Planococcus maritimu ML1206 Strain Enhances Stress Resistance and Extends the Lifespan in Caenorhabditis elegans via FOXO/DAF-16.

The antioxidant effect of probiotics has been widely recognized across the world, which is of great significance in food, medicine, and aquaculture. There are abundant marine microbial resources in the ocean, which provide a new space for humans to explore new probiotics. Previously, we reported on the anti-infective effects of Planococcus maritimu ML1206, a potential marine probiotic. The antioxidant activity of ML1206 in C. elegans was studied in this paper. The study showed that ML1206 could improve the ability of nematodes to resist oxidative stress and effectively prolong their lifespan. The results confirmed that ML1206 could significantly increase the activities of CAT and GSH-PX, and reduce the accumulation of reactive oxygen species (ROS) in nematodes under oxidative stress conditions. In addition, ML1206 promoted DAF-16 transfer to the nucleus and upregulated the expression of sod-3, hsp-16.2, and ctl-2, which are downstream antioxidant-related genes of DAF-16. Furthermore, the expression of the SOD-3::GFP and HSP-16.2::GFP was significantly higher in the transgenic strains fed with ML1206 than that in the control group fed with OP50, with or without stress. In summary, these findings suggest that ML1206 is a novel marine probiotic with an antioxidant function that stimulates nematodes to improve their defense abilities against oxidative stress and prolong the lifespan by regulating the translocation of FOXO/DAF-16. Therefore, ML1206 may be explored as a potential dietary supplement in aquaculture and for anti-aging and antioxidant purposes.

Can hemozoin alone cause host anaemia?

Both schistosomes and malaria parasites produce hemozoin and cause host anaemia. However, the relationship between anaemia and hemozoin is unclear. Although some studies have proposed that hemozoin is related to anaemia in malaria patients, whether hemozoin alone can cause anaemia in patients infected by malaria parasites or schistosomes is uncertain. To investigate the effect of hemozoin on hosts, ß-haematin was injected intravenously to normal mice. Then, liver and spleen tissues were observed. Mouse blood was examined. Red blood cells (RBCs), white blood cells (WBCs) and haemoglobin were analysed. Macrophage changes in the spleens and marrow cells were compared using immunofluorescence and H&E or Giemsa stain, respectively. We found that after 15 injections of ß-haematin, a large amount of ß-haematin was observed to deposit in the livers and spleens. Splenomegaly and bone marrow mild hyperplasia were detected. The average number of RBCs, average number of WBCs and average concentration of haemoglobin decreased significantly from 9.36 × 1012 cells/L to 8.7 × 1012 cells/L, 3.8 × 109 cells/L to 1.7 × 109 cells/L and 142.8 g/L to 131.8 g/L, respectively. In specific, the number of macrophages in the spleens greatly increased after ß-haematin infection. The results showed that injections of ß-haematin alone can cause anaemia possibly through hypersplenism.