Phenolic metabolites,biological activities,and isolated compounds of Terminalia muelleri extract

Context: Terminalia muelleri Benth. (Combretaceae), is rich with phenolics that have antioxidant and cytotoxic activities. No screening studies were published before on T. muelleri.

Objective: The study focused on isolation and identification of secondary metabolites from aqueous methanol leaf extract of T. muelleri and evaluation of its biological activities.

Materials and methods: The n-butanol extract was chromatographed on polyamide 6, and eluted with H₂O/MeOH mixtures of decreasing polarity, then separated by different chromatographic tools that yielded 10 phenolic compounds. The antioxidant activity of the extract was evaluated by investigating its total phenolic and flavonoid content and DPPH scavenging effectiveness. The extract and the two acylated flavones were evaluated for their anticancer activity towards MCF-7 and PC3 cancer cell lines. Molecular docking study of the acylated flavones was performed against topoisomerase enzyme.

Results and discussion: Two acylated flavonoids, apigenin-8-C-(2″-O-galloyl) glucoside 1 and luteolin-8-C-(2″-O-galloyl) glucoside 2, were isolated and identified for the second time in nature, with eight tannins (3–10), from the leaves of T. muelleri. The extract and compound 10 showed the most significant antioxidant activity (IC₅₀?=?3.55 and 6.34?μg/mL), respectively. The total extract and compound 2 demonstrated cytotoxic effect against MCF-7 with IC₅₀?=?29.7 and 45.2?μg/mL respectively, while compound 1 showed cytotoxic effect against PC3 (IC₅₀?=?40.8?μg/mL). The docking study of compounds 1 and 2 confirmed unique binding mode in the active site of human DNA topoisomerase enzyme.

Conclusions: Terminalia muelleri is a promising medicinal plant as it possesses high antioxidant activity and moderate cytotoxic activity against MCF-7.     

Chemical composition of Hypogymnia physodes lichen and biological activities of some its major metabolites

The aim of this study is to investigate chemical composition of acetone extract of the lichen Hypogymnia physodes and antioxidant, -microbial, and -cancer activities of some its major metabolites. Four depsidones (fumarprotocetraric-, 3-hydroxyphysodalic-, physodalic-, and physodic acids), two depsides (atranorin and chloroatranorin), and usnic acid were identified from the lichen H. physodes growing in Serbia using high-performance liquid chromatography with photodiode array detector. Antioxidant activity of isolated metabolites was evaluated by free radical scavenging, superoxide anion radical scavenging, and reducing power. As a result of this study physodic acid was found to have stronger antioxidant activities. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. All isolated compounds were highly active with minimum inhibitory concentration values ranging from 0.0008 to 1 mg/ml. Anticancer activity was tested against FemX (human melanoma) and LS 174 (human colon carcinoma) cell lines using microculture tetrazolium method. Tested compounds were found have strong anticancer activity toward both cell lines with IC₅₀ values ranging from 12.72 ± 0.35 to 24.63 ± 2.15 μg/ml. The present study shows that isolated lichen compounds demonstrated strong antioxidant, -microbial, and -cancer effects. The results suggest that this lichen can be used as new sources of the natural antimicrobial agents, antioxidants, and -cancer compounds.     

Antioxidant and cytotoxic activity of carotenes produced by Dunaliella salina under stress

Context Dunaliella salina Teodoresco (Dunaliellaceae) is one of the promising microalgae consumed as food and medicine for many years.

Objective Dunaliella salina was grown under different stress conditions for enhancing carotene production. The carotene enriched extract was evaluated for antioxidant and cytotoxic activity.

Materials and methods Carotene content was calculated under salinity, nitrogen and temperature stress conditions. Antioxidant activity was determined through DPPH assay by incubating the samples for 45?min with 250?μg/mL of extract and reducing power assay was performed with 50, 100, 150 and 200?μg/mL of extract. Cytotoxicity was determined by incubating ～2?×?10⁴ MCF-7 (breast cancer) cells with 250?μg of extract in each well for 72?h by MTT assay.

