The antitumor role of a newly discovered α-d-glucan from Holotrichia diomphalia Bates as a selective blocker of aldolase A

Diverse roles of aldolase enzymes in cancer development, drug resistance and therapeutic approaches as moonlighting enzymes

Aldolase enzymes, particularly ALDOA, ALDOB, and ALDOC, play a crucial role in the development and progression of cancer. While the aldolase family is mainly known for its involvement in the glycolysis pathway, these enzymes also have various pathological and physiological functions through distinct signaling pathways such as Wnt/β-catenin, EGFR/MAPK, Akt, and HIF-1α. This has garnered increased attention in recent years and shed light on other sides of this enzyme. Potential therapeutic strategies targeting aldolases include using siRNA, inhibitors like naphthol AS-E phosphate and TX-2098, and natural compounds such as HDPS-4II and L-carnosine. Additionally, anticancer peptides derived from ALDOA, like P04, can potentially increase cancer cells' sensitivity to chemotherapy. Aldolases also affect cancer drug resistance by different approaches, making them good therapeutic targets. In this review, we extensively explore the role of aldolase enzymes in various types of cancers in proliferation, invasion, migration, and drug resistance; we also significantly explore the possible treatment considering aldolase function.

An alkali-extracted neutral heteropolysaccharide from Phellinus nigricans used as an immunopotentiator in immunosuppressed mice by activating macrophages

A neutral heteropolysaccharide (PNANb) was isolated with alkali (0.1 M NaOH) from mycelia of Phellinus nigricans, and the structure, immunostimulating activity and some of the underlying molecular mechanisms of action of PNANb were explored in the current study. PNANb (14.95 kDa) predominantly consisted of Gal, Glc, and Man with minor Fuc. GC-MS and NMR analyses indicated that the backbone of PNANb was mainly composed of 6-α-Galp, 2,6-α-Galp with minor 3,6-β-Glcp, which was substituted with complex side chains at C-2 of 2,6-α-Galp and C-3 of 3,6-β-Glcp. Notably, PNANb (50 or 100 mg/kg) possessed immunoprotective effects in cyclophosphamide (Cy)-induced immunosuppressed C57BL/6 mice, which was supported by evidence including the enhancement of spleen and thymus indices, levels of serum immunoglobulins (IgG, IgM) and cytokines (IFN-γ, IL-2, IL-4, IL-10), and macrophage activity. However, the immunostimulation effects of PNANb were decreased when macrophages were depleted, underscoring the essential role of macrophages in the beneficial effects of PNANb in Cy-induced immunosuppressed mice. Further investigations in vitro indicated that PNANb activated macrophages through MAPK/NF-κB signaling pathways mediated by Toll-like receptor 4. Therefore, PNANb can serve as a prospective immunopotentiator in immunosuppression.

A novel glycoglycerolipid from Holotrichia diomphalia Bates: Structure characteristics and protective effect against DNA damage

A lipidated polysaccharide, HDPS-2II, was isolated from the dried larva of Holotrichia diomphalia, which is used in traditional Chinese medicine. The molecular weight of HDPS-2II was 5.9 kDa, which contained a polysaccharide backbone of →4)-β-Manp-(1 → 4,6)-β-Manp-(1 → [6)-α-Glcp-(1]n → 6)-α-Glcp→ with the side chain α-Glcp-(6 → 1)-α-Glcp-(6 → linked to the C-4 of β-1,4,6-Manp and four types of lipid chains including 4-(4-methyl-2-(methylamino)pentanamido)pentanoic acid, 5-(3-(tert-butyl)phenoxy)hexan-2-ol, N-(3-methyl-5-oxopentan-2-yl)palmitamide, and N-(5-amino-3-methyl-5-oxopentan-2-yl)stearamide. The lipid chains were linked to C-1 of terminal α-1,6-Glcp in carbohydrate chain through diacyl-glycerol. HDPS-2II exhibited DNA protective effects and antioxidative activity on H2O2- or adriamycin (ADM)-induced Chinese hamster lung cells. Furthermore, HDPS-2II significantly ameliorated chromosome aberrations and the accumulation of reactive oxygen species (ROS), reduced γ-H2AX signaling and the expressions of NADPH oxidase (NOX)2, NOX4, P22phox, and P47phox in ADM-induced cardiomyocytes. Mechanistically, HDPS-2II suppressed ADM-induced up-regulation of NOX2 and NOX4 in cardiomyocytes, but not in NOX2 or NOX4 knocked-down cardiomyocytes, indicating that HDPS-2II could relieve intracellular DNA damage by regulating NOX2/NOX4 signaling. These findings demonstrate that HDPS-2II is a new potential DNA protective agent.

