Production of phenolic compounds from <i>Spirulina maxima</i> microalgae and its protective effects

Abstract

The purpose of this study was to illustrate the enhancing process of phenolics synthesis in Spirulina maxima grown in Zarrouk’s medium supplemented with different concentration of NaNO3 and/or combined with phenylalanine (L-PA). Also, the protective efficacy of Spirulina polyphenolic (SPP) extracts against CCI4-induced microsomal lipid peroxidation and scavenging of hydroxyl radical formation were performed. The results revealed that the levels of NaNO3 and L-PA in growth medium had positive effects on the production of biomass (34-64 mg/day), total phenolics (4.51-16.96 mg/g d.w) and flavonoids (1.32-5.12 mg/g d.w) contents. The highest levels of these compounds were obtained in Zarrouk’s medium containing 3.77 g/L NaNO3 and 100 mg/L L-PA. The HPLC-DAD profile of all phenolic extracts of Spirulina showed the presence of large numbers of phenolic acids and flavonoids, in variable levels. Gallic, chlorogenic, cinnamic, pinostrobin and p-OH-benzoic were found as the most
abundant constituents among different extracts. Polyphenolic of Spirulina exhibited antioxidant effects  CCI4-induced lipid peroxidation (inhibition %) in liver homogenate and on DPPH radical scavenging activity (with IC50 values ranged from 23.22 to 35.62 ìg/ml), in dose-depended manner. Their protective potential was comparable to that of standard phenolic antioxidants (BHT, BHA and -tocopherol, with IC50 values ranged from 13.22 to 23.62 ìg/ml). Thus, S. maxima can be regarded as potent natural
sources of nutraceutical and functional ingredients.