Kukoamine B Research Articles

Lycium RIN negatively modulate the biosynthesis of kukoamine A in hairy roots through decreasing thermospermine synthase expression

Root bark (Lycii cortex) of Lycium contains high contents of characteristic bioactive compounds, including kukoamine A (KuA) and kukoamine B (KuB). RIPENING INHIBITOR (RIN) is well known as a master regulator of Solanaceaous fruit ripening. However, the role of RIN in the biosynthetic pathway of KuA in Lycium remains unclear. In this study, integrated transcriptomic, metabolomic analyses and hairy root system are used to characterize the role of RIN in KuA biosynthesis in Lycium. The ultra performance liquid chromatography electrospray ionization tandem mass spectrometry analysis revealed that KuA was significantly induced in LrRIN1 RNAi lines and not detected in overexpression lines. A total of 20,913 differentially expressed genes (DEGs) and 60 differentially accumulated metabolites (DAMs) were detected in LrRIN1 transgenic hairy roots, which were used for weighted gene co-expression network analysis. Our result reveals a high association between KuA and structural genes in the phenolamide pathway, which shows a negative correlation with LrRIN1. In addition, overexpression of the polyamine pathway gene thermospermine synthase LcTSPMS, a potential target gene of Lycium RIN, increased the contents of both KuA and KuB in L. chinense hairy root, indicating that TSPMS is responsible for KuA biosynthesis and is also the common upstream biosynthetic gene for both KuA and KuB. Our results lay a solid foundation for uncovering the biosynthetic pathway of KuA, which will facilitate the molecular breeding and genetic improvement of Lycium species.

Safety, tolerability, pharmacokinetics, and efficacy of kukoamine B in patients with sepsis: A randomized phase IIa trial

PurposeTo evaluate the safety, tolerability, pharmacokinetics, and efficacy of kukoamine B (KB), an alkaloid compound with high affinity for both lipopolysaccharide (LPS) and oligodeoxynucle-otides containing CpG motifs (CpG DNA), in patients with sepsis-induced organ failure. Materials and methodsThis was a multicenter, randomized, double-blind, placebo-controlled phase IIa trial. Patients with sepsis-induced organ failure were randomized to receive either KB (0.06, 0.12, or 0.24 mg/kg) or placebo, every 8 h for 7 days. Primary endpoint was safety, and secondary endpoints included pharmacokinetic (PK) parameters, changes in inflammatory mediators' level, and prognostic parameters. ResultsOf 44 patients enrolled, adverse events occurred in 28 patients [n = 20, 66.7% (KB pooled); n = 8, 57.1% (placebo)], while treatment emergent adverse events were reported in 14 patients [n = 10, 33.3% (KB pooled); n = 4, 28.6% (placebo)]. Seven patients died at 28-day follow-up [n = 4, 13.3% (KB pooled); n = 3, 21.4% (placebo)], none was related to study drug. PK parameters suggested dose-dependent drug exposure and no drug accumulation. KB did not affect clinical outcomes such as ΔSOFA score, vasopressor-free days or ventilator-free days. ConclusionsIn patients with sepsis-induced organ failure, KB was safe and well tolerated. Further investigation is warranted. Trial registrationhttp://ClinicalTrials.gov, NCT03237728.

Kukoamine B from Lycii Radicis Cortex Protects Human Keratinocyte HaCaT Cells through Covalent Modification by Trans-2-Nonenal

The unsaturated aldehyde trans-2-nonenal is known to be generated by lipid peroxidation at the surface of the skin in an aging-related manner and has harmful effects on keratinocytes in the skin. In this study, the protective effect of a Lycii Radicis Cortex (LRC) extract against trans-2-nonenal-induced cell damage on human keratinocyte cell lines (HaCaT) was investigated. Notably, treatment with the LRC extract resulted in an increase in cell survival, while trans-2-nonenal decreased the viability of HaCaT cells. For identification of interaction between the LRC extract and trans-2-nonenal, this mixture was incubated in simulated physiological conditions, showing a strong decrease in the amount of trans-2-nonenal by the LRC extract. Subsequent LC-ESI-MS analysis revealed that kukoamine B (KB) formed Schiff base-derived pyridinium adducts with trans-2-nonenal. Thus, these results suggest that KB could be a potential agent that may protect HaCaT cells by forming new products with trans-2-nonenal.

