In vitro antiproliferative and antioxidant activities of the extracts of Muntingia calabura leaves

The in vitro antiproliferative and antioxidant activities of the aqueous, chloroform and methanol extracts of Muntingia calabura leaves were determined in the present study. Assessed using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, the aqueous and methanol extracts of M. calabura inhibited the proliferation of MCF-7, HeLa, HT-29, HL-60 and K-562 cancer cells while the chloroform extract only inhibited the proliferation of MCF-7, HeLa, HL-60 and K-562 cancer cells. Interestingly, all extracts of M. calabura, which failed to inhibit the MDA-MB-231 cells proliferation, did not inhibit the proliferation of 3T3 (normal) cells, indicating its safety. All extracts (20, 100 and 500 μg/ml) were found to possess antioxidant activity when tested using the DPPH radical scavenging and superoxide scavenging assays with the methanol, followed by the aqueous and chloroform, extract exhibiting the highest antioxidant activity in both assays. The total phenolic content for the aqueous, methanol and chloroform extracts were 2970.4 ± 6.6, 1279.9 ± 6.1 and 2978.1 ± 4.3 mg/100 g gallic acid, respectively. In conclusion, the M. calabura leaves possess potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds, and thus, needs to be further explored.     

Potent in vitro cytotoxic and antioxidant activity of Careya arborea bark extracts

Careya arborea is used in traditional medicine for the treatment of tumors and other ailments. The successive chloroform and ethyl acetate extracts and crude 50% methanol extract exhibited potent cytotoxicity against cancerous RD, HEp-2 and HeLa cell lines. They were found to be safe against the normal Vero cell line. The methanol and aqueous extracts possessed strong antioxidant activity against many oxidants in the in vitro antioxidant screening. The total phenol content of these extracts was found to be high. The results suggest strong cytotoxic and antioxidant properties and support the ethnomedical claims for the plant.     

防已黄芪汤的抗氧化活性研究

目的测定防己黄芪汤(防己、黄芪、白术、甘草)中甲醇提取物和三氯甲烷提取物的抗氧化活性。方法采用2,2-二苯基-1-苦味基肼自由基清除(DPPH)实验、还原力实验、羟基自由基清除实验对其抗氧化活性进行研究。结果清除DPPH活性研究表明,甲醇提取物与三氯甲烷提取物的抗氧化能力较弱。还原能力实验证明三氯甲烷提取物的抗氧化能力只略低于甲醇提取物。清除羟基自由基实验结果则表明两种提取物均具有很高的清除羟基自由基能力。结论试验结果表明,甲醇提取物及三氯甲烷提取物具有很好的清除羟基自由基能力。     

Antioxidant, anti-inflammatory and antiproliferative activities of Kalanchoe gracilis (L.) DC stem

Oxidative stress and inflammation are related to several chronic diseases including cancer and atherosclerosis. Kalanchoe gracilis (L.) DC is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory and antiproliferative activities of the methanolic extract and fractions of the stem of K. gracilis. TEAC, total phenolic compound content, total flavonoid content, DPPH radical scavenging activity, reducing power, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were analyzed. Among all fractions, the chloroform fraction showed the highest TEAC and DPPH radical scavenging activities. The chloroform fraction also had the highest content of polyphenols and flavonoids. Chloroform fractions also decreased LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the methanolic extract and fractions were studied in vitro using HepG2 cells, and the results were consistent with their antioxidant capacities. Chloroform fractions had the highest antiproliferative activity with an IC(50) of 136.85 ± 2.32 μg/ml. Eupafolin also had good pharmacological activity in the antioxidant, anti-inflammation and antiproliferative. Eupafolin might be an important bioactive compound in the stem of K. gracilis. The above experimental data indicated that the stem of K. gracilis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.     

