Application of numerical modeling for optimization of selective hot water extraction of taxifolin from ‘milk thistle’ seeds

The term flavonoid is used for a class of plant chemicals known for their activity as highly potent antioxidants and accordingly their ability to protect the body against oxidative and free radical damage. Taxifolin has attracted our attention because it constitutes the flavonoid moiety in ‘milk thistle’ seeds. In this research, a novel optimization-extraction method of taxifolin from ‘milk thistle’ seeds has been developed. Total antioxidant content was measured to monitor the efficiency of the extraction under different experimental conditions (solid- liquid ratio, extraction time and extraction temperature /pressure). Response surface methodology based on numerical modeling was adopted for optimization of extraction procedures. High pressure liquid chromatograph (HPLC) analysis was applied to identify taxifolin and some other phenolics in the ‘milk thistle’ extract. Using this method allowed the development of an empirical polynomial model for the production of antioxidants compounds from ‘milk thistle’ seeds. Application of such models is of great importance for pharmaceutical industries.Key words: Milk thistle, extraction, numerical modeling, antioxidant, high pressure liquid chromatograph (HPLC)

EFFECT OF GRINDING AND PARTICLE SIZE ON SOME PHYSICAL AND RHEOLOGICAL PROPERTIES OF CHITOSAN

The present study was conducted to prepare nano-chitosan particles (CN) by ultrafine grinding  from crude chitosan powder (CC) using a ball mill with 130 numbers of zirconia beads in range from 0.5 to 1.5 mm diameter (75 beads 0.5 mm diameter, 30 beads 1.0 mm diameter and 25 beads 1.5 mm diameter). In addition, physical and rheological properties of chitosan solutions were determined. The results revealed that ultrafine grinding has effectively milled the chitosan particles to nanoscale. Prepared chitosan nanoparticles were characterized by  devices  X-Ray Diffraction (XRD), Zetasizer particle sizes and Zeta potential of chitosan particles (after milling for 30, 60 and 90 minutes). The particle size of nano-chitosan was distributed in a range of 250-600 nm. with a polydispersity index use as an anti-oxidant and antimicrobial with reducing the amount used to deliver the desired purpose. Additional research is required to further investigate the potential value-added utilization of these chitosan derivatives in improving the quality and safety of some food products

FUNCTIONAL, RHEOLOGICAL AND SENSORY CHARACTERISTICS OF DEFATTED-HYDROLYZED RICE BRAN AS FAT REPLACERS IN PREPARED BISCUIT

Defatted rice bran (DRB) and hydrolyzed defatted rice bran (DRBT) were prepared from rice bran meal (RBM). Proximate composition, oil and water binding capacities, emulsifying and foaming characteristics were determined. Effect of different substitution of DRB and DRBT as Fat replacers in biscuit on the farenograph parameters and sensory characteristics were also evaluated. The total protein, ash and crude fiber were significantly (P≤0.05) increased in each of DRB and DRBT compared to RBM. Defatted rice bran protein hydrolyzed improved the DRBT water, oil absorption index being 1.7. Used each of DRB or DRBT gave high emulsifying activity and stability indices in casein model system. The same trend was observed with foam activity and stability indices in egg albumin system. farenogram parameters significant (P≤0.05) affected by using DRB and DRBT. The prepared biscuits samples had high sensory scores with 10 to 50 % DRB and DRBT attributes and recorded non-significant (P≤0.05) differences compared to control sample

Production of Superoxide Anions by Keratinocytes Initiates P. acnes-Induced Inflammation of the Skin

Acne vulgaris is a chronic inflammatory disorder of the sebaceous follicles. Propionibacterium acnes (P. acnes), a gram-positive anareobic bacterium, plays a critical role in the development of these inflammatory lesions. This study aimed at determining whether reactive oxygen species (ROS) are produced by keratinocytes upon P. acnes infection, dissecting the mechanism of this production, and investigating how this phenomenon integrates in the general inflammatory response induced by P. acnes. In our hands, ROS, and especially superoxide anions (O2•−), were rapidly produced by keratinocytes upon stimulation by P. acnes surface proteins. In P. acnes-stimulated keratinocytes, O2•− was produced by NAD(P)H oxidase through activation of the scavenger receptor CD36. O2•− was dismuted by superoxide dismutase to form hydrogen peroxide which was further detoxified into water by the GSH/GPx system. In addition, P. acnes-induced O2•− abrogated P. acnes growth and was involved in keratinocyte lysis through the combination of O2•− with nitric oxide to form peroxynitrites. Finally, retinoic acid derivates, the most efficient anti-acneic drugs, prevent O2•− production, IL-8 release and keratinocyte apoptosis, suggesting the relevance of this pathway in humans

Lucy's Flat Feet: The Relationship between the Ankle and Rearfoot Arching in Early Hominins

BACKGROUND. In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossilize. Paleoanthropologists have relied on footprints and bony correlates of arch development, though little consensus has emerged as to when the arch evolved. METHODOLOGY/PRINCIPAL FINDINGS. Here, we present evidence from radiographs of modern humans (n=261) that the set of the distal tibia in the sagittal plane, henceforth referred to as the tibial arch angle, is related to rearfoot arching. Non-human primates have a posteriorly directed tibial arch angle, while most humans have an anteriorly directed tibial arch angle. Those humans with a posteriorly directed tibial arch angle (8%) have significantly lower talocalcaneal and talar declination angles, both measures of an asymptomatic flatfoot. Application of these results to the hominin fossil record reveals that a well developed rearfoot arch had evolved in Australopithecus afarensis. However, as in humans today, Australopithecus populations exhibited individual variation in foot morphology and arch development, and "Lucy" (A.L. 288-1), a 3.18 Myr-old female Australopithecus, likely possessed asymptomatic flat feet. Additional distal tibiae from the Plio-Pleistocene show variation in tibial arch angles, including two early Homo tibiae that also have slightly posteriorly directed tibial arch angles. CONCLUSIONS/SIGNIFICANCE. This study finds that the rearfoot arch was present in the genus Australopithecus. However, the female Australopithecus afarensis "Lucy" has an ankle morphology consistent with non-pathological flat-footedness. This study suggests that, as in humans today, there was variation in arch development in Plio-Pleistocene hominins.Leakey Foundatio

A systematic review of the safety of topical therapies for atopic dermatitis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75613/1/j.1365-2133.2006.07538.x.pd