Result Carotene content was significantly increased to 9.8 (3.5 M NaCl), 13.9 (37?°C), 8.2 (250?mM KNO₃) and 10.6?μg/mL (nitrogen-depleted medium) as compared with 3.2?μg/mL in normal conditions (1.7 M NaCl, 0.75?mM KNO₃ and 28?°C). Free radical scavenging activity increased at 3.0 and 3.5 M NaCl (27.8 and 57.5%, respectively), 37?°C (31.4%) and in nitrogen-depleted medium (41.9%) compared with normal (15%) conditions. Carotene content and scavenging activity were positively correlated under salinity (r?=?0.97), temperature (r?=?0.85) and nitrogen (r?=?0.7) stress conditions. Cytotoxicity against MCF-7 cell lines increased due to increase in carotene content suggesting that cytotoxicity may be associated with carotene accumulation.

Discussion and conclusions Carotene content enhanced by D. salina under stress conditions increased the antioxidant and cytotoxic activity.     

Bioactivity-guided isolation of anti-proliferative compounds from endemic Centaurea kilaea

Context: The genus Centaurea L. (Asteraceae) is one of the largest genera in Turkey. Compounds and extracts obtained from different Centaurea species have significant anti-cancer activity against various cancer cell lines.

Objective: To determine the anti-proliferative activity of isolates from the chloroform extract of C. kilaea Boiss.

Materials and methods: Eleven compounds were isolated using column chromatography and preparative TLC from the chloroform extract of aerial parts of endemic C. kilaea. The structures of the isolated compounds were elucidated by various spectroscopic methods, including UV, ^lH-NMR and ¹³C-NMR. Anti-proliferative activity of compounds (0.5–50?μg/mL) were measured against one normal cell line (L-929, mouse fibroblast) and three human cancer cell lines (Hela, cervix carcinoma; MCF-7, breast carcinoma; PC-3, prostate carcinoma) using MTT assay. Results were expressed as IC₅₀ values.

Results: None of the 11 compounds displayed activity against L-929 and HeLa. Two of these compounds, cnicin and cirsimaritin, showed fairly strong activity against MCF-7 and PC-3 with IC₅₀ values of 3.25 and 4.3?μg/mL, respectively.

Discussion and conclusion: This is the first report on cirsimaritin. Cirsimaritin and cnicin could serve as potential anti-cancer drug candidates against breast and prostate cancer, respectively.     

In vitro antioxidant and cytotoxic properties of ethanol extract of Alpinia oxyphylla fruits

Abstract

Context. Alpinia oxyphylla Miquel (Zingiberaceae) is a traditional Chinese herbal medicine widely used for the treatment of intestinal disorders, urosis and diuresis. However, information about antioxidant and cytotoxic properties of its fruits remains to be elucidated.

Objective: The ethanol crude extract (CE) and its fractions [petroleum ether fraction (PF), ethyl acetate fraction (EF), n-butanol fraction (BF) and water fraction (WF) extracted by petroleum ether, ethyl acetate, n-butanol and water, respectively] of A. oxyphylla fruits were investigated for their antioxidant activity and cytotoxicity.

Materials and methods: The total phenolic content (TPC) and antioxidant activity of the extracts were determined by Folin–Ciocalteu reagent, 1,1-diphenyl-2-picrylhydrazyl (DPPH^?), Trolox equivalent antioxidant capacity and reducing power assay. Cytotoxicity of the extracts (0–200?μg/mL) was tested on six human cancer cell lines (breast cancer cell line, cervix carcinoma cell line, lung adenocarcinoma cell line, liver carcinoma cell line, gastric cancer cell line and colon cancer cell line) using the sulforhodamine B assay.

