Selaginella Tamariscina Research Articles

The Effect of Selaginella tamariscina on Inhibition of Pancreatic Lipase and Lipid Accumulation

The Effect of Selaginella tamariscina on Inhibition of Pancreatic Lipase and Lipid Accumulation

Cloning and expression analysis in resurrection process of trehalose-6-phosphate synthase gene from Selaginella tamariscina

Selaginella tamariscina is a typical resuscitation medicinal plant with extreme drought tolerance. Trehalose plays an important role in the resurrection process, and the trehalose-6-phosphate synthase(TPS) is the key enzyme to synthesize trehalose in plants. In this study, the sequence of TPS was obtained by splicing from the transcriptome data of S. tamariscina. After the synthesis of cDNA based on the template of total RNA, the sequence was cloned by RT-PCR for verification and then analyzed by bioinformatics methods. The results indicated that the full-length coding sequence of StTPS was 2 799 bp (GenBank accession no. MH155231), and the encoded protein contained 932 amino acids. StTPS could be located in the chloroplastid according to subcellular localization prediction. There were two conserved domains belonging to glycogen phosphorylase glycosyltransferase (GPGTF) family but no signal peptide or transmembrane domain in StTPS. The expression of StTPS was determined by qRT-PCR and the variation of trehalose content was measured by HPLC-ELSD during the resurrection process of S. tamariscina. Meanwhile, the correlation between them was analyzed. The results showed that both the expression level of StTPS and the trehalose content increased associated with the extension of dehydration time, and declined associated with the extension of rehydration time which proved a significant positive correlation between the StTPS expression level and the trehalose content. The results suggested that the StTPS probably plays a central role in recovery process in S. tamariscina.

INSULIN-MIMETIC BIFLAVONOIDS FROM A VIETNAMESE MEDICINAL PLANT SELAGINELLA TAMARISCINA

During the search for antidiabetic agents from natural sources, four biflavonoids including amentoflavone (1), robustaflavone (2), cupressuflavone (3), and 3,8′′-biapogenin (4) have been isolated and structurally elucidated from the methanol extract of a Vietnamese medicinal plant Selaginella tamariscina by using combined chromatographic and spectroscopic experiments. All isolated compounds showed significant stimulatory effects on 2-NBDG glucose uptake in 3T3-L1 adipocyte cells. At a concentration of 10 μM, compounds 3 and 4 exhibited potential stimulatory effects by 1.47 and 1.44 fold of inductions as compared with the control (DMSO), respectively. In this assay, the positive control (insulin) showed an induction of 1.54 fold at a concentration of 100 nM. The result suggests that these biflavonoids maybe potential as insulin mimetics for developing antidiabetic agents.

Amentoflavone induces apoptosis and suppresses glycolysis in glioma cells by targeting miR-124-3p

Malignant glioma is the most common type of brain tumor with poor clinical outcome and survival. Therefore, it is imperative to develop novel therapeutic agents for managing glioma. The aim of this study was to investigate the role of amentoflavone (AF), an active flavonoid component in Selaginella tamariscina Spring, in glioma cells and the underlying mechanism of its action. Our results showed that miR-124-3p expression was significantly down-regulated in glioma tissues relative to normal brain tissues. AF decreased cell viability and triggered apoptosis in both glioma cell lines in a dose-dependent manner. AF induced apoptosis and inhibited glycolysis in the glioma cells by upregulating miR-124-3p. Furthermore, AF upregulated miR-124-3p by repressing DNMT1 through Sp1, which in turn was caused by the activation of ROS/AMPK signaling pathway by AF. In conclusion, AF could induce apoptosis and inhibited glycolysis in glioma cells via miR-124-3p. Our findings provide preliminary experimental data that support further investigation on the therapeutic efficacy of AF in glioma.

