Cytotoxic effects of aporphine alkaloids from the stems and leaves of Stephania dielsiana Y.C.Wu

Phytochemical studies of the stems and leaves of Stephania dielsiana Y.C.Wu yielded two new aporphine alkaloids (1 and 5), along with six known alkaloids (2-4 and 6-8). Their structures were characterised based on analyses of spectroscopic data, including one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS). The cytotoxic activities of the isolated compounds against a small panel of tumour cell lines were assessed by MTS assay. Interestingly, compound 2 exhibited particularly strong cytotoxic activities against HepG2, MCF7 and OVCAR8 cancer cell lines, with IC50 values of 3.20 ± 0.18, 3.10 ± 0.06 and 3.40 ± 0.007 µM, respectively. Furthermore, molecular docking simulations were carried out to explore the interactions and binding mechanisms of the most active compound (compound 2) with proteins. Our results contribute to understanding the secondary metabolites produced by S. dielsiana and provide a scientific rationale for further investigations of cytotoxicity of this valuable medicinal plant.

Four unreported aporphine alkaloids with antifungal activities from Artabotrys hexapetalus

In this study, the extract from Artabotrys hexapetalus showed strong antifungal activity against phytopathogenic fungi in vitro. Four unreported aporphine alkaloids, hexapetalusine A-D (1-4), were isolated from stems and roots of Artabotrys hexapetalus (L.f.) Bhandari, along with six known aporphine alkaloids (5-10). Their chemical structures were elucidated by extensive spectroscopic analysis. The absolute configurations of 1-3 were determined using single-crystal X-ray diffractions and ECD calculations. Hexapetalusine A-C (1-3) were special amidic isomers. Additionally, all isolated compounds were evaluated for their antifungal activity against four phytopathogenic fungi in vitro. Hexapetalusine D (4) exhibited weak antifungal activity against Curvularia lunata. Liriodenine (5) displayed significant antifungal activity against Fusarium proliferatum and Fusarium oxysporum f. sp. vasinfectum, which is obviously better than positive control nystatin, suggesting that it had great potential to be developed into an effective and eco-friendly fungicide.

Aporphine alkaloids and a naphthoquinone derivative from the leaves of Phaeanthus lucidus Oliv. and their α-glucosidase inhibitory activity

Three previously undescribed aporphine alkaloids, phaeanthuslucidines E-G, one previously undescribed naphthoquinone derivative, phaeanthusnaphthoquinone, and three known compounds were isolated from an EtOAc extract of the leaves of Phaeanthus lucidus Oliv. The structures of all previously undescribed compounds were established through extensive spectroscopic investigations and high-resolution mass spectroscopy. The 6aR configuration of phaeanthuslucidines E-G was assigned by comparing their ECD spectra and specific rotation values with the reported known compounds. Some isolated compounds were evaluated for their α-glucosidase inhibitory activity. Among these compounds, phaeanthuslucidine E showed the highest α-glucosidase inhibitory activity with an IC50 value of 17.9 ± 0.4 μM. The molecular docking of phaeanthuslucidine E was further studied.

Nuciferine alleviates collagen-induced arthritic in rats by inhibiting the proliferation and invasion of human arthritis-derived fibroblast-like synoviocytes and rectifying Th17/Treg imbalance

Rheumatoid arthritis (RA) is a chronic autoimmune disorder marked by persistent synovial inflammation and joint degradation, posing challenges in the development of effective treatments. Nuciferine, an alkaloid found in lotus leaf, has shown promising anti-inflammatory and anti-tumor effects, yet its efficacy in RA treatment remains unexplored. This study investigated the antiproliferative effects of nuciferine on the MH7A cell line, a human RA-derived fibroblast-like synoviocyte, revealing its ability to inhibit cell proliferation, promote apoptosis, induce apoptosis, and cause G1/S phase arrest. Additionally, nuciferine significantly reduced the migration and invasion capabilities of MH7A cells. The therapeutic potential of nuciferine was further evaluated in a collagen-induced arthritis (CIA) rat model, where it markedly alleviated joint swelling, synovial hyperplasia, cartilage injury, and inflammatory infiltration. Nuciferine also improved collagen-induced bone erosion, decreased pro-inflammatory cytokines and serum immunoglobulins (IgG, IgG1, IgG2a), and restored the balance between T helper (Th) 17 and regulatory T cells in the spleen of CIA rats. These results indicate that nuciferine may offer therapeutic advantages for RA by decreasing the proliferation and invasiveness of FLS cells and correcting the Th17/Treg cell imbalance in CIA rats.

Nuciferine reduces vascular leakage and improves cardiac function in acute myocardial infarction by regulating the PI3K/AKT pathway

The destruction of the microvascular structure and function can seriously affect the survival and prognosis of patients with acute myocardial infarction (AMI). Nuciferine has a potentially beneficial effect in the treatment of cardiovascular disease, albeit its role in microvascular structure and function during AMI remains unclear. This study aimed to investigate the protective effect and the related mechanisms of nuciferine in microvascular injury during AMI. Cardiac functions and pathological examination were conducted in vivo to investigate the effect of nuciferine on AMI. The effect of nuciferine on permeability and adherens junctions in endothelial cells was evaluated in vitro, and the phosphorylation level of the PI3K/AKT pathway (in the presence or absence of PI3K inhibitors) was also analyzed. In vivo results indicated that nuciferine inhibited ischemia-induced cardiomyocyte damage and vascular leakage and improved cardiac function. In addition, the in vitro results revealed that nuciferine could effectively inhibit oxygen-glucose deprivation (OGD) stimulated breakdown of the structure and function of human coronary microvascular endothelial cells (HCMECs). Moreover, nuciferine could significantly increase the phosphorylation level of the PI3K/AKT pathway. Finally, the inhibitor wortmannin could reverse the protective effect of nuciferine on HCMECs. Nuciferine inhibited AMI-induced microvascular injury by regulating the PI3K/AKT pathway and protecting the endothelial barrier function in mice.

Nuciferine prevents obesity by activating brown adipose tissue

Increasing evidence suggests that brown adipose tissue (BAT) plays an important role in obesity and related diseases. Increasing the amount or activity of BAT could prevent obesity. Therefore, a safe and effective method of activating BAT is urgently required. Here, we evaluated the potential effects of lotus leaf extract (LLE) on BAT function. We found that LLE substantially increased UCP1 mRNA and protein levels as well as thermogenic protein expression in primary brown adipocytes. Additionally, LLE treatment reduced diet-induced obesity and improved glucose homeostasis owing to BAT activation and increased energy expenditure. We found that nuciferine, an active ingredient of LLE, could dose-dependently activate BAT in vitro and in vivo, alleviate diet-induced obesity, and improve glucose homeostasis by increasing energy expenditure. Mechanistically, we found that nuciferine induced PPARG coactivator 1 alpha (PGC1-α) expression, which is a key gene involved in mitochondrial biogenesis promoter activity, by directly binding to RXRA. Furthermore, RXRA knockdown abolished expression of the nuciferine-induced mitochondrial and thermogenesis-related gene in primary brown adipocytes. In summary, we found that LLE and nuciferine have a notable effect on BAT activation and highlight the potential applications of the main component of LLE in preventing obesity and treating metabolic disorders.

Therapeutic Potential and Pharmacological Activities of (+)-Nantenine in Medicine: An Aporphine Class Phytocomponent of Nandina domestica Thunberg

Plant material and their derived byproducts have been used in medicine for the treatment of human disorders and complications. Plants give us a distinct class of natural compounds, commonly called secondary metabolites and better examples are the flavonoids, phenols, terpenoids, alkaloids, tannins, and carotenoids. Plant derived phytoproducts have been used for the treatment of human disorders in both traditional as well as modern medicine. Naturally occurring aporphines and their synthetic derivatives are well known in medicine for their pharmacological activities, including an affinity for dopaminergic, adrenergic and serotonergic receptors. (+)-nantenine is an aporphine alkaloid isolated from Nandina domestica and other plants. The aim of the present study is to analyze the biological potential and therapeutic effectiveness of nantenine in medicine. In the present work scientific information of nantenine for their medicinal uses and pharmacological activities have been collected from scientific databases such as Google, Google Scholar, PubMed, Scopus, and Science Direct . Scientific information of nantenine was further analyzed to know their health beneficial aspects in medicine. However, the detail pharmacological activity of nantenine has been discussed in the present work with its analytical aspects. Scientific data analysis described the medicinal importance and pharmacological activities of nantenine. Nantenine revealed adrenergic response, behavioral response, cardiovascular effect, vasorelaxant effect, acetylcholinesterase inhibitory potential, cytotoxicity, and biphasic tracheal relaxation. Present work also signified the biological potential of nantenine for their anti-inflammatory activity, anticonvulsant effect, antiserotonergic activities, anti-MDMA effect, antileishmanial activity, effect on histamine and serotonin, human 5-hydroxytryptamine (5-HT(2A)) and h5-HT(2B) receptors and isolated tissues. Further, the analytical techniques used for the separation, isolation and identification of nantenine have also been described in this work. The present scientific data describes the therapeutic potential and pharmacological activities of (+)-nantenine in medicine.

