Lycopodium Alkaloids from Phlegmariurus carinatus with Cytotoxic and Neuroprotective Effects.

One new fawcettimine-type alkaloid, phlecarinadine A (1), and twelve known ones (2-13) were isolated from the whole plant of Phlegmariurus carinatus. Their chemical structures were unambiguously established by extensive spectroscopic analyses, including nuclear magnetic resonance (NMR) spectroscopic and high resolution electrospray ionization mass spectrometry (HR-ESI-MS). The absolute configuration of 1 was elucidated by the electronic circular dichroism (ECD) technique. These compounds were tested for their cytotoxic and neuroprotective activities. None of these compounds revealed cytotoxic activity against five tumor cells. Phlegmariurine B (2) exhibited potential neuroprotective effects against hemin-induced HT22 cell damage, with a 17.76 % increase in cell survival at 10 µM. In further study, 2 can ameliorate hemin-induced neuronal cell death via an anti-apoptotic pathway. These findings suggest that 2 might be a valuable lead compound with neuroprotective activity.

A new abietane diterpenoid from Lycopodium complanatum.

A new abietane diterpenoid, 1ß, 11-epoxyabieta-12-hydroxy-8, 11, 13-triene-7-one (1), along with three known compounds (2-4), was isolated from Lycopodium complanatum. Their structures were confirmed by the analysis of 1D, 2D NMR and HRESIMS data, and comparison with previous spectral data. All compounds were tested for inhibitory activities against A549, HepG2 and MCF-7 tumor cell lines. [Figure: see text].

Cytotoxic and nitric oxide inhibitory activities of triterpenoids from Lycopodium clavatum L.

Using combined chromatographic separation techniques, three new triterpenoids named lycomclavatols A-C (1-3), a new natural product, methyl lycernuate-A (4), as well as seven known compounds (5-11), were isolated from the methanol extract of the whole plants of Lycopodium clavatum. Their chemical structures were established based on 1 D/2D NMR and HR-ESI-MS spectroscopic analyses. Among the isolates, compound 1 exhibited inhibitory activity on NO production in LPS-stimulated BV2 cells (IC50 = 36.0 µM). In addition, 1 was cytotoxic against both HepG2 and A549 cancer cell lines, with IC50 values of 40.7 and 87.0 µM, respectively. Compounds 10 and 11 showed cytotoxicity on only HepG2 and A549 cells, with IC50 values of 91.2 and 57.6 µM, respectively. Our results contribute to understanding more the secondary metabolites produced by L. clavatum and provide a scientific rationale for further investigations of anti-inflammatory and anticancer effects for this valuable medicinal plant.

Serratane triterpenoids from Lycopodium complanatum and their anti-cancer and anti-inflammatory activities.

Phytochemical investigation of the ethyl acetate fraction of Lycopodium complanatum led to eight new serratane triterpenoids (lycomplanatums A-H, 1-8), along with five known analogues (9-13). Their structures were elucidated by extensive spectroscopic methods, including 1D/2D NMR, HRESIMS, and DFT GIAO 13C NMR calculation. Among them, compounds 2 and 13 showed moderate antiproliferative effects against seven human cancer cell lines, especially for MCF-7 with IC50 values of 13.8-44.7 µM. Additionally, the compounds were screened for anti-inflammatory effects based on their inhibitory activities of nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 2 and 13 diminished NO production more potently than others in a concentration-dependent manner.

Antiproliferative effects of combinational therapy of Lycopodium clavatum and quercetin in colon cancer cells.