Genome Analysis of the Ancient Tracheophyte Selaginella tamariscina Reveals Evolutionary Features Relevant to the Acquisition of Desiccation Tolerance

Resurrection plants, which are the “gifts” of natural evolution, are ideal models for studying the genetic basis of plant desiccation tolerance. Here, we report a high-quality genome assembly of 301 Mb for the diploid spike moss Selaginella tamariscina, a primitive vascular resurrection plant. We predicated 27 761 protein-coding genes from the assembled S. tamariscina genome, 11.38% (2363) of which showed significant expression changes in response to desiccation. Approximately 60.58% of the S. tamariscina genome was annotated as repetitive DNA, which is an almost 2-fold increase of that in the genome of desiccation-sensitive Selaginella moellendorffii. Genomic and transcriptomic analyses highlight the unique evolution and complex regulations of the desiccation response in S. tamariscina, including species-specific expansion of the oleosin and pentatricopeptide repeat gene families, unique genes and pathways for reactive oxygen species generation and scavenging, and enhanced abscisic acid (ABA) biosynthesis and potentially distinct regulation of ABA signaling and response. Comparative analysis of chloroplast genomes of several Selaginella species revealed a unique structural rearrangement and the complete loss of chloroplast NAD(P)H dehydrogenase (NDH) genes in S. tamariscina, suggesting a link between the absence of the NDH complex and desiccation tolerance. Taken together, our comparative genomic and transcriptomic analyses reveal common and species-specific desiccation tolerance strategies in S. tamariscina, providing significant insights into the desiccation tolerance mechanism and the evolution of resurrection plants.

Biflavonoids Isolated from Selaginella tamariscina and Their Anti-Inflammatory Activities via ERK 1/2 Signaling.

Selaginella tamariscina (S. tamariscina) (Beauv.) Spring (Selaginellaceae) has been used in oriental medicine for the treatment of dysmenorrhea, chronic hepatitis, hyperglycemia, amenorrhea, hematuria, prolapse of the anus and metrorrhagia. In the present study, we isolated two strong anti-inflammatory compounds, the biflavonoids hinokiflavone (H) and 7′-O-methyl hinokiflavone (mH), from S. tamariscina and examined their anti-inflammatory activities in lipopolysaccharide (LPS)-mediated murine macrophages (RAW 264.7) and colon epithelial cells (HT-29). H and mH suppressed the production of the inflammatory mediators nitric oxide (NO), interleukin (IL)-6, IL-8, and tumor-necrosis factor (TNF)-α, which are most highly activated in inflammatory bowel disease (IBD). In addition, Western blot analysis revealed that H and mH suppressed the LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, and the activation of nuclear factor-κB (NF-κB) and extracellular regulated kinases (ERK) 1/2. These results suggest that H and mH are compounds having potent anti-inflammatory effects that could be used to treat such diseases as IBD.

Two new anthraquinone derivatives and one new triarylbenzophenone analog from Selaginella tamariscina

Two new anthraquinone derivatives, selaginones A (1) and B (2), and one new triarylbenzophenone analog, selagibenzophenone B (3), were isolated from Selaginella tamariscina (Beauv.) Spring. Their structures were established by 1D-, 2D-NMR and HR-ESI-MS data. Compounds 1 and 2 represent the uncommon examples of aryl substituted anthraquinone derivatives. Especially, compound 2 is a unique anthranone with exceptional structural feature, in which a p-hydroxyphenyl moiety is attached to the C-10 position. Compound 3 is the second naturally occurring triarylbenzophenone and showed moderate activity against SMCC-7721 and MHCC97-H cell lines with IC50 values of 39.8, 51.5 μM respectively.

Comparing coagulation activity of Selaginella tamariscina before and after stir-frying process and determining the possible active constituents based on compositional variation