Anti-Osteoporotic Effects of Kukoamine B Isolated from Lycii Radicis Cortex Extract on Osteoblast and Osteoclast Cells and Ovariectomized Osteoporosis Model Mice.

Osteoporosis is an abnormal bone remodeling condition characterized by decreased bone density, which leads to high risks of fracture. Previous study has demonstrated that Lycii Radicis Cortex (LRC) extract inhibits bone loss in ovariectomized (OVX) mice by enhancing osteoblast differentiation. A bioactive compound, kukoamine B (KB), was identified from fractionation of an LRC extract as a candidate component responsible for an anti-osteoporotic effect. This study investigated the anti-osteoporotic effects of KB using in vitro and in vivo osteoporosis models. KB treatment significantly increased the osteoblastic differentiation and mineralized nodule formation of osteoblastic MC3T3-E1 cells, while it significantly decreased the osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. The effects of KB on osteoblastic and osteoclastic differentiations under more physiological conditions were also examined. In the co-culture of MC3T3-E1 cells and monocytes, KB promoted osteoblast differentiation but did not affect osteoclast differentiation. In vivo experiments revealed that KB significantly inhibited OVX-induced bone mineral density loss and restored the impaired bone structural properties in osteoporosis model mice. These results suggest that KB may be a potential therapeutic candidate for the treatment of osteoporosis.

A Metabolomics Approach to Investigate Kukoamine B-A Potent Natural Product With Anti-diabetic Properties.

Due to the surge in type 2 diabetes mellitus (T2DM), treatments for chronic metabolic dysregulations with fewer side-effects are sought. Lycii Cortex (LyC), a traditional Chinese Medicine (TCM) herb has a long history of being widely prescribed to treat T2DM as alternative medicine; however, the bioactive molecules and working mechanism remained unknown. Previous studies revealed kukoamine B (KB) as a major and featured compound for LyC with bioactivities for anti-oxidation and acute inflammation, which may be related to anti-diabetes properties. This study aims to understand the efficacy and the mode of action of KB in the diabetic (db/db) mouse model using a metabolomics approach. Parallel comparison was conducted using the first-line anti-diabetic drugs, metformin and rosligtazone, as positive controls. The db/db mice were treated with KB (50 mg kg−1 day−1) for 9 weeks. Bodyweight and fasting blood glucose were monitored every 5 and 7 days, respectively. Metabolomics and high-throughput molecular approaches, including lipidomics, targeted metabolomics (Biocrates p180), and cytokine profiling were applied to measure the alteration of serum metabolites and inflammatory biomarkers between different treatments vs. control (db/db mice treated with vehicle). After 9 weeks of treatment, KB lowered blood glucose, without the adverse effects of bodyweight gain and hepatomegaly shown after rosiglitazone treatment. Lipidomics analysis revealed that KB reduced levels of circulating triglycerides, cholesterol, phosphatidylethanolamine, and increased levels of phosphatidylcholines. KB also increased acylcarnitines, and reduced systemic inflammation (cytokine array). Pathway analysis suggested that KB may regulate nuclear transcription factors (e.g., NF-κB and/or PPAR) to reduce inflammation and facilitate a shift toward metabolic and inflammatory homeostasis. Comparison of KB with first-line drugs suggests that rosiglitazone may over-regulate lipid metabolism and anti-inflammatory responses, which may be associated with adverse side effects, while metformin had less impact on lipid and anti-inflammation profiles. Our research from holistic and systemic views supports the conclusion that KB is the bioactive compound of LyC for managing T2DM, and suggests KB as a nutraceutical or a pharmaceutical candidate for T2D treatment. In addition, our research provides insights related to metformin and rosiglitazone action, beyond lowering blood glucose.

