Estrogenic Activity of Derris scandens Stem Extract and its Major Compounds Using MCF-7 Cell Proliferation Assay and Estrogen-Related Gene Expression.

Derris scandens, which contains isoflavones and prenylated derivatives, has analgesic and anti-inflammatory properties and is an ingredient in traditional Thai medicine for perimenopause and menopause. However, the estrogenic activity of D. scandens has not yet been explored. Therefore, this study aimed to examine the estrogenic activity of the stem extract of D. scandens and its isoflavone derivatives. In this study, we conducted a proliferation assay in MCF-7 cells, and used quantitative reverse transcription polymerase chain reaction to assess gene expression. We found that the relative cell proliferation of the compounds (1 µM) was ranked in the following order as compared to 0.1 nM 17ß-estradiol (100%): genistein (97.84%) > derrisisoflavone A (83.17%) > genistein-7-O-[α-rhamnopyranosyl-(1 → 6)-glucopyranoside] (69.55%) > 6,8-diprenylgenistein (51.91%) > lupalbigenin (18.72%). Furthermore, cotreatment with 1 µM lupalbigenin and 0.1 nM 17ß-estradiol was performed, which decreased cell proliferation to 80.38%. In vitro results suggest that lupalbigenin has an estrogen-antagonistic effect. At a dose of 1 µM, genistein had the strongest efficacy in increasing the expression of human estrogen receptor ß by 4.0-fold compared to the control. Furthermore, genistein-7-O-[α-rhamnopyranosyl-(1 → 6)]-ß-glucopyranoside augmented the gene expression of human estrogen receptor α and human estrogen receptor ß by 1.5- and 3.4-fold, respectively. Prenylated derivatives of genistein (derrisisoflavone A, 6,8-diprenylgenistein, and lupalbigenin) significantly suppressed the gene expression of the human androgen receptor. The administration of the crude extract at 10 µg/mL significantly suppressed human androgen receptor (0.6-fold) and transmembrane protease serine 2 (0.1-fold) expression but did not significantly affect human estrogen receptor α and human estrogen receptor ß gene expression. This herbal medicine may be safe for estrogen-exposed breast cancer patients.

Identification of Major Bioactive Anti-inflammatory Compounds of Derris scandens Stem Using RAW 264.7 Cells and HPLC-UV Analysis.

Derris scandens (DS) is widely recognized for its therapeutic properties, specifically its analgesic effects, which significantly alleviate muscle pain. The chemical constituents of DS stem include various isoflavone derivatives. However, there is currently a lack of specified anti-inflammatory chemical markers and analytical methods for quality control. The present study aimed to evaluate the anti-inflammatory activity of DS and its constituents using the RAW 264.7 cell model. The expression of inflammatory genes such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and 5-lipoxygenase (5-LOX) was examined using quantitative RT-PCR. An high-performance liquid chromatography with a UV detection method was developed to quantitatively analyze genistein-7-O-[α-rhamnopyranosyl-(1 → 6)]-ß-glucopyranoside, genistein, derrisisoflavone A, lupalbigenin, and 6,8-diprenylgenistein in DS stem. The developed HPLC-UV method demonstrated high sensitivity with limits of detection and quantification ranging from 0.01 to 0.06 µg/mL and 0.03 to 0.18 µg/mL, respectively. The accuracy of the method ranged from 93.3 to 109.6%. Furthermore, the repeatability and reproducibility of the method were suitable, as indicated by the relative standard deviations of ≤ 3.02% and ≤ 6.22%, respectively. The DS extract notably inhibited NO production, exhibiting effects comparable to those of 500 µM diclofenac, and substantially suppressed the expression of iNOS, COX-2, IL-6, and 5-LOX of lipopolysaccharide (LPS)-induced genes. As to the pure isoflavone derivatives, the order of NO production inhibition was found to be genistein > lupalbigenin > derrisisoflavone A > 6,8-diprenylgenistein > genistein-7-O-[α-rhamnopyranosyl-(1 → 6)]-ß-glucopyranoside. Genistein, derrisisoflavone A, and 6,8-diprenylgenistein significantly suppressed the upregulation of all LPS-induced genes. Consequently, these compounds are recommended as anti-inflammatory markers for the quantitative chemical analysis of DS.

Study on Chemical Components from Derris taiwaniana and Their Lung Epithelial Cell Protect Effects.