Results: The TPC of extracts varied from 8.2 to 20.3?mg gallic acid equivalents/g dry weight. DPPH radical scavenging effect of extracts decreased in the order of EF?>?BF?>?CE?>?PF?>?WF, with IC₅₀ values ranging from 74.7 to 680.8?μg/mL. 2,2-azo-bis(3-Ethylbenzothiazoline-6-sulfoic acid) diammonium salt scavenging activity ranged from 0.118 to 0.236?mmol Trolox equivalence/mg extract. The extracts exhibited concentration-dependent reducing power, and EF showed the highest reducing ability. A satisfactory correlation (R²?>?0.826) between TPC and antioxidant activity was observed. In addition, EF, PF and CE exhibited potent anticancer effects on six cancer cell lines with IC₅₀ values ranging from 40.1 to 166.3?μg/mL.

Discussion and conclusion: The ethanol extract of A. oxyphylla fruit, especially the EF, was found to possess potent antioxidant and anticancer activities, and thus a great potential for the application in food and drug products.     

Chemical composition,antioxidant, antitumor,anticancer and cytotoxic effects of Psidium guajava leaf extracts

Context Psidium guajava L. (Myrtaceae) leaves are used in traditional medicines for the treatment of cancer, inflammation and other ailments.

Objective The current study explores scientific validation for this traditional medication.

Materials and methods We used ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl hydrazil (DPPH) assays to estimate antioxidant activity of P. guajava leaf extracts (methanol, hexane and chloroform). Antitumour and in vivo cytotoxic activities were determined using potato disc assay (PDA) and brine shrimp lethality assay, respectively. Three human carcinoma cell lines (KBM5, SCC4 and U266) were incubated with different doses (10–100?μg/mL) of extracts and the anticancer activity was estimated by MTT assay. NF-κB suppressing activity was determined using electrophoretic mobility shift assay (EMSA). Chemical composition of the three extracts was identified by GC-MS. Total phenolic and flavonoid contents were measured by colorimetric assays.

Results and discussions The order of antioxidant activity of three extracts was methanol?>?chloroform?>?hexane. The IC₅₀ values ranged from 22.73 to 51.65?μg/mL for KBM5; 22.82 to 70.25?μg/mL for SCC4 and 20.97 to 89.55?μg/mL for U266 cells. The hexane extract exhibited potent antitumour (IC_50? value?=_?65.02?μg/mL) and cytotoxic (LC_50? value?=_?32.18?μg/mL) activities. This extract also completely inhibited the TNF-α induced NF-κB activation in KBM5 cells. GC-MS results showed that pyrogallol, palmitic acid and vitamin E were the major components of methanol, chloroform and hexane extracts. We observed significant (p?<?0.05) difference in total phenolic and flavonoid contents of different solvent extracts.

Conclusion The present study demonstrates that P. guajava leaf extracts play a substantial role against cancer and down-modulate inflammatory nuclear factor kB.     

Antioxidant and cytotoxic lignans from the roots of Bupleurum chinense

In the search for biologically active compounds from the roots of Bupleurum chinense D C., phytochemical investigation of its ethanol extract led to the isolation and identification of a new 8-O-4′ neolignan glucoside, saikolignanoside A (1), along with eight known lignans (2–9). Their structures were determined on the basis of IR, UV, HRESIMS, and NMR spectroscopic analyses. The antioxidant and cytotoxic effects of isolated compounds were evaluated in vitro. The isolated compounds (IC₅₀ > 200 μM) did not display 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Whereas compounds 1–2, 5, 7, and 9 exhibited potent 2, 2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging properties with IC₅₀ values ranging from 8.34 to 15.24 μM, while compounds 3–4, 6, 8 showed moderate properties. In addition, all compounds were evaluated for cytotoxicities against A549, HepG2, U251, Bcap-37, and MCF-7 cell lines. Compounds 5 and 9 (IC_50?相似文献   

Cytotoxic activity and chemical constituents of Anthemis mirheydari

Context The genus Anthemis L. (Asteraceae) comprises about 195 species which are widely used in the pharmaceutical, cosmetic and food industries.