Aporphine and amide alkaloids from Illigera parviflora

Three undescribed alkaloids (+)-9-hydroxy-N-acetylnordicentrine (1), illigeparvinine (2), and deca-(2E,4Z)-2,4-dienoic acid 4-hydroxy-2-phenethyl amide (3), along with 19 known analogues (4-22), were isolated from the ethnic medicinal plant Illigera parviflora. Their structures were established using NMR, MS, and other spectroscopic analyses as well as X-ray diffraction. Moderate inhibition of human gastric carcinoma (MGC-803) and breast adenocarcinoma (T-47D) cell lines proliferation was observed for actinodaphnine (4) with IC50 values of 28.74 and 11.65 μM, respectively. These findings contribute new anticancer potential compounds and expand the chemical diversity known from the valuable traditional medicinal plant I. parviflora.

An Overview of Chemistry, Kinetics, Toxicity and Therapeutic Potential of Boldine in Neurological Disorders

Boldine is an alkaloid obtained from the medicinal herb Peumus boldus (Mol.) (Chilean boldo tree; boldo) and belongs to the family Monimiaceae. It exhibits a wide range of pharmacological effects such as antioxidant, anticancer, hepatoprotective, neuroprotective, and anti-diabetic properties. There is a dearth of information regarding its pharmacokinetics and toxicity in addition to its potential pharmacological activity. Boldine belongs to the aporphine alkaloid class and possesses lipophilic properties which enable its efficient absorption and distribution throughout the body, including the central nervous system. It exhibits potent free radical scavenging activity, thereby reducing oxidative stress and preventing neuronal damage. Through a variety of neuroprotective mechanisms, including suppression of AChE and BuChE activity, blocking of connexin-43 hemichannels, pannexin 1 channel, reduction of NF-κβ mediated interleukin release, and glutamate excitotoxicity which successfully reduces neuronal damage. These results point to its probable application in reducing neuroinflammation and oxidative stress in epilepsy, Alzheimer's disease (AD), and Parkinson's disease (PD). Moreover, its effects on serotonergic, dopaminergic, opioid, and cholinergic receptors were further investigated in order to determine its applicability for neurobehavioral dysfunctions. The article investigates the pharmacokinetics of boldine and reveals that it has a low oral bioavailability and a short half-life, requiring regular dosage to maintain therapeutic levels. The review studies boldine's potential therapeutic uses and mode of action while summarizing its neuroprotective benefits.  Given the favorable results for boldine as a potential neurotherapeutic drug in laboratory animals, more research is required. However, in order to optimise its therapeutic potential, it must be more bioavailable with fewer detrimental side effects.

Diuretic, Natriuretic, And Ca2+-Sparing Effect Of The Alkaloid Boldine In Rats

BACKGROUND

Previous studies indicate the renal vasodilating effects of boldine, an alkaloid found in Peumus boldus. However, its potential to induce diuresis still needs to be studied.

METHODS

Wistar rats were used and the urine volume was noted for 8 h and further studied.

RESULTS

The acute treatment at 0.1 and 0.3 mg/kg of boldine showed a diuretic, natriuretic, and Ca2+-sparing effect in rats without changing the urinary elimination of K+and Cl-. When boldine was given in combination with hydrochlorothiazide, there was an increase in urinary volume compared to the vehicle group. However, this was not different from the treatments in its isolated form. Urine Ca2+values ​​remained low but were not enhanced by this association. The excretion of Na+and Cl- was significantly increased compared to the group that received only vehicle or boldine. On the other hand, although the association of amiloride plus boldine did not result in a diuretic effect, the increase in Na+and the reduction in K+excretion were significantly potentiated. Furthermore, in the presence of the non-selective muscarinic receptor antagonist atropine, boldine showed reduced capacity to increase urinary volume, maintaining the natriuretic and Ca2+-sparing effect, besides a very evident K+-sparing action. Similar results were obtained in the presence of the non-selective cyclooxygenase inhibitor indomethacin. Furthermore, boldine showed an ex vivo antiurolithiasis activity, reducing calcium oxalate's precipitation and crystallization.

CONCLUSIONS

This study reveals the diuretic, natriuretic, Ca2+-sparing, and antiurolithiatic effects of boldine, an action possibly related to muscarinic receptor activation and prostanoid generation.

Boldine Alters Serum Lipidomic Signatures after Acute Spinal Cord Transection in Male Mice

Traumatic spinal cord injury (SCI) results in wide-ranging cellular and systemic dysfunction in the acute and chronic time frames after the injury. Chronic SCI has well-described secondary medical consequences while acute SCI has unique metabolic challenges as a result of physical trauma, in-patient recovery and other post-operative outcomes. Here, we used high resolution mass spectrometry approaches to describe the circulating lipidomic and metabolomic signatures using blood serum from mice 7 d after a complete SCI. Additionally, we probed whether the aporphine alkaloid, boldine, was able to prevent SCI-induced changes observed using these 'omics platforms'. We found that SCI resulted in large-scale changes to the circulating lipidome but minimal changes in the metabolome, with boldine able to reverse or attenuate SCI-induced changes in the abundance of 50 lipids. Multiomic integration using xMWAS demonstrated unique network structures and community memberships across the groups.

Magnoflorine improves cognitive deficits and pathology of Alzheimer's disease via inhibiting of JNK signaling pathway

BACKGROUND

Cognitive deficit is the main clinical feature of Alzheimer's disease (AD), and the massive death of neuronal cells is the leading cause of cognitive deficits. So, there is an urgent clinical need to discover effective drugs to protect brain neurons from damage in order to treat AD. Naturally-derived compounds have always been an important source of new drug discovery because of their diverse pharmacological activities, reliable efficacy and low toxicity. Magnoflorine is a quaternary aporphine alkaloid, which naturally exist in some commonly used herbal medicines, and has good anti-inflammatory and antioxidant effects. However, magnoflorine has not been reported in AD.

HYPOTHESIS/PURPOSE

To investigate the therapeutic effect and mechanism of magnoflorine on AD.

METHODS

Neuronal damage was detected by flow cytometry, immunofluorescence and western blotting. Oxidative stress was measured by detection of SOD and MDA, as well as JC-1 and reactive oxygen species (ROS) staining. The APP/PS1 mice were given drugs by intraperitoneal injection (I.P.) every day for one month, and then the new object recognition and Morris water maze were used to detect the cognitive ability of the mice.

RESULTS

We demonstrated that magnoflorine reduced Aβ-induced PC12 cell apoptosis and intracellular ROS generation. Further studies found that magnoflorine significantly improved cognitive deficits and AD-type pathology. Most interestingly, the efficacy of magnoflorine was better than that of the clinical control drug donepezil. Mechanistically, based on RNA-sequencing analysis, we found that magnoflorine significantly inhibited phosphorylated c-Jun N-terminal kinase (JNK) in AD models. This result was further validated using a JNK inhibitor.

CONCLUSION

Our results indicate that magnoflorine improves cognitive deficits and pathology of AD through inhibiting of JNK signaling pathway. Thus, magnoflorine may be a potential therapeutic candidate for AD.

Dimeric aporphine alkaloids from the twigs of Trivalvaria costata (Hook.f. & Thomson) I.M.Turner

A phytochemical investigation of the twig extract of Trivalvaria costata (Hook.f. & Thomson) I.M.Turner has identified ten undescribed dimeric aporphine alkaloids, trivalcostatines A-J, one undescribed isoquinoline alkaloid, trivalcostaisoquinoline, and four known aporphine alkaloids. Their structures were elucidated by detailed analysis of NMR and HRESITOFMS data. Three of the dimeric aporphine structures were confirmed by single crystal X-ray diffraction analysis. All of the dimeric aporphine alkaloids were isolated as mixtures of atropisomers. Several of them were resolved by chiral-phase HPLC and the absolute configurations of the pure atropisomers were assigned by calculated and experimental ECD analysis. Bidebilines A and B, heteropsine, and urabaine showed α-glucosidase inhibitory activities with IC₅₀ values in the range of 4.1-11 μM.

Nuciferine attenuates atherosclerosis by regulating the proliferation and migration of VSMCs through the Calm4/MMP12/AKT pathway in ApoE(-/-) mice fed with High-Fat-Diet

BACKGROUND

Atherosclerosis (AS) is the pathological basis of multiple cardiovascular diseases. The pathogenesis of AS is closely related to the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). Nuciferine, an aporphine alkaloid from lotus leaf, has various pharmacological activities. However, the effect and mechanism of nuciferine on regulating proliferation and migration of VSMCs against AS is still unclear.

PURPOSE

To elucidate the pharmacological effect and molecular mechanism of nuciferine on AS in ApoE^(-/-) mice fed with High-Fat-Diet (HFD).

STUDY DESIGN

HFD-fed ApoE^(-/-) mice and 3% fetal bovine serum (FBS) induced mouse aortic vascular smooth muscle cells (MOVAS) were used to investigate the protective effect and mechanism of nuciferine on AS.