The ethanol extract of roots of Derris taiwaniana gave two undescribed compounds, 3,3'-dimethoxy-5'-hydroxystilbene-4-O-ß-apiofuranosyl-(1→6)-ß-D-glucopyranoside (1) and 4',5-dihydroxy-3'-methoxyisoflavone-7-O-ß-apiofuranosyl-(1→6)-ß-D-glucopyranoside (2), along with thirty known components. Among them, compounds 14, 16-17, 23, 26-32 were isolated from this genus for the first time. Their structures were established based on physico-chemical properties and spectroscopic data, the lung epithelial cell protective effects were evaluated using NNK-induced MLE-12 cells. Among them, 2α,3α-epoxy-5,7,3',4'-tetrahydroxyflavan-(4ß-8-catechin) (30) showed the best significant protective effect, speculated to be the key component of D. taiwaniana that plays a protective role in lung epithelial cells.

Four new isoflavones from Derris scandens and their in vitro antiproliferative effects.

Four new compounds (derriscandenon D (1), E (2), F (3), G (4)) and six known isoflavones (warangalone (5), millewanin E (6), rhynedlin A (7), 6,8-diprenylgenistein (8), isolupalbigenin (9), isoscandinone (10)) were isolated from the acetone extract of the branches of Derris scandens. These compounds were assayed for cell viability using the human lung carcinoma cell line A549, colorectal carcinoma cell line Colo205, epidermoid carcinoma cell line KB, the human acute lymphoblastic leukaemia cell line NALM-6, and human dermal fibroblasts. Compounds 2 and 3 significantly decreased the viability of KB cells, with IC50 values of 2.7 and 12.9 µM, respectively. In addition, compounds 2 and 3 reduced the mitochondrial membrane potential in KB cells. Compounds 2 and 3 strongly down-regulated the cell viability of cell lines KB and NALM-6, achieving IC50 values of 2.7 and 0.9 µM, respectively, compared with the positive control staurosporine at 1.25 and 0.01 µM, respectively.

A new anti-austerity agent, 4'-O-methylgrynullarin from Derris scandens induces PANC-1 human pancreatic cancer cell death under nutrition starvation via inhibition of Akt/mTOR pathway.

An ethanolic extract of Derris scandens flowers showed potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrient-deprived condition, with a PC50 value of 0.7 µg/mL. Phytochemical investigation of this active extract led to the isolation of four prenylated isoflavones (1-4) including a new compound named 4'-O-methylgrynullarin (1). The structure elucidation of the new compound was achieved by HRFABMS and NMR spectroscopic analysis. The isolated compounds exhibited potent anti-austerity activity against four different human pancreatic cancer cell lines under nutrient-deprived conditions. The new compound 4'-O-methylgrynullarin (1) was also found to inhibit PANC-1 cell migration and colony formation under nutrient-rich condition. Mechanistically, compound 1 inhibited key survival proteins in the Akt/mTOR signaling pathway. Therefore, 4'-O-methylgrynullarin (1) can be considered as a potential lead compound for the anticancer drug development based on the anti-austerity strategy.

Therapeutic Potential of Genus Pongamia and Derris: Phytochemical and Bioactivity.

Genus Pongamia and Derris belong to the Leguminosae family and are reported synonymously in literature. Although many compounds have been isolated from different plant parts but seed oil is known to produce non-edible medicinally important furanoflavonoids. The seed oil, commonly known as Karanj oil in Ayurvedic and Siddha traditional systems of medicine, is reported for the treatment of various skin infections and psoriasis. Several phytopharmacological investigations have proved the medicinal potential of furanoflavonoids in the skin and other disorders. Not only furanoflavonoids but several other important phenolic constituents such as chalcones, dibenzoylmethanes, aurones, isoflavones, flavanone dihydroflavonol, flavans, pterocarpans, rotenoids, coumarins, coumestans, stilbenoids and peltygynoids and their glycosides have been reported for different biological activities including antihyperglycemic, anti-inflammatory, anticancer, insecticidal, anti-alzheimer's, gastro protective, antifungal, antibacterial, etc. In the present review, the phytochemistry and pharmacological activities of the genera Pongamia and Derris have been summarized.

Three isoflavones from Derris scandens (Roxb.) Benth and their cancer chemopreventive activity and in vitro antiproliferative effects.

