Berberine-based self-assembly agents with enhanced synergistic antitumor efficacy.

Tumors are still a major threat to people worldwide. Nanodrug delivery and targeting systems can significantly improve the therapeutic efficacy of chemotherapeutic drugs for antitumor purposes. However, many nanocarriers are likely to exhibit drawbacks such as a complex preparation process, limited drug-loading capacity, untargeted drug release, and toxicity associated with nanocarriers. Therefore, new therapeutic alternatives are urgently needed to develop antitumor drugs. Natural products with abundant scaffold diversity and structural complexity, which are derived from medicinal plants, are important sources of new antitumor drugs. Here, two carrier-free berberine (BBR)-based nanoparticles (NPs) were established to increase the synergistic efficacy of tumor treatment. BBR can interact with glycyrrhetinic acid (GA) and artesunate (ART) to self-assemble BBR-GA and BBR-ART NPs without any nanocarriers, respectively, the formation of which is dominated by electrostatic and hydrophobic interactions. Moreover, BBR-GA NPs could lead to mitochondria-mediated cell apoptosis by regulating mitochondrial fission and dysfunction, while BBR-ART NPs induced ferroptosis in tumor cells. BBR-based NPs have been demonstrated to possess significant tumor targeting and enhanced antitumor properties compared with those of simple monomer mixes both in vitro and in vivo. These carrier-free self-assemblies based on natural products provide a strategy for synergistic drug delivery and thus offer broad prospects for developing enhanced antitumor drugs.

Target Separation and Potential Anticancer Activity of Withanolide-Based Glucose Transporter Protein 1 Inhibitors from Physalis angulata var. villosa.

The glucose transporter 1 (GLUT1) protein is involved in the basal-level absorption of glucose in tumor cells. Inhibiting GLUT1 decreases tumor cell proliferation and induces tumor cell damage. Natural GLUT1 inhibitors have been studied only to a small extent, and the structures of known natural GLUT1 inhibitors are limited to a few classes of natural products. Therefore, discovering and researching other natural GLUT1 inhibitors with novel scaffolds are essential. Physalis angulata L. var. villosa is a plant known as Mao-Ku-Zhi (MKZ). Withanolides are the main phytochemical components of MKZ. MKZ extracts and the components of MKZ exhibited antitumor activity in recent pharmacological studies. However, the antitumor-active components of MKZ and their molecular mechanisms remain unknown. A cell membrane-biomimetic nanoplatform (CM@Fe3O4/MIL-101) was used for target separation of potential GLUT1 inhibitors from MKZ. A new withanolide, physagulide Y (2), together with six known withanolides (1, 3-7), was identified as a potential GLUT1 inhibitor. Physagulide Y was the most potent GLUT1 inhibitor, and its antitumor activity and possible mechanism of action were explored in MCF-7 human cancer cells. These findings advance the development of technologies for the targeted separation of natural products and identify a new molecular framework for the investigation of natural GLUT1 inhibitors.

p-Quinone Methide-Mediated Nonenzymatic Formation of Chalcane-Containing Dimers in Dragon's Blood.

Chalcane-containing dimers are major compounds identified from dragon's blood, the red resin that accumulates in Dracaena trees after injury. The key step for the formation of these dimers was a p-quinone methide (p-QM, 3) mediated nonenzymatic Michael addition. Compound 3 is derived from the spontaneous dehydration of chalcane alcohol-M274 (2). Two dihydroflavonol-4-reductases, discovered in D. cambodiana, reduce dihydrochalcone-M272 (7) to 2. Moreover, the application potential of p-QMs was demonstrated using a 3-like p-QM to synthesize diverse dimeric derivatives.

Combining microbial and chemical syntheses for the production of complex natural products.