Optimization of ultrasound-assisted extraction of Imperata cylindrica polysaccharides and evaluation of its anti-oxidant and amelioration of uric acid stimulated cell apoptosis

An efficient, cost-effective and environmentally friendly ultrasound-assisted hot water method for Imperata cylindrica polysaccharide (ICPs) extraction was developed. According to the response surface results, the optimal ultrasonic time was 85 min, ultrasonic power was 192.75 W, temperature was 90.74 °C, liquid-solid ratio was 26.1, and polysaccharide yield was 28.50 %. The polysaccharide mainly consisted of arabinose (Ara), galactose (Gal), and glucose (Glc), with a molecular weight of 62.3 kDa. Ultrasound-assisted extraction of Imperata cylindrica polysaccharide (UICP) exhibited stronger anti-oxidant activity and ability to ameliorate cellular damage due to uric acid stimulation compared with traditional hot water extraction of Imperata cylindrica polysaccharide (ICPC-b). It also exhibited higher thermal stability, indicating its potential value for applications in the food industry.

α-Glucan derivatives as selective blockers of aldolase A: Computer-aided structure optimization and the effects on HCC

Aldolase A (ALDOA) promotes hepatocellular carcinoma (HCC) growth and is a potential therapeutic target. A previous study found an α-D-glucan (α-D-(1,6)-Glcp-α-D-(1,4)-Glcp, 10.0:1.0), named HDPS-4II, that could specifically inhibit ALDOA but its activity was not high enough. In this study, the derivatives of α-D-glucan binding to ALDOA were optimized using molecular docking, and its sulfated modification demonstrated the highest affinity with ALDOA among sulfated, carboxylated, and aminated derivatives. Sulfated HDPS-4II and dextrans with different molecular weights (1000 Da, 3000 Da, and 4000 Da) were prepared. Using MST assay, 3-O-sulfated HDPS-4II (SHDPS-4II) and 1000 Da dextran (SDextran1) showed higher affinities to ALDOA with Kd of 1.83 μM and 85.04 μM, respectively. Furthermore, SHDPS-4II and SDextran1 markedly inhibited the proliferation of HCC cells both in vitro and in vivo by blocking ALDOA. These results demonstrate that sulfated modification of α-D-glucans could enhance their affinities with ALDOA and anti-HCC effects.

Targeting metabolic reprogramming in hepatocellular carcinoma to overcome therapeutic resistance: A comprehensive review

Hepatocellular carcinoma (HCC) poses a heavy burden on human health with high morbidity and mortality rates. Systematic therapy is crucial for advanced and mid-term HCC, but faces a significant challenge from therapeutic resistance, weakening drug effectiveness. Metabolic reprogramming has gained attention as a key contributor to therapeutic resistance. Cells change their metabolism to meet energy demands, adapt to growth needs, or resist environmental pressures. Understanding key enzyme expression patterns and metabolic pathway interactions is vital to comprehend HCC occurrence, development, and treatment resistance. Exploring metabolic enzyme reprogramming and pathways is essential to identify breakthrough points for HCC treatment. Targeting metabolic enzymes with inhibitors is key to addressing these points. Inhibitors, combined with systemic therapeutic drugs, can alleviate resistance, prolong overall survival for advanced HCC, and offer mid-term HCC patients a chance for radical resection. Advances in metabolic research methods, from genomics to metabolomics and cells to organoids, help build the HCC metabolic reprogramming network. Recent progress in biomaterials and nanotechnology impacts drug targeting and effectiveness, providing new solutions for systemic therapeutic drug resistance. This review focuses on metabolic enzyme changes, pathway interactions, enzyme inhibitors, research methods, and drug delivery targeting metabolic reprogramming, offering valuable references for metabolic approaches to HCC treatment.

Engineering Phenothiazine-Based Functional Mimics of Host Defense Peptides as New Agrochemical Candidates: Design, Synthesis, and Antibacterial Evaluation

In the protracted "arms race" between host and plant pathogenic bacteria, host organisms have evolved powerful weapons known as host defense peptides (HDPs). However, natural HDPs are not suitable for large-scale applications; therefore, researchers have chosen to develop bespoke small-molecule functional mimics. Phenothiazine derivatives were developed as functional HDPs mimics, owing to their broad biological activity and high lipophilicity. The phenothiazine analogues designed in this study exhibited excellent in vitro bioactivity against the three Gram-negative bacteria Xanthomonas oryzae pv oryzae, Xanthomonas axonopodis pv citri, and Pseudomonas syringae pv actinidiae, with optimal EC50 values of 0.80, 0.31, and 1.91 μg/mL, respectively. Preliminary evidence suggests that compound C2 may act on bacterial cell membranes and interact with bacterial Deoxyribonucleic acid in the groove binding mode. In vivo trials showed that compound C2 was highly effective against rice leaf blight (51.97-56.69%), with activity superior to those of bismerthiazol (40.7-43.4%) and thiodiazole copper (30.2-37.1%). Our study provides strong evidence to support the development of phenothiazine derivatives into pesticide candidates.