Context: Selaginella tamariscina (P. Beauv.) Spring (Selaginellaceae) (ST) has been widely used in China as a medicine for improving blood circulation. However, its processed product, S. tamariscina carbonisatus (STC), possesses opposite haemostatic activity.Objective: To comprehensively evaluate the activity of ST and STC on physiological coagulation system of rats, and seek potential active substances accounting for the activity transformation of ST during processing.Materials and methods: The 75% methanol extracts of the whole grass (fine powder) of ST and STC were prepared, respectively. Male Sprague–Dawley rats were randomly divided into five groups: control group, model group, model + ST group, model + STC group and positive control group (model + Yunnanbaiyao). The duration of intragastric administration was 72 h at 12 h intervals. Haemorheology parameters were measured using an LB-2 A cone-plate viscometer and the existed classic methods, respectively. SC40 semi-automatic coagulation analyzer was employed to determine coagulation indices. Meanwhile, HPLC and LC-MS were applied for chemical analyses of ST and STC extracts.Results: STC shortened tail-bleeding time, increased whole blood viscosity (WBV) and plasma viscosity (PV), decreased erythrocyte sedimentation rate blood (ESR), reduced activated partial thromboplastin time (APTT) and increased the fibrinogen (FIB) content in the plasma of bleeding model rats. Although ST could shorten APTT and TT, the FIB content was significantly decreased by ST. Dihydrocaffeic acid with increased content in STC vs. ST showed haemostatic activity for promoting the platelet aggregation induced by collagen and trap-6, and reducing APTT and PT significantly with a concentration of 171.7 μM in vitro. Amentoflavone with reduced content in STC vs. ST inhibited ADP and AA-induced platelet aggregation significantly with a concentration of 40.7 μM.Discussion and conclusions: As the processed product of ST, STC showed strong haemostatic activity on bleeding rat through regulating the parameters involved in haemorheology and plasma coagulation system. Two active compounds, dihydrocaffeic acid and amentoflavone, might be partially responsible for the haemostatic and anticoagulant activity of STC and ST, respectively.

Inhibitory Effect of Selaginellins from Selaginella tamariscina (Beauv.) Spring against Cytochrome P450 and Uridine 5'-Diphosphoglucuronosyltransferase Isoforms on Human Liver Microsomes.

Selaginella tamariscina (Beauv.) has been used for traditional herbal medicine for treatment of cancer, hepatitis, and diabetes in the Orient. Numerous bioactive compounds including alkaloids, flavonoids, lignans, and selaginellins have been identified in this medicinal plant. Among them, selaginellins having a quinone methide unit and an alkylphenol moiety have been known to possess anticancer, antidiabetic, and neuroprotective activity. Although there have been studies on the biological activities of selaginellins, their modulatory potential of cytochrome P450 (P450) and uridine 5′-diphosphoglucuronosyltransferase (UGT) activities have not been previously evaluated. In this study, we investigated the drug interaction potential of two selaginellins on ten P450 isoforms (CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 2J2 and 3A) and six UGT isoforms (UGT1A1, 1A3, 1A4, 1A6, 1A9 and 2B7) using human liver microsomes and liquid chromatography-tandem mass spectrometry. Selaginellin and selaginellin M had high inhibitory potential for CYP2C8-mediated amodiaquine O-demethylation with IC50 values of 0.5 and 0.9 μM, respectively. Selaginellin and selaginellin M also showed medium inhibitory potential against CYP2C9, CYP2J2, UGT1A1, and UGT1A3 (1 μM < IC50 < 5 μM). These two selaginellins had low inhibitory potential against CYP1A2, CYP2A6, CYP2E1, and UGT1A6 (IC50 > 25 μM). This information might be helpful to predict possible drug interaction potential of between selaginellins and co-administered drugs.

Selagintamarlin A: A Selaginellin Analogue Possessing a 1H-2-Benzopyran Core from Selaginella tamariscina.

Selagintamarlin A (1), a novel selaginellin analogue featuring the unique motif of 1H-2-benzopyran, a new selaginpulvilin E (2), together with eight known analogues were isolated from Selaginella tamariscina. Their structures were elucidated by extensive spectroscopic analyses. A plausible biosynthetic pathway of 1 was also postulated. Compound 1 showed remarkable inhibitory activity against phosphodiesterase-4 (PDE4D2), with an IC50 value of 40 nM, which is 20-fold higher than that of the positive control (rolipram). Furthermore, compound 1 significantly inhibited tubulin polymerization.

PTP1B inhibitors from Selaginella tamariscina (Beauv.) Spring and their kinetic properties and molecular docking simulation

