Haslea ostrearia Pigment Marennine Affects Key Actors of Neuroinflammation and Decreases Cell Migration in Murine Neuroglial Cell Model

Abstract

Haslea ostrearia, a cosmopolitan marine pennate diatom, produces a characteristic blue pigment called marennine that causes the greening of filter-feeding organisms, such as oysters. Previous studies evidenced various biological activities of purified marennine extract, such as antibacterial, antioxidant and antiproliferative effects. These effects could be beneficial to human health. However, the specific biological activity of marennine remains to be characterized, especially regarding primary cultures of mammals. In the present study, we aimed to determine in vitro the effects of a purified extract of marennine on neuroinflammatory and cell migratory processes. These effects were assessed at non-cytotoxic concentrations of 10 and 50μg/mL on primary cultures of neuroglial cells. Marennine strongly interacts with neuroinflammatory processes in the immunocompetent cells of the central nervous system, represented by astrocytes and microglial cells. An anti-migratory activity based on a neurospheres migration assay has also been observed. These results encourage further study of Haslea blue pigment effects, particularly the identification of molecular and cellular targets affected by marennine, and strengthen previous studies suggesting that marennine has bioactivities which could be beneficial for human health applications.

The multifaceted nature of IL-10: regulation, role in immunological homeostasis and its relevance to cancer, COVID-19 and post-COVID conditions

“…Marennine, a blue pigment produced by Haslea ostrearia, a marine pennate diatom, acts on neuroinflammatory processes, inducing a strong up-regulation of IL-10 genes ( 287 ). Ulvan, a sulfated polysaccharide produced from a green marine algae Ulva Ohnoi, showed a mild immunomodulatory function increasing IL-10 levels ( 288 ).…”

The need to stabilize the bacterial community present in the cultures of the marine diatom Haslea ostrearia

“…Haslea ostrearia is a microalga species from the diatom family (Bacillariophyta) [1], highly present in the oyster beds of the French Atlantic coast [2]. Its particularity comes from its bluish color due to a pigment called marennine [3], making H. ostrearia a subject of study in regard to its economic interest, but also for its possible biomedical applications [4,5]. Indeed, when released into oyster cultures, its large presence colors the oysters' gills a greenish color [6, 7, 8], small changes occur in the oysters and greatly increase their market value in France [8, 9,10].…”