Background Colorectal cancer (CRC) is the third most prevalent form of cancer and fourth leading cause of morbidity worldwide. Surgical resection remains the only curative approach for CRC, but recurrence following surgery is the main problem and ultimate cause of death. Lycopodium clavatum and quercetin have been found to exert its anticancer properties. The aim of the present study is to investigate whether quercetin or L. clavatum extract and combination of both have any profound role in reducing major inflammatory cytokines in Colo-320 cells. Methods L. clavatum and Quercetin alone or in combination was administered to colon cancer cells and various toxicity markers, gene expression analyses of apototic genes and gelatin zymmography were performed. Results Quercetin (50 µm) in combination with L. clavatum extract (10 µL) distinctly reduced cell growth and highlighted their potential effects in extirpation of colon cancer cells. Treatment with increased dose of L. clavatum extract in combination with quercetin reduced the colony size and proliferation potential when compared to the sole treatment of plant extracts. In the antimicrobial assays, it was observed that Lycopodium alone exhibited antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Characterization of L. clavatum extract and quercetin was performed and confirmed the presence of flavonoids and alkaloids. Treatment with Lycopodium and quercetin combination induced significant down-regulation in activities of MMP2 and MMP9 tested by gelatin zymography. The combined treatment greatly affected the mRNA expression of p53, Bcl2, Bax, Caspase 3, Wnt 1, Cyclin D1, and Catalase genes in colon cancer cells. Conclusion The synergistic effect between Lycopodium and quercetin might bring forward the enhanced antitumorigenic properties of combinational therapy with natural products to successfully combat the cancer progression with minimal side effects and resistance to drugs.

Serratane triterpenoids isolated from Lycopodium clavatum by bioactivity-guided fractionation attenuate the production of inflammatory mediators.

Lycopodium clavatum has been used in traditional medicine for the treatment of kidney disorders, rheumatic arthritis, cystitis, and gastritis. We isolated a new serratane triterpenoid (2), and five known triterpenoids (1, 3-6) from the ethyl acetate fraction of L. clavatum by bioactivity-guided fractionation based on their suppression of inflammatory cytokines. Two different cell lines, RAW 264.7 and HT-29 were used to determine the anti-inflammatory activity of the isolated compounds. Among them, compounds 1, 2, 4, and 5 significantly inhibited the production of lipopolysaccharide (LPS)-induced NO in macrophages. Compounds 1, 2, 4, and 5 reduced inducible nitric oxide (iNOS) expression in RAW 264.7 cells and compounds 1 and 6 downregulated COX-2, which correlated with the reduced expression of PGE2. Compounds 1, 2, 4, and 5 downregulated pro-inflammatory cytokines, such as interleukin-1ß (IL-1ß) in macrophages, and additionally suppressed the levels of IL-8 in HT-29 cells. To determine the signaling pathways involved in the suppression of NO production by these compounds, we investigated ERK1/2 and nuclear factor-kappa B (NF-κB) expression by western blot analysis. We observed that these compounds downregulated the expression of LPS-induced NF-κB and pERK 1/2 in RAW 264.7 cells. Our results demonstrate that serratane triterpenoids isolated from L. clavatum may be used as potential candidates for treating inflammatory bowel disease (IBD) due to their anti-inflammatory effects.

Lycopodium Attenuates Loss of Dopaminergic Neurons by Suppressing Oxidative Stress and Neuroinflammation in a Rat Model of Parkinson's Disease.

Parkinson's disease, a chronic, age related neurodegenerative disorder, is characterized by a progressive loss of nigrostriatal dopaminergic neurons. Several studies have proven that the activation of glial cells, presence of alpha-synuclein aggregates, and oxidative stress, fuels neurodegeneration, and currently there is no definitive treatment for PD. In this study, a rotenone-induced rat model of PD was used to understand the neuroprotective potential of Lycopodium (Lyc), a commonly-used potent herbal medicine. Immunohistochemcial data showed that rotenone injections significantly increased the loss of dopaminergic neurons in the substantia nigra, and decreased the striatal expression of tyrosine hydroxylase. Further, rotenone administration activated microglia and astroglia, which in turn upregulated the expression of α-synuclein, pro-inflammatory, and oxidative stress factors, resulting in PD pathology. However, rotenone-injected rats that were orally treated with lycopodium (50 mg/kg) were protected against dopaminergic neuronal loss by diminishing the expression of matrix metalloproteinase-3 (MMP-3) and MMP-9, as well as reduced activation of microglia and astrocytes. This neuroprotective mechanism not only involves reduction in pro-inflammatory response and α-synuclein expression, but also synergistically enhanced antioxidant defense system by virtue of the drug's multimodal action. These findings suggest that Lyc has the potential to be further developed as a therapeutic candidate for PD.

