Investigation of the effect ofK. alvareziion antioxidant enzymes, cell viability and DNA damage in male rats

Neurotrophic Activity of the Carrageenophyte Kappaphycus alvarezii Cultivated at Different Depths and for Different Growth Periods in Various Areas of Indonesia

The carrageenophyte Kappaphycus alvarezii (Rhodophyta) has neurotrophic activity in primary hippocampal neurons. This seaweed is abundant and easily cultivated in tropical coastal areas. To determine the best growth conditions for neurotrophic activity, thalli were grown at different depths and for different periods in various areas of Indonesia. Neurotrophic activity was measured based on the number of primary neurites, the total length of the primary neurites, and the length of the longest neurite. K. alvarezii had higher neurotrophic activity than carrageenophytes K. striatum and Eucheuma denticulatum cultured under the same conditions. K. alvarezii grown at the surface for 45 days had higher (1.4- to 1.8-fold) neurotrophic activity than thalli grown at depth (2 m) or harvested sooner (15 days) (P < 0.05). Relatively high activities were detected in thalli cultured at Ternate and Garut, Indonesia. Therefore, from a commercial perspective, the culture conditions at the surface for 45 days were optimal for the production of both neurotrophic compounds and carrageenan. K. alvarezii produced neurotrophic compounds under various environmental conditions, although some conditions were optimal.

Pharmacological importance of sulphated polysaccharide carrageenan from red seaweed Kappaphycus alvarezii in comparison with commercial carrageenan

Pharmacological properties of native carrageenan (κ) extracted from Kappaphycus alvarezii and commercial carrageenan (Sigma-Aldrich) were evaluated using in vitro antioxidant, anticancer and antidiabetic studies. Phytochemical analysis of native and commercial carrageenans showed the presence of alkaloids, saponins, steroids, gums & mucilages and carbohydrate. Both native and commercial carrageenans exhibited better antioxidant activities such as total antioxidant capacity (87±0.47 and 82.6±0.47μg A.A/g), hydroxyl radical scavenging activity (61.4±0.27 and 58.66±0.31μg/ml), nitric oxide radical scavenging activity (80.42±0.22 and 73.66±0.22μg/ml), DPPH radical scavenging activity (56.26±0.20 and 53.67±0.082μg/ml) and reducing power assay (46.57±0.32 and 42.54±0.27μg/ml) at the maximum concentration of 100μg/ml carrageenans. These results indicated that native carrageenan from K. alvarezii possessed better antioxidant potential in comparison with commercial carrageenan. Anticancer activities of both carrageenans showed excellent inhibition on the growth of breast, colon, liver and osteosarcoma cell lines at the maximum concentration of 150μg/ml. Native carrageenan exhibited an excellent anticancer activity on colon carcinoma cell lines (67.66±0.168%) with the IC₅₀ value of 73.87μg/ml and commercial carrageenan possessed a potent inhibition on the growth of breast cancer cell lines (67.33±0.077%) with the IC₅₀ value of 123.8μg/ml. These results clearly indicated the beneficial effect of native and commercial carrageenans as anticancer agents being a free radical scavenger. Anti-diabetic property of both carrageenans showed inhibition effect on α- glucosidase enzyme. The inhibitory effect depends on concentration of carrageenans and it was recorded that maximum (74.49±1.05 and 67.42±0.63) inhibitory effect of α- glucosidase enzyme at 500μg/ml concentration.

Changes in rats' breast tumor ultrastructure and immune and messenger RNA responses caused by dietary Seaweed (Kappaphycus alvarezii) extract

The edible red seaweed Kappaphycus alvarezii or Eucheuma cottonii is commercially cultivated in the pristine tropical seas for carrageenan production. The systemic, cellular, and molecular effects of E. cottonii 50% alcohol extract [seaweed E. cottonii ethanol extract (SECE)] on breast cancer were investigated in a rat model. Mammary tumor was induced by subcutaneously injecting LA7 cells in female rat mammary pads. After 2 weeks of cancer growth, the rats received oral administration of either SECE [150 mg/kg body weight (BW) and 300 mg/kg BW] or tamoxifen. Electron microscopy imaging results confirmed macrophage activity and hematoxylin and eosin staining indicated that tumor histopathological alterations were restored toward normal structures by the seaweed extract. The extract suppressed tumor development and modulated the immune responses. This was evidenced by the microscopic observations, the increased spleen weight, size, spleen CD19 B cells, and blood immunoglobulin G (IgG) levels. The extract also increased the circulating total white blood cells, lymphocytes, segmented neutrophils count, T cells (CD3), T-helper cells (CD4), cytotoxic T cell (CD8), and nuclear factor-kappa beta expressions. The extract enhanced cancer cell death, by upregulating the Birc5, Chk1, and p53 levels and downregulating the tumor growth cellular Mdm2 (transformed mouse 3T3 cell double minute 2) messenger RNA (mRNA) expression. The extract showed no toxicity at 150 mg/kg BW in rats. The lectin-rich SECE showed tumor suppression by enhancing immune responses and upregulating the cancer cell apoptosis mRNA expressions.