Ecological characteristics of the brown alga Ishige okamurae Yendo in its natural habitat at Janggam, Shinan on the southwestern coast of Korea were investigated from March 2023 to February 2024. The population of I. okamurae formed extensive patches along the shoreline. Environmental factors such as seawater temperature, pH, salinity, and dissolved oxygen were monitored during this study. Growth and maturation of the I. okamurae population were assessed using both qualitative and quantitative methods. This alga showed a peak growth in October when the seawater temperature was 19.9°C. It had a mean length of 7.6±1.4 cm, a mean density of 4,466.6±288.9 ind. m-2, and a mean biomass of 663.9±85.3 fresh-wt. m-2. The effective cumulative temperature required for the alga’s maturation was estimated based on growth data with a biological zero temperature of 9.2°C. Sporangia were observed from June to November when seawater temperatures ranged from 20.5°C to 14.0°C. Unilocular sporangia first appeared in June, followed by simultaneous appearance of unilocular sporangia and plurilocular sporangia from July to September. From October to November, only unilocular sporangia were observed. Thallus development began at temperatures above 9.2°C. Maturation required approximately 577 degree-days for unilocular sporangia and 801 degree-days for plurilocular sporangia.

The biological activity of tissue specific stem cell is under the control of their specific microenvironment and the exogenous chemicals derived from digestive tract can be one of the constructing factors of that. It is suggested that the extract of brown algae Ishige okamurae has antioxidant-, apoptosis induction-, and antiinflammatory- effects. On the other hand, a few studies have shown that antioxidant assist inhibition of accumulation of fat. So we studied the effect of the extract of I. okamura on the cellular activity and differentiation of 3T3-L1 preadipocyte to adipose cell. The viability of cell was analyzed using 3-[4,5-dimethylthiazo-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. Adipogenesis of 3T3-L1 cell was analyzed after induction in the induction medium containing the I. okamurae extract. The cellular activity was high compared with the vehicle and 0.05 mM caffeine in all groups of I. okamurae extract treated cells. The extract of I. okamura inhibited accumulation of lipids in 10 and 50 μg/ml. The expression of the marker genes for adipocyte differentiation coincided with cytochemical results. These results suggest that the extract of I. okamurae increases the cellular viability of adipose precursor cells. On the other hand, it suppresses the differentiation of preadipocyte to adipocyte and accumulation of lipids in concentration-dependent manners. It may be possible that the major component of the extract can be applied in the control of adipose tissuegenesis.

Although, one of the etiologies of localized lipodystrophy of the subcutaneous connective tissue (cellulite) is the histological alternation of adipose tissue, the characteristics of expression of the components of extracellular matrix (ECM) components during adipogenesis are not uncovered. In this study, the effects of caffeine and Ishige okamurae originated diphlorethohydroxycarmalol (DPHC) on the expression of extracellualr fibers was analyzed with quantitative RT-PCR during differentiation induction of mouse subcutaneous adipose derived stem cells (msADSC) into adipocyte. The expression levels of Col1a, Col3a1, and Col61a were decreased by the adipogenci induction in a time-dependent manners. However, Col2a mRNA and Col4a1 mRNA expressions were oposit to them. Caffeine and DPHC stimulated the changes of the expression of these collagens. Eln mRNA expression was increased by induction. DPHC stimulated the expression of it. Mfap5 mRNA expression was deceased in both adipogenic cell and matured adipocytes. Caffeine suppressed the expression of Mfap5 but the effect of DPHC was different by the concentration. The expression of bioglycan, decorin, and lumican were also modified by caffeine and DPHC in a concentration-dependent manner. Based on this study, we revealed firstly the effects of caffeine and DPHC on the expression of collagens, elastin, and glycoproteins during adipogenesis of msADSCs. Those results suggest that DPHC may have antiadipogenic effect and has more positive effets on normal adipose tissue generation and work as suppressor the abnormality of ECM structure. Such results indicate that DPHC can be applied in keeping the stability of the ECM of adipogenic tissues.

Brown algae is variety of biological compounds, including xanthophyll, pigments, fucoidans, phycocolloids, and phlorotannins. Several studies concerning these types of compounds have pointed out the variety of biological benefits associated with the algae, including antioxidant, anticoagulant, antihypertension, antibacterial, and antitumor activities. Diphlorethohydroxy- carmalol (DPHC) is a phlorotannin compound isolated from the brown algae Ishige okamurae, with various biological activities in vitro and in vivo. Numerous studies have shown that antioxidant assist inhibition of accumulation of fat. So we studied that effect of DPHC isolated from Ishige okamurae modified the accumulation of fat on preadipocyte, 3T3-L1 cells in vitro. First, the viability of cell was analyzed after 0.4, 2, 10, 50 μg/ml of DPHC treatment using MTT (3-[4,5-dimethylthiazo-2-yl]-2,5-diphenyl tetrazolium bromide) assay. Second, proliferation of cell was analyzed after 0.4, 2, 10, 50 μg/ml of DPHC treatment through measure doubling time. 3T3-L1 cell differentiation into adipocyte was analyzed after induction in the induction medium containing DPHC. The metabolic activity was suppressed by DPHC in concentration dependent manner. Doubling of 3T3-L1 was delayed by the treatment of DPHC in concentration dependent manner. DPHC also inhibit accumulation of triglyceride in the adipocyte. The expression of the marker genes for adipocyte differentiation coincided with cytochemical results. Base on them, it is suggested that DPHC suppress proliferation of adipose precursor cell and differentiation into adipocytes.