In vitro evaluation of antioxidant and antibacterial activities of Eucheuma cottonii extract and its in vivo evaluation of the wound-healing activity in mice

Biochemical Composition and Seasonal Variations of the Madagascar Algae Eucheuma denticulatum (Solieriaceae, Rhodophyta)

Although the density and diversity of seaweeds in Madagascar is particularly high, these resources are underexploited and they are not part of the local population's eating habits. No study has been carried out on the nutritional properties and seasonal variation of Eucheuma species harvested in Madagascar. In this study, Eucheuma denticulatum was harvested monthly over two years (2021 and 2022) on the northeast coast of Madagascar (Sainte Marie Island). The compositional analysis revealed prominent sugars and minerals up to 41.0 and 39.5% dw, respectively. E. denticulatum showed slight variability over the seasons in the macroelements and oligoelements (Ca, K, Na, Mg, Fe, Mn) ranging from 22.8 ± 0.2 to 25.3 ± 0.1% dw in 2021 and 22.1 ± 0.3 to 26.5 ± 0.3% dw in 2022. Total amino acids varied from 2.3 ± 0.6 to 2.5 ± 0.6% dw during the two years. Seaweed extracts showed antioxidant activity by the in vitro method ranging from 2026 ± 2 to 2998 ± 4 μg.mL-1 in 2021, and from 1904 ± 2 to 2876 ± 4 μg.mL-1 in 2022. Finally, the principal component analysis (PCA) showed a correlation between protein content and environmental parameters. The nutritional characteristics therefore confirmed that E. denticulatum could potentially be used as a nutritious and functional food and could be incorporated in the diet of local populations.

Wound healing potential of silver nanoparticles from Hybanthus enneaspermus on rats

In this study, we green synthesized silver nanoparticles (Ag Nps) from Hybanthus enneaspermus leaves (HE-Ag NPs) and evaluated their antimicrobial and wound-healing properties. The synthesized HE-Ag NPs were characterized using various techniques, revealing face-centered polygonal structures, a well-dispersed appearance, and an average particle size of 42-51 nm. The antimicrobial effects of HE-Ag NPs and their embedded cotton fabrics were tested against several pathogens, showing effective inhibition of growth. The cytotoxicity and anti-inflammatory properties of HE-Ag NPs were assessed using MTT assays on L929 and RAW 264.7 cells and by measuring inflammatory cytokine levels in LPS-treated RAW 264.7 cells. HE-Ag NPs did not affect the viability of L929 and RAW 264.7 cells and significantly reduced inflammatory cytokine levels. In vivo studies using an excision wound model demonstrated that HE-Ag NPs-loaded ointment significantly increased hydroxyproline, total protein, and antioxidant levels and enhanced the wound contraction rate. These findings suggest that HE-Ag NPs have potent antimicrobial properties and promote wound healing, indicating their potential for use in topical ointments for wound care.

Kappaphycus alvarezii as a renewable source of kappa-carrageenan and other cosmetic ingredients

Kappa-carrageenan is one of the most traded marine-derived hydrocolloids used in the food-and-beverage, pharmaceuticals, and personal care/cosmetics industries. K. alvarezii (previously known as Kappaphycus alvarezii) is arguably the most important natural producer based on annual production size and near-homogeneity of the product (i.e., primarily being the kappa-type). The anticipated expansion of the kappa-carrageenan market in the coming years could easily generate >100,000 MT of residual K. alvarezii biomass per year, which, if left untreated, can severely affect the environment and economy of the surrounding area. Among several possible valorization routes, turning the biomass residue into anti-photoaging cosmetic ingredients could potentially be the most sustainable one. Not only optimizing the profit (thus better ensuring economic sustainability) relative to the biofuels- and animal feed-routes, the action could also promote environmental sustainability. It could reduce the dependency of the current cosmetic industry on both petrochemicals and terrestrial plant-derived bioactive compounds. Note how, in contrast to terrestrial agriculture, industrial cultivation of seaweeds does not require arable land, freshwater, fertilizers, and pesticides. The valorization mode could also facilitate the sequestration of more greenhouse gas CO2 as daily-used chemicals, since the aerial productivity of seaweeds is much higher than that of terrestrial plants. This review first summarizes any scientific evidence that K. alvarezii extracts possess anti-photoaging properties. Next, realizing that conventional extraction methods may prevent the use of such extracts in cosmetic formulations, this review discusses the feasibility of obtaining various K. alvarezii compounds using green methods. Lastly, a perspective on several potential challenges to the proposed valorization scheme, as well as the potential solutions, is offered.