Kukoamine B promotes TLR4-independent lipopolysaccharide uptake in murine hepatocytes.

Free bacterial lipopolysaccharide (LPS) is generally removed from the bloodstream through hepatic uptake via TLR4, the LPS pattern recognition receptor, but mechanisms for internalization and clearance of conjugated LPS are less clear. Kukoamine B (KB) is a novel cationic alkaloid that interferes with LPS binding to TLR4. In this study, KB accelerated blood clearance of LPS. KB also enhanced LPS distribution in the hepatic tissues of C57 BL/6 mice, along with LPS uptake in primary hepatocytes and HepG2 cells. By contrast, KB inhibited LPS internalization in Kupffer and RAW 264.7 cells. Loss of TLR4 did not affect LPS uptake into KB-treated hepatocytes. We also detected selective upregulation of the asialoglycoprotein receptor (ASGPR) upon KB treatment, and ASGPR colocalized with KB in cultured hepatocytes. Molecular docking showed that KB bound to ASGPR in a manner similar to GalNAc, a known ASGPR agonist. GalNAc dose-dependently reduced KB internalization, suggesting it competes with KB for ASGPR binding, and ASGPR knockdown also impaired LPS uptake into hepatocytes. Finally, while KB enhanced LPS uptake, it was protective against LPS-induced inflammation and hepatocyte injury. Our study provides a new mechanism for conjugated LPS hepatic uptake induced by the LPS neutralizer KB and mediated by membrane ASGPR binding.

Ultra performance liquid chromatography tandem mass spectrometry assay for determination of kukoamine B in human blood and urine.

In this paper, we report a sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method which is capable of quantifying kukoamine B (KB) levels in human blood and urine. Following solid phase extraction and direct dilution process, the analyte and its internal standard (D5-KB) run on an Acquity UPLC(®) HSS T3 column (2.1×50mm i.d., 1.8μm) by using a gradient elution method (run time was 1.5min). The mass spectrometric analysis was performed by using an API-5500 mass spectrometer coupled with an electro-spray ionization source. The MRM transitions of m/z 531.3(+)→222.1(+) and 536.3(+)→222.1(+) were used to quantify KB and D5-KB respectively. This assay method has been fully validated in terms of selectivity, linearity, lower limit of quantification, precision, accuracy, stability, recovery and matrix effect. The concentration range of this method is 10.0-2000.0ngmL(-1) in blood and 0.5-500.0ngmL(-1) in urine. Linearity (R(2)) of calibration curves were 0.9964±0.0022 and 0.9935±0.0053 for blood and urine, respectively (regression equation: y=ax+b). The precision (RSD%) of quality control samples is less than 10.3% for blood and less than 10.5% for urine. The accuracy (RE%) is within -4.0-11.3% and -11.7-12.5% for blood and urine respectively. KB was stable after 4h in ice-water bath, 1 freeze/thaw cycles and 180days at -80°C for blood samples; and was stable after 3h at room temperature, 3 freeze/thaw cycles and 180days at -80°C for urine samples. Recoveries of KB were 4.7±0.9% in blood and 96.5±1.3% in urine, respectively. Additionally, the applicability of this method has been proved by analyzing clinical samples from pharmacokinetic study of KB in human.

Neuroprotective effects of Kukoamine B against hydrogen peroxide-induced apoptosis and potential mechanisms in SH-SY5Y cells

Oxidative stress mediates the cell damage in several neurodegenerative diseases, including multiple sclerosis, Alzheimer's disease (AD) and Parkinson's disease (PD). This study aimed at investigating the protective effects of Kukoamine B (KuB) against hydrogen peroxide (H2O2) induced cell injury and potential mechanisms in SH-SY5Y cells. Our results revealed that treatment with KuB prior to H2O2 exposure effectively increased the cell viability, and restored the mitochondria membrane potential (MMP). Furthermore, KuB enhanced the antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and decreased the malondialdehyde (MDA) content. Moreover, KuB minimized the ROS formation and inhibited mitochondria-apoptotic pathway, MAPKs (p-p38, p-JNK, p-ERK) pathways, but activated PI3K-AKT pathway. In conclusion, we believed that KuB may potentially serve as an agent for prevention of several human neurodegenerative and other disorders caused by oxidative stress.

