Well-tolerated Spirulina extract inhibits influenza virus replication and reduces virus-induced mortality

Abstract

Influenza is one of the most common human respiratory diseases, and represents a serious public health concern. However, the high mutability of influenza viruses has hampered vaccine development, and resistant strains to existing anti-viral drugs have also emerged. Novel anti-influenza therapies are urgently needed, and in this study, we describe the anti-viral properties of a Spirulina (Arthrospira platensis) cold water extract. Anti-viral effects have previously been reported for extracts and specific substances derived from Spirulina, and here we show that this Spirulina cold water extract has low cellular toxicity, and is well-tolerated in animal models at one dose as high as 5,000 mg/kg, or 3,000 mg/ kg/day for 14 successive days. Anti-flu efficacy studies revealed that the Spirulina extract inhibited viral plaque formation in a broad range of influenza viruses, including oseltamivir-resistant strains. Spirulina extract was found to act at an early stage of infection to reduce virus yields in cells and improve survival in influenza-infected mice, with inhibition of influenza hemagglutination identified as one of the mechanisms involved. Together, these results suggest that the cold water extract of Spirulina might serve as a safe and effective therapeutic agent to manage influenza outbreaks, and further clinical investigation may be warranted.

In vitro activity of Spirulina platensis water extract against different Candida species isolated from vulvo-vaginal candidiasis cases

“…Following extensive washing with PBS, the incorporated dye was eluted by the addition of 50 μl of 0.1 M sodium citrate in 50% (v/v) ethanol (pH 4.2), and optical densities were read at 540 nm. The concentration resulting in 50% cell death compared with untreated controls (CC 50 ) was calculated according to the Reed-Muench method [ 38 , 39 ].…”

Nutraceuticals have potential for boosting the type 1 interferon response to RNA viruses including influenza and coronavirus

“…Oral administration of a cold-water spirulina extract rich in phycocyanin has been found to decrease mortality in influenza-infected mice. 14 The downstream consequences of hydrogen peroxide production might also be addressed by phase 2-inductive nutraceuticals, as these induce various peroxidase enzymes and promote the synthesis of glutathione, a cofactor for certain peroxidases and a catalyst in reactions that reconvert oxidized cysteine groups to their native form. 15 Glutathione production can also be promoted by administration of Nacetylcysteine (NAC), which has been shown to be protective in rodents infected with influenza.…”

Effects of Spirulina platensis on alloxan induced diabetic rats

“…Two species of this blue green algae are most commonly used as nutritional supplements, Spirulina platensis (S. Platensis) and Spirulina maxima (S.maxima) (Sixabela et al,2011;Tefera et al,2016). This microscopic, filamentous cyanobacterium has been claimed as a safe food for human consumption by many toxicological studies and currently belongs to the substances that are listed by the US Food and Drug Administration under the category of "Generally Recognized as Safe (GRAS)" (Sixabela et al, 2011;Chen et al, 2016).…”