In vitro Antioxidant Activities of Methanol and Aqueous Extract of Annona squamosa (L.) Fruit Pulp

The present study evaluated the antioxidant activity of the fruit of Annona squamosa by means of in vitro studies involving two different solvent extracts: methanol and aqueous. The antioxidant properties of the extract were determined by scavenging 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), lipid peroxidation (LPO), nitric oxide (NO), superoxide anion (O₂^?), hydroxyl radical (OH^?), reducing power and total antioxidant. The results showed that, compared to aqueous extract, a methanolic fruit extract of A squamosa has a higher percentage of inhibition of DPPH radical scavenging activity (97.99%), LPO (94.15%), NO scavenging activity (70.96%), O₂^? scavenging activity and OH^? scavenging activity (78.68% and 85.25%, respectively), total antioxidant activity (206 μg α-tocopherol/g) and reducing power (56.0 μg of ascorbic acid/g). The results obtained in the in vitro models clearly suggest that methanol extract has higher antioxidant activity than the aqueous extract due to a higher presence of phenolic and flavonodal constituents in the methanol extract.     

Evaluation of antioxidant and antimicrobial properties of Soymida febrifuga leaf extracts

The present study was designed to evaluate the antioxidant and antimicrobial properties of hexane (LH), methanol (LM) and aqueous (LA) extracts of Soymida febrifuga (Maliaceae) leaves, which is a traditional folk medicine in India. No pharmacological evaluation of this plant (except antiplasmodial activity) has been reported to date. Antioxidant activity of different extracts was evaluated by DPPH free radical scavenging activity, taking total phenolic content (TPC) as an index. Antimicrobial activity was tested against six bacterial and five fungal strains using the agar hole diffusion method and the minimum inhibitory concentrations (MIC) and minimum microbicidal concentration (MMC) were determined for all the test organisms against the extracts. The results showed that the methanol and aqueous extracts of leaf had a higher antioxidant activity and total phenolic content than the hexane extract. The antioxidant activity and TPC of the extracts were highly correlated. Extracts also showed several degrees of antimicrobial activity against different microbes. The methanol extract was more potent against Aspergillus fumigatus and Candida tropicana. The lowest MIC values obtained for LM, LA and LH were 78, 156, 625 microg/mL against A. fumigatus, C. tropicana and C. albicans, respectively. Hence, this study confirms that Soymida febrifuga leaves possess potent antioxidant and antimicrobial activity.     

Antioxidant properties and xanthine oxidase inhibitory effects of Tamus communis L. root extracts

This study was conducted to search for xanthine oxidase (XO) inhibitors from the root extracts of Tamus communis L. traditionally used in folk medicine in Algeria. Root extracts with different solvents were screened for purified milk xanthine oxidase inhibition. The root extracts (methanol, chloroform and ethyl acetate) and proteins, obtained in distilled water, inhibited bovine, sheep and human milk XO from three species in a concentration-dependent manner, with an additional superoxide scavenging capacity, which reached its highest level with ethyl acetate extract (IC(50) = 0.15, 0.04 and 0.09 g/L) for bovine XO, sheep XO and human XO, respectively. The antioxidant potential was confirmed with the non-enzymatic method, total radical-trapping antioxidant parameter (TRAP) assay, which showed that the Tamus communis L. extracts have a potential antioxidant activity in the same order obtained by using the reduction of cytochrome c, an enzymatic method, in which the antioxidant activity followed a decreasing order: ethyl acetate extract > chloroform extract > protein.     

Bioactivity-guided isolation of antiproliferative compounds from Centaurea arenaria

The antiproliferative effects of n-hexane, chloroform and aqueous methanol extracts prepared from the whole plant of Centaurea arenaria M.B. ex Willd. were investigated against cervix adenocarcinoma (HeLa), breast adenocarcinoma (MCF7) and skin epidermoid carcinoma (A431) cells, using the MTT assay. The chloroform extract displayed high tumour cell proliferation inhibitory activity (higher than 85% at 10 μg/mL concentration), and was therefore subjected to a bioassay-guided multistep separation procedure. Flavonoids (eupatilin, eupatorin, 3'-methyleupatorin, apigenin and isokaempferid), lignans (arctigenin, arctiin and matairesinol), the sesquiterpene cnicin, serotonin conjugates (moschamine and cis-moschamine), β-amyrin and β-sitosterin-β-D-glycopyranoside, identified by means of UV, MS and NMR spectroscopy, were obtained for the first time from this species. The isolated compounds were also evaluated for their tumour cell growth inhibitory activities on HeLa, MCF7 and A431 cells, and different types of secondary metabolites were found to be responsible for the antitumour effects of the extracts; in addition to moderately active compounds (isokaempferid and moschamine), especially apigenin, eupatorin, arctigenin, arctiin, matairesinol and cnicin exert marked antitumour effects against these cell lines.     