Objective Anthemis mirheydari Iranshar, an endemic plant from Iran, was investigated for its cytotoxic properties and chemical constituents.

Materials and methods The whole parts of the plant (320?g) were extracted by dichloromethane and methanol for four days, successively. The cytotoxic activity of both dichloromethane and methanol extracts were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric methods against three human cancer cell lines including LS180, MCF-7 and MOLT-4. Different concentrations (10–100?μg/mL) of the plant extracts were tested to obtain IC₅₀ values. The dichloromethane extract of A. mirheydari was subjected to silica gel-column and thin layer chromatography for purification of its chemical constituents and the isolated compounds were further tested against MOLT-4 cells. The structures of the pure compounds were elucidated using different spectral data including nuclear magnetic resonance and electron impact mass spectra.

Results The IC₅₀ values of the dichloromethane extract were 30.8?±?6.7, 25.2?±?6.5 and 8.6?±?1.1?μg/mL (means?±?standard error) for the above-mentioned cell lines, respectively. Two triterpenoids, taraxasterol (1) and pseudotaraxasterol (2), one sterol, β-sitosterol (3) and one coumarin, 7-methoxycoumarin (4) were isolated from the extract. The IC₅₀ of the mixture of compounds 1 and 2 as well as compounds 3 and 4 were higher (>100?μM) than that reported for the dichloromethane extract against MOLT-4 cells.

Conclusion The dichloromethane extract was the most active one among the tested material.     

Anti-acetylcholinesterase activity and antioxidant properties of extracts and fractions of Carpolobia lutea

Context: There is an unmet need to discover new treatments for Alzheimer’s disease. This study determined the anti-acetylcholinesterase (AChE) activity, DPPH free radical scavenging and antioxidant properties of Carpolobia lutea G. Don (Polygalaceae).

Objective: The objective of this study is to quantify C. lutea anti-AChE, DPPH free radical scavenging, and antioxidant activities and cell cytotoxicity.

Materials and methods: Plant stem, leaves and roots were subjected to sequential solvent extractions, and screened for anti-AChE activity across a concentration range of 0.02–200?μg/mL. Plant DPPH radical scavenging activity, reducing power, and total phenolic and flavonoid contents were determined, and cytotoxicity evaluated using human hepatocytes.

Results: Carpolobia lutea exhibited concentration-dependent anti-AChE activity. The most potent inhibitory activity for the stem was the crude ethanol extract and hexane stem fraction oil (IC₅₀?=?140?μg/mL); for the leaves, the chloroform leaf fraction (IC₅₀?=?60?μg/mL); and for roots, the methanol, ethyl acetate and aqueous root fractions (IC₅₀?=?0.3–3?μg/mL). Dose-dependent free radical scavenging activity and reducing power were observed with increasing stem, leaf or root concentration. Total phenolic contents were the highest in the stem: ～632?mg gallic acid equivalents/g for a hexane stem fraction oil. Total flavonoid content was the highest in the leaves: ～297?mg quercetin equivalents/g for a chloroform leaf fraction. At 1?μg/mL, only the crude ethanol extract oil was significantly cytotoxic to hepatocytes.

Discussion and conclusions: Carpolobia lutea possesses anti-AChE activity and beneficial antioxidant capacity indicative of its potential development as a treatment of Alzheimer’s and other diseases characterized by a cholinergic deficit.     

Antinociceptive and antioxidant potential of the crude ethanol extract of the leaves of Ageratum conyzoides grown in Bangladesh

Abstract

Context: Ageratum conyzoides Linn. (Asteraceae) is an annual herbaceous plant with a long history of traditional medicinal and agricultural uses; it is usually grown in the northeast part of Bangladesh.