METHODS

Oil red O staining was used to detect the atherosclerotic lesions. Western blotting and immunofluorescence were used to determine calmodulin 4 (Calm4) expression and localization. CCK-8 assay, transwell and wound-healing assays were used to measure the migration and proliferation of MOVAS cells.

RESULTS

Nuciferine at 40 mg/kg significantly ameliorated the aortic lesion and vascular plaque in AS model, which was equal to the effect of the positive control drug (atorvastatin). In addition, nuciferine attenuated the migration and proliferation of VSMCs in vivo and in vitro. Importantly, nuciferine down-regulated the increase of Calm4 induced by HFD-fed in ApoE^(-/-) mice or 3% FBS induced MOVAS cells. However, the inhibitory effect of nuciferine on the migration and proliferation of MOVAS cells was blocked when Calm4 was overexpressed. Furthermore, we found that nuciferine suppressed MMP12 and PI3K/Akt signaling pathway via Calm4.

CONCLUSION

Our results illustrated that Calm4 promoted the proliferation and motility of MOVAS by activating MMP12/Akt signaling pathway in AS. Nuciferine has a significant anti-atherogenic effect by regulating the proliferation and migration of VSMCs through the Calm4/MMP12/AKT signaling pathway. Thus, Calm4 could potentially be a new target for AS therapy, and nuciferine could be a potential drug against AS.

Semisynthetic Transformations on (+)-Boldine Reveal a 5-HT2A/2CR Antagonist

Aporphine alkaloids have shown affinity for serotonin receptors (5-HTRs), and there has been a recent upsurge of interest in aporphines as 5-HT_2CR ligands. 1,2,9,10-Tetraoxygenated aporphine alkaloids in particular have demonstrated good affinity for 5-HTRs. In continued efforts to understand the impacts of structural modification of the 1,2,9,10-tetraoxygenated aporphine template on affinity, selectivity, and activity at 5-HT₂R subtypes, we used (+)-boldine (8) as a semisynthetic feedstock in the preparation of C-2-alkoxylated (+)-predicentrine analogues. Compound 10n, which contains a benzyloxy group at C-2, has been identified as a novel 5-HT_2CR ligand with strong affinity (4 nM) and moderate selectivity versus 5-HT_2BR and 5-HT_2AR (12-fold and 6-fold, respectively). Compound 10n functions as an antagonist at 5-HT_2A and 5-HT_2C receptors. Computational experiments indicate that several hydrophobic interactions as well as strong H-bond and salt bridge interactions between the protonated amine moiety in 10n and Asp134 are responsible for the potent 5-HT_2CR affinity of this compound. Furthermore, compound 10n displays favorable predicted drug-like characteristics, which is encouraging toward future optimization.

Antioxidant, Antidiabetic, Anticholinergic, and Antiglaucoma Effects of Magnofluorine

Magnofluorine, a secondary metabolite commonly found in various plants, has pharmacological potential; however, its antioxidant and enzyme inhibition effects have not been investigated. We investigated the antioxidant potential of Magnofluorine using bioanalytical assays with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD^•+), and 1,1-diphenyl-2-picrylhydrazyl (DPPH^•) scavenging abilities and K₃[Fe(CN)₆] and Cu²⁺ reduction abilities. Further, we compared the effects of Magnofluorine and butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-Tocopherol, and Trolox as positive antioxidant controls. According to the analysis results, Magnofluorine removed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC₅₀ value of 10.58 μg/mL. The IC₅₀ values of BHA, BHT, Trolox, and α-Tocopherol were 10.10 μg/mL, 25.95 μg/mL, 7.059 μg/mL, and 11.31 μg/mL, respectively. Our results indicated that the DPPH· scavenging effect of Magnofluorine was similar to that of BHA, close to that of Trolox, and better than that of BHT and α-tocopherol. The inhibition effect of Magnofluorine was examined against enzymes, such as acetylcholinesterase (AChE), α-glycosidase, butyrylcholinesterase (BChE), and human carbonic anhydrase II (hCA II), which are linked to global disorders, such as diabetes, Alzheimer’s disease (AD), and glaucoma. Magnofluorine inhibited these metabolic enzymes with Ki values of 10.251.94, 5.991.79, 25.411.10, and 30.563.36 nM, respectively. Thus, Magnofluorine, which has been proven to be an antioxidant, antidiabetic, and anticholinergic in our study, can treat glaucoma. In addition, molecular docking was performed to understand the interactions between Magnofluorine and target enzymes BChE (D: 6T9P), hCA II (A:3HS4), AChE (B:4EY7), and α-glycosidase (C:5NN8). The results suggest that Magnofluorine may be an important compound in the transition from natural sources to industrial applications, especially new drugs.

Stephalagine, an aporphinic alkaloid with therapeutic effects in acute gout arthritis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Gout is an inflammatory disease characterized by the accumulation of monosodium urate crystals (MSU) in the joints, leading to severe pain and inflammation. Stephalagine is a Brazilian Savanna aporphine alkaloid isolated from Annona crassiflora Mart. Fruit peel, that has been popularly used to treat rheumatism and have been described with antinociceptive properties. However, no studies evaluated the possible therapeutic properties of stephalagine in arthritic pain.

AIM OF THE STUDY

To evaluate the possible antinociceptive and anti-inflammatory effects of stephalagine in an acute gout attack in mice.

MATERIALS AND METHODS

Adult male wild type C57BL/6/J/UFU mice (20-25 g) were used (process number 018/17). The treated group received stephalagine (1 mg/kg, by gavage) and the vehicle group received saline (10 mL/kg, by gavage), both 1 h before the MSU crystals (100 μg/ankle joint) administration. All groups were analyzed for mechanical allodynia, thermal hyperalgesia, overt pain-like behaviors, and edema development at 2, 4, 6 and 24 h after injections. Synovial fluid and the ankle articulation from the injected joint were collected 4 h after administrations for myeloperoxidase enzyme activity, IL-1β measurement, and histological analysis.

RESULTS

Stephalagine had a significant antinociceptive effect on mechanical allodynia, when compared to vehicle group at 2-24 h after intra-articular injection of MSU and 2 h for spontaneous and cold thermal sensitivity. Stephalagine was also able to significantly reduce the articular edema (45 ± 1%), the activity of the myeloperoxidase enzyme (37 ± 6%), and IL-1β levels (43 ± 3%). The histological analysis confirms that stephalagine dramatically reduced the number of infiltrating inflammatory cells (75 ± 6%) in MSU injected animals. Also, stephalagine treatment did not alter the uric acid levels, xanthine oxidase activity, AST and ALT activities, urea and creatinine levels, neither cause any macroscopic changes in the mice's weight, deformations, changes in the coat, or feces.

CONCLUSION

Stephalagine may be an alternative for the management of gout, once it was able to induce antinociceptive and anti-inflammatory effects without causing adverse effects on the evaluated parameters.

Corybungines A-K: Isoquinoline alkaloids from Corydalis bungeana with dopamine D2 receptor activity

Eleven undescribed isoquinoline alkaloids corybungines A-K including a protoberberine-type alkaloid, an isoquinoline alkaloid with a unique 6-norprotoberberine skeleton, one 13,14-seco-protoberberine-type alkaloid, two 1a,14-seco-protoberberine-type alkaloids with a 4-(hydroxymethyl)phenoxy moiety and six aporphine alkaloids, together with seven known alkaloids, have been isolated from the whole herb extract of Corydalis bungeana Turcz. Their structures and absolute configurations were elucidated based on an analysis of spectroscopic data and electronic circular dichroism (ECD) spectra. (R)-stephanine displayed high antagonistic activity against the dopamine D2 receptor with an IC₅₀ value of 0.85 ± 0.09 μM in CHO-D2 cells. Additionally, corybungines D, F, H, (R)-roemerine, (R)-vireakine and (R)-tuduranine showed moderate D2 antagonism (IC₅₀ 5.20-26.07 μM). The preliminary structure-activity relationships (SARs) of aporphine alkaloids were discussed.

Nuciferine Inhibits TMEM16A in Dietary Adjuvant Therapy for Lung Cancer

Lung cancer is a malignant tumor with the highest morbidity and mortality rates. Food therapy is a common adjuvant treatment for lung cancer due to its safety and painlessness. Developing new functional food and exploring novel drug targets is important for lung cancer adjuvant therapy. This study confirmed that the active ingredient nuciferine of the lotus leaf was a novel TMEM16A inhibitor by whole-cell patch clamp experiments and site-directed mutagenesis experiments. CCK8 assay, colony formation assay, wound healing assay, and Annexin-V assay were combined to prove that nuciferine inhibited the proliferation and migration of lung cancer cells and promoted cancer cell apoptosis by targeting TMEM16A. Moreover, the combination of nuciferine and cisplatin significantly enhanced the anti-cancer effect of cisplatin. In addition, the signal transduction pathway of nuciferine regulating LA795 cell proliferation, migration, and apoptosis was confirmed by western blot experiments. In vivo experiments showed that nuciferine was a safe and effective natural anti-cancer product for lung cancer. Tissue section pathological detection and pharmacokinetic experiments verified that intragastric administration of nuciferine significantly enhanced the cancer therapy effect of cisplatin and counteracted the toxicity of high concentrations of cisplatin. Therefore, nuciferine is an ideal functional food for adjuvant lung cancer treatment.

