A polysaccharide fraction from “ipê-roxo” (Handroanthus heptaphyllus) leaves with gastroprotective activity

An arabinogalactan isolated from Cynanchum atratum promotes lymphangiogenesis and lymphatic vessel remodeling to alleviate secondary lymphedema

Secondary lymphedema is a chronic and incurable disease lacking satisfactory therapeutic drugs. It primarily results from lymphatic vessel dysfunction resulting from factors such as tumor-related surgery, injury, or infection. Promoting lymphangiogenesis and lymphatic vessel remodeling is crucial for restoring tissue fluid drainage and treating secondary lymphedema. In this study, we discovered that the oral administration of a type-II arabinogalactan (CAPW-1, molecular weight: 64 kDa) significantly promoted lymphangiogenesis and alleviated edema in mice with secondary lymphedema. Notably, the tail diameter of the CAPW-1200 group considerably decreased in comparison to that of the lymphedema group, with an average diameter difference reaching 0.98 mm on day 14. CAPW-1 treatment also reduced the average thickness of the subcutaneous area in the CAPW-1200 group to 0.37 mm (compared with 0.73 mm in the lymphedema group). It also facilitated the return of injected indocyanine green (ICG) from the tail tip to the sciatic lymph nodes, indicating that CAPW-1 promoted lymphatic vessel remodeling at the injury site. In addition, CAPW-1 enhanced the proliferation and migration of lymphatic endothelial cells. This phenomenon was associated with the activation of the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway, thereby promoting the expression of vascular endothelial growth factor-C (VEGF-C), which can be abolished using a TLR4 antagonist. Despite these findings, CAPW-1 did not alleviate the symptoms of lymphedema or restore lymphatic drainage in VEGFR3flox/flox/Prox1-CreERT2 mice. In summary, CAPW-1 alleviates secondary lymphedema by promoting lymphangiogenesis and lymphatic vessel remodeling through the activation of the TLR4/NF-κB/VEGF-C signaling pathway, indicating its potential as a therapeutic lymphangiogenesis agent for patients with secondary lymphedema.

Glucans from Armillaria luteo-virens: Structural Characterization and In Vivo Immunomodulatory Investigation under Different Administration Routes

Polysaccharides fromArmillaria luteo-virens (ALP) were investigated for structural characterization and immunomodulatory activities. Three fractions (ALP-1, ALP-2, and ALP-3) were obtained with the yield of 2.4, 3.7, and 3.0 wt %, respectively. ALP-1 was proposed as a β-(1 → 3)(1 → 6)-glucan with a triple-helix conformation; ALP-2 and ALP-3 were both identified as α-(1 → 4)(1 → 6)-glucan differing in their Mw and branching degree with a spherical conformation. The in vitro digestibility experiment and in vivo experiments using cyclophosphamide (CY)-treated mice demonstrated that intraperitoneal injection of α-glucan (1 mg·kg-1·day-1) and intragastric gavage of β-glucan (10 mg·kg-1·day-1) both effectively restored the decrease in body weight, immune organ indexes, immune cell activities, serum immune marker levels, colonic short-chain fatty acids (SCFA) levels, and Bacteroidetes/Firmicutes ratio in immunosuppression mice. This study provides novel insights into the immunomodulatory activity of α- and β-glucans under different administration routes, thereby promoting their application in both food and pharmaceutical areas.

Water-soluble polysaccharides from Piper regnellii (Pariparoba) leaves: Structural characterization and antinociceptive and anti-inflammatory activities

Piper regnellii is a plant popularly known as "Pariparoba" and it is widely used in folk medicine to treat pain, inflammation, among others. This work presents the extraction, purification and characterization of polysaccharides present in the plant leaves and evaluation of their anti-inflammatory and antinociceptive activities. From the crude aqueous extract of P. regnellii leaves, a polysaccharide fraction named PR30R, predominantly constituted of arabinose, galactose and galacturonic acid monosaccharide units, was obtained. Methylation and NMR analysis showed that the main polysaccharides of PR30R are a type II arabinogalactan, formed by a β-D-Galp-(1 → 3) main chain, substituted at O-6 by side chains of β-D-Galp-(1 → 6), which are substituted at O-3 by non-reducing α-L-Araf ends, and a homogalacturonan, formed by →4)-α-D-GalpA-(1→ units. Intraperitoneal administration of the crude polysaccharide fraction PRSF reduced significantly nociception induced by acetic acid in mice at the doses tested, and the PR30R fraction, derived from PRSF, presented antinociceptive and anti-inflammatory effects at a dose of 0.1096 mg/kg (PRSF ED50). These data support the use of the plant leaves in folk medicine as an herbal tea to treat pain and inflammation.