Diabetes is one of the most popular worldwide diseases, regulated by the defects in insulin secretion, insulin action, or both. The overexpression of protein tyrosine phosphatase 1B (PTP1B) was found to down-regulate the insulin-receptor activation. PTP1B has been known as a strategy for the treatment of diabetes via the regulation of insulin signal transduction pathway. Herein, we investigated the PTP1B inhibitors isolated from natural sources. The chemical investigation of Selaginella tamariscina (Beauv.) Spring revealed seven unsaturated alkynyl phenols 1–7, four new selaginellins T–W 1–4 together with three known compounds 5–7 isolated from the aerial parts. The structures of the isolates were determined by spectroscopic techniques (1D/2D-NMR, MS, and CD). The inhibitory effects of these isolates on the PTP1B enzyme activity were investigated. Among them, compounds 2–7 significantly exhibited the inhibitory effects with the IC50 values ranging from 4.8 to 15.9μM. Compound 1 moderately displayed the inhibitory activity with an IC50 of 57.9μM. Furthermore, active compounds were discovered from their kinetic and molecular docking analysis. The results revealed that compounds 2 and 4–7 were mixed-competitive inhibitors, whereas compound 3 was a non-competitive inhibitor. This data confirm that these compounds exhibited potential inhibitory effect on the PTP1B enzyme activity.

Therapeutic Effects of Selaginella tamariscina on the Model of Acute Gout with Hyperuricemia in Rats Based on Metabolomics Analysis

Gout is a disease of purine metabolic disorders which results from long‐term hyperuricemia and the sodium urate deposition in and around the joints. Selaginella tamariscina (ST) is an important traditional Chinese herbal medicine and is used for the treatment of gout and hyperuricemia. In this study, the rat model of acute gout with hyperuricemia was established by intraperitoneal injection of xanthine and oxonic acid potassium salt and articular injection monosodium urate (MSU). The effect of ST in the treatment of gout was investigated by measuring joint swelling, the expression of IL‐1β in serum and histological changes of joint by haematoxylin eosin (H&amp;E) staining. Subsequently, urine metabolomics analysis for biomarkers discovery in acute gout with hyperuricemia rats was performed by the ultra‐performance liquid chromatography‐electrospray ionization quadruple time‐of‐flight mass spectrometry (UPLC‐ESI‐QTOF/MS) combined with chemometric approach. Principal component analysis (PCA) and orthogonal partial least squares‐discriminant analysis (OPLS‐DA) were used to detect potential biomarkers. A total of 18 potential biomarkers were identified mainly including tryptophan metabolism; tyrosine metabolism; lysine methylation; pyrimidine metabolism; purine metabolism; TCA cycle and fatty acid metabolisms. This study indicates that ST could efficiently ameliorate the disease of acute gout with hyperuricemia in rats. The related metabolic biomarkers could provide useful information and the metabolic mechanism could be used for further study about the model of acute gout with hyperuricemia in rats.

AKR1B10-inhibitory Selaginella tamariscina extract and amentoflavone decrease the growth of A549 human lung cancer cells in vitro and in vivo

Ethnopharmacological relevanceSelaginella tamariscina (P.Beauv.) Spring is a traditional medicinal plant used to treat various human diseases, including cancer, in Asia. The detailed molecular mechanism underlying the anti-cancer effects of this plant and the anti-cancer action of the combinatorial treatment of S. tamariscina and doxorubicin have not yet been investigated. Aim of the studyWe evaluated the inhibitory activity of S. tamariscina extract (STE) and its major compound, amentoflavone, on human aldo-keto reductase family 1B10 (AKR1B10), which is a detoxification enzyme involved in drug resistance, to evaluate their anti-cancer effects and their potential as adjuvant agents for doxorubicin cancer chemotherapy. Materials and methodsWe tested the AKR1B10 inhibitory activity of STE and amentoflavone via an in vitro biochemical assay using recombinant human AKR1B10. We tested the anti-proliferative activity in A549, NCI-H460, SKOV-3, and MCF-7 human cancer cells, which contain different expression levels of AKR1B10, and determined the combination index to evaluate whether the addition of STE and amentoflavone is synergistic or antagonistic to the anti-cancer action of doxorubicin. We finally evaluated the in vivo anti-tumor effects of STE in a nude mouse xenograft model of A549 cells. ResultsSTE and amentoflavone potently inhibited human AKR1B10 and synergistically increased the doxorubicin anti-proliferative effect in A549 and NCI-H460 human lung cancer cells that express a high level of AKR1B10 mRNA and protein. STE also significantly inhibited A549 tumor growth in animal experiments. ConclusionOur results suggest that STE and amentoflavone could be potential anti-cancer agents that target AKR1B10 and might be candidate adjuvant agents to boost the anti-cancer effect of doxorubicin.

Amentoflavone enhances osteogenesis of human mesenchymal stem cells through JNK and p38 MAPK pathways.