A triple combination strategy of UHPLC-MSn, hypolipidemic activity and transcriptome sequencing to unveil the hypolipidemic mechanism of Nelumbo nucifera alkaloids

ETHNOPHARMACOLOGICAL RELEVANCE

Nelumbo nucifera (N. nucifera), a kind of edible Chinese herbal, has been studied in treating hyperlipidemia. However, the hypolipidemic mechanism of N. nucifera remains unknown. Aims of this review: We aimed to screen the effective constituent of N. nucifera alkaloids and elucidated the potential mechanism for treating hyperlipidemia. A triple combination strategy of UHPLC-MSⁿ, hypolipidemic activity and transcriptome sequencing was built to unveil the hypolipidemic mechanism of Nelumbo nucifera alkaloid.

MATERIALS AND METHODS

We comprehensively investigated the characterization of N. nucifera alkaloids by using UHPLC-LTQ-Orbitrap MSⁿ. And the hypolipidemic activity of candidate active ingredients were evaluated on sodium oleate-induced HepG2 cell. Finally, O-nornuciferine and N. nucifera alkaloid extraction were analyzed by RNA sequence (RNA-seq) to decipher the underlying hypolipidemic mechanism and were verified by qRT-PCR.

RESULTS

35 compounds were identified from N. nucifera alkaloid extraction by UHPLC-LTQ-Orbitrap MSⁿ. Among them, O-nornuciferine and N. nucifera alkaloid extraction which showed significant hypolipidemic activity were analyzed by transcriptome sequencing. After the intervention of O-nornuciferine and N. nucifera alkaloid extraction, 1 and 158 differentially expressed genes (DEGs) were identified, severally. The enrichment analysis indicated that the hypolipidemic effect was adjusted by the expression of numerous key DEGs involved in bile secretion, glycerolipid and sphingolipid metabolism, PPAR signaling pathway.

CONCLUSIONS

O-nornuciferine and N. nucifera alkaloids had exibited significant effects in hyperlipidemia. The candidate genes were LDLR, LPL and ANGPTL4, etc. It was most likely that they adjusted lipid metabolism by modulating expression levels of various key factors which were involved in bile secretion, glycerolipid metabolism, sphingolipid metabolism and PPAR signaling pathway, and so on. This study clarified the hypolipidemic mechanism of the alkaloids in N. nucifera, and laid a foundation for the subsequent development of clinical application and better quality of N. nucifera.

Natural Aporphine Alkaloids with Potential to Impact Metabolic Syndrome

The incidence and prevalence of metabolic syndrome has steadily increased worldwide. As a major risk factor for various diseases, metabolic syndrome has come into focus in recent years. Some natural aporphine alkaloids are very promising agents in the prevention and treatment of metabolic syndrome and its components because of their wide variety of biological activities. These natural aporphine alkaloids have protective effects on the different risk factors characterizing metabolic syndrome. In this review, we highlight the activities of bioactive aporphine alkaloids: thaliporphine, boldine, nuciferine, pronuciferine, roemerine, dicentrine, magnoflorine, anonaine, apomorphine, glaucine, predicentrine, isolaureline, xylopine, methylbulbocapnine, and crebanine. We particularly focused on their impact on metabolic syndrome and its components, including insulin resistance and type 2 diabetes mellitus, endothelial dysfunction, hypertension and cardiovascular disease, hyperlipidemia and obesity, non-alcoholic fatty liver disease, hyperuricemia and kidney damage, erectile dysfunction, central nervous system-related disorder, and intestinal microbiota dysbiosis. We also discussed the potential mechanisms of actions by aporphine alkaloids in metabolic syndrome.

New Tyramine- and Aporphine-Type Alkamides with NO Release Inhibitory Activities from Piper puberulum

Three new tyramine-type alkamides (1-3), three new natural products (4-6), five new N-acylated/formylated aporphine alkamides with different ratios of rotational isomers (7-11), and 20 known alkamides (12-31) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of compounds 7, 8, and 10 were determined by single-crystal X-ray diffraction analysis. In the biological activity assay, compounds 3, 5, and 10-23 displayed inhibitory effects against lipopolysaccharide-induced NO release in BV-2 microglial cells, exhibiting IC₅₀ values of 0.93-45 μM.

Oxocrebanine: A Novel Dual Topoisomerase inhibitor, Suppressed the Proliferation of Breast Cancer Cells MCF-7 by Inducing DNA Damage and Mitotic Arrest

BACKGROUND

DNA topoisomerase (Topo) inhibition plays key role in breast cancer treatment. Stephania hainanensis H. S. Lo et Y. Tsoong (S. hainanensis), a Li nationality plant that has abundant aporphine alkaloids, can inhibit Topo.

PURPOSE

To identify a dual Topo inhibitor, a deep and systematic study of active aporphine alkaloids in S. hainanensis and their mechanisms of inhibiting breast cancer proliferation and Topo activity are essential.

STUDY DESIGN

This study aimed to assess the anti-breast cancer and Topo inhibitory activities of oxocrebanine and explore the underlying mechanisms.

METHODS

The growth inhibitory activities of 12 compounds in S. hainanensis were screened by MTT assay in MCF-7, SGC-7901, HepG-2 cells, and compared with the effects on human normal mammary epithelial MCF-10A cells as non cancer control cells. The Topo inhibitory activity was assessed by DNA relaxation and unwinding assays, kDNA decatenation assay and western blot. Cell cycle and autophagy analyses were carried out with flow cytometry and staining. Acridine orange staining and α-tubulin morphology were observed by fluorescence microscopy. Western blot was used to examine microtubule assembly dynamics and the expression levels of key proteins associated with DNA damage, autophagy and mitotic arrest.

RESULTS

Oxocrebanine was the anti-breast cancer active alkaloid in S. hainanensis. It exhibited the best inhibitory effect on MCF-7 cells with an IC₅₀ of 16.66 μmol/l, and had only weak effect on the proliferation of MCF-10A cells. Oxocrebanine inhibited Topo I and II α in a cell-free system and in MCF-7 cells. The DNA unwinding assay suggested that oxocrebanine intercalated with DNA as a catalytic inhibitor. Oxocrebanine regulated the levels of Topo I and IIα and DNA damage-related proteins. Oxocrebanine led to the mitotic arrest, and these effects occurred through both p53-dependent and p53-independent pathways. Oxocrebanine induced autophagy, abnormal α-tubulin morphology and stimulated enhanced microtubule dynamics.

CONCLUSION

Oxocrebanine was the anti-breast cancer active aporphine alkaloid in S. hainanensis. Oxocrebanine was a Topo I/IIα dual inhibitor, catalytic inhibitor and DNA intercalator. Oxocrebanine caused DNA damage, autophagy, and mitotic arrest in MCF-7 cells. Oxocrebanine also disrupted tubulin polymerization. Accordingly, oxocrebanine held a great potential for development as a novel dual Topo inhibitor for effective breast cancer treatment.

Magnoflorine prevent the skeletal muscle atrophy via Akt/mTOR/FoxO signal pathway and increase slow-MyHC production in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora cordifolia (TC) is being used as a blood purifier in Ayurveda since ancient time. It is a very popular immunomodulator and holds anti-inflammatory and anti-oxidative potential, hence anti-aging properties. Therefore, it is also known as 'Amrita' in Ayurveda and is widely used to treat diabetes mellitus type II (T2DM) and its secondary complications; however, its underlying mechanism was not expedited to date. AIM-: To explore the in vivo therapeutic efficiency and mechanism of action of TC and its secondary constitute magnoflorine on the skeletal muscle atrophy in the rat model of T2DM.

METHOD

Animal model of T2DM was developed using streptozotocin (STZ) injection followed by intervention with TC, metformin, and magnoflorine for three weeks. Confirmation of T2DM and abrogation of atrophic markers and possible mechanisms on supplementation of TC and magnoflorine were explored using histology, bio-assays, Western blotting, and q-PCR.

RESULT

TC and Magnoflorine supplementations significantly (p ≤ 0.05) decreased the fasting blood glucose (FBG) levels in T2DM rats. Both treatments prevented the lean body, individual skeletal muscle mass, and myotubes diameter loss (p ≤ 0.05). Magnoflorine significantly reduced the degradation of the protein indicated by biochemical markers of atrophy i.e. decreased serum creatine kinase (CK) levels and increased myosin heavy chain-β (MyHC-β) levels in muscles. Q-PCR and western blotting supported the findings that magnoflorine significantly increased the mRNA and protein abundances (~3 fold) of MyHC-β.TC and magnoflorine efficiently decreased the expression of ubiquitin-proteasomal E3-ligases (Fn-14/TWEAK, MuRF1, and Atrogin 1), autophagy (Bcl-2/LC3B), and caspase related genes along with calpains activities in T2DM rats. Both TC and magnoflorine also increased the activity of superoxide dismutase, GSH-Px, decreased the activities of β-glucuronidase, LPO, and prevented any alteration in the catalase activity. In contrast, magnoflorine increased expression of TNF-α and IL-6 whereas TC and metformin efficiently decreased the levels of these pro-inflammatory cytokines (p ≤ 0.05). However, magnoflorine was found to increase phosphorylation of Akt more efficiently than TC and metformin.