瑞香狼毒系统溶剂法分离提取部位的体外抗肿瘤活性

目的:分离筛选瑞香狼毒中抗肿瘤活性部位.方法:用系统溶剂法对瑞香狼毒95%乙醇提取物进行分离,MTT比色法对分离得到的部位进行体外抗肿瘤活性的测定.结果:石油醚提取物和氯仿提取物对体外培养肿瘤细胞表现出较强的抑制作用,在测定浓度范围内呈现出良好剂量依赖性抑制作用,而正丁醇和甲醇提取部位在测定浓度范围内则显示出很弱的抑制作用;在各提取部位中石油醚提取物的体外抗肿瘤作用最强.结论:石油醚提取部位是瑞香狼毒中的体外抗肿瘤活性部位.     

In vitro antiproliferative effect of six Salvia species on human tumor cell lines

This study was designed to examine the in vitro antiproliferative activity of the methanol crude extracts of six Salvia species: Salvia dominica L. leaves, Salvia lanigera Desf. aerial parts, Salvia menthaefolia Ten. roots, Salvia palaestina Benth. aerial parts, Salvia sclarea L. roots and Salvia spinosa L. aerial parts. Extracts were screened for their possible antitumoral activity by MTT test on nine human cancer cell lines: glioblastoma (DBTRG-05MG, T98G, U-87MG), colorectal adenocarcinoma (WiDr and HT-29), prostate adenocarcinoma (MDA Pca2b), choriocarcinoma (JEG-3), endometrium adenocarcinoma (HEC-1A) and B lymphoblast (CIR). IC(50) values were determined for only five extracts and ranged from 90 to 400 microg/mL approximately. Salvia menthaefolia extract exhibited marked antiproliferative activity against all tumor cell lines showing lower IC(50) values, while S. spinosa, S. sclarea and S. dominica extracts showed a degree cytotoxic activity dependent on the cell line type. Finally S. palaestina extract revealed a moderate antiproliferative effect only against three cell lines. Salvia lanigera extract displayed toxic activity at all concentrations tested. The results strengthen the evidence that the genus Salvia could be considered a natural resource of potential antitumor agents.     

Antioxidant Activity and Cytotoxicity of the Traditional Indonesian Medicine Tahongai (Kleinhovia hospita L.) Extract

We investigated the leaves of Kleinhovia hospita, a plant which has been traditionally used in Indonesia as phytotherapy to cure liver disease, to describe antioxidant materials from plant sources. K. hospita leaves were extracted with methanol and further partitioned into n-hexane, diethyl ether, and ethyl acetate. The antioxidant activity of each fraction and the residue was assessed using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method and their cytotoxicity on HepG2 liver cancer cells was determined by a MTT assay. The K. hospita leaf methanol extract showed strong antioxidant activity (96%) compared with vitamin C (98%) by the DPPH method and the measured activity from the subsequent extracts of the methanol extract were 48.9% for n-hexane, 74.0% for diethyl ether, 84.3% for ethyl acetate, and 77.1% for the residue. The MTT assay showed the cytotoxicity of the methanol extract on HepG2 cells at 14%, 76%, and 80% at concentrations of 50μg/mL, 87.5μg/mL, and 125μg/mL, respectively. Leaf extracts of the medicinal plant K. hospita showed potent antioxidant activity and moderate cytotoxicity on HepG2 liver cancer cells.     