Arabinogalactan Alleviates Lipopolysaccharide-Induced Intestinal Epithelial Barrier Damage through Adenosine Monophosphate-Activated Protein Kinase/Silent Information Regulator 1/Nuclear Factor Kappa-B Signaling Pathways in Caco-2 Cells

Intestinal epithelial barrier (IEB) damage is an important aspect in inflammatory bowel disease (IBD). The objective of this study was to explore the protective effects and mechanisms of arabinogalactan (AG) on lipopolysaccharide (LPS)-stimulated IEB dysfunction. The results show that AG (1, 2, and 5 mg/mL) mitigated 100 μg/mL LPS-stimulated IEB dysfunction through increasing transepithelial electrical resistance (TEER), reducing fluorescein isothiocyanate (FITC)-dextran (4 kDa) flux, and up-regulating the protein and mRNA expression of tight junction (TJ) proteins (Claudin-1, Zonula occludens-1 (ZO-1) and Occludin). In addition, AG ameliorated LPS-stimulated IEB dysfunction by reducing interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β levels, decreasing the reactive oxygen species (ROS) level, increasing superoxide dismutase (SOD) activity, increasing the glutathione (GSH) level, and decreasing the levels of malondialdehyde (MDA) and intracellular calcium ([Ca2+]i). Furthermore, 2 mg/mL AG up-regulated the expression of silent information regulator 1 (SIRT1), the phosphorylated adenosine monophosphate-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and inhibited the phosphorylation of nuclear factor kappa-B (NF-κB) and the inhibitor of NF-κBα (IκBα). Therefore, AG could maintain IEB integrity by activating AMPK/SIRT1 and inhibiting the NF-κB signaling pathway. In conclusion, AG can regulate the AMPK/SIRT1/NF-κB signaling pathway to reduce inflammation and oxidative stress, thus alleviating LPS-stimulated IEB damage.

Gastroprotective Effects of the Aqueous Extract of Finger Citron Pickled Products against Ethanol-Induced Gastric Damage: In Vitro and In Vivo Studies

Finger citron pickled products (FCPP), as folk remedies, are famous in southern China for protecting gastric mucosa. However, the gastric mucosa protection of FCPP has not been reported yet, and its effective mechanism is unclear. In this study, the protective mechanism of FCPP aqueous extract on gastric mucosa was investigated in vitro and in vivo for the first time, using human gastric mucosa epithelial cells (GES-1) and acute alcoholic gastric ulcer rat model respectively. Furthermore, we also investigated the main substances in the aqueous extract that exert gastroprotective activity using a GES-1 scratch test and basic chemical composition analysis. FCPP aqueous extract was found to play a protective and reparative role in GES-1 by promoting the secretion of trefoil factor thyroid transcription factor 2 (TFF2) and inhibiting the secretion of tumor necrosis factor-α (TNF-α) in cells damaged by alcohol. The ulcer index of gastric tissue induced by alcohol was significantly decreased (p < 0.01) after pretreatment with FCPP aqueous extract, indicating that FCPP aqueous extract had a good protective effect on the stomach mucosa. Moreover, FCPP aqueous extract could increase superoxide dismutase (SOD) activity and inhibit malondialdehyde (MDA) content, exhibiting good antioxidant capacity. Aqueous extract of FCPP could also effectively inhibit the increase of cytokines TNF-α, interleukin-1β (IL-1β) and interleukin-6 (IL-6) in serum of rats, and promote the increase of anti-inflammatory cytokines interleukin-10 (IL-10) to some extent. Furthermore, FCPP aqueous extract could inhibit the expression of nuclear factor kappa-B (NF-κB/P65) protein, caspase-1 protein and IL-1β protein in the gastric tissue of rats, while promoting the expression of IκBα protein, indicating that the gastric mucosa protection effects of FCPP aqueous extract were mainly dependent on the NF-κB/caspase-1/IL-1β axis. The polysaccharides in FCPP aqueous extract might be the main components that exerted gastroprotective activity, as demonstrated by GES-1 cell scratch assay. This study confirmed that FCPP aqueous extract presented promising potential in protecting gastric mucosa and avoiding gastric ulcers, which could provide an experimental basis for further utilizing the medicinal value and developing new products of FCPP.