CONCLUSION

TC, and magnoflorine are found to be effective to control fasting blood glucose levels significantly in T2DM rats. It also promoted the Akt phosphorylation, suppressed autophagy and proteolysis that might be related to blood glucose-lowering efficacy of magnoflorine and TC. However, increased muscle weight, specifically of the soleus muscle, expression of IL-6, and slow MyHC indicated the increased myogenesis in response to magnoflorine and independent from its hypoglycemic activity.

Intervention of standardized ethanol leaf extract of Annickia polycarpa, (DC.) Setten and Maas ex I.M. Turner. (Annonaceae), in Plasmodium berghei infested mice produced anti-malaria action and normalized gross hematological indices

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is a global public health burden due to large number of annual infections and casualties caused by its hematological complications. The bark of Annickia polycarpa is an effective anti-malaria agent in African traditional medicine. However, there is no standardization parameters for A. polycarpa. The anti-malaria properties of its leaf are also not known.

AIM OF THE STUDY

To standardize the ethanol leaf extract of A. polycarpa (APLE) and investigate its anti-malaria properties and the effect of its treatment on hematological indices in Plasmodium berghei infected mice in the Rane's test.

MATERIALS AND METHODS

Malaria was induced by inoculating female ICR mice with 1.0 × 107P. berghei-infected RBCs in 0.2 mL (i.p.) of blood. Treatment was commenced 3 days later with APLE 50, 200, 400 mg/kg p.o., Quinine 30 mg/kg i.m. (Standard drug) or sterile water (Negative control) once daily per group for 4 successive days. Anti-malarial activity and gross malaria indices such as hyperparasitemia, mean change in body weight and mean survival time (MST) were determined for each group. Changes in white blood cells (WBCs), red blood cells (RBCs), platelets (PLT) counts, hemoglobin (HGB) concentration, hematocrit (HCT) and mean corpuscular volume (MCV) were also measured in the healthy mice before infection as baseline and on day 3 and 8 after inoculation using complete blood count. Standardization was achieved by UHPLC-MS chemical fingerprint analysis and quantitative phytochemical tests.

RESULTS

APLE, standardized to its total alkaloids, phenolics and saponin contents, produced significant (P < 0.05) dose-dependent clearance of mean hyperparasitemia of 22.78 ± 0.93% with the minimum parasitemia level of 2.01 ± 0.25% achieved at 400 mg/kg p.o. on day 8. Quinine 30 mg/kg i.m. achieved a minimum parasitemia level of 6.15 ± 0.92%. Moreover, APLE (50-400 mg/kg p.o.) evoked very significant anti-malaria activity of 89.22-95.50%. Anti-malaria activity of Quinine 30 mg/kg i.m. was 86.22%. APLE also inverse dose-dependently promotes weight gain with the effect being significant (P < 0.05) at 50 mg/kg p.o. Moreover, APLE dose-dependently increased the MST of malaria infested mice with 100% survival at 400 mg/kg p.o. Quinine 30 mg/kg i.m. also produce 100% survival rate but did not promote (P > 0.05) weight gain. Hematological studies revealed the development of leukocytopenia, erythrocytosis, microcytic anemia and thrombocytopenia in the malaria infected mice which were reverted with the treatment of APLE 50-400 mg/kg p.o. or Quinine 30 mg/kg i.m. but persisted in the negative control. The UHPLC-MS fingerprint analysis of APLE led to identification of one oxoaporphine and two aporphine alkaloids (1-3). Alkaloids 1 and 3 are being reported in this plant for the first time.

CONCLUSION

These results indicate that APLE possessed significant anti-malaria, immunomodulatory, erythropoietic and hematinic actions against malaria infection. APLE also has the ability to revoke deleterious physiological alteration produced by malaria and hence, promote clinical cure. These properties of APLE are due to its constituents especially, aporphine and oxoaporphine alkaloids.

Akkermansia muciniphila: A potential novel mechanism of nuciferine to improve hyperlipidemia

BACKGROUND

Intestinal microbiota is a novel drug target of metabolic diseases, especially for those with poor oral bioavailability. Nuciferine, with poor bioavailability, has an anti-hyperlipidemic effect at low dosages.

PURPOSE

In the present study, we aimed to explore the role of intestinal microbiota in the anti-hyperlipidemic function of nuciferine and identify the key bacterial targets that might confer the therapeutic actions.

METHODS

The contribution of gut microbes in the anti-hyperlipidemic effect of nuciferine was evaluated by conventional and antibiotic-established pseudo-sterile mice. Whole-metagenome shotgun sequencing was used to characterize the changes in microbial communities by various agents.

RESULTS

Nuciferine exhibited potent anti-hyperlipidemic and liver steatosis-alleviating effects at the doses of 7.5-30 mg/kg. The beneficial effects of nuciferine were substantially abolished when combined with antibiotics. Metagenomic analysis showed that nuciferine significantly shifted the microbial structure, and the enrichment of Akkermansia muciniphila was closely related to the therapeutic effect of nuciferine.

CONCLUSIONS

Our results revealed that gut microbiota played an essential role in the anti-hyperlipidemic effect of nuciferine, and enrichment of Akkermansia muciniphila represented a key mechanism through which nuciferine exerted its therapeutic effects.

A multiple-targets alkaloid nuciferine overcomes paclitaxel-induced drug resistance in vitro and in vivo

OBJECTIVE

Multidrug resistance (MDR) is the major barrier to the successful treatment of chemotherapy. Compounds from nature products working as MDR sensitizers provided new treatment strategies for chemo-resistant cancers patients.

METHODS

We investigated the reversal effects of nuciferine (NF), an alkaloid from Nelumbo nucifera and Nymphaea caerulea, on the paclitaxel (PTX) resistance ABCB1-overexpressing cancer in vitro and in vivo, and explored the underlying mechanism by evaluating drug sensitivity, cell cycle perturbations, intracellular accumulation, function and protein expression of efflux transporters as well as molecular signaling involved in governing transporters expression and development of MDR in cancer.

RESULTS

NF overcomes the resistance of chemotherapeutic agents included PTX, doxorubicin (DOX), docetaxel, and daunorubicin to HCT-8/T and A549/T cancer cells. Notably, NF suppressed the colony formation of MDR cells in vitro and the tumor growth in A549/T xenograft mice in vivo, which demonstrated a very strong synergetic cytotoxic effect between NF and PTX as combination index (CI) (CI<0.1) indicated. Furthermore, NF increased the intracellular accumulation of P-gp substrates included DOX and Rho123 in the MDR cells and inhibited verapamil-stimulated ATPase activity. Mechanistically, inhibition of PI3K/AKT/ERK pathways by NF suppressed the activation of Nrf2 and HIF-1α, and further reduced the expression of P-gp and BCRP, contributing to the sensitizing effects of NF against MDR in cancer.

CONCLUSION

This novel finding provides a promising treatment strategy for overcoming MDR and improving the efficiency of chemotherapy by using a multiple-targets MDR sensitizer NF.

Rapid structural characterisation of benzylisoquinoline and aporphine alkaloids from Ocotea spixiana acaricide extract by HPTLC-DESI-MSn

INTRODUCTION

Lauraceae alkaloids are a structurally diverse class of plant specialised secondary metabolites that play an important role in modern pharmacotherapy, being useful as well as model compounds for the development of synthetic analogues. However, alkaloids characterisation is challenging due to low concentrations, the complexity of plant extracts, and long processes for accurate structural determinations.

OBJECTIVE

The use of high-performance thin layer chromatography coupled with desorption electrospray ionisation multistage mass spectrometry (HPTLC DESI-MSⁿ ) as a fast tool to identify alkaloids present in Ocotea spixiana extract and evaluate the extract's acaricide activity.

METHODS

Ocotea spixiana twigs were extracted by conventional liquid-liquid partitioning. HPTLC analysis of the ethyl acetate extract was performed to separate isobaric alkaloids prior to DESI-MSⁿ analysis, performed from MS³ up to MS⁷ . The extract's acaricide activity against Rhipicephalus microplus was evaluated by in vitro (larval immersion test) and in silico tests.

RESULTS

HPTLC-DESI-MSⁿ analysis was performed to identify a total of 13 aporphine and four benzylisoquinoline-type alkaloids reported for the first time in O. spixiana. In vitro evaluation of the extract and the alkaloid boldine showed significant activity against R. microplus larvae. It was established in silico that boldine had important intermolecular interactions with R. microplus acetylcholinesterase enzyme.

