Effect of hot water extracts of Arthrospira maxima (spirulina) against respiratory syncytial virus.

BACKGROUND: Spirulina (Arthrospira maxima) hot water extracts such as calcium spirulan (Ca-SP) have demonstrated antiviral effects against herpes simplex virus (HSV), human immunodeficiency virus-1 (HIV-1), and influenza virus infections. There is no prior evidence suggesting the anti-viral activity of the spirulina hot water extract against respiratory syncytial virus (RSV). PURPOSE: There are currently no effective antivirals available to treat RSV infection. Therefore, the development of safe and novel anti-RSV drugs is urgent and necessary. The aim of this work was to demonstrate the anti-RSV activity of spirulina hot water extracts and determine the potential mechanism of action. METHODS: Cytotoxicity and anti-RSV activity of spirulina hot water extracts were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutralization assays, respectively. Potential mechanisms and components were assessed using time of addition, attachment, internalization, pull-down assays, and composition analysis. RESULTS: The polysaccharide-enriched high-molecular weight fraction (>100 kDa, SHD1) had a high total sugar content, with rhamnose accounting for approximately 60 mol% of total monosaccharides. The main glycosyl linkages included 3-, 4-, and 2,3-rhamnopyranosyl linkages. All spirulina hot water extracts showed no toxicity toward human epithelial type 2 (HEp-2) cells but demonstrated anti-RSV activity. The SHD1 had a half maximal effective concentration (EC50) of 0.0915 mg/ml and a selective index (SI) of >261.5 against RSV. SHD1 significantly reduced viral yield in a dose-dependent manner during the RSV attachment stage. SHD1 disrupted RSV internalization and inhibited RSV attachment (G) protein binding to heparan sulfate receptors on the host cell surface, thus preventing RSV attachment and entry. CONCLUSION: SHD1 serves as an effective candidate for novel drug development against RSV infection.

[Screening for neonatal inborn errors of metabolism by electrospray ionization-tandem mass spectrometry and follow-up].

OBJECTIVE: To determine the impact of expanded newborn screening using tandem mass spectrometry (MS/MS) on the overall detection rate of inborn errors of metabolism in Zhejiang province and to assess the outcome of the patients who were diagnosed. METHOD: Blood spots were collected between days 3 and 6 of life from the newborns. All samples were subjected to MS/MS analysis using Waters Quattro API. Confirmation tests included amino acid analysis, urinary organic acids by GC-MS, routine blood analysis, biochemistry, blood gas analysis, blood glucose and ammonia tests, blood homocysteine, lactate and pyruvate tests, urine acetone tests, biotin and biotin enzyme profile and DNA analysis. Standard treatment protocol was given to the patients. Protein restricted diet, special powdered formula and medicines recommended for the patients with amino acidemias. Protein restricted diet and L-carnitine, folic acid and Vitamin B12 supplementation were given for the patients with organic acidemia. L-carnitine was given to the patients with primary carnitine deficiency. The overall epidemiology, prognosis, follow-up of the screening program were also investigated in the neonates. RESULT: A total of 129 415 neonates were investigated for 26 inborn errors of metabolism during the period. Twenty-three newborns were confirmed as having inborn errors of metabolism, including 13 with amino acidemias, 6 with organic acidemias and 4 with fatty acid oxidation disorders. The prevalence was 1:5626. Positive predictive value was 2.10%, specificity was 99.72% and sensitivity 100%. Seventeen children remain asymptomatic during the follow-up. Five patients had motor and mental developmental delay. One patient presented metabolic disorders during the follow-up. No death occurred in this series of patients. CONCLUSION: This strategy represents a valuable preventive medicine approach by enabling diagnosis and treatment before the onset of symptoms.