Cytotoxic polyhydroxy serratene triterpenoids from Lycopodium complanatum.

Phytochemical investigation of the 70% aqueous EtOH extract of Lycopodium complanatum led to six new polyhydroxy serratene triterpenoids (serrat A-F, 1-6), along with a known analogue (7). Their structures and configurations were elucidated by data analysis of HRESIMS, 1D and 2D NMR, in combination with comparisons of reported experimental spectroscopic data. All the isolates were evaluated cytotoxic activities against HepG2 cells, MCF-7 cells and series human lung cancer cell lines A549, Calu-6, NCI-H441, NCI-H226 and NCI-H1975. The results indicated that certain compounds inhibited proliferation of human cancer cells. Moreover, all compounds possessed selective cytotoxic activities on MCF-7 cells. Further, possible biosynthesis pathways of these compounds were proposed.

Evaluation of potential anti-cancer activity of cationic liposomal nanoformulated Lycopodium clavatum in colon cancer cells.

Research dealing with early diagnosis and efficient treatment in colon cancer to improve patient's survival is still under investigation. Chemotherapeutic agent result in high systemic toxicity due to their non-specific actions on DNA repair and/or cell replication. Traditional medicine such as Lycopodium clavatum (LC) has been claimed to have therapeutic potentials against cancer. The present study focuses on targeted drug delivery of cationic liposomal nanoformulated LC (CL-LC) in colon cancer cells (HCT15) and comparing the efficacy with an anti-colon cancer drug, 7-ethyl-10-hydroxy-camptothecin (SN38) along with its nanoformulated form (CL-SN38). The colloidal suspension of LC was made using thin film hydration method. The drugs were characterised using ultraviolet, dynamic light scattering, scanning electron microscopy, energy, dispersive X-ray spectroscopy. Invitro drug release showed kinetics of 49 and 89% of SN38 and LC, whereas CL-SN38 and CL-LC showed 73 and 74% of sustained drug release, respectively. Studies on morphological changes, cell viability, cytotoxicity, apoptosis, cancer-associated gene expression analysis of Bcl-2, Bax, p53 by real-time polymerase chain reaction and western blot analysis of Bad and p53 protein were performed. Nanoformulated LC significantly inhibited growth and increased the apoptosis of colon cancer cells indicating its potential anti-cancer activity against colon cancer cells.

Abietane diterpenoids from Lycopodium complanatum.

Five new abietane diterpenoids (complanatins A-E, 1-5) have been isolated from the club moss Lycopodium complanatum, along with two known abietane diterpenoids (xanthoperol and sugiol). Their structures were determined by comprehensive analysis of 1D, 2D NMR, CD and HRESIMS data. The cytotoxic effects of five compounds (1-4, 7) were evaluated in three human lung cancer cell lines (MSTO-211H, NCI-H2052 and NCI-H226). Compounds 3 and 4 exhibited cytotoxic activities against the three cell lines. In addition, a plausible biogenetic pathway of compounds 1-7 was proposed.

Ethanol Extract of Lycopodium serratum Thunb. Attenuates Lipopolysaccharide-Induced C6 Glioma Cells Migration via Matrix Metalloproteinase-9 Expression.