CONCLUSION

The present study demonstrated that HPTLC-DESI-MSⁿ is a useful analytical tool to identify isoquinoline alkaloids in plant extracts. The acaricide activity of the O. spixiana ethyl acetate extract can be correlated to the presence of alkaloids.

Synergistic or Additive Pharmacological Interactions between Magnoflorine and Cisplatin in Human Cancer Cells of Different Histological Origin

Magnoflorine is an aporphine alkaloid present in plant species belonging to the Berberidaceae, Magnoliaceae, Menispermaceae, or Papaveraceae botanical families. The interest of magnoflorine has increased recently due to its multiplicity of pharmacological properties. The aim of this study was the analysis of combined anti-proliferative effect of magnoflorine and cisplatin and the assessment of drug–drug pharmacological interaction between these agents using isobolographic method in MDA-MB-468 human breast, NCIH1299 lung, TE671 rhabdomyosarcoma, or T98G glioblastoma cancer cell lines. Magnoflorine in combination with cisplatin at a fixed ratio of 1:1 augmented their anticancer action and yielded synergistic or additive pharmacological interactions by means of isobolographic method, therefore combined therapy using these two active agents can be a promising chemotherapy regimen in the treatment of some types of breast, lung, rhabdomyosarcoma, and glioblastoma cancers.

Advances in Chemistry and Bioactivity of Magnoflorine and Magnoflorine-Containing Extracts

The review collects together some recent information on the identity and pharmacological properties of magnoflorine, a quaternary aporphine alkaloid, that is widely distributed within the representatives of several botanical families like Berberidaceae, Magnoliaceae, Papaveraceae, or Menispermaceae. Several findings published in the scientific publications mention its application in the treatment of a wide spectrum of diseases including inflammatory ones, allergies, hypertension, osteoporosis, bacterial, viral and fungal infections, and some civilization diseases like cancer, obesity, diabetes, dementia, or depression. The pharmacokinetics and perspectives on its introduction to therapeutic strategies will also be discussed.

1-(2'-Bromobenzyl)-6,7-dihydroxy-N-methyl-tetrahydroisoquinoline and 1,2-Demethyl-nuciferine as Agonists in Human D2 Dopamine Receptors

Certain D₂-like dopamine receptor (DR) agonists are useful therapeutically as antiparkinsonian drugs, whereas D₂-like DR antagonists or partial agonists are proven effective as antipsychotics. Two isoquinoline derivatives, 1-(2'-bromobenzyl)-6,7-dihydroxy-N-methyl-tetrahydroisoquinoline (Br-BTHIQ, 1) and 1,2-demethyl-nuciferine (aporphine, 2), were herein synthesized, and their dopaminergic affinity in cloned human D₂R, D₃R, and D₄R subtypes and their behavior as agonists/antagonists were evaluated. They showed affinity values (K_i) for hD₂, hD₃, and hD₄ DR within the nanomolar range. The trends in affinity were hD₄R ≫ hD₃R > hD₂R for Br-BTHIQ (1) and hD₂R > hD₄R > hD₃R for 1,2-demethyl-nuciferine (2). The functional assays of cyclic adenosine monophosphate signaling at human D₂R showed a partial agonist effect for Br-BTHIQ (1) and full agonist behavior for aporphine (2), with half maximal effective concentration values of 2.95 and 10.2 μM, respectively. Therefore, both isoquinolines 1 and 2 have emerged as lead molecules for the synthesis of new therapeutic drugs that ultimately may be useful to prevent schizophrenia and Parkinson's disease, respectively.

Stephalagine, an aporphine alkaloid from Annona crassiflora fruit peel, induces antinociceptive effects by TRPA1 and TRPV1 channels modulation in mice

Pain relief represents a critical unresolved medical need. Consequently, the search for new analgesic agents is intensively studied. Annona crassiflora, a native species of the Brazilian Savanna, represents a potential source for painful treatment. This study aimed to investigate the antinociceptive potential of A. crassiflora fruit peel, focusing on its major alkaloid, stephalagine, in animal models of pain evoked by the activation of transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) channels. Male C57BL/6/J mice were submitted to formalin-, cinnamaldehyde-, and capsaicin-induced nociception tests to assess nociceptive behavior, and to the open-field and rotarod tests for motor performance analyses. Moreover, the stephalagine's effect was tested on capsaicin- and cinnamaldehyde-induced Ca²⁺ influx in spinal cord synaptosomes. In silico assessments of the absorption, distribution, metabolism and central nervous system permeability of stephalagine were carried out. The ethanol extract and alkaloidal fraction reduced the nociception induced by formalin. When administered by oral route (1 mg/kg), stephalagine reduced the spontaneous nociception and paw edema induced by TRPV1 agonist, capsaicin, and by TRPA1 agonists, cinnamaldehyde- and formalin, without altering the animals' locomotor activity. The prediction of in silico pharmacokinetic properties of stephalagine suggests its capacity to cross the blood-brain barrier. Furthermore, this alkaloid reduces the capsaicin- and cinnamaldehyde-mediated Ca²⁺ influx, indicating a possible modulation of TRPV1 and TRPA1 channels, respectively. Together, our results support the antinociceptive and anti-edematogenic effects of the A. crassiflora fruit peel and suggest that these effects are triggered, at least in part, by TRPV1 and TRPA1 modulation by stephalagine.

Magnoflorine Enhances LPS-Activated Pro-Inflammatory Responses via MyD88-Dependent Pathways in U937 Macrophages

Magnoflorine, a major bioactive metabolite isolated from Tinospora crispa, has been reported for its diverse biochemical and pharmacological properties. However, there is little report on its underlying mechanisms of action on immune responses, particularly on macrophage activation. In this study, we aimed to investigate the effects of magnoflorine, isolated from T. crispa on the pro-inflammatory mediators generation induced by LPS and the concomitant NF-κB, MAPKs, and PI3K-Akt signaling pathways in U937 macrophages. Differentiated U937 macrophages were treated with magnoflorine and the release of pro-inflammatory mediators was evaluated through ELISA, while the relative mRNA expression of the respective mediators was quantified through qRT-PCR. Correspondingly, western blotting was executed to observe the modulatory effects of magnoflorine on the expression of various markers related to NF-κB, MAPK and PI3K-Akt signaling activation in LPS-primed U937 macrophages. Magnoflorine significantly enhanced the upregulation of TNF-α, IL-1β, and PGE₂ production as well as COX-2 protein expression. Successively, magnoflorine prompted the mRNA transcription level of these pro-inflammatory mediators. Magnoflorine enhanced the NF-κB activation by prompting p65, IκBα, and IKKα/β phosphorylation as well as IκBα degradation. Besides, magnoflorine treatments concentration-dependently augmented the phosphorylation of JNK, ERK, and p38 MAPKs as well as Akt. The immunoaugmenting effects were further confirmed by investigating the effects of magnoflorine on specific inhibitors, where the treatment with specific inhibitors of NF-κB, MAPKs, and PI3K-Akt proficiently blocked the magnoflorine-triggered TNF-α release and COX-2 expression. Magnoflorine furthermore enhanced the MyD88 and TLR4 upregulation. The results suggest that magnoflorine has high potential on augmenting immune responses.

Magnoflorine with hyaluronic acid gel promotes subchondral bone regeneration and attenuates cartilage degeneration in early osteoarthritis

OBJECTIVE

To investigate efficacy of Chinese medicine magnoflorine combined with hyaluronic acid (HA)-gel in promoting subchondral bone (SCB) regeneration and attenuating cartilage degeneration in early osteoarthritis (OA).

METHODS

MC3T3-E1 under magnoflorine treatment was assayed by XTT to determine cell viability. Cell proliferation was reflected through cell cycle. Osteoblast mineralization was stained by Alizarin Red. Standardized bone canal of 1 mm in diameter and 4 mm in depth was made on tibial medial plateau of 4-month-old Dunkin-Hartley spontaneous knee OA guinea pigs. Guinea pigs (n = 5/group) were treated once intra-bone canal injection of 2 μl HA-gel, 2 μl HA-gel+50 ng magnoflorine and null (Defect) respectively, except sham group. The left hind limbs were harvested for μCT scan and histopathological staining 2-month post-surgery.

RESULTS

25 μg/ml magnoflorine treatment significantly increased cell viability, S-phase and mineralization of MC3T3-E1 cells. In vivo, HA-gel + magnoflorine treatment significantly altered SCB microstructure; changes included increase in bone volume fraction (BV/TV), trabecular number (Tb.N), connectivity density (Conn.Dn), and decrease in degree of anisotropy (DA), which implied trabecular bone regeneration. Treatment also resulted in a decrease in modified Mankin's scores, and an increase in volume ratio of hyaline cartilage (HC)/calcified cartilage (CC) and fractal dimension (FD, roughness indicator of osteochondral conjunction), compared to Defect and HA groups. Furthermore, FD was positively associated with volume ratio of HC/CC and negatively associated with modified Mankin's scores. Finally, histological results showed that due to a faster regeneration of SCB with the HA-gel + magnoflorine treatment, the reduction of cartilage matrix and the decreased expression of chondrogenic signals were attenuated.