Gastroprotective activity of polysaccharide from the fruiting body of Hericium erinaceus against acetic acid-induced gastric ulcer in rats and structure of one bioactive fraction

This study aimed at investigating gastroprotective activity of Hericium erinaceus polysaccharide (HEP) and characterizing one of its bioactive fractions. Acetic acid-induced gastric ulcer (GU) rat model was used to evaluate the gastroprotective activity of HEP, while H₂O₂-induced injury GES-1 cell model was conducted to screen the bioactive fractions from HEP. Moreover, one of the bioactive fractions was characterized using methylation and 1D/2D NMR analysis. Results indicated HEP treatment could ameliorate acetic acid-induced GU in rats. HEP supplement decreased levels of interleukin-6, tumor necrosis factor-α and malondialdehyde and myeloperoxidase activity, and increased releases of nitric oxide, prostaglandin E2, epidermal growth factor, vascular endothelial growth factor and basic fibroblast growth factor and superoxide dismutase activity in gastric tissues of ulcerated rats. Five purified polysaccharides from HEP were screened to be bioactive fractions with cytoprotection on H₂O₂-induced injury in GES-1 cells. Among them, RP-S was characterized to be a (1 → 6)-β-D-glucan, whose backbone was composed of →6)-β-D-Glcp-(1 → residue and branched with T-β-D-Glcp-(1 → residue at O-3 position. In conclusion, HEP possessed gastroprotection against acetic acid-induced GU in rats and one of its bioactive fractions was a β-D-glucan. This study supports the utilization of HEP in anti-GU and provides evidences for the structure of gastroprotective HEP.

Malva parviflora Leaves and Fruits Mucilage as Natural Sources of Anti-Inflammatory, Antitussive and Gastro-Protective Agents: A Comparative Study Using Rat Models and Gas Chromatography

Malva parviflora L., Little mallow, has been traditionally used as an alternative food source. It acts as a medicinal herb containing a potential source of mucilage thus herein; we aimed to assess the toxicity, anti-inflammatory, antitussive and gastro-protective actions of M. parviflora mucilage extracted from its leaves (MLM) and fruit (MFM). Toxicity studies were investigated by in vitro hemolytic assay whereas acute anti-inflammatory and antitussive activities were assessed by carrageenan-induced paw edema and sulphur dioxide induced cough model in rats, respectively. Gastro-protective effects were studied using ethanol induced acute and chronic gastric ulcer rat models. Their metabolic profiles were determined using gas chromatography. The results revealed that MLM and MFM were non-toxic towards human erythrocytes and their lethal doses were found to be greater than 5 g/kg. Pretreatment with MLM (500 mg/kg) and MFM (500 mg/kg) significantly reduced the carrageenan-induced paw thickness (p < 0.001). Maximum edema inhibition (%) was observed at 4 h in diclofenac sodium (39.31%) followed by MLM (27.35%) and MFM (15.68%). Animals pretreated with MLM (500 mg/kg) significantly lower the cough frequency in SO2 gas induced cough models in contrast to control. Moreover, MLM at doses of 250 and 500 mg/kg reduced the ethanol induced gastric mucosal injuries in acute gastric ulcer models presenting ulcer inhibition of 23.04 and 38.74%, respectively. The chronic gastric ulcer model MFM (500 mg/kg) demonstrated a remarkable gastro-protective effect showing 63.52% ulcer inhibition and results were closely related to standard drug sucralfate. In both models, MLM and MFM decreased gastric juice volume and total acidity in addition to an increased gastric juice pH and gastric mucous content justifying an anti-secretary role of this mucilage that was further confirmed by histopathological examination. Meanwhile, GC analyses of the mucilage revealed their richness with natural as well as acidic monosaccharides. It is concluded that MLM and MFM can be used therapeutically for the management of inflammation, cough and gastric ulcer.

