Chemical Characterization, Antitumor, and Immune-Enhancing Activities of Polysaccharide from Sargassum pallidum

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Approaches of marine compounds and relevant immune mediators in Autism Spectrum Disorder: Opportunities and challenges

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects social skills, language, communication, and behavioral skills, significantly impacting the individual's quality of life. Recently, numerous works have centered on the connections between the immune and central nervous systems and the influence of neuroinflammation on autism symptomatology. Marine natural products are considered as important alternative sources of different types of compounds, including polysaccharides, polyphenols, sterols, carotenoids, terpenoids and, alkaloids. These compounds present anti-inflammatory, neuroprotective and immunomodulatory activities, exhibiting a potential for the treatment of many diseases. Although many studies address the marine compounds in the modulation of inflammatory mediators, there is a gap regarding their use in the regulation of the immune system in ASD. Thus, this review aims to provide a better understanding regarding cytokines, chemokines, growth factors and immune responses in ASD, as well as the potential of bioactive marine compounds in the immune regulation in ASD. We expect that this review would contribute to the development of therapeutic alternatives for controlling immune mediators and inflammation in ASD.

Research Progress of Polysaccharide-Gold Nanocomplexes in Drug Delivery

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drug's effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Purification, Structural Characterization, and Antitumor Activity of a Polysaccharide from Perilla Seeds

A previous study found that a crude Perilla seed polysaccharide (PFSP) fraction exhibited obviously antitumor activity; however, the structural characterization and antitumor properties of this polysaccharide remain unclear. In this study, the PFSP was extracted and purified via combined column chromatography, and the structure of a single polysaccharide fraction was characterized by methylation, IC, GC-MS, NMR, and AFM. The results demonstrated that the efficient antitumor polysaccharide fraction PFSP-2-1 was screened from PFSP with a relative molecular weight of 8.81 × 106 Da. The primary structure of the PFSP main chain was →1)-Araf-(5→, →1,3)-Galp-(6→, →1)-Galp-(6→, →1,3)-Araf-(5→ and →1)-Xylp-(4→, and that of the side chains was →1)-Arap, →1,3)-Galp-(6→, →1)-Araf and →1)-Glcp-(4→, →1)-Galp-(3→ and →1)-Glcp, leading to a three-dimensional helical structure. CCK-8 experiments revealed that PFSP-2-1 significantly inhibited the growth of human hepatocellular carcinoma cells in vitro (p < 0.05), and its inhibitory effect positively correlation with the concentration of PFSP-2-1, and when the concentration of PFSP-2-1 was 1600 µg/mL, it showed the highest inhabitation rate on three hepatocellular carcinoma cells (HepG-2, Hep3b, and SK-Hep-1), for which the survival rates of HepG-2, Hep3b, and SK-Hep-1 were 53.34%, 70.33%, and 71.06%. This study clearly elucidated the structure and antitumor activity of PFSP-2-1, which lays a theoretical foundation for revealing the molecular mechanism of antitumor activity of Perilla seed polysaccharides and provides an important theoretical basis for the development of high-value Perilla.

Fucoidan derived from Sargassum pallidum alleviates metabolism disorders associated with improvement of cardiac injury and oxidative stress in diabetic mice

Type 2 diabetes mellitus (T2DM) and its complications have become a serious global health epidemic. Cardiovascular complications have considered as a major cause of high mortality in diabetic patients. Fucoidans from brown algae have diverse medicinal activities, however, few studies reported pharmacological activity of Sargassum. pallidum fucoidan (Sp-Fuc). Therefore, the aim of this study was to investigate the effects of Sp-Fuc on diabetic symptoms and cardiac injury in spontaneous diabetic db/db mice. SP-Fuc at 200 mg/(kg/d) was administered intragastrically to db/db mice for 8 weeks, the effects on hyperlipidemia, hyperglycemia, insulin resistance, and cardiac damage, as well as oxidative stress, inflammation, Nrf2/ARE, and NF-κB signaling pathways, were investigated. Our data demonstrated that Sp-Fuc significantly (p < 0.05) decreased body weights, hyperlipidemia, and hyperglycemia in db/db mice, along with improved insulin sensitivity. Additionally, Sp-Fuc significantly (p < 0.05) alleviated cardiac dysfunction and pathological morphology of cardiac tissue. Sp-Fuc also significantly (p < 0.05) decreased lipid peroxidation, increased antioxidant function, as well as reduced cardiac inflammation, possibly through Nrf2/ARE and NF-κB signaling. Sp-Fuc can ameliorate the metabolism disorders of glucose and lipid in diabetic mice by activating Nrf2/ARE antioxidant signaling, simultaneously reducing cardiac redox imbalance and inflammatory damage. The present findings provide a perspective on the therapy strategy for T2DM and its complications.