CONCLUSION

Our study elucidated the potential benefits of HA-gel + magnoflorine in promoting SCB regeneration and revealed a protective effect of stimulating recovery of the SCB integrity on attenuating cartilage degradation to prevent OA progression.

Nuciferine Inhibits Proinflammatory Cytokines via the PPARs in LPS-Induced RAW264.7 Cells

Inflammation is important and has been found to be an underlying cause in many acute and chronic human diseases. Nuciferine, a natural alkaloid containing an aromatic ring, is found in the nelumbo nucifera leaves. It has been shown to have potential anti-inflammatory activities, but the molecular mechanism has remained unclear. In this study, we found that nuciferine (10 μM) significantly inhibited the lipopolysaccharide (LPS)-induced inflammatory cytokine IL-6 and TNF-α production in RAW 264.7 cells. In addition, the luciferase reporter assay results of different subtypes of the peroxisome proliferator-activated receptor (PPAR) showed that nuciferine dose-dependently activated all the PPAR activities. Specific inhibitors of PPARα and PPARγ significantly abolished the production of inflammatory cytokines as well as IκBα degradation. However, PPARδ inhibitor did not show this effect. Our results suggested a potential molecular mechanism of the anti-inflammatory effects of nuciferine in LPS-induced inflammation, at least in part, by activating PPARα and PPARγ in RAW 264.7 cells.

Aporphine Alkaloids from Illigera aromatica from Guangxi Province, China

Three undescribed aporphine alkaloids laurodionine B (1), illigerine A (2), and N-formyl-laurolitsine (3) were isolated from the methanolic extracts of the Chinese medicinal plant, Illigera aromatica, together with three known analogues (4-6). The chemical structures of 1-6 were identified by spectroscopic methods including 1D and 2D NMR (¹H, ¹³C, COSY, HSQC, and HMBC) and high resolution mass spectrometry (HRESIMS). Compounds 1-3 showed moderate inhibitory activities in vitro against two cultured tumor cell lines, Hela and SMMC7721, with IC₅₀ values of 32.42-62.90 μM. Only compound 1 had in vitro cytotoxic activity against Bcap37 cells, with the IC₅₀ value of 90.61 μM.

New aporphine alkaloids from the aerial parts of Piper semiimmersum §

Two new aporphine alkaloids, semiimmersumines A (1) and B (2), along with 20 known compounds, were isolated from the aerial parts of Piper semiimmersum (Piperaceae). The structures of the new compounds were elucidated based on the analysis of 1D and 2D NMR, MS, and CD data. The absolute configuration of semiimmersumine A (1) was determined by single crystal X-ray diffraction analysis using anomalous dispersion with copper radiation. The effects of all compounds from the plant on rabbit platelet aggregation induced by thrombin (IIa) or PAF were also evaluated.

Nuciferine inhibits LPS-induced inflammatory response in BV2 cells by activating PPAR-γ

Nuciferine, a bioactive component extracted from the lotus leaf, has been reported to have various anti-inflammatory effects. In the present study, we aimed to investigate the anti-inflammatory effects and mechanism of nuciferine on lipopolysaccharide (LPS)-stimulated BV2 microglia cells. The anti-inflammatory activity of nuciferine was measured by ELISA to detect the inflammatory mrdiators secretion in LPS-simulated BV2 microglia cells. The results demonstrated that nuciferine significantly inhibited LPS-induced TNF-α, IL-1β, PGE₂ and NO secretion. LPS-induced NF-κB activation was also suppressed by nuciferine. Further studies showed that nuciferine increased the expression of PPAR-γ. Functional aspects were analyzed using PPAR-γ specific inhibitor GW9662, which attenuated the LPS-induced secretion of proinflammatory mediators, such as TNF-α, IL-1β, PGE₂, and NO. In conclusion, these results suggested that nuciferine activated PPAR-γ, which subsequently inhibited LPS-induced inflammation in BV2 cells.

Telomerase Inhibition by a New Synthetic Derivative of the Aporphine Alkaloid Boldine

Telomerase, the enzyme responsible for cell immortality, is an important target in anti-cancer drug discovery. Boldine, an abundant aporphine alkaloid of Peumus boldus, is known to inhibit telomerase at non-toxic concentrations. Cytotoxicity of N-benzylsecoboldine hydrochloride (BSB), a synthetic derivative of boldine, was determined using the MTT method in MCF7 and MDA-MB231 cells. Aliquots of cell lysates were incubated with various concentrations of BSB in qTRAP (quantitative telomere repeat amplification protocol)-ligand experiments before substrate elongation by telomerase or amplification by hot-start Taq polymerase. The crystal structure of TERT, the catalytic subunit of telomerase from Tribolium castaneum, was used for docking and molecular dynamics analysis. The qTRAP-ligand data gave an IC₅₀ value of about 0.17 &plusmn; 0.1 &micro;M for BSB, roughly 400 times stronger than boldine, while the LD₅₀ in the cytotoxicity assays were 12.5 and 21.88 &micro;M, respectively, in cells treated for 48 h. Although both compounds interacted well with the active site, MD analysis suggests a second binding site with which BSB interacts via two hydrogen bonds, much more strongly than boldine. Theoretical analyses also evaluated the IC₅₀ for BSB as submicromolar. BSB, with greater hydrophobicity and flexibility than boldine, represents a promising structure to inhibit telomerase at non-toxic concentrations.

Nuciferine Relaxes Tracheal Rings via the Blockade of VDLCC and NSCC Channels

This study aimed to elucidate the mechanisms of nuciferine (a main aporphine alkaloid of lotus leaf extract), which can induce relaxation in contracted tracheal rings. Under Ca²⁺-free and 2 mM Ca²⁺ conditions, we found that nuciferine had no effect on the resting muscle tone of tracheal rings. In contrast, nuciferine relaxed high K⁺-contracted mouse tracheal rings in a dose-dependent manner and inhibited both Ca²⁺ influx and voltage-dependent L-type Ca²⁺ channel currents induced by high K⁺. Similarly, nuciferine also inhibited acetylcholine-induced contractions in mouse tracheal rings in a dose-dependent manner. Meanwhile, both acetylcholine-induced intracellular Ca²⁺ influx and whole-cell currents of nonselective cation channels were blocked by nuciferine. Together, the results indicate that nuciferine-induced relaxation in tracheal rings mainly occurred due to the inhibition of extracellular Ca²⁺ influx through the blockade of voltage-dependent L-type Ca²⁺ channels and/or nonselective cation channels. These results suggest that nuciferine has a therapeutic effect on respiratory diseases associated with the aberrant contraction of airway smooth muscles and/or bronchospasm.

Guaianolide sesquiterpene lactones and aporphine alkaloids from the stem bark of Guatteria friesiana

Three guaianolide sesquiterpenes, denoted guatterfriesols A-C, and four aporphine alkaloid derivatives were isolated from the stem bark of the Amazonian plant Guatteria friesiana. Thus far, sesquiterpene lactones have not been described in Annonaceae. Structures of the previously undescribed compounds were established by using 1D and 2D NMR spectroscopy in combination with MS. The absolute stereochemistry was assigned via NOE NMR experiments, ECD spectroscopy, and theoretical calculations using the TDDFT approach. Among the isolated compounds, the alkaloid guatterfriesidine showed anti-glycation activity by inhibiting the formation of advanced glycation end-products (AGEs) through the prevention of oxidation in both BSA/methylglyoxal and BSA/fructose systems.

Antiproliferative Dimeric Aporphinoid Alkaloids from the Roots of Thalictrum cultratum

Inspired by the intriguing structures and bioactivities of dimeric alkaloids, 11 new thalifaberine-type aporphine-benzylisoquinoline alkaloids, thalicultratines A-K, a tetrahydroprotoberberine-aporphine alkaloid, thalicultratine L, and five known ones were isolated from the roots of Thalictrum cultratum. Their structures were defined on the basis of NMR and HRESIMS data. The antiproliferative activities of compounds 1-17 were evaluated against human leukemia HL-60 and prostate cancer PC-3 cells. Most alkaloids showed potent cytotoxicity against selected cancer cells. Preliminary SARs are discussed. The most active new compound (3), with an IC₅₀ value of 1.06 μM against HL-60 cells, was selected for mechanism of action studies. The results revealed that compound 3 induced apoptosis and arrested the HL-60 cell cycle at the S phase with the loss of mitochondria membrane potential. The nuclear morphological Hoechst 33258 staining assay was also carried out, and the results confirmed apoptosis.