OBJECTIVE: To elucidate how ethanol extract of L. serratum (ELS) could exert anti-migratory effects on glioma with the suppression of nuclear factor kappa B (NF-κB) downstream pathway. METHODS: Cell viability of ELS on C6 glioma was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Nitric oxide (NO) assay and 2',7'-dichlorofluorescin diacetate (DCFH-DA) assay were applied to measure NO production and reactive oxygen species (ROS) generation on lipopolysaccharide (LPS)-induced C6 glioma cells. NF-κB, mitogen-activated protein kinase (MAPK), inducible nictric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein were determined by Western blot. Wound healing assay was used to investigate the inhibitory effect of ELS on fetal bovine serum (FBS)-induced migration and matrix metalloproteinase (MMP)-9 and -2 activity was examined by zymography. RESULTS: ELS suppressed LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 through inhibiting the expression of chemokine CCL2 (or monocyte chemoattractant protein-1, MCP-1). In addition, ELS inhibited the expression of iNOS, COX-2, and the production of NO by LPS in C6 glioma cells. ELS also significantly decreased serum-induced migration of C6 glioma cells in scratch wound healing in a dose-dependent manner (P<0.01). The activity of MMP-9 and -2 were also significantly attenuated by ELS with LPS treatment (P<0.01). CONCLUSIONS: Our results suggest that downregulation of MMP-9 gene expression might be involved in the anti-migration effect of ELS against LPS-induced C6 glioma cells.

A Single Oxidosqualene Cyclase Produces the Seco-Triterpenoid α-Onocerin.

8,14-seco-Triterpenoids are characterized by their unusual open C-ring. Their distribution in nature is rare and scattered in taxonomically unrelated plants. The 8,14-seco-triterpenoid α-onocerin is only known from the evolutionarily distant clubmoss genus Lycopodium and the leguminous genus Ononis, which makes the biosynthesis of this seco-triterpenoid intriguing from an evolutionary standpoint. In our experiments with Ononis spinosa, α-onocerin was detected only in the roots. Through transcriptome analysis of the roots, an oxidosqualene cyclase, OsONS1, was identified that produces α-onocerin from squalene-2,3;22,23-dioxide when transiently expressed in Nicotiana bethamiana In contrast, in Lycopodium clavatum, two sequential cyclases, LcLCC and LcLCD, are required to produce α-onocerin in the N. benthamiana transient expression system. Expression of OsONS1 in the lanosterol synthase knockout yeast strain GIL77, which accumulates squalene-2,3;22,23-dioxide, verified the α-onocerin production. A phylogenetic analysis predicts that OsONS1 branches off from specific lupeol synthases and does not group with the known L. clavatum α-onocerin cyclases. Both the biochemical and phylogenetic analyses of OsONS1 suggest convergent evolution of the α-onocerin pathways. When OsONS1 was coexpressed in N. benthamiana leaves with either of the two O. spinosa squalene epoxidases, OsSQE1 or OsSQE2, α-onocerin production was boosted, most likely because the epoxidases produce higher amounts of squalene-2,3;22,23-dioxide. Fluorescence lifetime imaging microscopy analysis demonstrated specific protein-protein interactions between OsONS1 and both O. spinosa squalene epoxidases. Coexpression of OsONS1 with the two OsSQEs suggests that OsSQE2 is the preferred partner of OsONS1 in planta. Our results provide an example of the convergent evolution of plant specialized metabolism.

Increased of the hepatocytes and splenocytes apoptosis accompanies clinical improvement and higher survival in mice infected with Trypanosoma cruzi and treated with highly diluted Lycopodium clavatum.

Recent evidence includes apoptosis as a defense against Trypanosoma cruzi infection, which promotes an immune response in the host induced by T cells, type 1, 2 and 17. Currently, there is no medicine completely preventing the progression of this disease. We investigated the immunological and apoptotic effects, morbidity and survival of mice infected with T. cruzi and treated with dynamized homeopathic compounds 13c: Kalium causticum (GCaus), Conium maculatum, (GCon), Lycopodium clavatum (GLy) and 7% alcohol solution (control, vehicle compounds, GCI). There was significant difference in the increase of apoptosis in the treated groups, compared with GCI, which might indicate action of the compounds in these cells. Infected animals treated with Lycopodium clavatum presented better performance compared with other groups. GLy showed a higher amount of hepatocytes and splenocytes undergoing apoptosis, higher number of apoptotic bodies in the liver, predominance of Th1 response, increased TNF-α and decreased IL-6, higher survival, lower morbidity, higher water consumption, body temperature, tendency to higher feed intake and weight gain compared with GCI. Conium maculatum had worse results with increased Th2 response with increased IL-4, worsening of the infection with early mortality of the animals. Together, these data suggest that highly diluted medicines modulate the immune response and apoptosis, affecting the morbidity of animals infected with a highly virulent strain of T. cruzi, being able to minimize the course of infection, providing more alternative approaches in the treatment of Chagas disease.