Octanoyl esterification of low molecular weight sulfated galactan enhances the cellular uptake and collagen expression in fibroblast cells

Low molecular weight sulfated galactan (LMSG) supplemented with octanoyl ester (Oct-LMSG) demonstrated superior wound healing activity compared to the unsupplemented LMSG in a fibroblast wound model. To test the hypothesis that the increased bioactivity of Oct-LMSG may depend on its penetration into the plasma membrane, its cellular uptake was investigated and collagen production in fibroblast cells was assessed for the first time. The cellular uptake of Oct-LMSG was examined using indirect immunofluorescence and a confocal laser scanning microscope. In addition, the degree of fibroblast activation associated with this uptake was evaluated. The results indicated increased LMSG internalization in fibroblasts treated with Oct-LMSG. Transmission electron micrographs revealed the ultrastructure of active protein production in fibroblasts upon treatment with Oct-LMSG. In addition, Oct-LMSG upregulated the expression of type I collagen mRNA and proteins, as well as related signaling molecules involved in collagen synthesis, including collagen type I α1 chain (Col1A1), Col1A2, phosphorylated (p)-Smad2/3 and p-Smad4. The current findings support the notion that the supplementation of LMSG with octanoyl enhanced its cellular uptake into fibroblasts and, as a result, regulated the expression of type I collagen in fibroblasts via the activation of the Smad signaling pathway. This study demonstrates the therapeutic potential of Oct-LMSG in promoting tissue regeneration.

Rehashing Our Insight of Seaweeds as a Potential Source of Foods, Nutraceuticals, and Pharmaceuticals

In a few Southeast Asian nations, seaweeds have been a staple of the cuisine since prehistoric times. Seaweeds are currently becoming more and more popular around the world due to their superior nutritional value and medicinal properties. This is because of rising seaweed production on a global scale and substantial research on their composition and bioactivities over the past 20 years. By reviewing several articles in the literature, this review aimed to provide comprehensive information about the primary and secondary metabolites and various classes of bioactive compounds, such as polysaccharides, polyphenols, proteins, and essential fatty acids, along with their bioactivities, in a single article. This review also highlights the potential of seaweeds in the development of nutraceuticals, with a particular focus on their ability to enhance human health and overall well-being. In addition, we discuss the challenges and potential opportunities associated with the advancement of pharmaceuticals and nutraceuticals derived from seaweeds, as well as their incorporation into different industrial sectors. Furthermore, we find that many bioactive constituents found in seaweeds have demonstrated potential in terms of different therapeutic attributes, including antioxidative, anti-inflammatory, anticancer, and other properties. In conclusion, seaweed-based bioactive compounds have a huge potential to play an important role in the food, nutraceutical, and pharmaceutical sectors. However, future research should pay more attention to developing efficient techniques for the extraction and purification of compounds as well as their toxicity analysis, clinical efficacy, mode of action, and interactions with regular diets.

Manilkara zapota L. extract topical ointment application to skin wounds in rats speeds up the healing process

