The Antioxidant and Immunomodulatory Potential of Coccoloba alnifolia Leaf Extracts.

Oxidative stress has been associated with different diseases, and different medicinal plants have been used to treat or prevent this condition. The leaf ethanolic extract (EE) and aqueous extract (AE) from Coccoloba alnifolia have previously been characterized to have antioxidant potential in vitro and in vivo. In this study, we worked with EE and AE and two partition phases, AF (ethyl acetate) and BF (butanol), from AE extract. These extracts and partition phases did not display cytotoxicity. The EE and AE reduced NO production and ROS in all three concentrations tested. Furthermore, it was observed that EE and AE at 500 µg/mL concentration were able to reduce phagocytic activity by 30 and 50%, respectively. A scratch assay using a fibroblast cell line (NHI/3T3) showed that extracts and fractions induced cell migration with 60% wound recovery within 24 h, especially for BF. It was also observed that AF and BF had antioxidant potential in all the assays evaluated. In addition, copper chelation was observed. This activity was previously not detected in AE. The HPLC-DAD analysis showed the presence of phenolic compounds such as p-cumaric acid and vitexin for extracts, while the GNPS annotated the presence of isoorientin, vitexin, kanakugiol, and tryptamine in the BF partition phase. The data presented here demonstrated that the EE, AE, AF, and BF of C. alnifolia have potential immunomodulatory effects, antioxidant effects, as well as in vitro wound healing characteristics, which are important for dynamic inflammation process control.

Immunostimulatory Effect of Sulfated Galactans from the Green Seaweed Caulerpa cupressoides var. flabellata.

Sulfated polysaccharides (SPs) obtained from green seaweeds are structurally heterogeneous molecules with multifunctional bioactivities. In this work, two sulfated and pyruvated galactans were purified from Caulerpa cupressoides var. flabellata (named SP1 and SP2), and their immunostimulatory effect was evaluated using cultured murine macrophage cells. Both SPs equally increased the production of nitric oxide, reactive oxygen species, and the proinflammatory cytokines TNF-α and IL-6. NMR spectroscopy revealed that both galactans were composed primarily of 3)-ß-d-Galp-(1→3) units. Pyruvate groups were also found, forming five-membered cyclic ketals as 4,6-O-(1'carboxy)-ethylidene-ß-d-Galp residues. Some galactoses are sulfated at C-2. In addition, only SP2 showed some galactose units sulfated at C-4, indicating that sulfation at this position is not essential for the immunomodulatory activity of these galactans. Overall, the data showed that the galactans of C. cupressoides exhibited immunostimulating activity with potential therapeutic applications, which can be used in the development of new biomedical products.

Caulerpa Cupressoides Var. Flabellata.

Green seaweeds are rich sources of sulfated polysaccharides (SPs) with potential biomedical and nutraceutical applications. The aim of this work was to evaluate the immunostimulatory activity of SPs from the seaweed, Caulerpa cupressoides var. flabellata on murine RAW 264.7 macrophages. SPs were evaluated for their ability to modify cell viability and to stimulate the production of inflammatory mediators, such as nitric oxide (NO), intracellular reactive oxygen species (ROS), and cytokines. Additionally, their effect on inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) gene expression was investigated. The results showed that SPs were not cytotoxic and were able to increase in the production of NO, ROS and the cytokines, tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). It was also observed that treatment with SPs increased iNOS and COX-2 gene expression. Together, these results indicate that C. cupressoides var. flabellata SPs have strong immunostimulatory activity, with potential biomedical applications.

Myrciaria tenella (DC.) O. Berg (Myrtaceae) Leaves as a Source of Antioxidant Compounds.

Myrciaria species are widely studied to identify their chemical composition and evaluate their biological activity. Since evidence supporting the potential antioxidant and antiproliferative activity of Myrciaria tenella is lacking, the aim of this work was to evaluate these activities in six different leaf extracts: hexane (CHE), chloroform (CCE), ethanolic (CEE), methanolic (CME), aqueous final (CFAE), and only aqueous (CAE). The presence of phenolic compounds, tannin, saponin, and ursolic acid was determined by thin layer chromatography (TLC). CEE, CME, and CFAE showed in vitro antioxidant activity at the initiation, propagation, and termination stages of oxidative damage. Moreover, no toxicity was observed in the 3T3 non-cancerous cell line. On the other hand, all extracts promoted cell death in the tumor cell lines human cervical adenocarcinoma cell line (HeLa) and human stomach gastric adenocarcinoma cell line (AGS). Based on these results, the effect of CEE on the AGS cell line was analyzed using flow cytometry, and necrosis and late apoptosis were observed. Finally, the Caenorhabditis elegans model showed that CEE was able to reduce the basal reactive oxygen species (ROS) level. Ultra-performance liquid chromatography (UPLC) analysis showed rutin as the major compound in CEE. Therefore, Myrciaria tenella fresh leaves may be potential sources of molecules possessing antioxidant and antiproliferative activities.