Three undescribed isoflavones, derriscandenon A, B, and C, together with seven known isoflavones were isolated and structurally characterized during a study of the chemical constituents in the leaves of Derris scandens (Roxb.) Benth (Leguminosae, Fabaceae) collected in Bangladesh. The inhibitory activity of the compounds against activation of Epstein-Barr virus antigen (EBV-EA) by 12-O-tetradecanoylphorbo-13-acetate (TPA) was measured to identify possible chemopreventive agents. Mild inhibitory effects (IC50 278-290 mol ratio/32 pmol TPA) against EBV-EA induction compared with curcumin (IC50 341 mol ratio/32 pmol TPA) were observed for four known compounds (lupalbigenin, isopalbigenin, glyurallin, and isangustone A). Next, we focused on antitumor effects and investigated cell viability, cell proliferation, and mitochondria membrane potential by using an MTT assay, a live cell monitoring system, and fluorescence staining. Of the seven isoflavones tested for cell viability, a dose-dependent decrease in cell viability was observed for four isoflavones (derriscandenon B and C, derrubone, and glyurallin) in KB cells and two compounds (derriscandenon B and isochandaisone) in NALM6-MSH+ cells. In addition, the proliferation of KB cells was significantly inhibited by these four compounds at a concentration of 5 µM. The mitochondria membrane potentials of KB cells treated with derriscandenon C, derrubone, and glyurallin at the IC50 concentration were decreased by about 55%, whereas undescribed compound derriscandenon B had no effect. Our results show that some of the compounds isolated from D. scandens may be suitable as seed compounds for cancer prevention and therapy.

Anticariogenic Activities of Derris reticulata Ethanolic Stem Extract Against Streptococcus mutans.

BACKGROUND AND OBJECTIVE: Streptococcus mutans is a dominant causative pathogen of dental caries, which is a major oral health problem affecting million people worldwide. Derris reticulata is a medicinal plant possessing antimicrobial activity against several Gram-positive pathogenic bacteria. None the less, its effects on growth and cariogenic properties of S. mutans has not been clearly established. This study aimed to investigate the antibacterial and anti cariogenic activities of the D. reticulata ethanolic stem extract. MATERIALS AND METHODS: The TLC analysis was performed to authenticate the D. reticulata sample. Minimum inhibition concentration and minimum bactericidal concentration were determined by using broth dilution and drop plate methods, respectively. Sucrose dependent and sucrose independent-adherences, biofilm formation and glycolytic pH drop assays were performed to evaluate the anticariogenic activity. RESULTS: The ethanolic stem extract of D. reticulata possessed the antibacterial activity against S. mutans with the MIC and MBC of 0.875±0.250 and 1.750±0.500 mg mL-1, respectively. The extract at the lower concentrations of sub-MIC also had significant inhibitory actions against the cariogenic properties of S. mutans, including surface adherence, biofilm formation and glycolytic acid production. CONCLUSION: The D. reticulata stem extract had a substantial anticariogenic activities and thus potentially be developed as an oral health care product for dental caries prevention in the near future.

Anti-Angiogenic Activity of Rotenoids from the Stems of Derris trifoliata.

The plants in the genus Derris have proven to be a rich source of rotenoids, of which cytotoxic effect against cancer cells seem to be pronounced. However, their effect on angiogenesis playing a crucial role in both cancer growth and metastasis has been seldom investigated. This study aimed at investigating the effect of the eight rotenoids (1: -8: ) isolated from Derris trifoliata stems on three cancer cells and angiogenesis. Among them, 12a-hydroxyrotenone (2: ) exhibited potent inhibition on both cell growth and migration of HCT116 colon cancer cells. Further, anti-angiogenic assay in an ex vivo model was carried out to determine the effect of the isolated rotenoids on angiogenesis. Results revealed that 12a-hydroxyrotenone (2: ) displayed the most potent suppression of microvessel sprouting. The in vitro assay on human umbilical vein endothelial cells was performed to determine whether compound 2: elicits anti-angiogenic effect and its effect was found to occur via suppression of endothelial cells proliferation and tube formation, but not endothelial cells migration. This study provides the first evidence that compound 2: could potently inhibit HCT116 cancer migration and anti-angiogenic activity, demonstrating that 2: might be a potential agent or a lead compound for cancer therapy.

