Micronutrient deficiencies affect up to 2 billion people and are the leading cause of cognitive and physical disorders in the developing world. Food fortification is effective in treating micronutrient deficiencies; however, its global implementation has been limited by technical challenges in maintaining micronutrient stability during cooking and storage. We hypothesized that polymer-based encapsulation could address this and facilitate micronutrient absorption. We identified poly(butylmethacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methylmethacrylate) (1:2:1) (BMC) as a material with proven safety, offering stability in boiling water, rapid dissolution in gastric acid, and the ability to encapsulate distinct micronutrients. We encapsulated 11 micronutrients (iron; iodine; zinc; and vitamins A, B2, niacin, biotin, folic acid, B12, C, and D) and co-encapsulated up to 4 micronutrients. Encapsulation improved micronutrient stability against heat, light, moisture, and oxidation. Rodent studies confirmed rapid micronutrient release in the stomach and intestinal absorption. Bioavailability of iron from microparticles, compared to free iron, was lower in an initial human study. An organotypic human intestinal model revealed that increased iron loading and decreased polymer content would improve absorption. Using process development approaches capable of kilogram-scale synthesis, we increased iron loading more than 30-fold. Scaled batches tested in a follow-up human study exhibited up to 89% relative iron bioavailability compared to free iron. Collectively, these studies describe a broad approach for clinical translation of a heat-stable ingestible micronutrient delivery platform with the potential to improve micronutrient deficiency in the developing world. These approaches could potentially be applied toward clinical translation of other materials, such as natural polymers, for encapsulation and oral delivery of micronutrients.
Asiatic acid (AA) is a pleiotropic neuroprotective agent that has been shown to attenuate infarct volume in mouse and rat models of focal ischemia and has a long clinically relevant therapeutic time-window. Because in a future trial AA would be administered with tissue-plasminogen activator (t-PA), the only approved acute stroke therapy, we sought to determine the effect of AA when co-administered with t-PA in a rat focal embolic stroke model. Male rats were treated with AA (75 mg/kg) alone, low-dose t-PA (2.5 mg/kg) alone, or a combination of AA and low-dose t-PA at 3 h after inducing embolic stroke. AA significantly reduced infarct volume whereas low-dose t-PA alone did not reduce infarct volume compared with vehicle. Significantly, combination treatment further enhanced reduction of infarct volume versus AA alone. Treatment with AA reduced cytochrome c (CytoC) and apoptosis-inducing factor (AIF) release from brain mitochondria after ischemia. AA was also neuroprotective against L-glutamate-induced toxicity in primary cortical neurons. In summary, combination treatment with AA and low-dose t-PA at 3 h after embolic stroke reduces infarct volume, improves neurological outcome, and provides neuroprotection. The neuroprotective effects of AA were partially associated with reduction of AIF and CytoC release.Key words asiatic acid; tissue-plasminogen activator (t-PA); neuroprotection; rat embolic stroke model; stroke Stroke is a leading cause of mortality and the largest single cause of adult disability worldwide.1) Tissue-plasminogen activator (t-PA) is the only approved pharmacological therapy. However, thrombolysis with t-PA is limited by its narrow time window and the risk of hemorrhagic complications. There is a desperate need for additional safe and effective agents. Asiatic acid (AA) is a triterpene isolated from Centella asiatica which has been widely used as an antioxidant and anti-inflammatory herb in Ayurvedic medicine. AA has also been shown to display neuroprotective properties both in vitro and in vivo.2) In cellular systems, AA is neuroprotective against rotenone and H 2 O 2 -induced injury in SH-SY5Y cells 3) and offers protection against β-amyloid-induced cell death in the neuroblastoma B103 cell line. 4,5) It also reduced H 2 O 2 -related cell death and decreased intracellular free radical concentrations.4) Furthermore, AA derivatives rescue primary rat cortical cells from glutamate-induced toxicity.6) Also, AA was recently reported to alleviate hemodynamic and metabolic alterations via restoring endothelial nitric oxide synthase (eNOS)/inducible nitric oxide synthase (iNOS) expression, oxidative stress, and inflammation in diet-induced metabolic syndrome rats and to regulates the carbohydrate metabolism by modulating the key regulatory enzymes in diabetic rats. 7,8) AA inhibits adipogenic differentiation of bone marrow stromal cells and attenuates ethanol-induced hepatic injury via suppression of oxidative stress and Kupffer cell activation. 9,10)
Mutants have been isolated in S. cereuisiae with the phenotype of growth on pyruvate but not on glucose, or growth on rich medium with pyruvate but inhibition by glucose. Screening of mutagenized cultures was either without an enrichment step, or after enrichment using the antibiotic netropsin (YOUNG et al. 1976) or inositol starvation (HENRY, DONAHUEand CULBERTSON 1975). One class of mutants lacked pyruvate kinase (p y k), another class had all the enzymes of glycolysis, and one mutant lacked phosphoglucose isomerase (pgi, MAITRA 1971). Partial reversion of pyruvate kinase mutants on rich medium containing glucose gave double mutants now'also lacking hexokinase (hzk), phosphofructokinase (pfk), or several enzymes of glycolysis (gcr) . In diploids the mutations were recessive. pyk, pgi, pfk, and gcr segregated 2:2 from their wild-type alleles. PYK hxk, PYK pfk, and PYK gcr segregants grew on glucose.
Magnetic particles and magnetometry were used to noninvasively measure motion of particle-containing organelles in macrophages as well as to monitor the disappearance of particles from tissues. We compared these parameters in the liver (where macrophages are attached to the endothelium) and in the lungs (where macrophages were mobile on epithelial surfaces). Submicrometric magnetic particles were injected intravenously (1.5 mg/kg) into rats; 94% was taken up by the liver. Rats were also instilled intratracheally (1.0 mg/kg) with the same particles. Ultrastructural analyses showed that almost all particles were ingested by macrophages in both organs. Periodically, the retained particles were magnetized and aligned with an external magnet. After the magnet was removed, the decay of the resulting remanent field (relaxation) was followed for 25 min. Relaxation parameters (t1/2 and lambda 0) in the liver were constant from 30 min to 30 days after particle administration, but relaxation in lungs showed a time-dependent increase during the 1st day due to the slower rate of particle phagocytosis. Relaxation in both organs primarily reflects the motion of particle-containing organelles as they are rotated by the cytoskeleton. Relaxation in the lungs may also reflect cell translocation or even changes in alveolar shape. Clearance of particles from the lungs or liver was measured by following B0 (initial magnetic field strength). After correction for growth, the clearance t1/2 was 17.7 and 27.3 days for the lungs and liver, respectively. Bulk transport of particles is probably a more important clearance mechanism in the lungs than in the liver.
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