Objective: The ethanol extract of the plant leaves was evaluated for preliminary phytochemical screening with its antinociceptive and antioxidant activities.

Materials and methods: The preliminary phytochemical analysis was performed on the basis of standard procedures. The analgesic activity of the extract was investigated using the acetic acid-induced writhing method in mice. Five complementary tests such as DPPH free radical scavenging, nitric oxide (NO) scavenging, reducing power, Fe⁺⁺ ion chelating ability and total phenolic content were used for determining antioxidant activities.

Results: The results of preliminary phytochemical analysis showed the presence of alkaloids, reducing sugars, saponins, gums, steroids, tannins and flavonoids. The extract possessed a significant dose-dependent DPPH free radical scavenging activity with an IC₅₀ value of 18.91?μg/ml compared to ascorbic acid (IC₅₀: 2.937?μg/ml) and butylated hydroxyanisole (IC₅₀: 5.10?μg/ml). The IC₅₀ value of the extract for NO scavenging (41.81?μg/ml) was also found to be significant compared to the IC₅₀ value of ascorbic acid (37.93?μg/ml). Moreover, the extract showed reducing power activity and Fe⁺⁺ ion chelating ability. The total phenolic amount was also calculated as quite high (378.37?mg/g of gallic acid equivalents) in the crude ethanol extract.

Discussion and conclusion: Therefore, the obtained results tend to suggest the antinociceptive and antioxidant activities of the ethanol extract of the plant leaves and justify its use in folkloric remedies.     

Anti-inflammatory,anti-cholinergic and cytotoxic effects of Sida rhombifolia

Context: Sida (Malvaceae) has been used as a traditional remedy for the treatment of diarrhoea, malarial, gastrointestinal dysentery, fevers, asthma and inflammation.

Objectives: This study evaluates the anti-inflammatory, cytotoxic and anti-cholinergic activities of Sida rhombifolia Linn. whole plant for the first time.

Materials and methods: S. rhombifolia whole plant was extracted by n-hexane, ethyl acetate and methanol using Soxhlet apparatus. The plant extracts were evaluated for their antioxidant (DPPH, FIC and FRAP), anti-inflammatory (NO and protein denaturation inhibitions), cytotoxic (MTT) and anti-cholinesterase (AChE) properties in a range of concentrations to obtain IC₅₀ values. GC-MS analysis was carried out on the n-hexane extract.

Results and discussion: The ethyl acetate extract exhibited the most significant antioxidant activities by scavenging DPPH radicals and ferrous ions with EC₅₀ of 380.5 and 263.4?μg/mL, respectively. In contrast, the n-hexane extract showed the strongest anti-inflammatory activity with IC₅₀ of 52.16 and 146.03?μg/mL for NO and protein denaturation inhibition assays, respectively. The same extract also revealed the strongest effects in anti-cholinesterase and cytotoxic tests at the concentration of 100?μg/mL, AChE enzyme inhibition was 58.55% and human cancer cells, SNU-1 and Hep G2 inhibition was 68.52% and 47.82%, respectively. The phytochemicals present in the n-hexane extract are palmitic acid, linoleic acid and γ-sitosterol.

Conclusions: The present study revealed that the n-hexane extract possessed relatively high pharmacological activities in anti-inflammation, cytotoxicity and anti-cholinesterase assays. Thus, further work on the detail mechanism of the bioactive phytochemicals which contribute to the biological properties are strongly recommended.     

Isolation and identification of three new chromones from the leaves of Pimenta dioica with cytotoxic,oestrogenic and anti-oestrogenic effects

Context: Pimenta dioica (L.) Merr. (Myrtaceae) is used in Costa Rican traditional medicine for women’s health. Our previous work showed that P. dioica extracts were oestrogenic.

Objectives: This work identifies phytochemicals from P. dioica that are responsible for the plant’s oestrogen-like activities.

