Investigating the Synergistic Antibacterial Activity of Epiphytic Bacterial Polyketides and Biopolymer Alginates from Marine Microalgae

The objective was framed to analyse the synergistic antibacterial activity and woundhealing ability of the developed polyketide-alginate polymers. Alginates were extracted from a brown seaweed Padina tetrastromatica and used as a synergistic compound along with bacterial polyketides. Polyketides and alginate polymer combinations were used against test bacteria to determine the synergistic antibacterial activity. A novel wound-healing film was developed using polyketide and alginates with synergistic concentrations and its degradability and wound-healing ability was investigated. The findings in the present research showed most significantly that, Staphylococcus aureus showed complete synergy with the mean MIC value of 0.03 μg/ml and with best FIC value of 0.24 (p<0.5). Degradation of developed films revealed that more moisture leads to more release of antibacterial alginate content at the wound site and hence more degradation. This was evident from the FESEM analysis. In vitro wound-healing assay revealed that the developed polyketide-alginate polymers exhibited cell migration and proliferation after 24th hour of incubation at 370C indicating the wound-healing abilities. Hence, it can be concluded that the biochemical compounds present in the developed polyketide-alginate polymers are considered highly significant in treating any types of wounds.

Effect of solvents on bioactive compounds and antioxidant activity of Padina tetrastromatica and Gracilaria tenuistipitata seaweeds collected from Bangladesh

Seaweeds are now recognized as a treasure of bioactive compounds. However, the bioactivity of seaweed originating in Bangladesh is still unexplored. So, this study was designed to explore the secondary metabolites and antioxidant activities of solvent extracts of Padina tetrastromatica and Gracilaria tenuistipitata. Phytochemical screening and FTIR spectra confirm the diverse type of bioactive compounds. Antioxidant activity of extracts were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), reducing power (RP), phosphomolybdenum, hydrogen peroxide and nitric oxide (NO) scavenging assays. Here, methanolic extract of P. tetrastromatica showed highest amount of total phenolic content (85.61 mg of GA/g), total flavonoid content (41.77 mg of quercetin/g), DPPH (77.07%), ABTS (77.65%), RP (53.24 mg AAE/g), phosphomolybdenum (31.58 mg AAE/g), hydrogen peroxide (67.89%) and NO (70.64%) assays compared to its methanolic extracts of G. tenuistipitata. This study concluded that methanol as a solvent extract of brown seaweed (P. tetrastromatica) exhibited bioactivity and antioxidant potentiality which will be useful for pharmacological as well as in functional food application.

Nutritional Profile, Antioxidative and Antihyperglycemic Properties of Padina tetrastromatica from Tioman Island, Malaysia

Seaweeds are an important ingredient of functional foods recommended for daily food, due to their unique compositions and nutritional value. Padina tetrastromatica is a brown edible seaweed that is commonly found along the coastal regions of Peninsular Malaysia and consumed as food by some coastal communities. This study investigates the nutritional and antihyperglycaemic potential of P. tetrastromatica extracts, which is generally accepted as an important functional food. In our methodology, we induced diabetes intraperitoneally in experimental animals with a dose of 65 mg kg−1 body weight of streptozotocin. Oral treatment with 200 and 400 mg kg−1 of P. tetrastromatica ethanolic and ethyl acetate extracts were initiated, respectively, to experimental rats once daily for 18 days. Metformin was used as the positive control. Biochemical estimations and histopathological analysis were included in this study. Treatment with P. tetrastromatica extracts significantly lowered the plasma glucose levels in Streptozotocin-induced diabetic rats. In addition, P. tetrastromatica extract treatment also showed a significant reduction in serum alanine transaminase levels. However, no significant changes were observed in serum aspartate transaminase levels. The ethyl acetate extract of P. tetrastromatica at 400 mg kg−1 dose shows some nephroprotective effect, which is observed from the significant increase in the plasma albumin levels. Histopathological evaluation revealed no marked morphological changes in tissues of the isolated organs of the ethyl acetate extract-treated group, revealing the safe nature of P. tetrastromatica.