Enzymatic and non-enzymatic antioxidant,anti-inflammatory and anticancer activities of Floscopa scandens Lour

OBJECTIVE: To explore the total phenolic and flavonoid content, enzymatic, non-enzymatic antioxidant properties, anti-inflammation and anticancer activities of hexane, ethyl acetate and methanol extracts of Floscopa scandens(F. scandens).METHODS: Non-enzymatic antioxidant activity was examined by 2, 2-diphenyl-1-picrylhydrazyl assay, nitric oxide scavenging assay, hydroxyl radical scavenging assay, reducing power assay, hydrogen peroxide scavenging assay, superoxide scavenging assay and metal chelating assay. Enzymatic antioxidant ability was screened for the antioxidant enzymes such as ascorbate oxidase, peroxidase, catalase and polyphenol oxidase. The anti-inflammatory property was proved with the inhibition of protein denaturation and protease inhibitory assays. In vitro anticancer activity was assessed by cell viability assay.RESULTS: Methanol extract contained high amount of phenols(198.41 mg catechol equivalent/gram extract) and flavonoids(101.70 mg quercetin equivalent/gram extract) showed higher activity than hexane and ethyl acetate extracts in all experiments. Fresh plant showed considerable enzymatic antioxidant activity.CONCLUSION: The results revealed that the methanol extracts of F. scandens could be used as a potential source of antioxidant, anti-inflammatory and anticancer bioactive compounds.     

Anti-leukemic activity of Wattakaka volubilis leaf extract against human myeloid leukemia cell lines

Ethnopharmacological relevance

Wattakaka volubilis has been traditionally used in Ayurvedic medicine in India for treatment of several ailments such as bronchial asthma, inflammations, tumors, piles, leucoderma, application to boils, rat bite etc.

Aim of the study

The present study was designed to investigate anti-leukemic activity of the crude aqueous methanolic extract and to identify active compounds from the leaves of Wattakaka volubilis.

Materials and methods

The leaves of Wattakaka volubilis were extracted with aqueous methanol. Liquid–liquid fractionation of the crude methanolic extract with different organic solvents was done and the fractions were screened for in vitro anti-leukemic activity using different leukemic cell lines. The active fractions were then subjected to chromatographic separation for isolation of bioactive compounds. Structure of isolated compound was elucidated by spectroscopic methods. The in vitro anti-leukemic activities of different extracts of the leaves and isolated compound WVP were studied in U-937, HL-60 and K-562 cell-lines by using cell count, MTT [(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] and DNA laddering assays, flow-cytometric and confocal microscopic techniques.

Results

Kaempferol-3-O-[α-l-rhamnopyranosyl-(1→4)-O-α-l-rhamnopyranosyl-(1→6)-O]-β-d-glucopyranoside (WVP) was isolated from crude leaves extract of Wattakaka volubilis. Both the n-butanolic extract (WVB) of Wattakaka volubilis and its isolate WVP were found to be responsible for in vitro anti-leukemic activity. The IC₅₀ values of WVB were found be 120, 100 and 50 (μg/ml) in U937, K562, and HL-60 cell lines, respectively. Whereas, the pure isolate WVP exhibited anti-leukemic activity with IC₅₀ values of 13.5, 10.8, and 13.2 (μg/ml) in U937, K562, and HL-60 cell lines, respectively. The flow-cytometric analysis confirms that the cell cycle arrest occurs at G1 phase in case of U937 and K562 cell lines and G2/M phase in case of HL60 cell lines. Similarly both confocal microsocopic analysis and DNA laddering assay confirm the apoptosis and cell cycle arrests of leukemic cells.

Conclusion

The overall results provide evidence for the ethnopharmacological relevance for use of the plant Wattakaka volubilis in developing novel agents for the treatment of leukemia.     