Nature, a rich source of bioactive natural products, serves as a massive pool of drug candidates for the pharmaceutical industry. However, the supply of these structurally complex chemicals is costly as most of the natural products are scarce in nature, thus requiring de novo synthesis. The supply chain issue hinders the development of novel therapeutic agents from natural products. Microbial synthesis, based on the expression of biosynthetic genes in a suitable microbial host to produce certain chemicals, is a sustainable strategy to produce complex natural products. However, this strategy requires gaining insights into the biosynthesis of target molecules. Most natural products are biosynthetically unknown or not fully elucidated; thus, the sole application of microbial synthesis strategy to produce a given molecule is challenging. In this review, we highlight a strategy that combines microbial and chemical syntheses to tackle the supply chain issue in developing drugs from natural products. We believe this strategy can revive the drug development pipeline for natural products.

[Serum 25-hydroxyvitamin D expression and its correlation in patients with vestibular neuritis].

Objective:To investigate the expression level of serum 25-（OH） D and its correlation in patients with vestibular neuritis（VN）. Methods:30 acute VN patients and 50 age-and sex-matched healthy controls who attended the Otolaryngology, Head and Neck Surgery Department of the First Hospital of Shanxi Medical University from October 2020 to October 2021 were selected. The demographic and clinical data of all subjects were recorded, the levels of serum 25-（OH） D and inflammatory markers were measured and compared, and the changes of serum 25-（OH） D levels in convalescent patients with VN were followed up. Results:The serum level of 25-（OH） D in the acute phase VN group was significantly lower than that in healthy controls[（10.14±2.92） ng/mL vs （20.61±4.70） ng/mL, P<0.01], and the deficiency rate of 100.0%（30/30） was significantly higher than 54.0%（27/50）. Moreover, the serum level of 25-（OH） D in the recovery period（3 months later） was significantly higher[（10.14±2.92） ng/mL vs （15.94±4.88） ng/mL, P<0.01], and the deficiency rate was significantly decreased by 76.7%（23/30）. However, the serum 25-（OH） D level was significantly lower in both the VN group than that in both the acute period and the recovery group, and the deficiency rate was significantly higher than that in the control group. Multivariate binary Logistic regression model analysis showed that low-level serum 25-（OH） D was associated with the onset of VN, with an OR value of 0.193（95%CI=0.043-0.861, P=0.031）. In addition, the results of this study showed that peripheral blood leukocyte（WBC） and neutrophil / lymphocyte ratio（NLR） levels in the acute VN group were significantly higher than in healthy controls[（7.65±3.02） ×108/L vs （5.50±2.50） ×108/L, P<0.01; （2.46±2.95） ×100% vs（1.67±0.92） ×100%, P<0.01 ], and there was no significant difference in Platelet / lymphocyte ratio（PLR） and and average platelet volume（MPV） levels in the two groups（P>0.05）. There were no significant differences in age distribution, sex ratio, body mass index, persistent health problems, or lifestyle groups（P>0.05）. Conclusion:This study is the first to detect serum 25-（OH） D level and inflammation index level, and dynamically assess the serum 25-（OH） D level in different stages, found that low serum 25-（OH） D is associated with the onset of VN, physiological concentration of serum 25-（OH） D is a protective factor of VN, vitamin D supplementation therapy may be a new target of VN treatment.

Promising natural lysine specific demethylase 1 inhibitors for cancer treatment: advances and outlooks.

Lysine specific demethylase 1 (LSD1), a transcriptional corepressor or coactivator that serves as a demethylase of histone 3 lysine 4 and 9, has become a potential therapeutic target for cancer therapy. LSD1 mediates many cellular signaling pathways and regulates cancer cell proliferation, invasion, migration, and differentiation. Recent research has focused on the exploration of its pharmacological inhibitors. Natural products are a major source of compounds with abundant scaffold diversity and structural complexity, which have made a major contribution to drug discovery, particularly anticancer agents. In this review, we briefly highlight recent advances in natural LSD1 inhibitors over the past decade. We present a comprehensive review on their discovery and identification process, natural plant sources, chemical structures, anticancer effects, and structure-activity relationships, and finally provide our perspective on the development of novel natural LSD1 inhibitors for cancer therapy.