Inhibitory effects of Kukoamine B on the inflammatory response of small intestine in lipopolysaccharide-induced septic mice and its potential mechanisms

To study the role of Kukoamine B (KB) in inhibiting the inflammatory response of small intestine in septic mice and its molecular mechanisms. Twenty-four male ICR mice were randomly divided into control group, model group, and KB intervention group (each, n = 8). Sepsis model was reproduced by intra-peritoneal injection of 20 mg/kg lipopolysaccharide (LPS), while equivalent normal saline was given in control group, and 20 μg/kg KB was injected through caudal vein 4 hours after LPS challenge in KB intervention group. The blood/tissue samples (jejunum and ileum) were harvested 8 hours after LPS injection. The levels of plasma LPS, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured. The pathological changes in small intestine tissues were observed under light microscope, while the levels of inflammatory cytokines TNF-α and IL-1β in the tissue homogenates (jejunum and ileum) were assessed by enzyme linked immunosorbent assay (ELISA). The activity of myeloperoxidase (MPO) was measured by colorimetry. The expression of intercellular adhesion molecule-1 (ICAM-1) was determined by immunohistochemistry. The expressions of inducible nitric oxide synthase (iNOS) mRNA was assayed by reverse transcription-polymerase chain reaction (RT-PCR). The activation of nuclear factor-Κβ (NF-Κβ) was determined by Western Blot. The mice in model group were found to have an increase in microvascular permeability, interstitial edema, and infiltration of white blood cells, and the levels of LPS, TNF-α and IL-1β in their plasma, with an increase in concentrations of TNF-α and IL-1β, activity of MPO, positive expression of ICAM-1, expression of iNOS mRNA and NF-ΚB protein in small intestine (jejunum and ileum). Compared with model group, in mice with KB intervention, microvascular permeability, interstitial edema, and infiltration of white blood cells were reduced significantly, while the levels of LPS, TNF-α and IL-1β in plasma, the concentration of TNF-α and IL-1β, the activity of MPO, the positive expression of ICAM-1, the expression of iNOS mRNA and NF-ΚB protein in small intestine (jejunum and ileum) were significantly decreased [plasma LPS (kEU/L): 654.09±28.13 vs. 1 155.65±47.15, TNF-α (ng/L): 12.75±0.47 vs. 30.61±0.71, IL-1β (ng/L): 53.06±5.32 vs. 64.47±2.61; jejunum TNF-α (ng/L): 43.27±1.20 vs. 64.82±2.09, IL-1β (ng/L): 326.38±14.47 vs. 535.22±13.48, MPO (U/g): 0.14±0.01 vs. 0.32±0.02, iNOS mRNA (2(-ΔΔCt)): 2.39±0.13 vs. 10.80±0.22, NF-ΚB protein (gray value): 0.687±0.062 vs. 1.404±0.046; ileum TNF-α (ng/L): 62.75±3.92 vs. 104.24±2.82, IL-1β(ng/L): 408.06±1.70 vs. 521.97±1.16, MPO (U/g): 0.36±0.08 vs. 0.66±0.05, iNOS mRNA (2(-ΔΔCt)): 1.65±0.11 vs. 3.59±0.29, NF-ΚB protein (gray value): 0.830±0.114 vs. 1.609±0.051, all P <0.05]. KB can combine with LPS and inhibit LPS/Toll-like receptor 4 (TLR4) signaling pathway, thereby significantly inhibit the inflammatory response and protect the function of the small intestine in LPS-induced septic mice.

A novel role of kukoamine B: Inhibition of the inflammatory response in the livers of lipopolysaccharide-induced septic mice via its unique property of combining with lipopolysaccharide.

