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

Nutritional and biofunctional characterizations of four novel edible aquatic plants of Bangladesh

Aquatic plants are a cheap and renewable biomass rich in bioactive and biofunctional compounds, holding valorization prospects for use in food and pharmaceuticals. Four commonly found edible aquatic plants in Bangladesh, namely red water lily (Nymphaea nouchali), white water lily (Nympheae alba), malancha (Alternanthera philoxeroides), and red seaweed (Gracilaria tenuistipitata), were compared in terms of proximate composition, bioactive compounds, antioxidant activity, mineral and heavy metal contents, and amino acid composition. The crude protein content was the highest in A. philoxeroids (26.96 %), followed by G. tenuistipitata (25.21 %), N. nouchali (25.14 %), and N. alba (23.54 %). The sequence of crude lipid content of four aquatic plants was A. philoxeroids (4.8 %) > N. nouchali (4.0 %) > G. tenuistipitata (3.4 %) > N. alba (2.4 %). The aquatic plants were rich in carbohydrates, with G. tenuistipitata having 37.02 %, significantly (P < 0.05) lower than N. alba (46.12 %), N. nouchali (45.73 %), and A. philoxeroids (42.88 %). The ash content in the studied plants varied between 14.63 % and 24.97 %. Substantial numbers of bioactive compounds were identified in these plants: 42 in N. alba, 41 in N. nouchali, 40 in A. philoxeroides, and 36 in G. tenuistipitata, as determined by GC-MS analysis. G. tenuistipitata showed the highest amount of total phenolic (121.05 ± 2.43 mg gallic acid equivalent/g) and flavonoid (128.03 ± 0.79 mg quercetin equivalent/g) content. The DPPH, hydrogen peroxide, and ferric reducing power assays showed the free radical scavenging ability increased in a dose dependent manner. These aquatic plants contained substantial amounts of minerals, namely Ca ranging from 42.05 ± 2.34 to 441.65 ± 4.67 mg/kg, K ranging from 80.15 ± 1.82 to 97.81 ± 1.74 mg/kg, and Na ranging from 41.16 ± 1.32 to 53.37 ± 1.64 mg/kg. The heavy metal contents of Cu, Ni, and Pb were 0.93 ± 0.06 to 1.25 ± 0.09 mg/kg, 0.44 ± 0.02 to 3.86 ± 0.56 mg/kg, and 0.22 ± 0.02 to 0.67 ± 0.05 mg/kg, respectively. Thirteen different amino acids were identified, with leucine, glycine, alanine, lysine, and phenylalanine dominating, and their contents varying by species. Therefore, regular consumption of these aquatic plants might be a healthy approach to addressing malnutrition and enhancing biofunctional activities.

Nutritional composition and phenolic contents of Gracilariopsis longissima, Padina tetrastromatica and Ulva intestinalis from the Bay of Bengal, Bangladesh coast

Seaweeds have become the focus of experts in recent years due to their biological characteristics and the variety of uses they have for both humans and animals. Biochemical composition, amino acids, fatty acids, and phenolic components were analyzed to explore the nutritive value of Gracilariopsis longissima, Padina tetrastromatica, and Ulva intestinalis from the Bay of Bengal, Bangladesh coast. Proximate composition and mineral content were determined according to the AOAC method. The high-performance liquid chromatography amino acid analysis system was used for the amino acid analysis and the fatty acid profile of the extracted oils was assessed as their methyl esters. The Folin-Ciocalteu technique was used to estimate the phenolic content and the aluminum chloride colorimetric technique was used to calculate the total flavonoid content. The three different species of seaweed had significantly different proximate compositions (P < 0.05), with G. longissima having the highest protein content. Except for sulfur, the mineral contents were likewise considerably higher (P < 0.05) in G. longissima. Although the amounts of the essential amino acids were greater than 50 % of the total amino acids in the three studied seaweed species, the total amino acid composition of these three species differed significantly (P < 0.05). The findings indicated that lipid levels were low in all the assessed species, but unsaturated fatty acid levels were high, with G. longissima exhibiting the highest amounts. The results showed that, compared to the other species, G. longissima had a substantially higher (P < 0.05) level of total phenolic and flavonoid content. The three studied seaweed appear to be excellent for nutrition based on their overall nutritional profiles. However, due to high protein, unsaturated fatty acid, essential amino acid, and total phenolic and flavonoid content, G. longissima is the most promising seaweed that will be helpful for pharmaceutical and multifunctional food applications.

