Beijing urban particulate matter-induced injury and inflammation in human lung epithelial cells and the protective effects of fucosterol from Sargassum binderi (Sonder ex J. Agardh).

Particulate matter (PM) air pollution has gradually become a widespread problem in East Asia. PM may cause unfamiliar inflammatory responses, oxidative stress, and pulmonary tissue damage, and a comprehensive understanding of the underlying mechanisms is required in order to develop effective anti-inflammatory agents. In this study, fine dust collected from Beijing, China (CPM) (size < PM13 with majority < PM2.5) was evaluated for its oxidative stress- and inflammation-inducing effects, which cause cell damage, in A459 human lung epithelial cells. Oxidative stress was marked by an increase in intracellular ROS levels and the production of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and heme oxygenase-1 (HO-1). Upon induction of oxidative stress, a marked increase was observed in the expression of key inflammatory mediators such as COX-2 and PGE2 and the pro-inflammatory cytokines TNF-α and IL-6 via NF-kB and MAPK pathways. Cellular damage was marked by a reduction in viability, increased lactate dehydrogenase (LDH) release, formation of apoptotic and necrotic bodies, accumulation of sub-G1 phase cells, and DNA damage. Apoptosis was found to be mediated via the activation of caspases through the mitochondria-mediated pathway. Fucosterol, purified from the brown alga Sargassum binderi (Sonder ex J. Agardh) by bio-assay-guided fractionation and purification, exhibited potential therapeutic effects against CPM-induced detrimental effects. Further studies could focus on developing fucosterol, in forms such as steroidal inhalers, against PM-induced pulmonary tissue inflammation.

Purification and Structural Characterization of Sulfated Polysaccharides Derived from Brown Algae, Sargassum binderi: Inhibitory Mechanism of iNOS and COX-2 Pathway Interaction.

Among the components derived from brown algae, anionic sulfated polysaccharides, which contain sulfated fucose as the major monosaccharide, exert significant biological activities. In this study, we purified and structurally characterized sulfated polysaccharides from brown algae, Sargassum binderi (S. binderi; SBPs), and evaluated their biological activity in vitro and in vivo. The SBPs were separated based on their charges and their biophysical properties were investigated according to their functional groups, structural features, and molecular weights using FTIR, NMR, and MALS. Among all the SBPs, Fraction 4 (SBP-F4), with an average molecular weight of 2.867 × 105 g/mol, had the highest polysaccharide and sulfate contents (75.15 ± 0.25% and 24.08 ± 0.18%, respectively). The biological activities of SBP-F4 were investigated further in vitro and in vivo. Our results showed that SBP-F4 significantly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in LPS-activated macrophages. Moreover, in the LPS-treated zebrafish model, a significant decrease in cell death and NO production was observed. Collectively, these results show that SBPs not only exert protective effects against LPS-induced cytotoxicity but also inhibit the activation and anti-inflammatory activity of macrophages. Therefore, polysaccharides derived from S. binderi are potential anti-inflammatory agents for use in clinical settings.

Sustainable approach in phlorotannin recovery from macroalgae.

In this present study, alcohol/salt liquid biphasic system was used to extract phlorotannin from brown macroalgae. Liquid biphasic system is a new green technology that integrated with various processes into one-step, by concentrating, separating and purifying the bioproduct in a unit operation. The solvent used is non-toxic and there is potential for solvent recovery which is beneficial to the environment. Phlorotannin is a bioactive compound that has gained much attention due to its health beneficial effect. Therefore, the isolation of phlorotannin is lucrative as it contains various biological activities that are capable to be utilised into food and pharmaceutical application. By using 2-propanol/ammonium sulphate system, the highest recovery of phlorotannin was 76.1% and 91.67% with purification factor of 2.49 and 1.59 from Padina australis and Sargassum binderi, respectively. A recycling study was performed and the salt phase of system was recycled where maximum salt recovery of 41.04% and 72.39% could be obtained from systems containing P. australis and S. binderi, respectively. Similar recovery of phlorotannin was observed after performing two cycles of the system, this concludes that the system has good recyclability and eco-friendly.

