NEUROPROTECTIVE EFFECT OF ARTOCARPUS LAKOOCHA EXTRACT AND OXYRESVERATROL AGAINST HYDROGEN PEROXIDE-INDUCED TOXICITY IN SH-SY5Y CELLS

Objective: Artocarpus lakoocha Roxb. is a traditional medical plant native to Southeast Asia and used as a dried aqueous extract so-called puag haad. Its role (and its major ingredient, oxyresveratrol) as an antioxidant neuroprotectant were explored.Methods: Differentiated SH-SY5Y neuroblastoma cells in 96-well plates were challenged with 200 µM H2O2 for 4 h and either Trolox (100 µM), oxyresveratrol (5-100 µM), or puag haad (1.2-25 µg/ml) applied 2 h before H2O2 or for 20 h after H2O2 washout. Cell viability, mitochondrial function, intracellular ROS, and lipid peroxidation were assessed.Results: Continuous presence of both H2O2 and antioxidant reduced mitochondrial function by ~50% but only by 30% with antioxidant. Sustained 24 h H2O2 showed no recoveries with antioxidants. Cell viability was modestly restored when antioxidants accompanied H2O2 for 4 h and both washed for another 20 h, but little recovery of mitochondrial function even though antioxidants removed ROS and prevent lipid peroxidation. Antioxidants added for 20 h after H2O2 marginally improve mitochondria and modestly restore cell viability, but lipid peroxidation was completely reversed.Conclusion: These results show that mitochondrial protection was illusive, yet both tested compounds, puag haad and oxyresveratrol, improved cell viability and especially ROS levels and lipid peroxidation. The potency oxyresveratrol on the redox-sensitive expression of antioxidant enzymes and its pharmacokinetics suggests that oral puag haad could provide effective protection in transient neurodegenerative disease.Â

Spirogyra neglecta inhibits the absorption and synthesis of cholesterol in vitro

Background: Spirogyra neglecta (SN) has many nutritional benefits and it is commonly used to ameliorate different human conditions including inflammation, gastric ulcer, hyperglycemia, and hyperlipidemia. However, the mechanism of the hypocholesterolemic effect of SN still remains unclear. Therefore, the present study was aimed to evaluate the effect of SN extract particularly on cholesterol absorption and synthesis mechanisms. Methods: For cholesterol absorption, the uptake of cholesterol was measured by using tritium radiolabeling of cholesterol in Caco-2 cells. Bile acid binding, micelles size, and cholesterol solubility were analyzed in in vitro assays, while cholesterol synthesis was evaluated by using a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase assay kit. Results: SN extract was found to decrease cholesterol uptake in Caco-2 cells and decreased the solubility of cholesterol in micelles. The SN extract bound to taurocholate, taurodeoxycholate, and glycodeoxycholate bile acids, and increased micelles size. SN has also demonstrated an inhibitory effect on HMG-CoA reductase (HMGR) enzymatic activity. For further experimentation, the treatment combination of SN and ezetimibe (0.04 mg/mL) showed a greater significant reduction in cholesterol uptake than the extract alone. Conclusion: These observations suggested that inhibitory cholesterol absorption effects of SN could be mediated through the modulation of size and solubility of cholesterol micelles, resulting in interference of cholesterol uptake. In addition, SN inhibited the rate limiting step of cholesterol synthesis. This study provides supporting evidence for the potential usage of SN as a cholesterol lowering agent

Effects of silk sericin on the proliferation and apoptosis of colon cancer cells

Sericin is a silk protein woven from silkworm cocoons (Bombyx mori). In animal model, sericin has been reported to have anti-tumoral action against colon cancer. The mechanisms underlying the activity of sericin against cancer cells are not fully understood. The present study investigated the effects of sericin on human colorectal cancer SW480 cells compared to normal colonic mucosal FHC cells. Since the size of the sericin protein may be important for its activity, two ranges of molecular weight were tested. Sericin was found to decrease SW480 and FHC cell viability. The small sericin had higher anti-proliferative effects than that of the large sericin in both cell types. Increased apoptosis of SW480 cells is associated with increased caspase-3 activity and decreased Bcl-2 expression. The anti-proliferative effect of sericin was accompanied by cell cycle arrest at the S phase. Thus, sericin reduced SW480 cell viability by inducing cell apoptosis via caspase-3 activation and down-regulation of Bcl-2 expression. The present study provides scientific data that support the protective effect of silk sericin against cancer cells of the colon and suggests that this protein may have significant health benefits and could potentially be developed as a dietary supplement for colon cancer prevention

Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation

The effect of dietary sericin on rats

ABSTRACT: Dietary proteins have been reported to be beneficial for lipid metabolism, tissue growth, development, and repair, as well as immune response. The interactions of dietary proteins and their digested products may regulate the physiology and metabolism of the gastrointestinal tract. However, proteins are largely digested before reaching the large intestine. The present study investigated the use of the non-dietary protein, silk sericin, in rats. Rats were fed either with casein or sericin proteins. Their body weight, food consumption, and complete blood count were measured. The results showed that during the experimental periods, rats fed with casein and sericin diets had no significant changes on body weight, food consumption, or complete blood count. Sericin-fed rats had a significantly decreased CD8a and CD80 positive cells when compared with standard casein protein. In conclusion, dietary proteins may have a differential impact on the leukocyte profile. The mechanisms underlying these changes are not clear but they might be due to the different amino acid compositions of the proteins studied

Potential of Coffee Fruit Extract and Quinic Acid on Adipogenesis and Lipolysis in 3T3-L1 Adipocytes

This study was to assess the impact of different colors of coffee fruit (green, yellow and red) on adipogenesis and/or lipolysis using 3T3-L1 adipocytes. Characterization of chemical onstituents in different colors of coffee fruit extracts was determined by ESI-Q-TOF-MS. The cytotoxicity of the extracts in 3T3-L1 preadipocytes were evaluated by MTT assay. Oil-red O staining and amount of glycerol released in 3T3-L1 adipocytes were measured for lipid accumulation and lipolysis activity. All coffee fruit extracts displayed similar chromatographic profiles by chlorogenic acid > caffeoylquinic acid > caffeic acid. Different colors of raw coffee fruit possessed inhibitory adipogenesis activity in 3T3-L1 adipocytes, especially CRD decreased lipid accumulation approximately 47%. Furthermore, all extracts except CYF and their major compounds (malic, quinic, and chlorogenic acid) increased glycerol release. Our data suggest that different colors of coffee fruit extract have possessed anti-adipogenic and lipolytic properties and may contribute to the anti-obesity effects

Bio-derived and biocompatible poly(lactic acid)/silk sericin nanogels and their incorporation within poly(lactide-co-glycolide) electrospun nanofibers

Bio-derived and biocompatible nanogels based on poly(lactic acid) (PLA) and silk sericin (SS) have been synthesized for the first time. Low molecular weight PLA and SS were first modified using allyl glycidyl ether to create a PLA macromonomer and an SS multifunctional crosslinker (PLAM and SSC, respectively), as confirmed by NMR and FTIR spectroscopies. Nanogels were synthesized from PLAM/SSC and N′,N-methylene bisacrylamide (N′,N-mBAAm) as an additional bifunctional crosslinker via classical free-radical polymerization at systematically varied levels of additional crosslinking (0, 0.5, 1.0, 1.5 and 2.0 w/w% N′,N-mBAAm). Higher crosslink densities led to smaller nanogel particles with reduced accumulative drug release. Crosslinked PLAM/SSC nanogels at 0.5% N′,N-mBAAm with 400–500 nm diameter particles were shown to be non-toxic to the normal human skin fibroblast cell line (NHSF) and selected for incorporation within poly(lactide-co-glycolide) (PLGA) electrospun nanofibers. These embedded nanogel-PLGA nanofibers were non-toxic to the NHSF cell line and exhibited higher cell proliferation than pure PLGA nanofibers, due to their higher hydrophilicity induced by the PLAM/SSC nanogels. This work shows that our new crosslinked-PLAM/SSC nanogels have potential for use not only in the field of drug delivery but also for tissue regeneration by embedding them within nanofibers to create hybrid scaffolds