Development of selective bispecific Wnt mimetics for bone loss and repair.

The Wnt signaling pathway is intricately connected with bone mass regulation in humans and rodent models. We designed an antibody-based platform that generates potent and selective Wnt mimetics. Using this platform, we engineer bi-specific Wnt mimetics that target Frizzled and low-density lipoprotein receptor-related proteins and evaluate their effects on bone accrual in murine models. These synthetic Wnt agonists induce rapid and robust bone building effects, and correct bone mass deficiency and bone defects in various disease models, including osteoporosis, aging, and long bone fracture. Furthermore, when these Wnt agonists are combined with antiresorptive bisphosphonates or anti-sclerostin antibody therapies, additional bone accrual/maintenance effects are observed compared to monotherapy, which could benefit individuals with severe and/or acute bone-building deficiencies. Our data support the continued development of Wnt mimetics for the treatment of diseases of low bone mineral density, including osteoporosis.

Dietary luteolin attenuates chronic liver injury induced by mercuric chloride via the Nrf2/NF-κB/P53 signaling pathway in rats.

Mercury exposure is a common cause of metal poisoning which is biotransformed to highly toxic metabolites thus eliciting biochemical alterations and oxidative stress. Luteolin, a phenolic compound found in many natural products, has multiple biological functions. Our study was aimed to explore the biological effects of luteolin in a liver injury model induced in rats by mercuric chloride (HgCl2). Criteria for injury included liver enzyme, glutathione and malondialdehyde levels, histopathology, TUNEL assay, hepatocyte viability and reactive oxygen species levels. The results showed that luteolin protected against HgCl2-induced liver injury. Luteolin increased total nuclear factor-erythroid-2-related factor 2 (Nrf2) levels in the presence of HgCl2. Upregulation of its downstream factors, heme oxygenase-1 and NAD(P)H quinone oxidoreductase 1, was also observed. This suggested that protection by luteolin against HgCl2-induced liver injury involved Nrf2 pathway activation. Luteolin also decreased expression of nuclear factor-κB (NF-κB) and P53. HgCl2 exposure led to increased Bcl-associated X protein (Bax), and decreased Bcl-2-related protein long form of Bcl-x (Bcl-xL) and B-cell leukemia/lymphoma-2 (Bcl-2) expression, leading to an increased Bax/Bcl-2 ratio. Taken together, our data suggested that decreasing oxidative stress is a protective mechanism of luteolin against development of HgCl2-induced liver injury, through the Nrf2/NF-κB/P53 signaling pathway in rats.

Effects of selenium on apoptosis and abnormal amino acid metabolism induced by excess fatty acid in isolated rat hepatocytes.

SCOPE: Increased serum free fatty acid (FFA) occurs in subjects with non-alcoholic fatty liver disease (NAFLD) and also triggers oxidative stress, apoptosis, and insulin resistance. Selenium (Se) is an antioxidant agent. However, the effect of Se on NAFLD or diabetes is still unclear. We investigated the effect of Se on apoptosis and abnormal amino acid metabolism initiated by excess FFA in isolated rat hepatocytes. METHODS AND RESULTS: Primary hepatocytes from rats were isolated and exposed to excessive FFA (0.5 mM oleate/palmitic acid 2:1) and 0.1 µM Se. Se protected primary hepatocytes against oxidative stress and apoptosis induced by excess FFA, but did not play a role on abnormal amino acid metabolism and insulin resistance initiated by FFA in isolated rat hepatocytes. CONCLUSION: Although Se had the capability of preventing the apoptosis initiated by ROS, insulin resistance failed to be reversed in hepatocytes exposed to FFA. This failure may be attributed to the limitation of Se in regulating branched chain amino acids abundance. This indicates that apoptosis and insulin resistance might be involved in different pathways when isolated hepatocytes were exposed to FFA and Se.