Process optimization and characterization of hydrolysate from underutilized brown macroalgae (Padina tetrastromatica) after fucoidan extraction through subcritical water hydrolysis

The growing demand for macroalgal biomass as a source of proteins, peptides, and amino acids is garnering attention for their biological and functional properties. This study depicts the use of emerging green techniques, i.e. subcritical water, to hydrolyze protein from Padina tetrastromatica. The biomass was treated with subcritical water at varying temperatures between 100 and 220 °C for 10-40 min at a biomass to water proportion of 1:50 (w/v) and pressure of 4.0 MPa. The optimum conditions for recovering the maximum protein (127.2 ± 1.1 mg g-1), free amino acids (58.4 ± 1.0 mg g-1), highest degree of hydrolysis (58.8 ± 1.2 %) and low molecular weight peptides (<650 Da) were found to be 220 °C for 10 min. The amino acid profiling of the hydrolysate revealed that it contains 45 % essential amino acids, with the highest concentration of methionine (0.18 %), isoleucine (0.12 %) and leucine (0.10 %). It was found that the hydrolysate contains phenolics (23.9 ± 1.4 mg GAE g-1) and flavonoids (1.23 ± 0.1 mg QE g-1), which are largely responsible for antioxidant activity. The hydrolysate effectively inhibits acetylcholinesterase and α-amylase in vitro, with IC50 values of 17.9 ± 0.1 mg mL-1 and 16.0 ± 0.5 %, respectively, which can help prevent Alzheimer's disease and diabetes mellitus. Consequently, this study reveals that utilizing eco-friendly subcritical water hydrolysis method, 79 % of the protein was recovered from P. tetrastromatica, which might be an effective source of bioactive peptides in various nutraceutical, pharmaceutical and cosmeceutical applications.

Preparation, in vitro and in vivo evaluation of pinocembrin-loaded TPGS modified liposomes with enhanced bioavailability and antihyperglycemic activity

PURPOSE

To prepare polyethylene glycol succinate-vitamin E modified pinocembrin (PCB)-loaded liposomes (PCBT-liposomes) and evaluate PCBT-liposomal pharmacokinetics and antihyperglycemic activity.

SIGNIFICANCE

The novel PCBT-liposomes demonstrated a promising application prospect as a nano drug carrier for future research.

METHODS

Thin film dispersion was used to prepare PCBT-liposomes. We measured a series of characterization, followed by in vitro cumulative release, in vivo pharmacokinetic study, and antihyperglycemic activity evaluation.

RESULTS

PCBT-liposomes displayed spherical and bilayered nanoparticles with mean particle size (roughly 92 nm), negative zeta potential (about -26.650 mV), high drug encapsulation efficiency (87.32 ± 1.34%) and good storage (at 4 or 25 °C) stability during 48 h after hydration. The cumulative release rate of PCBT-liposomes was markedly higher than free PCB in four different pH media. In vivo investigation showed that PCBT-liposomes could obviously improve oral bioavailability of PCB by 1.96 times, whereas the C_max, MRT_0-t, and T_1/2 of PCBT-liposomes were roughly 1.700 ± 0.139 µg·mL^-1, 12.695 ± 1.647 h, and 14.244 h, respectively. In terms of biochemical analysis, aspartate amino-transferase (AST), alanine amino-transferase (ALT), interleukin-1 (IL-1), and tumor necrosis factor-α (TNF-α) concentrations in serum of diabetic mice were respectively decreased 28.28%, 17.23%, 17.77%, and 8.08% after PCBT-liposomal treatment.

CONCLUSION

These results show PCBT-liposomal preparation as an excellent nano-carrier which has the potential to improve water solubility, bioavailability, and antihyperglycemic activity of PCB, amid broadening the application of PCB in the clinical settings.