Stereocontrolled Semisyntheses of Elliptone and 12aß-Hydroxyelliptone.

Operationally simple, stereocontrolled semisyntheses of the anticancer rotenoids elliptone and 12aß-hydroxyelliptone, isolated from Derris elliptica and Derris trifoliata, respectively, are described. Inspired by the work of Singhal, elliptone was prepared from rotenone via a dihydroxylation-oxidative cleavage, chemoselective Baeyer-Villiger oxidation, and acid-catalyzed elimination sequence. Elaboration of elliptone to 12aß-hydroxyelliptone was achieved via a diastereoselective chromium-mediated Étard-like hydroxylation. The semisynthesis of elliptone constitutes an improvement over previous methods in terms of safety, scalability, and yield, while the first synthesis of 12aß-hydroxyelliptone is also described.

5,7,4'-Trihydroxy-6,8-diprenylisoflavone and lupalbigenin, active components of Derris scandens, induce cell death on breast cancer cell lines.

BACKGROUND: Natural products are a potential source for cancer chemotherapeutic development. This current study was performed to investigate the anti-tumor potential of 5,7,4'-trihydroxy-6,8-diprenylisoflavone (TD) and lupalbigenin (LB), plant flavonoids found in Derris scandens Benth (family: Leguminosae), in cancer and normal cell lines. METHODS: The human breast cancer cell lines MCF-7, MDA-MB-231 and MDA-MB-468, the human colon cancer cell line SW-620, and the mouse fibroblast cell line L-929 were used to test their anti-cancer activity. Apoptotic cell levels were measured by staining with annexin-V and propidium iodide and Western blot analysis was performed to confirm the apoptotic mechanism. RESULTS: The results revealed that TD and LB showed specific cytotoxicity against MDA-MB-231 and MCF-7 cells. To elucidate mode of cell death via cytotoxic activities, breast cancer cell lines were treated. TD and LB induced MDA-MB-231 and MCF-7 cells to apoptosis, with the highest number of apoptotic cells at 24 and 72h, respectively. Furthermore, TD and LB inhibited cell cycle progression via up-regulation of p21. Both compounds stimulated apoptosis through down-regulation of bcl-2, up-regulation of bax and releasing of cytochrome C proteins. CONCLUSIONS: TD and LB have significant anti-cancer effects against human breast cancer cells via cell cycle arrest and the induction of apoptosis through mitochondria signaling pathways, and may be potential anti-cancer agents for the treatment of breast cancer.

Bioassay-Guided Isolation of Two Flavonoids from Derris scandens with Topoisomerase II Poison Activity.

Derris scandens (ROXB.) BENTH. (Fabaceae) is used as an alternative treatment for cancer in Thai traditional medicine. Investigation of the topoisomerase II (Top2) poison of compounds isolated from this plant may reveal new drug leads for the treatment of cancer. Bioassay-guided isolation was performed on an extract of D. scandens stems using a yeast cell-based assay. A yeast strain expressing the top2-1 temperature-sensitive mutant was used to assay Top2 activity. At the permissive temperature of 25°C, yeast cells were highly sensitive to Top2 poison agents. At the semi-permissive temperature of 30°C, where enzyme activity was present but greatly diminished, cells displayed only marginal sensitivity. The bioassay-guided fractionation of the extract led to the isolation of two known isoflavones: 5,7,4'-trihydroxy-6,8-diprenylisoflavone (1) and lupalbigenin (2). These two compounds also displayed cytotoxicity against three different cancer cell lines, KB, MCF-7 and NCI-H187. In conclusion, Top2 poison agents from D. scandens are reported for the first time, substantiating the use of D. scandens in Thai traditional medicine for cancer treatment.

[Studies on flavonoids from Derris eriocarpa].