Kukoamine B (KB), derived from the traditional Chinese herb cortex Lycii, exerts anti-inflammatory effects due to its potent affinity with lipopolysaccharide (LPS) and CpG DNA; however, little is known regarding whether the in vivo administration of KB can effectively inhibit inflammation in septic mice. The present study thus aimed to investigate the inhibitory effects of KB on the inflammatory response in the livers of LPS-induced septic mice. KB treatment in the LPS-induced septic mice significantly decreased the plasma level of LPS. In addition, KB protected against liver injury, as confirmed by improved histology and decreased aminotransferase levels in the serum. Further experiments revealed that KB attenuated liver myeloperoxidase activity and reduced the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. These effects were accompanied by decreases in the levels of tumor necrosis factor α and interleukin-1β in the liver tissue. In parallel, the activity of nuclear factor-κ-gene binding (NF-κB) in the livers of LPS-induced septic mice was markedly inhibited with KB treatment. In combination, these results demonstrate that KB inhibits inflammation in septic mice by reducing the concentrations of plasma LPS, decreasing leukocyte sequestration and interfering with NF-κB activation, and, therefore, suppressing the pro-adhesive phenotype of endothelial cells.

Inhibitory effect of kukoamine B on lung inflammatory responses in mice with sepsis

To investigate the inhibitory effect of kukoamine B (KB) on lung inflammatory responses in mice with sepsis and its possible molecular mechanism. Twenty-eight male mice were randomly divided into control group (n=8), lipopolysaccharide (LPS) group (n=10), and LPS + KB group (n=10). Sepsis model was reproduced by intra-peritoneal injection of 20 mg/kg LPS, while equivalent normal saline was given in control group, and 20 μg/kg KB was injected through caudal vein 4 hours after LPS challenge in LPS + KB group. After 8 hours of LPS challenge, the concentration of LPS in plasma and the activity of myeloperoxidase (MPO) in the lung tissue were determined. The contents of tumor necrosis factor-α (TNF-α) and interleukin-1β(IL-1β) in plasma, alveolar lavage fluid and lung tissue homogenates were assessed by enzyme linked immunosorbent assay (ELISA). The activation of nuclear factor-ΚB (NF-ΚB) and the expression of inducible nitric oxide synthase (iNOS) in lung tissue were determined by Western Blot. The pathological changes in lung tissues were observed with hematoxylin-eosin (HE) staining. The expression of intercellular adhesion molecule-1 (ICAM-1) in lung tissue was determined by immunohistochemistry. Compared with control group, the concentration of LPS in plasma (1 155.650±147.149 kEU/L vs. 31.390±18.859 kEU/L), MPO activity (1.177±0.093 U/g vs. 0.775±0.166 U/g), NF-ΚB activity (gray value: 1.557±0.105 vs. 0.824±0.032) and the expression of iNOS (gray value: 0.650±0.129 vs. 0.392±0.097) were significantly increased in LPS group (all P<0.05). After KB intervention, the concentration of LPS (624.461±149.012 kEU/L), MPO activity (0.919±0.023 U/g), NF-ΚB activity (1.127±0.074) and the expression of iNOS (0.425±0.066) were significantly lowered (all P<0.05). Compared with control group, the contents of TNF-α (47.325±13.864 ng/L vs. 6.534±0.544 ng/L, 13.382±2.231 ng/L vs. 3.748±0.692 ng/L, 31.127±7.399 ng/L vs. 14.948±4.673 ng/L) and IL-1β (74.329±11.890 ng/L vs. 29.921±6.487 ng/L, 9.422±2.674 ng/L vs. 1.105±0.364 ng/L, 528.509±32.073 ng/L vs. 109.945±13.561 ng/L) in plasma, alveolar lavage fluid and lung tissue homogenates were obviously enhanced in LPS group (all P<0.05). With KB intervention, the contents of TNF-α (20.331±7.789 ng/L, 7.145±1.202 ng/L, 15.966±2.946 ng/L) and IL-1β (57.707±8.098 ng/L, 2.212±0.878 ng/L, 426.154±11.270 ng/L) were markedly reduced (plasma TNF-α: F=16.052, P=0.002; IL-1β: F=20.649, P=0.000; lung tissue homogenates TNF-α: F=31.134, P=0.001; IL-1β: F=22.792, P=0.002; alveolar lavage fluid TNF-α: F=10.013, P=0.009; IL-1β: F=319.857, P=0.000). In addition, leukocyte infiltration to the lung tissue was attenuated, and the expression of ICAM-1 was reduced by KB in histological examination. KB, as a neutralizer of LPS, can inhibit the release of inflammatory mediators, reduce the pulmonary inflammatory response and protect the function of lung in septic mice.