GSPE reduces lead-induced oxidative stress by activating the Nrf2 pathway and suppressing miR153 and GSK-3ß in rat kidney.

Lead (Pb) is a global environmental health hazard that leads to nephrotoxicity. However, the effective treatment of Pb-induced nephrotoxicity remains elusive. Grape seed procyanidin extract (GSPE) has beneficial properties for multiple biological functions. Therefore, the present study investigated whether GSPE reduced Pb-induced nephrotoxicity as well as the protective mechanism of GSPE in a well-established 35-day Pb induced nephrotoxicity rat model. The results showed that GSPE normalized Pb-induced oxidative stress, histological damage, inflammatory, apoptosis, and changes of miR153 and glycogen synthase kinase 3ß (GSK-3ß) levels in rat kidney. Moreover, GSPE enhanced the induction of phase II detoxifying enzymes (heme oxygenase-1 and NAD(P)H quinone oxidoreductase 1) by increasing nuclear factor-erythroid-2-related factor 2 (Nrf2) expression. This study identifies for the first time that Pb-induced oxidative stress in rat kidney is attenuated by GSPE treatment via activating Nrf2 signaling pathway and suppressing miR153 and GSK-3ß. Nrf2 signaling provides a new therapeutic target for renal injury induced by Pb, and GSPE could be a potential natural agent to protect against Pb-induced nephrotoxicity.

The impact of grape seed extract treatment on blood pressure changes: A meta-analysis of 16 randomized controlled trials.

BACKGROUNDS AND OBJECTIVE: Several clinical trials have shown that grape seed extract can reduce blood pressure, but the results are often irreproducible. We therefore sought to systematically evaluate the impact of grape seed extract treatment on the changes of systolic/diastolic blood pressure (SBP/DBP) by meta-analyzing available randomized controlled trials. METHODS: Trial selection and data extraction were completed independently by 2 investigators. Effect-size estimates were expressed as weighted mean difference (WMD) and 95% confidence interval (CI). RESULTS: Twelve articles involving 16 clinical trials and 810 study subjects were analyzed. Overall analyses found significant reductions for SBP (WMD = -6.077; 95% CI: -10.736 to -1.419; P = 0.011) and DBP (WMD = -2.803; 95% CI: -4.417 to -1.189; P = 0.001) after grape seed extract treatment. In subgroup analyses, there were significant reductions in younger subjects (mean age < 50 years) for SBP (WMD = -6.049; 95% CI: -10.223 to -1.875; P = 0.005) and DBP (WMD = -3.116; 95% CI: -4.773 to -1.459; P < 0.001), in obese subjects (mean body mass index ≥ 25 kg/m) for SBP (WMD = -4.469; 95% CI: -6.628 to -2.310; P < 0.001), and in patients with metabolic syndrome for SBP (WMD = -8.487; 95% CI: -11.869 to -5.106; P < 0.001). Further meta-regression analyses showed that age, body mass index, and baseline blood pressure were negatively associated with the significant reductions of SBP and DBP after treatment. There was no indication of publication bias. CONCLUSION: Our findings demonstrate that grape seed extract exerted a beneficial impact on blood pressure, and this impact was more obvious in younger or obese subjects, as well as in patients with metabolic disorders. In view of the small sample size involved, we agree that confirmation of our findings in a large-scale, long-term, multiple-dose randomized controlled trial, especially among hypertensive patients is warranted.

Fialuridine induces acute liver failure in chimeric TK-NOG mice: a model for detecting hepatic drug toxicity prior to human testing.