Amentoflavone is a bioflavonoid found in a variety of traditional Chinese medicines such as Gingko and Selaginella tamariscina. It has been reported that amentoflavone has anti-inflammatory, antioxidant, antiviral and anticancer effects. However, the effect of amentoflavone on osteogenic differentiation of human mesenchymal stem cells (hMSCs) has not been studied. In this study, we aim to explore the effect of amentoflavone on the proliferation and osteogenic differentiation of hMSCs. The results showed that amentoflavone significantly enhanced the proliferation, alkaline phosphatase (ALP) activity and mineralization in hMSCs. Western blot analysis revealed that the expression of runt-related transcription factor 2 and osterix proteins was upregulated in amentoflavone-treated hMSCs. Furthermore, we investigated the possible signaling pathways responsible for osteogenic differentiation of hMSCs by amentoflavone. We found that amentoflavone significantly increased the levels of phosphorylated JNK and p-p38. The amentoflavone-induced increases of ALP and mineralization were significantly diminished when the JNK and p38 MAPK pathways were blocked by selected inhibitors (SP600125, SB203580) in hMSCs. Furthermore, in vivo evidence indicated that amentoflavone protected against the dexamethasone-induced inhibition of osteoblast differentiation in tg(sp7:egfp) zebrafish larvae. Thus, we showed for the first time that amentoflavone improves the osteogenesis of hMSCs through the JNK and p38 MAPK pathway. Amentoflavone may be beneficial in treating bone-related disorders.

Cellular Biochemical Changes in Selaginella tamariscina (Beauv.) Spring and Sellaginella plana (Desv. ex Poir.) Heiron. as Induced by Desiccation.

The biochemical changes in two Selaginella species namely, S. tamariscina (Beauv.) Spring and S. plana (Desv. ex Poir.) Heiron., as induced by desiccation and subsequent rehydration were explored. Plants were allowed to dehydrate naturally by withholding irrigation until shoot's relative water content (RWC) reached <10%. After which, dehydrated plants were watered until fully rehydrated states were obtained which was about 90% RWC or more. Desiccation-tolerance characteristics were observed in S. tamariscina while desiccation-sensitivity features were seen in S. plana. Membrane integrity was maintained in S. tamariscina but not in S. plana as evidenced in the relative electrolyte leakage measurements during desiccation phase and the subsequent rehydration stage. Pigment analyses revealed conservation of some chlorophylls and carotenoids during desiccation and reaching control levels following rehydration in S. tamariscina. Very low pigment contents were found in S. plana during desiccation phase and the pigments were not recovered during rehydration attempt. Meanwhile, compatible solute determination showed rise in total sugar and proline contents of desiccated S. tamariscina only, indicating presence of biochemical protection machineries in this species and absence of such in S. plana during dehydrating conditions. These data indicate that one key element for desiccation-tolerance in lower vascular plants is the ability to protect tissues from severe damages caused by intense desiccation.

Soluble Epoxide Hydrolase Inhibitory Activity of Selaginellin Derivatives from Selaginella tamariscina.

Selaginellin derivatives 1–3 isolated from Selaginella tamariscina were evaluated for their inhibition of soluble epoxide hydrolase (sEH) to demonstrate their potential for the treatment of cardiovascular disease. All selaginellin derivatives (1–3) inhibited sEH enzymatic activity and PHOME hydrolysis, in a dose-dependent manner, with IC50 values of 3.1 ± 0.1, 8.2 ± 2.2, and 4.2 ± 0.2 μM, respectively. We further determined that the derivatives function as non-competitive inhibitors. Moreover, the predicted that binding sites and interaction between 1–3 and sEH were solved by docking simulations. According to quantitative analysis, 1–3 were confirmed to have high content in the roots of S. tamariscina; among them, selaginellin 3 exhibited the highest content of 189.3 ± 0.0 μg/g.