Characterisation of fucoidan extracted from Malaysian Sargassum binderi.

Fucoidan is a sulphated polysaccharide that consists mainly of fucose, normally found in brown seaweeds. In this study, fucoidan was extracted from Sargassum binderi (Fsar) from Malaysia and subsequently characterised. The chemical characteristics of Fsar were found to be different than those of commercial food grade fucoidan (Fysk) and those of previously studied fucoidans. NMR analysis proposed that the main structure of Fsar is →3)fuc-2-OSO3(-)(1→3)fuc(1→. The molecular weight (47.87kDa) and degree of sulphation (0.20) of Fsar were higher than those of Fysk, at 27.98kDa and 0.15, respectively. However, Fsar's polydispersity index (1.12) and fucose content (34.50%) were lower than those of Fysk, at 1.88 and 43.30%, respectively. Both Fsar and Fysk showed similar thermo-gravimetric properties with four mass losses, amorphous in nature and negative optical rotations. Results show that Fsar has fundamental characteristics of fucoidan with different structural conformation i.e. variation in glycosidic linkages and sulphate group orientation.

Chemical properties and toxicology studies of fucoidan extracted from Malaysian Sargassum binderi.

Fucoidan is a sulfated polysaccharide that consists mainly of fucose and is found in brown seaweeds. In this study, fucoidan was extracted from Sargassum binderi (Fsar) from Malaysia and subsequently characterized in terms of composition, structure and toxicology. It was found that the molecular weight, polydispersity index, monosaccharide profile and degree of sulfation of Fsar differed from those of commercial food-grade fucoidan (Fysk). NMR analysis suggested that the main structure of Fsar was →3)fuc-2-OSO3 -(1→3)fuc-2-OSO3 -(1→. A cytotoxicity study employing up to 200 mg/mL Sargassum binderi extract showed that cell inhibition was less than 50% (IC50), while acute toxicity results classified S. binderi as category 5 (unclassified) according to the OECD Guideline 423, as no mortality was observed at the highest dosage (2,000 mg/kg). Both toxicity results showed that this material is safe to be consumed. The chemical characteristics and non-toxicity of Fsar demonstrate its potential in biological and food product applications.

Larvicidal activity, inhibition effect on development, histopathological alteration and morphological aberration induced by seaweed extracts in Aedes aegypti (Diptera: Culicidae).

OBJECTIVE: To investigate the larvicidal activity, inhibition effect on development, histopathological alteration and morphological aberration induced by the extracts derived from seaweeds Bryopsis pennata (B. pennata), Sargassum binderi (S. binderi) and Padina australis in Aedes aegypti (Ae. aegypti) larvae and to characterize the phytochemical components of the three seaweeds. METHODS: Larvicidal activity of the seaweeds towards the larvae of Ae. aegypti was determined according to WHO. The inhibition effect of seaweeds was assessed by determining the mortality, adult emergence rate, larval and pupa duration of the treated larvae. Histopathological effect on midgut epithelium of larvae and morphological aberration induced by the methanol extracts were examined. Phytochemical analysis was done to determine the presence of alkaloids, saponins, steroids and terpenoids in the seaweeds. RESULTS: Chloroform partition of B. pennata extract exhibited the strongest larvicidal activity (LC50 = 82.55 µg/mL), followed by methanol extract of B. pennata (LC50 = 160.07 µg/mL) and chloroform partition of S. binderi extract (LC50 = 192.43 µg/mL). The methanol extract of S. binderi exhibited the strongest effect on prolongation of larval period (1.5-fold longer as compared to control) and resulted in strongest inhibition effect in adult emergence (98.67%). The histopathological study showed that larvae treated with seaweed extracts had cytopathological alteration of the midgut epithelium. The morphological observation revealed that the anal papillae and terminal spiracles of larvae were the common sites of aberrations. CONCLUSIONS: The study provided information on various effects of seaweed extracts on Ae. aegypti. Further investigation on identifying the active compounds and their mechanisms of action is recommended.