Inhibition of pro-inflammatory mediators and tumor cell proliferation by Anisomeles indica extracts

Anisomeles indica (L.) Kuntze (Labiatae), is a traditional anti-inflammatory herb used in Taiwan. The aqueous and methanolic extracts of whole plants, leaves, flowers and stems; and chloroform and n-butanol fractions of methanol extract, from A. indica were investigated for their anti-inflammatory activity on murine peritoneal macrophages. In addition, the tumor cells proliferation inhibition activities of these extracts were also evaluated against a panel of tumor cell lines such as Colon 205, PC 3, HepG2 and MCF 7. Treatment with A. indica extracts did not reduce cell viability at any dose used. However, all the extracts significantly inhibited the enhanced production of NO radicals, and pro-inflammatory cytokines (TNF-alpha, and IL-12) induced by LPS/IFN-gamma in a dose-dependent manner. Furthermore, methanolic extracts of leaves and flowers significantly and dose-dependently arrest mitogen-stimulated spleen cells in G0/G1 stage, in addition to their cell proliferation inhibition against Colon 205, MCF 7 and PC 3 by 94, 82; 98, 71; 82, 98%, respectively, at 200 microg/mL concentration. This is the first report on A. indica extracts for their growth inhibitory activities, against inflammatory mediator production, and human tumor cell lines, colon, prostate, hepatoma and breast cells proliferation.     

Chemical compositions, anti-inflammatory, antiproliferative and radical-scavenging activities of Actinidia callosa var. ephippioides

Oxidative stress and inflammation are related to several chronic diseases including cancer. Actinidia callosa var. ephippioides (ACE) is a special folk medicinal plant from Taiwan. The aim of this study is to evaluate the antioxidant, anti-inflammatory, and antiproliferative activities of the methanol extract and fractions from the stem of ACE. Trolox Equivalent Antioxidant Capacity (TEAC), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, total phenolic content, flavonoid content, inhibition on nitric oxide (NO) productions by LPS-induced RAW264.7 cell, and on lung cancer cell proliferation were employed. Among all fractions, ethyl-acetate fraction (EA-ACE) showed higher TEAC, DPPH radical scavenging activities, polyphenol and flavonoid contents, respectively. EA-ACE also decreased the LPS-induced NO production and expressions of inducible nitric-oxide synthase (iNOS) in RAW264.7 cells. EA-ACE had the highest antiproliferative activity with an IC(50) (The concentrations required for inhibition of 50% of cell viability) of 469.17 ± 3.59 μg/mL. Catechin also had good effects in the antioxidant and anti-inflammatory activities. Catechin might be an important bioactive compound in the stem of ACE. The above experimental data indicated that the stem of ACE is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.     

Investigation of in vitro antioxidant activity of dihydromyricetin and flavonoids rich extract from vine tea(Ampelopsis grossedentata)

Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the total flavonoids found in vine tea,including three bioactive flavonoids,and the total phenolic contents in the aqueous methanol extracts of 10 vine tea samples.In addition,this study also aimed to examine the antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract.Methods:The total flavonoids and total phenolic content assay of extracts from vine tea were performed by ultraviolet-visible spectroscopy and epoch microplate spectrophotometer,respectively.Three bioactive flavonoids were quantified simultaneously using high performance liquid chromatography.The antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract was evaluated in vitro using six different methods.Results:Vine tea contained a large number of flavonoids,with dihydromyricetin as its main constituent.The flavonoid-rich extract exhibited a significant scavenging effect on superoxide anion radicals,and on 3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl radicals.It also possessed definite activity in lipid peroxidation inhibition,ferric reduction,and the moderation of Fe2+ion chelation ability.There was a significant negative correlation between dihydromyricetin content and antioxidant activity in the vine tea samples,including superoxide anion radical scavenging activity(P=−0.754,P<0.05),lipid peroxidation inhibition activity(P=−0.759,P<0.05),ferric-reducing antioxidant power(P=−0.843,P<0.01),respectively.Dihydromyricetin played a dominant role in the antioxidant activities of the flavonoid-rich extract.Conclusion:Vine tea’s flavonoid-rich extract could be used as a new antioxidant source to safeguard against oxidative stress.     