Identification and characterization of L-lysine decarboxylase from Huperzia serrata and its role in the metabolic pathway of lycopodium alkaloid.

Lysine decarboxylation is the first biosynthetic step of Huperzine A (HupA). Six cDNAs encoding lysine decarboxylases (LDCs) were cloned from Huperzia serrata by degenerate PCR and rapid amplification of cDNA ends (RACE). One HsLDC isoform was functionally characterized as lysine decarboxylase. The HsLDC exhibited greatest catalytic efficiency (kcat/Km, 2.11 s-1 mM-1) toward L-lysine in vitro among all reported plant-LDCs. Moreover, transient expression of the HsLDC in tobacco leaves specifically increased cadaverine content from zero to 0.75 mg per gram of dry mass. Additionally, a convenient and reliable method used to detect the two catalytic products was developed. With the novel method, the enzymatic products of HsLDC and HsCAO, namely cadaverine and 5-aminopentanal, respectively, were detected simultaneously both in assay with purified enzymes and in transgenic tobacco leaves. This work not only provides direct evidence of the first two-step in biosynthetic pathway of HupA in Huperzia serrata and paves the way for further elucidation of the pathway, but also enables engineering heterologous production of HupA.

Lysine-derived Alkaloids: Overview and Update on Biosynthesis and Medicinal Applications with Emphasis on Quinolizidine Alkaloids.

BACKGROUND: Plants produce a vast variety of specialized metabolites which can be a rich source for lead compounds for the development of new drugs. Alkaloids are one the largest groups of plant specialized metabolites important for natural product based pharmaceuticals. Of these, lysine (Lys)-derived alkaloids exhibit a wide range of pharmacological properties which are beneficial for humans. For instance they have anticancer, anti-Alzheimer's disease, anti-inflammatory, hypocholesterolemic and antiarrhtymic effects. Lys-derived alkaloids are widely distributed throughout the plant kingdom: they can be found in various species from clubmosses to flowering plants. Lys is one of the most essential amino acids for humans and livestock and is synthesized in the plastids of land plants. Lys-derived alkaloids can be divided into four major groups including quinolizidine, lycopodium, piperidine, and indolizidine alkaloids. Despite the importance of these compounds, the biosynthetic pathways of Lys-derived alkaloids are not well understood. With the exception of indolizidine alkaloids, Lys decarboxylase (LDC) is the enzyme involved in the first committed step of the biosynthesis by catalyzing the transformation of L-Lys into cadaverine. Cadaverine is then oxidized by copper amine oxidase (CuAO) and spontaneously cyclized to Δ1-piperideine Schiff base which is a universal intermediate for the production of various Lys-derived alkaloids. CONCLUSION: In this review, we briefly summarize the recent understanding about the structures, occurrences, analytical procedures, biosyntheses, and potential health effects and medical applications of Lys-derived alkaloids with emphasis on quinolizidine alkaloids (QAs).

Molecular Evolution and Functional Characterization of a Bifunctional Decarboxylase Involved in Lycopodium Alkaloid Biosynthesis.