Structural elucidation and anti-diabetic osteoporotic activity of an arabinogalactan from Phellodendron chinense Schneid

Phellodendron chinense Schneid. was widely used as a medicinal herb for the treatment of diabetic osteoporosis in China. In this study, an arabinogalactan, named as PPCP-1, was isolated from the bark of Phellodendron chinense Schneid., and purified by DEAE-cellulose DE52 and Sephacryl S-200 HR column chromatography. The structure of PPCP-1 was characterized as a repeating unit consisting of →3)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→, →5)-α-l-Araf-(1→, →4)-α-d-Glcp-(1→, →3)-α-d-Glcp-(1→, →4)-α-d-Manp-(1→ with branches of →5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→ and terminal α-l-Araf. Pharmacologically, the oral administration of PPCP-1 preserved osteoporosis associated with hyperglycemia by inhibiting α-glucosidase activity, improving glucose tolerance, decreasing the accumulation of advanced glycation end products (AGEs), as well as down-regulating the expression of receptor for AGEs in tibias of streptozotocin-induced diabetic rats. Collectively, the present study suggested that the arabinogalactan PPCP-1 from Phellodendron chinense Schneid. might potentially be used as functional foods for bone health and/or developed for drug discovery for alleviating diabetic osteoporosis.

Polysaccharide fractions from Handroanthus heptaphyllus and Handroanthus albus barks: Structural characterization and cytotoxic activity

Barks of trees of the genus Handroanthus are known for their antitumor activity, which is attributed to naphthoquinones. Another class of molecules that has shown antitumor activity are the polysaccharides, however those from Handroanthus barks have never been studied. Accordingly, the aim of this study was to extract polysaccharides from H. heptaphyllus and H. albus barks, to characterize them structurally and to evaluate their cytotoxic effects on the human colon and human breast cancer cell lines, Caco-2 and MCF-7, respectively. The polysaccharides were extracted with boiling water and fractionated by freeze-thawing process. The soluble polysaccharide fractions HHBSF and HABSF were characterized by monosaccharide composition, methylation and NMR analyses, and their effects on proliferation of Caco-2 and MCF-7 cells were evaluated using MTT cell viability assay. HHBSF and HABSF were mainly constituted of galactoglucomannan, type II arabinogalactan (AGII) and type I rhamnogalacturonan (RGI), however, only HABSF significantly inhibited the growth of MCF-7 (CC50 = 327 μg/mL) and Caco-2 (CC50 = 2258 μg/mL) cells. Differences in the fine structure and proportion of their polysaccharides, and maybe in the composition of associated phenolic compounds could explain the different effects of HHBSF and HABSF.

A polysaccharide fraction from Handroanthus albus (yellow ipê) leaves with antinociceptive and anti-inflammatory activities

Handroanthus albus, commonly known as yellow ipê, is a native and widely distributed tree in Brazil. An aqueous soluble polysaccharide fraction (HASP) was obtained from its leaves, and monosaccharide composition, glycosidic linkage analysis by methylation and NMR spectroscopy indicated that HASP is mainly composed of a type II arabinogalactan, and suggested that other polysaccharides could also be present in a smaller proportion. HASP was able to promote antinociception in formalin-induced (second phase) and on glutamate-induced nociception tests, besides reducing the number of abdominal contortions induced by acetic acid in mice. Moreover, HASP reduced acetic acid-induced leukocyte infiltration in the peritoneal cavity and showed anti-edematogenic activity, decreasing mechanical allodynia and myeloperoxidase activity in the carrageenan-induced paw edema model. These results showed that the polysaccharide fraction HASP from H. albus leaves has interesting antinociceptive and anti-inflammatory activities.

Extraction, purification, and determination of the gastroprotective activity of glucomannan from Bletilla striata

In this study, a water-soluble polysaccharide (BSP) was extracted and purified from pseudobulb of Bletilla striata. The preliminary structure and gastroprotective activity of BSP were analyzed. Results indicate that BSP is a glucomannan with a molar ratio of 7.45:2.55 (Man:Glc), and its molecular weight is approximately 1.7 × 10⁵ Da. BSP displayed outstanding protective action against ethanol-induced GES-1 cell injury in vitro, as well as, excellent gastroprotective activity in vivo. Especially, a high-dose of BSP (100 mg/kg) could reduce the ulcer index of the gastric mucosa and increase the percentage of ulcer inhibition, which possibly caused by enhancing the antioxidant capacity and inhibiting the apoptotic pathway in gastric tissue. Interestingly, BSP exhibited a comparative gastroprotective activity to that of positive control (omeprazole). In summary, our results indicated that BSP could be considered as a potential supplement for the prevention of gastric injury.