In-vitro evaluation of immunomodulatory activity of sulphation-modified total ginsenosides derivative-3

Background

Ginseng has been used in biomedicine to prevent and treat decreased physical and mental capacities. Total ginsenosides (TG) from ginseng root which have antitumor and immune-enhancing properties, are the principal active components of Panax ginseng, while the sulphation-modified TG derivative-3 (SMTG-d3) was expected to enhance the anticancer activity in conventional medicinal treatments.

Methods

The chlorosulphonic acid-pyridine technique, used for the sulfation modification of TG to improve their biological activity, and the infrared spectroscopic characteristics of TG and SMTG-d3 were investigated, and the effects of SMTG-d3 on immunocytes and cytokines relevant to tumor treatment were assessed. The MTT assay was used to assess the effect of TG and SMTG-d3 on the cytotoxicity and T-lymphocytic proliferation against mouse splenocytes. The LDH method was employed to evaluate NK activity induced by TG or SMTG-d3. The production levels of splenocytes-secreted IL-2 and IFN-γ and peritoneal macrophages-secreted TNF-α were determined using mouse ELISA kits.

Results and discussion

It showed that the ideal conditions for the sulfation modification of TG: the volume ratio of chlorosulfonic acid to pyridine lower than 1:2.5; controlled amount of chlorosulfonic acid; and a yield of 51.5% SMTG-d3 (2 h, < 45°C). SMTG-d3 showed two characteristic absorption peaks at 1,230 cm^-1 and 810 cm^-1, indicating the formation of sulfuric acid esters and the presence of sulfuric acid groups. SMTG-d3 exhibited higher antitumor immunological activity than TG by promoting the proliferation of T lymphocytes and the production of IFN-γ and TNF-α, thus enhancing NK cell activity, and reducing cytotoxicity. The findings imply sulfated modification represents an effective method of enhancing the immunomodulatory activities of TG and could be used as the basis for developing new drug target compounds; SMTG-d3 can serve as an antitumor immunomodulator and can be considered an effective and prospective herbal formulation in clinical applications.

Marine Compounds for Melanoma Treatment and Prevention

Melanoma is considered a multifactorial disease etiologically divided into melanomas related to sun exposure and those that are not, but also based on their mutational signatures, anatomic site, and epidemiology. The incidence of melanoma skin cancer has been increasing over the past decades with 132,000 cases occurring globally each year. Marine organisms have been shown to be an excellent source of natural compounds with possible bioactivities for human health applications. In this review, we report marine compounds from micro- and macro-organisms with activities in vitro and in vivo against melanoma, including the compound Marizomib, isolated from a marine bacterium, currently in phase III clinical trials for melanoma. When available, we also report active concentrations, cellular targets and mechanisms of action of the mentioned molecules. In addition, compounds used for UV protection and melanoma prevention from marine sources are discussed. This paper gives an overview of promising marine molecules which can be studied more deeply before clinical trials in the near future.

Characterization of Plocamium telfairiae Extract-Functionalized Au Nanostructures and Their Anti-Adipogenic Activity through PLD1

Here, Au nanostructure (AuNS) biosynthesis was mediated through ethanolic extract of Plocamium telfairiae (PT) without the use of stabilizers or surfactants. PT-functionalized AuNSs (PT-AuNSs) were analyzed using ultraviolet–visible spectroscopy, dynamic light scattering, high-resolution transmission electron microscopy, energy-dispersive spectroscopy, and Fourier-transform infrared spectroscopy. Stable monodisperse PT-AuNSs were synthesized, with a mean size of 15.36 ± 0.10 nm and zeta potential of −35.85 ± 1.36 mV. Moreover, biosynthetic AuNPs with a face-centered structure of PT-AuNS exhibited crystalline characteristics. In addition, many functional groups playing important roles in the biological reduction of PT extracts were adsorbed on the surface of PT-AuNSs. Furthermore, the effects of PT-AuNSs on adipogenesis in immature adipocytes were investigated. PT-AuNSs reduced morphological changes, lowered triglyceride content, and increased lipid accumulation by approximately 78.6% in immature adipocytes compared with the values in mature adipocytes (MDI-induced). PT-AuNS suppressed lipid accumulation by downregulating the transcript and protein expression of C/EBPα, PPARγ, SREBP 1, FAS, and aP2. Finally, PT-AuNS induced the transcript and protein expression of UCP1, PRDM16, and PGC1a, thereby increasing mitochondrial biogenesis in mature adipocytes and effectively inducing brown adipogenesis. In this study, the biosynthesized PT-AuNS was used as a potential therapeutic candidate because it conferred a potent anti-lipogenic effect. As a result, it can be used in various scientific fields such as medicine and the environment.