Anti‐Inflammatory Activities of Biapigenin Mediated by Actions on p38 MAPK Pathway

Biapigenin is a naturally occurring biflavonoid found in Selaginella tamariscina. This study aimed to investigate the anti‐inflammatory activity of biapigenin and its mechanisms of action, and to identify possible target proteins. Biapigenin suppressed nitric oxide (NO) production, as well as tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, and macrophage inflammatory protein (MIP)‐2 cytokine release. Moreover, biapigenin completely inhibited IL‐1β, inducible nitric oxide synthases (iNOS), and MIP‐2 mRNA expression and partially suppressed MIP‐1 and TNF‐α expression. Lipopolysaccharide (LPS)‐induced upregulation of p38 mitogen‐activated protein kinase (MAPK) phosphorylation was significantly reduced by biapigenin. Fluorescence titration experiment revealed that biapigenin bound to p38 with a high binding affinity of 2.57 × 106 M−1. These results suggest that biapigenin demonstrates anti‐inflammatory activities by the regulation of phosphorylation of p38 MAPK pathway. Our results strongly suggest that biapigenin may be a potent biflavonoid inhibitor of p38 MAPK and have therapeutic applications in the treatment of inflammatory diseases.

New Selaginellin derivatives from Selaginella tamariscina

Two new selaginellin derivatives selaginellin P (1) and selaginellin Q (2) were isolated from Selaginella tamariscina. The structures of 1 and 2 were established as 2,4′-dihydroxy-4-methyl-3-[(4-hydroxyphenyl)ethynyl]biphene (1) and 2,4′-dihydroxy-3-[(4-hydroxyphenyl)ethynyl]biphene (2) on the basis of spectroscopic means including HR-ESI-MS, 1D, and 2D NMR experiments.

Soluble Epoxide Hydrolase Inhibitory Constituents from Selaginella tamariscina

A novel norneolignan, tamariscinol T (1), and six known compounds, protocatechuic acid (2), vanillic acid (3), caffeic acid (4), amentoflavone (5), 2,3‐dihydroamentoflavone (6), and 2″,3″‐dihydroamentoflavone (7), were isolated from Selaginella tamariscina. Their structures were elucidated using 1D/2D NMR, high‐resolution electrospray ionization mass spectrometry (HR‐ESI‐MS), and infrared (IR), ultraviolet (UV), and circular dichroism (CD) spectroscopy. The effects of the isolated compounds on soluble epoxide hydrolase (sEH) activity were then evaluated. Compounds 5–7 potently inhibited sEH activity with IC50 values of 24.3 ± 1.6, 5.4 ± 0.1, and 11.9 ± 0.1 μM, respectively. In addition, analysis of the kinetics of compounds 5–7 revealed that their inhibitory actions were noncompetitive, with inhibition constants (Ki) of 24.4 ± 1.2, 8.6 ± 0.4, and 5.3 ± 0.6 μM, respectively.

Comparison of cytotoxic activities of extracts from Selaginella species.

Background:Selaginella species are resurrection plants, which are known, possess various molecular bioactivities depending on species, but only a few species have been detailed observe in the advanced research.Objective:The objective of the following study is to compare the chemical profiles of different species of Selaginella and to investigate cytotoxicity and induction of apoptosis activities of some species of Selaginella.Materials and Methods:The high-performance liquid chromatography (HPLC) method was developed for chemical analysis. Ethyl acetate, ethanol and water-soluble extracts from seven Selaginella species were submitted to 3-(4,5-dimenthyl thizol-2-yl)-2,5-diphenyl tetrazolium bromide assay, flow cytometry, deoxyribonucleic acid (DNA) laddering analysis and caspase-3 expression using Bel-7402, HT-29 and HeLa cells.Results:The HPLC analysis revealed two major common peaks, which were identified as amentoflavone and robustaflavone and another three main peaks in their chromatograms. The results showed that S. labordei, Selaginella tamariscina and Selaginella uncinata had relatively stronger activities on Bel-7402 and HeLa cells and Selaginella moellendorfii had moderate antiproliferation activities, but Selaginella remotifolia and Selaginella pulvinata had almost no inhibitory activities. The main active components were in the ethyl acetate extracts which had abundant biflavonoids. The effects of these extracts on cell proliferation and apoptosis in different cells were not the same, they were more apparent on HeLa cells than on HT-29 cells. The assay of DNA laddering analysis and caspase-3 expression further confirmed that inducing cell apoptosis was one of antitumor mechanisms and antitumor activities of Selaginella species were related to apoptosis induced by caspase family.Conclusion:S. labordei, S. tamariscina and S. uncinata would be potential antitumor agents.