Poor circulation, unresolved inflammation, neuropathy, and infection make wound care difficult. Manilkara zapota (M. zapota) antibacterial and antioxidant properties may help speed up the healing process. The present investigation aimed to evaluate the wound healing activity of M. zapota bark ethanolic extract (MZE) by employing in-vitro migration scratch assay and in-vivo animal models. Wistar albino rats were used for the in-vivo wound healing models. No treatment was given to Group I; Group II received povidone-iodine (5% W/W); Group III received MZE (5% W/W); and Group IV received MZE (10% W/W). Linear incision models and excision wound models were used to induce injury. The ointments were applied immediately to the wounds after causing the injury. The percentage of wound contraction, the length of the epithelization period, and the wound's tensile strength were all calculated. The scratch assay assessed the test drug's potential for wound healing in-vitro. H₂O₂ and DPPH scavenging assays were used to measure antioxidant activity. A p < 0.05 was used to define statistical significance. On days 4, 8, 12, 16, and 20, the wound contraction potential of animals treated with MZE ointment was significantly higher (p < 0.001) than that of the control group. On day 20, the proportion of wound contraction in MZE-treated animals was 99.88%, compared to 83.86% in untreated animals. The test group had a significantly (p < 0.01) faster time to full epithelization than the control group. In the incision model, the control group had considerably lower mechanical strength (p < 0.001) than animals treated with MZE. In addition, MZE caused a significant increase (p < 0.001) in total protein and hydroxyproline levels. In the scratch experiment, test drug-treated cells showed a higher rate of cell migration than untreated cells. Furthermore, animals treated with MZE showed increased levels of epithelial tissue, collagen proliferation, and keratinization. To summarize, the current study found that M. zapota improved wound healing activity both in vitro and in vivo, as evidenced by the study results. M. zapota extract has significant wound-healing potential and could be a viable source of wound-healing nutraceuticals.

Antioxidant Biomaterials in Cutaneous Wound Healing and Tissue Regeneration: A Critical Review

Natural-based biomaterials play an important role in developing new products for medical applications, primarily in cutaneous injuries. A large panel of biomaterials with antioxidant properties has revealed an advancement in supporting and expediting tissue regeneration. However, their low bioavailability in preventing cellular oxidative stress through the delivery system limits their therapeutic activity at the injury site. The integration of antioxidant compounds in the implanted biomaterial should be able to maintain their antioxidant activity while facilitating skin tissue recovery. This review summarises the recent literature that reported the role of natural antioxidant-incorporated biomaterials in promoting skin wound healing and tissue regeneration, which is supported by evidence from in vitro, in vivo, and clinical studies. Antioxidant-based therapies for wound healing have shown promising evidence in numerous animal studies, even though clinical studies remain very limited. We also described the underlying mechanism of reactive oxygen species (ROS) generation and provided a comprehensive review of ROS-scavenging biomaterials found in the literature in the last six years.

A review focusing on the benefits of plant-derived polysaccharides for osteoarthritis

Osteoarthritis (OA) is a chronic joint disease characterized by progressive cartilage degeneration, which imposes a heavy physical and financial burden on the middle-aged and elderly population. As the pathogenesis of OA has not been fully elucidated, it is of great importance to develop targeted therapeutic or preventive medications. Traditional therapeutic drugs, such as non-steroidal anti-inflammatory drugs, steroids and opioids, have significant side effects, making the exploration for safe and effective alternative therapeutic drugs urgent. In recent years, many studies have reported the role of plant-derived polysaccharides in anti-inflammation, anti-oxidation, regulation of chondrocyte metabolism and proliferation, and cartilage protection, and have demonstrated their great potential in the treatment of OA. Therefore, by focusing on studies related to the intervention of plant-derived polysaccharides in OA, including in vivo and in vitro experiments, this review aimed to classify and summarize the existing research findings according to different mechanisms of action. In addition, reports on plant-derived polysaccharides as nanoparticles were also explored. Then, candidate monomers and theoretical bases were provided for the further development and application of novel drugs in the treatment of OA.

Dietary Sargassum angustifolium (Macro-Algae, Sargassaceae) extract improved antioxidant defense system in diazionon-exposed common carp, Cyprinus carpio