Structural characterization and anti-inflammatory activity of neutral polysaccharides from American ginseng

American ginseng, a precious classic herbal medicine, is used extensively in China for life prolongation purpose. This study aimed to elucidate the structure and anti-inflammatory activity of a neutral polysaccharide isolated from American ginseng (AGP-A). Nuclear magnetic resonance in conjunction with gas chromatography-mass spectrometry were used to analyze AGP-A's structure, whereas Raw264.7 cell and zebrafish models were employed to assess its anti-inflammatory activity. According to the results, AGP-A has a molecular weight of 5561 Da and is primarily consisted of glucose. Additionally, linear α-(1 → 4)-glucans with α-D-Glcp-(1 → 6)-α-Glcp-(1→ residues linked to the backbone at C-6 formed the backbone of AGP-A. Furthermore, AGP-A significantly decreased pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) in Raw264.7 cell model. AGP-A in zebrafish model significantly lower the massive recruitment of neutrophils to the neuromast of the caudal lateral line. Inflammation may be relieved by the AGP-A component in American ginseng based on these results. In conclusion, our study shows the structural characterization, remarkable anti-inflammatory properties of AGP-A and its potential curative efficacy as a safe, valid natural anti-inflammatory medicine.

Piperlonguminine attenuates renal fibrosis by inhibiting TRPC6

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang (LWDH) is a classic prescription that has been used to the treatment of "Kidney-Yin" deficiency syndrome for more than 1000 years in China. Recent studies have confirmed that LWDH can prevent the progression of renal fibrosis. Numerous studies have demonstrated the critical role that TRPC6 plays in the development of renal fibrosis. Due to the complex composition of LWDH and its remarkable therapeutic effect on renal fibrosis, it is possible to discover new active ingredients targeting TRPC6 for the treatment of renal fibrosis.

AIM OF STUDY

This study aimed to identify selective TRPC6 inhibitors from LWDH and evaluate their therapeutical effects on renal fibrosis.

MATERIALS AND METHODS

Computer-aided drug design was used to screen the biologically active ingredients of LWDH, and their affinities to human TRPC6 protein were detected by microcalorimetry. TRPC6, TRPC3, and TRPC7 over-expressed HEK293 cells were constructed, and the selective activities of the compounds on TRPC6 were determined by measuring [Ca²⁺]_i in these cells. To establish an in vitro model of renal fibrosis, human renal proximal tubular epithelial HK-2 cells were stimulated with TGF-β1. The therapeutic effects of LWDH compounds on renal fibrosis were then tested by detecting the related proteins. TRPC6 was knocked-down in HK-2 cells to investigate the effects of LWDH active ingredients on TRPC6. Finally, a unilateral ureteral obstruction model of renal fibrosis was established to test the therapeutic effect.

RESULTS

From hundreds of LWDH ingredients, 64 active components with oral bioavailability ≥30% and drug-likeness index ≥0.18 were acquired. A total of 10 active components were obtained by molecular docking with TRPC6 protein. Among them, 4 components had an affinity with TRPC6. Piperlonguminine (PLG) had the most potent affinity with TRPC6 and blocking effect on TRPC6-mediated Ca²⁺ entry. A 100 μM of PLG showed no detectable inhibition on TRPC1, TRPC3, TRPC4, TRPC5, or TRPC7-mediated Ca²⁺ influx into cells. In vitro results indicated that PLG concentration-dependently inhibited the abnormally high expression of α-smooth muscle actin (α-SMA), collagen I, vimentin, and TRPC6 in TGF-β1-induced HK-2 cells. Consistently, PLG also could not further inhibit TGF-β1-induced expressions of these protein biomarkers in TRPC6 knocked-down HK-2 cells. In vivo, PLG dose-dependently reduced urinary protein, serum creatinine, and blood urea nitrogen levels in renal fibrosis mice and markedly alleviated fibrosis and the expressions of α-SMA, collagen I, vimentin, and TRPC6 in kidney tissues.

CONCLUSION

Our results showed that PLG had anti-renal fibrosis effects by selectively inhibiting TRPC6. PLG might be a promising therapeutic agent for the treatment of renal fibrosis.

Preparation and anti-tumor activity of selenium nanoparticles based on a polysaccharide from Paeonia lactiflora

The combination of selenium and polysaccharides is one of the significant ways to ameliorate the anti-cancer effects of polysaccharides. PLP50-1, a homogeneous polysaccharide purified from the aqueous extract of Paeonia lactiflora, had a molecular weight of 1.52 × 10⁴ Da and consisted of α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and →6)-β-D-Fruf-(2→. PLP50-1 showed weak anti-tumor effects against A549 cells. To ameliorate the activity of PLP50-1, the complex nanoparticles combining P. lactiflora polysaccharide with selenium were constructed successfully. Structural properties of the polysaccharide-based selenium nanoparticles (PLP-SeNPs) were clarified using various means. The results displayed that a kind of monodisperse spherical nanoparticles containing high selenium content (39.1 %) with controllable size was constructed and showed satisfactory stability. The cellular anti-tumor assay indicated that PLP-SeNPs had stronger antiproliferative activity against A549 cells than PLP50-1. Additionally, the zebrafish experiments displayed that PLP-SeNPs inhibited the proliferation and migration of A549 cells significantly and blocked the angiogenesis.