Recent advances in biological properties of brown algae-derived compounds for nutraceutical applications

The increasing demand for nutraceuticals in the circular economy era has driven the research toward studying bioactive compounds from renewable underexploited resources. In this regard, the exploration of brown algae has shown significant growth and maintains a great promise for the future. One possible explanation could be that brown algae are rich sources of nutritional compounds (polyunsaturated fatty acids, fiber, proteins, minerals, and vitamins) and unique metabolic compounds (phlorotannins, fucoxanthin, fucoidan) with promising biological activities that make them good candidates for nutraceutical applications with increased value-added. In this review, a deep description of bioactive compounds from brown algae is presented. In addition, recent advances in biological activities ascribed to these compounds through in vitro and in vivo assays are pointed out. Delivery strategies to overcome some drawbacks related to the direct application of algae-derived compounds (low solubility, thermal instability, bioavailability, unpleasant organoleptic properties) are also reviewed. Finally, current commercial and legal statuses of ingredients from brown algae are presented, considering future therapeutical and market perspectives as nutraceuticals.

In Vitro and In Vivo Anticancer and Genotoxicity Profiles of Green Synthesized and Chemically Synthesized Silver Nanoparticles

Silver nanoparticles were green synthesized (Ag-PTs) employing the crude extract of Padina tetrastromatica, a marine alga, and their anticancer and safety profile were compared with those of chemically synthesized silver nanoparticles (Ag-NPs) by in vitro and in vivo models. Ag-PT exhibited potent cytotoxicity against B16-F10 (IC₅₀ = 3.29), MCF-7 (IC₅₀ = 4.36), HEPG2 (IC₅₀ =3.89), and HeLa (IC₅₀ = 4.97) cancer cell lines, whereas they exhibited lower toxicity on normal CHO-K1 cells (IC₅₀ = 5.16). The potent anticancer activity of Ag-PTs on cancer cells is due to the liberation of ions from the nanoparticles. Increased ion internalization to the cells promotes reactive oxygen species (ROS) production and ultimately leads to cell death. The in vitro anticancer results and in vivo melanoma tumor regression study showed significant inhibition of melanoma tumor growth due to Ag-PT treatment. Ag-PT is involved in the upregulation of the p53 protein and downregulation of Sox-2 along with the Ki-67 protein. The antitumor effects of Ag-PTs may be due to the additional release of ions at a lower pH of the tumor microenvironment than that of the normal tissue. The results of safety investigations of Ag-PT by studying mitotic chromosome aberrations (CAs), micronucleus (MN) induction, and mitotic index (MI) demonstrated Ag-PT to be less genotoxic compared to Ag-NP. The bioefficacy and toxicology outcomes together demonstrated that the green synthesized silver nanoparticles (Ag-PTs) could be explored to develop a biocompatible, therapeutic agent and a vehicle of drug delivery for various biomedical applications.

Antidiabetic potential of seaweed and their bioactive compounds: a review of developments in last decade

Diabetes Mellitus is a public health problem worldwide due to high morbidity and mortality rate associated with it. Diabetes can be managed by synthetic hypoglycemic drugs, although their persistent uses have several side effects. Hence, there is a paradigm shift toward the use of natural products having antidiabetic potential. Seaweeds, large marine benthic algae, are an affluent source of various bioactive compounds, including phytochemicals and antioxidants thus exhibiting various health promoting properties. Seaweed extracts and its bioactive compounds have antidiabetic potential as they inhibit carbohydrate hydrolyzing enzymes in vitro and exhibit blood glucose lowering effect in random and post prandial blood glucose tests in vivo. In addition, they have been associated with reduced weight gain in animals probably by decreasing mRNA expression of pro-inflammatory cytokines with concomitant increase in mRNA expression levels of anti-inflammatory cytokines. Their beneficial effect has been seen in serum and hepatic lipid profile and antioxidant enzymes indicating the protective role of seaweeds against free radicals mediated oxidative stress induced hyperglycemia and associated hyperlipidemia. However, the detailed and in-depth studies of seaweeds as whole, their bioactive isolates and their extracts need to be explored further for their health benefits and wide application in food, nutraceutical and pharmaceutical industries.