Assessment of the phytochemical and antitrypanosomal properties of some extracts of leaves, stem and root bark of Landolphia sp., P. Beauv

INTRODUCTION/JUSTIFICATION: There is urgent need to source for alternative chemotherapy against trypanosmosis, a disease of major importance in human and economic animals. MATERIALS AND METHODS: Therefore, petroleum ether, chloroform, methanol and aqueous extracts sequentially obtained from the leaves, stem and root barks of Landolphia uniflora were evaluated for their in vitro and in vivo antitrypanosomal activities against Trypanosoma brucei brucei, as well as their phytochemical constituents. RESULTS: Steroids and triterpenes, resins, tannins, saponins and flavonosides were detected in almost all the extracts, but alkaloid was absent in methanol extract of the stem and stem, as well as the chloroform extract of the root bark. In vitro, all extracts of the roots displayed significant antitrypanosomal activity, while only the chloroform extracts of the leaves and stem bark showed activity at both test concentrations (4 and 2 mg/ml). However, under in vivo condition, the methanol extracts showed the greatest activity, eliminating parasitaemia within the 10 days treatment period and prolonging survival period at 200 and 300 mg/kg body weight intramuscular doses. CONCLUSION: These results suggest that Landolphia uniflora could be useful in the management of trypanosomiasis.     

Antioxidant, anti-inflammatory, and antiproliferative activities of Taxillus sutchuenensis

Inflammation is related to several chronic diseases, including cancer and atherosclerosis. Taxillus sutchuenensis (Lecomte) Danser is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antiproliferative activities of the aqueous-thanol extract from T. sutchuenensis (AETS) and its fractions. TEAC, DPPH radicals, total phenolic compounds, total flavonoid content, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were tested. Among all fractions, the ethyl-acetate (EA) fraction showed the highest TEAC and DPPH radical scavenging activities. The EA fraction also had the highest polyphenol and flavonoid content. The EA fractions also decreased LPS-induced NO production and the expression of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the aqueous/ethanol extract and fractions were studied in vitro using A549 cells, and the results were consistent with their antioxidant capacities. EA fractions had the highest antiproliferative activity with an IC(50) of 454.38 ± 1.48 μg/ml. Quercetin also had antioxidant, anti-inflammatory, and antiproliferative activities. Quercetin might be an important bioactive compound in T. sutchuenensis. The experimental data indicated that T. sutchuenensis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.     

Antibacterial potential from Indian Suregada angustifolia

Phytochemical analysis of the leaves from Indian Suregada angustifolia (Baill. ex Muell. Arg.) Airy Shaw (Euphorbiaceae) resulted in the isolation and identification of six known compounds, viz. friedelin, epi-friedelinol, n-octacosanol, alpha-amyrin, beta-sitosterol and beta-sitosterol-3-beta-D-glucopyranoside. Aqueous (room temperature, boiled and autoclaved) and various solvent (methanol, chloroform and hexane) extracts of leaves were tested against 12 human pathogenic bacteria by the agar well-diffusion method. Aqueous extracts did not express any activity. Antibacterial activity was recorded in the order of methanol, hexane and chloroform extracts. Maximum activity recorded against Staphylococcus aureus (skin infections) in methanol and hexane extracts and moderate activity recorded against diarrhoea causing bacteria, Vibrio vulnificus (hexane extract) and Vibrio cholerae (chloroform extract).     

Antioxidant and cytotoxic activities of Retama raetam subsp. Gussonei

The aim of this study was to evaluate the in vitro antioxidant and cytotoxic activities of the methanol extracts of Retama raetam subsp. gussonei leaves and seeds. The antioxidant activity of the extracts was assessed by means of two different tests: (1) bleaching of the stable 2,2-diphenyl-1-picrylhydrazil (DPPH) radical; and (2) lipid peroxidation of liposomes which were prepared from bovine brain extract. In both tests used leaves extract showed a significant antioxidant effect. The extract of leaves also demonstrated a good cytotoxic activity against COR-L23 (large cell carcinoma) cell line.