The effects of different dietary levels of algae (Sargassum angustifolium) extract were investigated on the antioxidant system of common carp, Cyprinus carpio. Fish (30.2 ± 2.1 g) were fed 0 (control), 5, 10 and 15 g/kg basal diet of Sargassum angustifolium extract (SAE) for 60 days and then exposed to an environmentally relevant concentration of diazinon (2 mg/l) for 24 h. The biochemical assays were conducted in two times including at the end of feeding period and after 24 h exposure to diazinon. According to the results, malondialdehyde (MDA) levels in the liver remained unchanged (P>0.01) during feeding period, while significantly increased in response to diazinon in control and fish fed 5 and 10 g/kg diet SAE (P<0.01). The hepatic metabolic enzymes (AST: Aspartate aminotransferase, ALT: alanine aminotransferase, LDH: lactate dehydrogenase, CK: creatine kinase) showed no significant changes in all groups during feeding period, while these enzymes increased in Non-SAE supplemented fish and those fed 5 and 10 g/kg SAE after exposure to diazinon (P<0.01). Although little elevations were observed in the activity of hepatic antioxidant enzymes (CAT: catalase, SOD: superoxide dismutase, GPx: Glutathione peroxidase) in fish fed SAE, these elevations were not significant (P>0.01). After exposure to diazinon, antioxidant enzymes significantly decreased in control and fish fed 5 g/kg diet SAE, while the fish of 10 and 15 g/kg diet SAE treatments showed significant elevations (P<0.01). The antioxidant-related genes (sod, cat, gpx) significantly expressed more in response to dietary SAE compared to control (P<0.01). After exposure to diazinon, all groups showed significant elevations in antioxidant-related genes (P<0.01). In conclusion, the results of the present study revealed the antioxidant enhancing effects of SAE at dietary levels of 10 and 15 g/kg diet, which this effect may be attributed to some antioxidant components in the chemical composition of the macro-algae or to the direct effect of SAE on antioxidant defence system of the fish.

Therapeutic Potential and Nutraceutical Profiling of North Bornean Seaweeds: A Review

Malaysia has a long coastline surrounded by various islands, including North Borneo, that provide a suitable environment for the growth of diverse species of seaweeds. Some of the important North Bornean seaweed species are Kappaphycus alvarezii, Eucheuma denticulatum, Halymenia durvillaei (Rhodophyta), Caulerpa lentillifera, Caulerpa racemosa (Chlorophyta), Dictyota dichotoma and Sargassum polycystum (Ochrophyta). This review aims to highlight the therapeutic potential of North Bornean seaweeds and their nutraceutical profiling. North Bornean seaweeds have demonstrated anti-inflammatory, antioxidant, antimicrobial, anticancer, cardiovascular protective, neuroprotective, renal protective and hepatic protective potentials. The protective roles of the seaweeds might be due to the presence of a wide variety of nutraceuticals, including phthalic anhydride, 3,4-ethylenedioxythiophene, 2-pentylthiophene, furoic acid (K. alvarezii), eicosapentaenoic acid, palmitoleic acid, fucoxanthin, β-carotene (E. denticulatum), eucalyptol, oleic acid, dodecanal, pentadecane (H. durvillaei), canthaxanthin, oleic acid, pentadecanoic acid, eicosane (C. lentillifera), pseudoephedrine, palmitic acid, monocaprin (C. racemosa), dictyohydroperoxide, squalene, fucosterol, saringosterol (D. dichotoma), and lutein, neophytadiene, cholest-4-en-3-one and cis-vaccenic acid (S. polycystum). Extensive studies on the seaweed isolates are highly recommended to understand their bioactivity and mechanisms of action, while highlighting their commercialization potential.

Anticancer, Antioxidant, and Antibacterial Activities of the Methanolic Extract from Sphagneticola trilobata (L.) J. F Pruski Leaves

This study aims to investigate the potential of bioactive secondary metabolites contained in Sphagneticola trilobata (L.) J.F Pruski leaves as novel plant-derived anticancer agent. Qualitative bioactive compound contents in the methanolic extract of S. trilobata leaves were screened using phytochemical method. Antioxidant evaluation was carried out using 2,2-diphenyl-1-picrylhydrazyl assay; antibacterial – using well diffusion method on Escherichia coli and Salmonella typhi; and cytotoxicity – using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on MCF-7 cell line and Vero Cell. It was found that the methanolic extract exhibited antioxidant activity with an IC₅₀ value of 124.34 μg/mL. The inhibition zone values against E. coli and S. thypi (at extract concentration of 100 mg/mL) were 34.33 and 36 mm, respectively. In vitro MTT assay showed that our extract successfully reached 96% mortality with LC₅₀ = 189.287 μg/mL, where the selective index of 2.5 suggest its selectivity against MCF-7 breast cancer cell line. In conclusion, the data of biological activities suggest the potential development of methanolic extract from S. trilobata leaves as a phytomedicine for breast cancer treatment.