Kukoamine B, a novel dual inhibitor of LPS and CpG DNA, is a potential candidate for sepsis treatment

Lipopolysaccharides (LPS) and oligodeoxynucleotides containing CpG motifs (CpG DNA) are important pathogenic molecules for the induction of sepsis, and thus are drug targets for sepsis treatment. The present drugs for treating sepsis act only against either LPS or CpG DNA. Hence, they are not particularly efficient at combating sepsis as the latter two molecules usually cooperate during sepsis. In this study, a natural alkaloid compound kukoamine B (KB) is presented as a potent dual inhibitor for both LPS and CpG DNA. The affinities of KB for LPS and CpG DNA were assessed using biosensor technology. Direct interaction of KB with LPS and CpG DNA were evaluated using neutralization assays. Selective inhibitory activities of KB on pro-inflammatory signal transduction and cytokine expression induced by LPS and CpG DNA were analysed by cellular assays. Protective effects of KB in a sepsis model in mice were elucidated by determining survival and circulatory LPS and tumour necrosis factor-alpha (TNF-α) concentrations. KB had high affinities for LPS and CpG DNA. It neutralized LPS and CpG DNA and prevented them from interacting with mouse macrophages. KB selectively inhibited LPS- and CpG DNA-induced signal transduction and expression of pro-inflammatory mediators without interfering with signal pathways or cell viability in macrophages. KB protected mice challenged with heat-killed Escherichia coli, and reduced the circulatory levels of LPS and TNF-α. This is the first report of a novel dual inhibitor of LPS and CpG DNA. KB is worthy of further investigation as a potential candidate to treat sepsis.

Dual targets guided screening and isolation of Kukoamine B as a novel natural anti-sepsis agent from traditional Chinese herb Cortex lycii

Treating sepsis remains challenging at present. Bacterial lipopolysaccharide (LPS) and bacterial DNA/CpG DNA are important pathogenic molecules and drug targets for sepsis. It is thus a promising strategy to treat sepsis by discovering agents that neutralize LPS and CpG DNA simultaneously. In this study, we present evidences of the biosensor based screening and isolation of active anti-sepsis fractions and monomers from traditional Chinese herbs using dual targets (LPS and CpG DNA) guided drug discovery strategy. Firstly, LPS or CpG DNA was immobilized on surfaces of cuvettes in the biosensor to establish a screening platform. Then, Cortex lycii with both highest affinities was selected out from one hundred and fourteen traditional Chinese herbs. In subsequent experiments, chromatography was utilized and coupled with the biosensor to purify fractions with a higher affinity for LPS and CpG DNA. In line with affinity assay, these fractions were shown to neutralize LPS and CpG DNA and inhibit their activity in vitro and in vivo. Lastly, the contributing monomer Kukoamine B (KB) was purified. KB neutralized LPS and CpG DNA in vitro. It inhibited TLR4, TLR9 and MyD88 mRNA expressions up-regulated by LPS and CpG DNA, and also attenuated the LPS and CpG DNA elicited nuclear translocation of NF-κB p65 protein in RAW264.7 cells. It also protected mice from lethal challenge of heat-killed E. coli, a mixture of LPS and CpG DNA. In conclusion, we presented a dual target guided discovery of a novel anti-sepsis agent KB from traditional Chinese herbs via combination of biosensor technology and chromatography methods.