1.Enhancing photon utilization efficiency for astaxanthin production from Haematococcus lacustris using a split-column photobioreactor.
Kim ZH1, Park H1, Lee HS1, Lee CG1. J Microbiol Biotechnol. 2016 Apr 8. doi: 10.4014/jmb.1601.01082. [Epub ahead of print]
A split-column photobioreactor (SC-PBR), consisting of two bubble columns with different sizes, was developed to enhance photon utilization efficiency in an astaxanthin production process from Haematococcus lacustris. Among the two columns, only the smaller column of SC-PBR was illuminated. Astaxanthin productivities and photon efficiencies of SC-PBRs were compared to a standard bubble-column PBR (BC-PBR). Astaxanthin productivity of SC-PBR was improved by 28%, while photon utilization efficiencies were 28-366% higher than the original BC-PBR. The results clearly show that the effective light regime of SC-PBR could enhance production of astaxanthin.
2.Functional food red yeast rice (RYR) for metabolic syndrome amelioration: a review on pros and cons.
Patel S1. World J Microbiol Biotechnol. 2016 May;32(5):87. doi: 10.1007/s11274-016-2035-2. Epub 2016 Apr 2.
Red yeast rice (RYR), the fermentation product of mold Monascus purpureus has been an integral part of Oriental food and traditional Chinese medicine, long before the discovery of their medicinal roles. With the identification of bioactive components as polyketide pigments (statins), and unsaturated fatty acids, RYR has gained a nutraceutical status. Hypercholesterolemic effect of this fermented compound has been validated and monacolin K has been recognized as the pivotal component in cholesterol alleviation. Functional similarity with commercial drug lovastatin sans the side effects has catapulted its popularity in other parts of the world as well. Apart from the hypotensive role, ameliorative benefits of RYR as anti-inflammatory, antidiabetic, anticancer and osteogenic agent have emerged, fueling intense research on it. Mechanistic studies have revealed their interaction with functional agents like coenzyme Q10, astaxanthin, vitamin D, folic acid, policosanol, and berberine.
3.Astaxanthin reduces isoflurane-induced neuroapoptosis via the PI3K/Akt pathway.
Wang CM1, Cai XL1, Wen QP1. Mol Med Rep. 2016 Mar 21. doi: 10.3892/mmr.2016.5035. [Epub ahead of print]
Astaxanthin is an oxygen-containing derivative of carotenoids that effectively suppresses reactive oxygen and has nutritional and medicinal value. The mechanisms underlying the effects of astaxanthin on isoflurane‑induced neuroapoptosis remain to be fully understood. The present study was conducted to evaluate the protective effect of astaxanthin to reduce isoflurane‑induced neuroapoptosis and to investigate the underlying mechanisms. The results demonstrated that isoflurane induced brain damage, increased caspase‑3 activity and suppressed the phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (Akt) signaling pathway in an in vivo model. However, treatment with astaxanthin significantly inhibited brain damage, suppressed caspase‑3 activity and upregulated the PI3K/Akt pathway in the isoflurane‑induced rats. Furthermore, isoflurane suppressed cell growth, induced cell apoptosis, enhanced caspase‑3 activity and downregulated the PI3K/Akt pathway in organotypic hippocampal slice culture.
4.Astaxanthin Protects Primary Hippocampal Neurons against Noxious Effects of Aβ-Oligomers.
Lobos P1, Bruna B1, Cordova A1, Barattini P1, Galáz JL1, Adasme T1, Hidalgo C2, Muñoz P3, Paula-Lima A4. Neural Plast. 2016;2016:3456783. doi: 10.1155/2016/3456783. Epub 2016 Mar 1.
Increased reactive oxygen species (ROS) generation and the ensuing oxidative stress contribute to Alzheimer's disease pathology. We reported previously that amyloid-β peptide oligomers (AβOs) produce aberrant Ca(2+) signals at sublethal concentrations and decrease the expression of type-2 ryanodine receptors (RyR2), which are crucial for hippocampal synaptic plasticity and memory. Here, we investigated whether the antioxidant agent astaxanthin (ATX) protects neurons from AβOs-induced excessive mitochondrial ROS generation, NFATc4 activation, and RyR2 mRNA downregulation. To determine mitochondrial H2O2 production or NFATc4 nuclear translocation, neurons were transfected with plasmids coding for HyperMito or NFATc4-eGFP, respectively. Primary hippocampal cultures were incubated with 0.1 μM ATX for 1.5 h prior to AβOs addition (500 nM). We found that incubation with ATX (≤10 μM) for ≤24 h was nontoxic to neurons, evaluated by the live/dead assay.