The immune system plays a pivotal role as the initial fortress protecting the organism from the detrimental effects of diseases, whether they are transmitted by infectious agents or develop independently. To enhance the immune system, immunostimulants derived from natural sources are commonly employed. Research into fucoidan has yielded many findings, but its definitive role in immune system activation is yet to be fully established. Hence, this blog post introduces the study “The immunostimulatory effects of fucoidan on the cellular and humoral immune response in Wistar rats” by Rochmah Kurnijasanti et al. This particular study serves to showcase the capacity of fucoidan to fine-tune the body’s defense mechanisms, encompassing the two primary branches of immunity: the cellular response and the humoral response, when examined under controlled laboratory conditions.
The study began with forty rats in excellent condition, which were then allocated into five equal groups. Using Wistar albino rats, an in vivo experiment with fucoidan was conducted to evaluate cyclophosphamide-induced myelosuppression, delayed-type hypersensitivity (DTH) reactions, phagocytic activity, hemagglutination antibody (HA) titers, and neutrophil adhesion capacity.
Initially, when neutrophils were incubated with nylon fibers (NF), a reduction in their numbers was observed due to cell adhesion to the fibers. When male Wistar albino rats were administered fucoidan at a dose of 300 mg per kg of body weight, neutrophil adhesion increased significantly compared to the control group. However, no such effect was observed at doses of 75 mg/kg or 150 mg/kg. These collected data lead to the conclusion that fucoidan demonstrates immunostimulatory characteristics.
In order to assess the capacity of rats to produce antibodies when fucoidan was administered orally, SRBC (sheep red blood cell) agglutination titers were used as a measurement tool. A significant increase in agglutinating antibody titers was observed—compared to rats in the control group—only when fucoidan was administered at a dose of 300 mg per kg of body weight.
The DTH reaction, which is also recognized as the footpad reaction, was the method that was chosen in order to assess the cellular immune response to fucoidan. Fucoidan significantly and dose-dependently enhanced DTH reactivity in rats. When fucoidan was administered at a dose of 300 mg/kg BW, DTH reactivity was significantly elevated compared to the control group. Fucoidan appears to have activated T cells, as evidenced by the augmented DTH response to a cell-dependent antigen in rats.
Additionally, there’s a link between increased phagocytic activity and how quickly carbon particles are cleared. The phagocytic activity of the RES (reticuloendothelial system) was assessed based on the rate at which carbon particles were cleared from the bloodstream. Researchers noted that ingesting fucoidan orally resulted in a dose-related enhancement in the rate at which RES cells cleared carbon particles from the system. Compared to the control group, a significant phagocytic index was observed in rats administered fucoidan at a dose of 300 mg/kg BW; however, no significant differences were noted at doses of 75 mg/kg BW and 150 mg/kg BW. These results suggest that fucoidan possesses phagocytic activity.
Administration of cyclophosphamide via the intraperitoneal route at 30 mg/kg BW leads to a marked drop in the counts of hemoglobin, leukocytes, erythrocytes, and platelets. When cyclophosphamide and fucoidan were co-administered, a more pronounced recovery of bone marrow function was observed—in a dose-dependent manner—compared to administration of cyclophosphamide alone. Relative to the group administered cyclophosphamide alone, the group administered fucoidan at a dose of 300 mg/kg BW exhibited a marked increase in all parameters: hemoglobin, erythrocytes (RBC), leukocytes (WBC), and platelet counts.
The research outcomes indicate that fucoidan has the ability to stimulate both cellular and humoral immune responses, and this influence is directly related to the amount administered. Additionally, evidence shows that fucoidan effectively boosts cellular, humoral, and non-specific immune responses.
Source: Open Vet J. 2024 Aug 31;14(8):1794–1800. doi: 10.5455/OVJ.2024.v14.i8.7