BACKGROUND: Seven of 15 clinical trial participants treated with a nucleoside analogue (fialuridine [FIAU]) developed acute liver failure. Five treated participants died, and two required a liver transplant. Preclinical toxicology studies in mice, rats, dogs, and primates did not provide any indication that FIAU would be hepatotoxic in humans. Therefore, we investigated whether FIAU-induced liver toxicity could be detected in chimeric TK-NOG mice with humanized livers. METHODS AND FINDINGS: Control and chimeric TK-NOG mice with humanized livers were treated orally with FIAU 400, 100, 25, or 2.5 mg/kg/d. The response to drug treatment was evaluated by measuring plasma lactate and liver enzymes, by assessing liver histology, and by electron microscopy. After treatment with FIAU 400 mg/kg/d for 4 d, chimeric mice developed clinical and serologic evidence of liver failure and lactic acidosis. Analysis of liver tissue revealed steatosis in regions with human, but not mouse, hepatocytes. Electron micrographs revealed lipid and mitochondrial abnormalities in the human hepatocytes in FIAU-treated chimeric mice. Dose-dependent liver toxicity was detected in chimeric mice treated with FIAU 100, 25, or 2.5 mg/kg/d for 14 d. Liver toxicity did not develop in control mice that were treated with the same FIAU doses for 14 d. In contrast, treatment with another nucleotide analogue (sofosbuvir 440 or 44 mg/kg/d po) for 14 d, which did not cause liver toxicity in human trial participants, did not cause liver toxicity in mice with humanized livers. CONCLUSIONS: FIAU-induced liver toxicity could be readily detected using chimeric TK-NOG mice with humanized livers, even when the mice were treated with a FIAU dose that was only 10-fold above the dose used in human participants. The clinical features, laboratory abnormalities, liver histology, and ultra-structural changes observed in FIAU-treated chimeric mice mirrored those of FIAU-treated human participants. The use of chimeric mice in preclinical toxicology studies could improve the safety of candidate medications selected for testing in human participants. Please see later in the article for the Editors' Summary.

Distance-dependent metal-enhanced quantum dots fluorescence analysis in solution by capillary electrophoresis and its application to DNA detection.

Here the distance dependence of metal-enhanced quantum dots (QDs) fluorescence in solution is studied systematically by capillary electrophoresis (CE). Complementary DNA oligonucleotides-modified CdSe/ZnS QDs and gold nanoparticles (Au NPs) were connected together in solution by the hybridization of complementary oligonucleotides, and a model system (QD-Au) for the study of metal-enhanced QDs fluorescence was constructed, in which the distance between the QDs and Au NPs was controlled by adjusting the base number of the oligonucleotide. In our CE experiments, the metal-enhanced fluorescence of the QDs solution was only observed when the distance between the QDs and Au NPs ranged from 6.8 to 18.7 nm, and the maximum enhancement by a factor of 2.3 was achieved at 11.9 nm. Furthermore, a minimum of 19.6 pg of target DNA was identified in CE based on its specific competition with the QD-DNA in the QD-Au system. This work provides an important reference for future study of metal-enhanced QDs fluorescence in solution and exhibits potential capability in nucleic acid hybridization analysis and high-sensitivity DNA detection.

Simultaneous detection of dual single-base mutations by capillary electrophoresis using quantum dot-molecular beacon probe.

Here a novel capillary electrophoresis (CE) for simultaneous detection of dual single-base mutations using quantum dot-molecular beacon (QD-MB) probe is described. Two QD-MB probes were designed using 585 and 650-nm emitting CdTe QDs which were covalently conjugated to MBs with different DNA oligonucleotide sequences by amide linkage and streptavidin-biotin binding, respectively. The hybridizations of QD-MB probes with different DNA targets were then monitored by CE, and results indicated that the two QD-MB probes specifically hybridized with their complementary DNA sequences, respectively. Target DNA identification was observed to have a high sensitivity of 16.2 pg in CE. Furthermore, the simultaneous detection of dual single-base mutations in a given DNA oligonucleotide was successfully achieved in CE using above two QD-MB probes. This novel CE-assisted QD-MB biosensor offers a promising approach for simultaneous detection of multiple single-base mutations, and exhibits potential capability in the single nucleotide polymorphism (SNP) analysis and high-sensitivity DNA detection.