Two plant-derived aporphinoid alkaloids exert their antifungal activity by disrupting mitochondrial iron-sulfur cluster biosynthesis

Eupolauridine and liriodenine are plant-derived aporphinoid alkaloids that exhibit potent inhibitory activity against the opportunistic fungal pathogens Candida albicans and Cryptococcus neoformans However, the molecular mechanism of this antifungal activity is unknown. In this study, we show that eupolauridine 9591 (E9591), a synthetic analog of eupolauridine, and liriodenine methiodide (LMT), a methiodide salt of liriodenine, mediate their antifungal activities by disrupting mitochondrial iron-sulfur (Fe-S) cluster synthesis. Several lines of evidence supported this conclusion. First, both E9591 and LMT elicited a transcriptional response indicative of iron imbalance, causing the induction of genes that are required for iron uptake and for the maintenance of cellular iron homeostasis. Second, a genome-wide fitness profile analysis showed that yeast mutants with deletions in iron homeostasis-related genes were hypersensitive to E9591 and LMT. Third, treatment of wild-type yeast cells with E9591 or LMT generated cellular defects that mimicked deficiencies in mitochondrial Fe-S cluster synthesis including an increase in mitochondrial iron levels, a decrease in the activities of Fe-S cluster enzymes, a decrease in respiratory function, and an increase in oxidative stress. Collectively, our results demonstrate that E9591 and LMT perturb mitochondrial Fe-S cluster biosynthesis; thus, these two compounds target a cellular pathway that is distinct from the pathways commonly targeted by clinically used antifungal drugs. Therefore, the identification of this pathway as a target for antifungal compounds has potential applications in the development of new antifungal therapies.

The Absolute Configuration and Cytotoxic Properties of Roehybridine β-N-oxide

Roehybridine β-N-oxide (RNO) is a proaporphine-tryptamine dimer alkaloid froti Roemeria hybrida. RNO possesses five stefeogenic centers and so far. its absolute configuration has not been determined. In this study, the absolute configuration of RNO was established as 6aS,7aR,6R,9S,1OR by comparing experimental and TDDFT calculated electronic circular dichroism (ECD) spectra. In addition, we have reported an amendment indicating exact (1)H and (13)C chemical shifts of RNO. RNO exhibited cytotoxic activity when tested in vitro against prostate cancer cell lines including PC3 and DU145. The IC(50) values of RNO against PC3 and DU145 were 13.3 and 15.1 μg/mL, respectively.

Synthesis and Structure-Activity Relationships of a Series of Aporphine Derivatives with Antiarrhythmic Activities and Acute Toxicity

Some aporphine alkaloids, such as crebanine, were found to present arrhythmic activity and also higher toxicity. A series of derivatives were synthesized by using three kinds of aporphine alkaloids (crebanine, isocorydine, and stephanine) as lead compounds. Chemical methods, including ring-opening reaction, bromination, methylation, acetylation, quaternization, and dehydrogenation, were adopted. Nineteen target derivatives were evaluated for their antiarrhythmic potential in the mouse model of ventricular fibrillation (VF), induced by CHCl₃, and five of the derivatives were investigated further in the rat model of arrhythmia, induced by BaCl₂. Meanwhile, preliminary structure-activity/toxicity relationship analyses were carried out. Significantly, N-acetamidesecocrebanine (1d), three bromo-substituted products of crebanine (2a, 2b, 2c), N-methylcrebanine (2d), and dehydrostephanine (4a) displayed antiarrhythmic effects in the CHCl₃-induced model. Among them, 7.5 mg/kg of 2b was able to significantly reduce the incidence of VF induced by CHCl₃ (p < 0.05), increase the number of rats that resumed sinus rhythm from arrhythmia, induced by BaCl₂ (p < 0.01), and the number of rats that maintained sinus rhythm for more than 20 min (p < 0.01). Therefore, 2b showed remarkably higher antiarrhythmic activity and a lower toxicity (LD50 = 59.62 mg/kg, mice), simultaneously, indicating that 2b could be considered as a promising candidate in the treatment of arrhythmia. Structural-activity analysis suggested that variationsin antiarrhythmic efficacy and toxicity of aporphines were related to the C-1,C-2-methylenedioxy group on ring A, restricted ring B structural conformation, N-quaternization of ring B, levoduction of 6a in ring C, and the 8-, 9-, 10-methoxy groups on ring D on the skeleton.

The first total syntheses of (±)-norphoebine, dehydrophoebine, oxophoebine, dehydrocrebanine, oxocrebanine and uthongine and their cytotoxicity against three human cancer cell lines

The first total syntheses of (±)-norphoebine, dehydrophoebine, oxophoebine, dehydrocrebanine, oxocrebanine and uthongine have been achieved. The crucial step involved the formation of ring C by a microwave-assisted direct biaryl coupling to produce the aporphine skeleton in high yields. The synthetic alkaloids were evaluated for their cytotoxicity against three human cancer cell lines MCF7, KB and NCI-H187. The results showed that uthongine was the best candidate of the series and it exhibited cytotoxicity against a human breast cancer MCF7 line with an IC50 = 3.05 μM.

Boldine Inhibits Mouse Mammary Carcinoma In Vivo and Human MCF-7 Breast Cancer Cells In Vitro

Boldine is an aporphine alkaloid widely consumed in the folk medicine of some regions. Its anticancer potential has been shown but not yet elucidated. We compared the antitumor effect of orally and parenterally applied boldine in mice bearing solid Ehrlich tumor. We also explored the effects of boldine on breast adenocarcinoma MCF-7 cells in vitro. Repeated i. p. injections of 30, 60, or 90 mg boldine/kg, either alone or combined with doxorubicin, slowed tumor growth in vivo. The latter two doses also prolonged the post-therapeutic survival of the mice. When fed food supplemented with boldine at a dose of 90 mg/kg, the tumor-bearing mice survived significantly longer, but there was no effect on tumor size. Interestingly, continuous p. o. administration did not produce detectable levels of boldine in plasma or tissue samples, in contrast to high but short-lived concentrations after i. p. injections. There was neither antagonism nor synergism between boldine and doxorubicin, except a possible synergism of i. p. boldine 90 mg/kg combined with doxorubicin when compared with doxorubicin alone.Boldine was cytotoxic to MCF-7 cells and reduced their viability and proliferation in vitro. Exposure to boldine decreased bromodeoxyuridine incorporation and histone H3 phosphorylation but did not induce apoptosis. Boldine treatment resulted in p38, ERK, and JNK activation in the mitogen-activated protein kinase pathway in a dose-dependent manner. Since bioavailability in mice seems to be different from that reported in rats, pharmacokinetic studies in humans are needed to evaluate the role of boldine in the beneficial effects of Boldo infusions.

Cerasoidine, a Bis-aporphine Alkaloid Isolated from Polyalthia cerasoides during Screening for Wnt Signal Inhibitors

A new bis-aporphine alkaloid, cerasoidine (1), was isolated from the root extract of Polyalthia cerasoides together with the known bis-aporphine bidebiline E (2) during screening for compounds with Wnt signal inhibitory activities. The structure of cerasoidine (1) was established by X-ray analysis and shown by chiral HPLC analyses and electronic circular dichroism to be a 57:43 mixture of R(-)- and S(+)-atropisomers. Bidebiline E (2) exhibited inhibition of transcriptional activity of TCF/β-catenin with an IC50 value of 20.2 μM and was also found to inhibit Wnt signaling by decreasing nuclear β-catenin.

Cytotoxic Alkaloids from the Stem of Xylopia laevigata

Xylopia laevigata (Annonaceae), known locally as "meiú" or "pindaíba", is widely used in folk medicine in Northeastern Brazil. In the present work, we performed phytochemical analyses of the stem of X. laevigata, which led to the isolation of 19 alkaloids: (-)-roemerine, (+)-anonaine, lanuginosine, (+)-glaucine, (+)-xylopine, oxoglaucine, (+)-norglaucine, asimilobine, (-)-xylopinine, (+)-norpurpureine, (+)-N-methyllaurotetanine, (+)-norpredicentrine, (+)-discretine, (+)-calycinine, (+)-laurotetanine, (+)-reticuline, (-)-corytenchine, (+)-discretamine and (+)-flavinantine. The in vitro cytotoxic activity toward the tumor cell lines B16-F10 (mouse melanoma), HepG2 (human hepatocellular carcinoma), K562 (human chronic myelocytic leukemia) and HL-60 (human promyelocytic leukemia) and non-tumor peripheral blood mononuclear cells (PBMCs) was tested using the Alamar Blue assay. Lanuginosine, (+)-xylopine and (+)-norglaucine had the highest cytotoxic activity. Additionally, the pro-apoptotic effects of lanuginosine and (+)-xylopine were investigated in HepG2 cells using light and fluorescence microscopies and flow cytometry-based assays. Cell morphology consistent with apoptosis and a marked phosphatidylserine externalization were observed in lanuginosine- and (+)-xylopine-treated cells, suggesting induction of apoptotic cell death. In addition, (+)-xylopine treatment caused G₂/M cell cycle arrest in HepG2 cells. These data suggest that X. laevigata is a potential source for cytotoxic alkaloids.

7,7-Dimethylaporphine and Other Alkaloids from the Bark of Guatteria friesiana

Phytochemical investigation of the bark of Guatteria friesiana afforded 12 new aporphines (1-12), along with nine known alkaloids (13-21). The structures of the new alkaloids were determined on the basis of spectroscopic data interpretation. The cytotoxic activity of the isolated compounds against a small panel of tumor cell lines was assessed using the Alamar blue assay.