Derris eriocarpa, a traditional Chinese medicine belonging to the family of Leguminosae, is widely distributed mainly over Yunnan, Guangxi and Guizhou of China. Modern pharmacological researches on this herb showed that it had extensive bioactivities, such as promoting urination, removing dampness and cough and reducing inspissated mucus and other biological activities. The extensive studies on the chemical constituents of this plant have resulted in the isolation of triterpenoids, steroids, fatty acid and others, but the flavone compounds haven't reported before. In our further research on the ethyl acetate of this plant, nine flavone compounds were obtained by column chromatography on silica gel, Sephadex LH-20, semi-prep HPLC, polyamide column chromatography and recrystallization for separation and purification. The structures were determined on the basis of extensive spectroscopic analysis, including MS, NMR experiments and comparison with spectroscopic data in the literature, respectively, as diosmetin (1), 3, 3'-di-O-methylquercetin (2), afromosin (3), 6, 3'-dihydroxy-7, 4'-dimethoxyisoflavone (4), odoratin (5), 7, 3'-dihydroxy-8, 4'-dimethoxyisoflavone (6), 6, 4'-dihydroxy-7, 3'-dimethoxyisoflavone (7), 5, 7, 4'-trihydroxy-3, 3', 5'-trimethoxyflavone (8), and alpinumisoflavone (9). All these compounds were isolated from Derris eriocarpa How for the first time. And the in vitro assays showed that compound 2 possessed moderate inhibitory activity against human cancer cells K562 and HEL.

Isolation and characterization of a new bioactive isoflavone from Derris eriocarpa.

Derris eriocarpa How is an important medicinal plant, which is used as Zhuang ethnomedicine and Dai ethnomedicine to treat various diseases. One new compound, 3',4'-di-O-methylene-5-hydroxy-7-methoxy-6-isopentenyl isoflavone (1) and a known synthetic but new naturally occurring compound trans-3,4,5-trimethoxy-4'-isopentenyloxyl-stilbene (2), together with five known compounds, 5,7-dimethoxy-6-(3-methyl-2-butenyl)-4'-hydroxyl isoflavones (3), robustone (4), trans-3,4,5,4'-tetramethoxy-stilbene (5), robustic acid (6), and robustin (7) were isolated from the stem of D. eriocarpa. Spectroscopic analysis revealed the chemical structures of compounds 1-7.. Compounds 1 and 3 exhibited significant scavenging activities against 1,1-diphenyl-2-picrylhydrazyl radical and superoxide anions. Compounds 1-3 exhibited potent antiproliferative activity on Hela cells.

Lupalbigenin from Derris scandens Sensitizes Detachment-induced Cell Death in Human Lung Cancer Cells.

BACKGROUND/AIM: The ability of cancer cells to resist to anoikis has been shown to augment cancer cell metastasis in many cancers. In search for potential substances for anti-metastatic approaches, this study aimed to investigate anoikis-sensitizing activity of lupalbigenin, extracted from Derris scandens. MATERIALS AND METHODS: Human lung cancer cells were treated with non-cytotoxic concentrations of lupalbigenin in a detachment condition. Anoikis was evaluated at various time points using MTT viability assays. The effect of lupalbigenin on anchorage-independent growth was performed by soft-agar assay. The survival signaling proteins, as well as regulatory proteins of apoptosis and metastasis, were examined by western blot analysis. RESULTS: Lupalbigenin treatment significantly down-regulated survival proteins, including protein kinase B (pAKT/AKT) and extracellular signal-regulated kinase (pERK/ERK), as well as anti-apoptotic protein B-cell lymphoma 2 (BCL-2), resulting in the enhancement of the cellular response to anoikis and the decrease of growth and survival in an anchorage-independent condition. CONCLUSION: Lupalbigenin sensitizes detachment-induced cell death in human lung cancer cell through down-regulation of pro-survival proteins.

Antioxidant, α-glucosidase inhibitory activity and sub-chronic toxicity of Derris reticulata extract: its antidiabetic potential.

BACKGROUND: Antidiabetic activity of Derris reticulata extract on alloxan-induced diabetic rats has been reported. The extract was found to lower blood glucose and inhibit intestinal glucose absorption. The aim of this study was to further investigate mechanisms underlying the antihyperglycemic activity of D. reticulata extract in vitro. METHODS: The aqueous extract was obtained from D. reticulata stem. Phytochemical screening, total phenolic, and flavanoid contents were examined. ABTS and DPPH scavenging assays, and FRAP method were used to determine in vitro antioxidant activities. Measurement of cell viability on alloxan-induced cellular damage was performed in the insulin-secreting RINm5F cells by MTT assay. The effects of the extract on α-glucosidase activity and insulin release were studied. In addition, sub-chronic toxicity test in rats was also conducted. RESULTS: The results revealed that the extract, which consisted of terpenoids, saponins, tannins and flavonoids, possessed moderate radical scavenging activities. Pre-treatment of RINm5F cells with the extract was also found to exert moderate, but significant, in vitro protection against alloxan, an oxidative stress producing agent. Unlike glibenclamide, the extract did not stimulate insulin secretion. However, the extract was found to inhibit α-glucosidase activity similar to acarbose. It was found that in sub-chronic toxicity studies D. reticulata extract did not cause mortality or produce any remarkable haematological, biochemical and histopathological adverse effects in rats. CONCLUSIONS: The data suggest that the possible mechanisms underlying antihyperglycemic activity of D. reticulata extract are cytoprotective effect on pancreatic cells, presumably by its antioxidant activity, and inhibition of α-glucosidase. Sub-chronic toxicity study also provides scientific evidence to corroborate the safety of this plant as an alternative antidiabetic agent.

