solubility are predisposed to low and variable oral bioavailability and, therefore, to variability in clinical response. Despite significant efforts to "design in" acceptable developability properties (including aqueous solubility) during lead optimization, approximately 40% of currently marketed compounds and most current drug development candidates remain poorly water-soluble. The fact that so many drug candidates of this type are advanced into development and clinical assessment is testament to an increasingly sophisticated understanding of the approaches that can be taken to promote apparent solubility in the gastrointestinal tract and to support drug exposure after oral administration. Here we provide a detailed commentary on the major challenges to the progression of a poorly water-soluble lead or development candidate and review the approaches and strategies that can be taken to facilitate compound progression. In particular, we address the fundamental principles that underpin the use of strategies, including pH adjustment and salt-form selection, polymorphs, cocrystals, cosolvents, surfactants, cyclodextrins, particle size reduction, amorphous solid dispersions, and lipid-based formulations. In each case, the theoretical basis for utility is described along with a detailed review of recent advances in the field. The article provides an integrated and contemporary discussion of current approaches to solubility and dissolution enhancement but has been deliberately structured as a series of stand-alone sections to allow also directed access to a specific technology (e.g., solid dispersions, lipid-based formulations, or salt forms) where required.

Bioavailability of bioactive food compounds: a challenging journey to bioefficacy

Abstract: Bioavailability is a key step in ensuring bioefficacy of bioactive food compounds or oral drugs. Bioavailability is a complex process involving several different stages: liberation, absorption, distribution, metabolism and elimination phases (LADME). Bioactive food compounds, whether derived from various plant or animal sources, need to be bioavailable in order to exert any beneficial effects. Through a better understanding of the digestive fate of bioactive food compounds we can impact the promotion of health and improvement of performance. Many varying factors affect bioavailability, such as bioaccessibility, food matrix effect, transporters, molecular structures and metabolizing enzymes. Bioefficacy may be improved through enhanced bioavailability. Therefore, several technologies have been developed to improve the bioavailability of xenobiotics, including structural modifications, nanotechnology and colloidal systems. Due to the complex nature of food bioactive compounds and also to the different mechanisms of absorption of hydrophilic and lipophilic bioactive compounds, unravelling the bioavailability of food constituents is challenging. Among the food sources discussed during this review, coffee, tea, citrus fruit and fish oil were included as sources of food bioactive compounds (e.g. (poly)phenols and polyunsaturated fatty acids (PUFAs)) since they are examples of important ingredients for the food industry. Although there are many studies reporting on bioavailability and bioefficacy of these bioactive food components, understanding their interactions, metabolism and mechanism of action still requires extensive work. This review focuses on some of the major factors affecting the bioavailability of the aforementioned bioactive food compounds.

Plant Secondary Metabolites: Occurrence, Structure And Role In The Human Diet

Abstract: Plant secondary metabolites have been a fertile area of chemical investigation for many years, driving the development of both analytical chemistry and of new synthetic reactions and methodologies. The subject is multi-disciplinary with chemists, biochemists and plant scientists all contributing to our current understanding. In recent years there has been an upsurge in interest from other disciplines, related to the realisation that secondary metabolites are dietary components that may have a considerable impact on human health, and to the development of gene technology that permits modulation of the contents of desirable and undesirable components. Plant Secondary Metabolites: Occurrence, Structure and Role in the Human Diet addresses this wider interest by covering the main groups of natural products from a chemical and biosynthetic perspective with illustrations of how genetic engineering can be applied to manipulate levels of secondary metabolites of economic value as well as those of potential importance in diet and health. These descriptive chapters are augmented by chapters showing where these products are found in the diet, how they are metabolised and reviewing the evidence for their beneficial bioactivity. © 2006 by Blackwell Publishing Ltd.