Formulation of Novel Wound Healing Hydrogel Using Extracts of Padina Tetrastromatica and Determining its Antibacterial Activity against Wound Pathogens

Seaweeds are rich in polysaccharides and also possess antiviral, antibacterial, antifungal, antiprotozoal, and antifertility activities. The present study covers the effective wound healing and prevention by Hydrogel prepared from extracts of seaweeds. The seaweed was extracted with solvents and the crude extract was separated using analytical thin-layer chromatography (TLC). The separated compounds and prepared hydrogel were tested for their potential antibacterial activity and anti-inflammatory activity against Staphylococcus aureus and Klebsiella pneumoniae bacteria. This study represented that the extracts of Padina tetrastromatica contain a variety of phytochemical compounds, which can effectively protect the body from inflammation and thus can be used as a potent source of natural protecting compounds.

Anticoagulant Properties from Marine Algae – A Systemic Review

The anticoagulants are used to eliminate mainly blood clots. They are offered to patients who are at risk of developing clots, in order to improve their general wellbeing. Anticoagulant namely heparin, has many disadvantages like thrombocytopenia, antithrombin defensives, bleeding disorders and etc. The marine algae are sulphated polysaccharides has many advantages from commercially available anticoagulant which is derived from the animal's sources. The anticoagulant is found in various species of marine algae, mainly from the red, brown and green algae and its determined by various methods, namely APTT, PT, TT, CT. The marine algae species are Padina tetrastromatica, Ulva fasciata, Corallina, Asparagopsis taxiformis, Grateloupia filicina, Ulva rigida, Bursatella leachii, Agardhiella subulate, Turbinaria ornate, Monostroma angicava, Arthrospira platensis, Sargassum tenerrimum, Sargassum wightii, Turbinaria conoides, Lomentaria catenate, Gracilaria debilis, and Monostroma nitidum are some of the species revealed its anticoagulant properties. The anticoagulant produced by the marine species are compared with standard namely heparin by in vitro and in vivo methods and the review result reveal that the anticoagulant values produced are nearer to the standard and in some species, the value are more than that of standard. The sample are crude extracted one and some samples are isolated from different fraction.

Culture of Three Seaweed Species in Cox’s Bazar Coast, Bangladesh

The experimental culture of 3 seaweed species, i.e. Hypnea musciformis, Enteromorpha intestinalis and Padina tetrastromatica in three locations of Cox’s Bazar coast, Bangladesh using 4×4 m horizontal coir rope net method were conducted during 2016 to 2018. Results showed that the biomass yield was highest from H. musciformis (30.23±0.40 kg fw m−1) and significantly differ from E. intestinalis (24.50±0.08 kg fw m−1) and P. tetrastromatica (10.18±0.45 kg fw m−1). The Daily Growth Rate (DGR) of H. musciformis (8.88% day−1) was also higher than the DGR of E. intestinalis (6.55% day−1) and P. tetrastromatica (6.74% day−1). Saint Martin’s Island showed higher biomass yield of seaweeds than Bakkhali and Inani due to favourable water quality. In context to physico-chemical parameters of seaweed farming, Cox's Bazar coast is suitable for seaweed cultivation, although more suitable culture areas and longer culture period yet to be identified. The findings of the present study suggest that the cultivation of H. musciformis is viable and coastal people can take up such activities as seasonal income generating activity in coastal water. Bangladesh J. Zool. 49(1): 47-56, 2021

Effect of Solvents on Bioactive Compounds and Antioxidant Activity of Padina Tetrastromatica and Gracilaria Tenuistipitata Seaweeds Collected From Bangladesh

Seaweeds are now recognized as a treasure of bioactive compounds. However, the seaweed of Bangladesh is still unexplored. So, this study was designed to explore the secondary metabolites and antioxidant activities of solvent extracts of Padina tetrastromatica and Gracilaria tenuistipitata. Phytochemical screening and Fourier transform infrared (FTIR) confirm the diverse type of bioactive compounds. Antioxidant activity of extracts were evaluated by 1, 1-diphenyl-2- picrylhydrazyl (DPPH), 2, 2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), reducing power (RP), phosphomolybdenum and hydrogen peroxide assays. Here, methanolic extract of P. tetrastromatica showed the highest amount of total phenolic content (85.61 mg of GA/g), total flavonoid content (41.77 mg of quercetin/g), which showed as potent antioxidant properties confirmed by DPPH (77.07%), ABTS (77.65%), RP (53.24 mg AAE/g), phosphomolybdenum (31.58 mg AAE/g) and hydrogen peroxide (67.89%) assays followed by ethanol and water. This study concluded that bioactive compound and antioxidant activities are dose and solvent-dependent and seaweed type.