Cytotoxicity of compounds from the fruits of Derris indica against cholangiocarcinoma and HepG2 cell lines.

Two new compounds, derrivanone (1) and derrischalcone (2), were isolated from the crude hexane extract of the fruits of Derris indica. In addition, 14 known compounds were isolated from the fruits of this plant. Chalcones 2-4 showed strong cytotoxicity against cholangiocarcinoma cell line (M156) and human hepatoma HepG2 cells. In addition, flavanones 15 and 16 exhibited potent and high cytotoxic efficacy.

Ethanolic extract from Derris scandens Benth mediates radiosensitzation via two distinct modes of cell death in human colon cancer HT-29 cells.

Enhancing of radioresponsiveness of tumors by using radiosensitizers is a promising approach to increase the efficacy of radiation therapy. Recently, the ethanolic extract of the medicinal plant, Derris scandens Benth has been identified as a potent radiosensitizer of human colon cancer HT29 cells. However, cell death mechanisms underlying radiosensitization activity of D scandens extract have not been identified. Here, we show that treatment of HT-29 cells with D scandens extract in combination with gamma irradiation synergistically sensitizes HT-29 cells to cell lethality by apoptosis and mitotic catastrophe. Furthermore, the extract was found to decrease Erk1/2 activation. These findings suggest that D scandens extract mediates radiosensitization via at least two distinct modes of cell death and silences pro-survival signaling in HT-29 cells.

Consumer and farmer safety evaluation of application of botanical pesticides in black pepper crop protection.

This study presents a consumer and farmer safety evaluation on the use of four botanical pesticides in pepper berry crop protection. The pesticides evaluated include preparations from clove, tuba root, sweet flag and pyrethrum. Their safety evaluation was based on their active ingredients being eugenol, rotenone, ß-asarone and pyrethrins, respectively. Botanical pesticides from Acorus calamus are of possible concern because of the genotoxic and carcinogenic ingredient ß-asarone although estimated margins of exposure (MOE) for consumers indicate a low priority for risk management. For the other three botanical pesticides the margin of safety (MOS) between established acute reference doses and/or acceptable daily intake values and intake estimates for the consumer, resulting from their use as a botanical pesticide are not of safety concern, with the exception for levels of rotenone upon use of tuba root extracts on stored berries. Used levels of clove and pyrethrum as botanical pesticides in pepper berry crop production is not of safety concern for consumers or farmers, whereas for use of tuba root and sweet flag some risk factors were defined requiring further evaluation and/or risk management. It seems prudent to look for alternatives for use of sweet flag extracts containing ß-asarone.

Derris scandens Benth extract potentiates radioresistance of Hep-2 laryngeal cancer cells.

The use of herbal products as radiosensitizers is a promising approach to increase the efficacy of radiotherapy. However, adverse effects related to the use of herbal medicine on radiotherapy are not well characterized. The present study concerns the impact of Derris scandens Benth extract on the radiosensitivity of Hep-2 laryngeal cancer cells. Pretreatment with D. scandens extract prior to gamma irradiation significantly increased clonogenic survival and decreased the proportion of radiation-induced abnormal nuclei of Hep-2 cells. Furthermore, the extract was found to enhance radiation-induced G2/M phase arrest, induce Akt activation, and increase motility of Hep-2 cells. The study thus indicated that D. scandens extract potentiates radioresistance of Hep-2 cells, further demonstrating the importance of cellular background for the adverse effect of D. scandens extract on radiation response in a laryngeal cancer cell line.