Lycopodium alkaloids (LAs) are derived from lysine (Lys) and are found mainly in Huperziaceae and Lycopodiaceae. LAs are potentially useful against Alzheimer's disease, schizophrenia, and myasthenia gravis. Here, we cloned the bifunctional lysine/ornithine decarboxylase (L/ODC), the first gene involved in LA biosynthesis, from the LA-producing plants Lycopodium clavatum and Huperzia serrata We describe the in vitro and in vivo functional characterization of the L. clavatum L/ODC (LcL/ODC). The recombinant LcL/ODC preferentially catalyzed the decarboxylation of l-Lys over l-ornithine (l-Orn) by about 5 times. Transient expression of LcL/ODC fused with the amino or carboxyl terminus of green fluorescent protein, in onion (Allium cepa) epidermal cells and Nicotiana benthamiana leaves, showed LcL/ODC localization in the cytosol. Transgenic tobacco (Nicotiana tabacum) hairy roots and Arabidopsis (Arabidopsis thaliana) plants expressing LcL/ODC enhanced the production of a Lys-derived alkaloid, anabasine, and cadaverine, respectively, thus, confirming the function of LcL/ODC in plants. In addition, we present an example of the convergent evolution of plant Lys decarboxylase that resulted in the production of Lys-derived alkaloids in Leguminosae (legumes) and Lycopodiaceae (clubmosses). This convergent evolution event probably occurred via the promiscuous functions of the ancestral Orn decarboxylase, which is an enzyme involved in the primary metabolism of polyamine. The positive selection sites were detected by statistical analyses using phylogenetic trees and were confirmed by site-directed mutagenesis, suggesting the importance of those sites in granting the promiscuous function to Lys decarboxylase while retaining the ancestral Orn decarboxylase function. This study contributes to a better understanding of LA biosynthesis and the molecular evolution of plant Lys decarboxylase.

Serralongamines B-D, three new Lycopodium alkaloids from Lycopodium serratum var. longipetiolatum, and their inhibitory effects on foam cell formation in macrophages.

Three new Lycopodium alkaloids, serralongamines B-D (1-3), have been isolated from the club moss Lycopodium serratum var. longipetiolatum, and the structures were elucidated on the basis of spectroscopic data and chemical transformation. 1 and 3 significantly exhibited the inhibitory activity against foam cell formation in human macrophages, one of characteristic features of early atherosclerotic lesions.

New Lycopodium alkaloids from Phlegmariurus squarrosus.

Four new Lycopodium alkaloids (1-4), together with 15 known ones, were isolated from club moss Phlegmariurus squarrosus. Notably, 8α-hydroxylycojapodine A (1) was the first derivative of lycojapodine A (5) which was a novel C16N-type Lycopodium alkaloid with an unprecedented 6/6/6/7 tetracyclic ring system. Their structures were elucidated based on the spectroscopic data, including 1D and 2D NMR techniques.

Lycojaponicuminol A-F: cytotoxic serratene triterpenoids from Lycopodium japonicum.

Six new serratene triterpenoids (1-6), together with nine known triterpenoid compounds were isolated from the extract of club moss Lycopodium japonicum. The structures of isolated compounds were established by spectroscopic methods. The cytotoxic activities of all compounds were evaluated against three human cancer cell lines in vitro by MTT assay. Compounds 2, 6-8 and 11 exhibited moderate activities against all three cell lines with IC50 values of 2.28-11.81 µg/mL.

Apigenin, a bioactive flavonoid from Lycopodium clavatum, stimulates nucleotide excision repair genes to protect skin keratinocytes from ultraviolet B-induced reactive oxygen species and DNA damage.

In this study, we examined the antioxidative and the DNA protective potentials of apigenin, a flavonoid polyphenol isolated from Lycopodium clavatum, in both in-vitro (HaCaT skin keratinocytes) and in-vivo (mice) models against UV-B radiation. We used DAPI staining in UV-B-irradiated HaCaT skin keratinocytes pre-treated with and without apigenin to assess DNA damage. We also used a flow-cytometric analysis in mice exposed to UV-B radiation with or without topical application of apigenin to assess, through a comet assay, chromosomal aberrations and quanta from reactive oxygen species (ROS) generation. Data from the stability curves for the Gibb's free energy determined from a melting-temperature profile study indicated that apigenin increased the stability of calf thymus DNA. Immunofluorescence studies revealed that apigenin caused a reduction in the number of cyclobutane pyrimidine dimers (CPDs) after 24 h, the time at which the nucleotide excision repair (NER) genes were activated. Thus, apigenin accelerated reversal of UV-B-induced CPDs through up-regulation of NER genes, removal of cyclobutane rings, inhibition of ROS generation, and down-regulation of NF-κB and MAPK, thereby revealing the precise mechanism of DNA repair.