Materials and methods: P. dioica leaves were collected in Costa Rica in 2005. Fractions resulting from chromatographic separation of a methanol extract were tested at 50?μg/mL in a competitive oestrogen receptor-binding assay. Active compounds were isolated by HPLC and identified by NMR and MS. Pure compounds were tested at 1?μM in the oestrogen-responsive SEAP reporter gene assay. The effects on cell viability, cytotoxicity and apoptosis were investigated in breast cancer (MCF-7 and SK-BR3) and gastric cancer (AGS and NCI-N87) cell lines using the ApoTox-Glo and Caspase-Glo assays and qPCR.

Results: Quercitrin and three new chromones, including a 2-phenoxychromone, 6,8-di-C-methylcapillarisin (1) were isolated and identified. Compound 1 caused a 6.2-fold increase in SEAP expression at 1?μM (p?2 caused a 6.0-fold increase in SEAP, inhibited the growth of MCF-7, AGS and NCI-N87 cells (IC₅₀ 54.27, 38.13 and 51.22?μg/mL, respectively), and induced apoptosis via caspase 8 and increased the Bax/Bcl-2 mRNA ratio in MCF-7 cells. Compound 3 was anti-oestrogenic in MCF-7 cells.

Discussion and conclusions: Compounds from P. dioica have oestrogenic, anti-oestrogenic and cytotoxic effects that may explain the ethnomedical use of this plant.     

Silibinin sensitizes chemo-resistant breast cancer cells to chemotherapy

Context: Multiple drug resistance is the major obstacle to conventional chemotherapy. Silibinin, a nontoxic naturally occurring compound, has anticancer activity and can increase the cytotoxic effects of chemotherapy in various cancer models.

Objective: To evaluate the effects of silibinin on enhancing the sensitivity of chemo-resistant human breast cell lines to doxorubicin (DOX) and paclitaxel (PAC).

Materials and methods: The cells were treated with silibinin (at 50 to 600?μM concentrations) and/or chemo drugs for 24 and 48?h, then cell viability and changes in oncogenic proteins were determined by MTT assay and Western blotting/RT-PCR, respectively. Flow cytometry was used to study apoptosis in the cells receiving different treatments. The antitumorigenic effects of silibinin (at 200 to 400?μM concentration) were evaluated by mammosphere assay.

Results: Silibinin exerted significant growth inhibitory effects with IC₅₀ ranging from 200 to 570?μM in different cell lines. Treatment of DOX-resistant MDA-MB-435 cells with silibinin at 200?μM reduced DOX IC₅₀ from 71 to 10?μg/mL and significantly suppressed the key oncogenic pathways including STAT3, AKT, and ERK in these cells. Interestingly treatment of DOX-resistant MDA-MB-435 cells with silibinin at 400?μM concentration for 48?h induced a 50% decrease in the numbers of colonies as compared with DMSO-treated cells. Treatment of PAC-resistant MCF-7 cells with silibinin at 400?μM concentration generated synergistic effects when it was used in combination with PAC at 250?nM concentration (CI?=?0.81).

Conclusion: Silibinin sensitizes chemo-resistant cells to chemotherapeutic agents and can be useful in treating breast cancers.     

Antimalarial and antiplasmodial activity of husk extract and fractions of Zea mays

Context: Zea mays L. (Poacae) husk decoctions are traditionally used in the treatment of malaria by various tribes in Nigeria.

Objective: To assess the antimalarial and antiplasmodial potentials of the husk extract and fractions on malaria parasites using in vivo and in vitro models.

Materials and methods: The ethanol husk extract and fractions (187–748?mg/kg, p.o.) of Zea mays were investigated for antimalarial activity against Plasmodium berghei using rodent (mice) malaria models and in vitro activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using the SRBR green assay method. Median lethal dose and cytotoxic activities against HeLa and HEKS cells were also carried out. The GCMS analysis of the most active fraction was carried out.

Results: The husk extract (187–748?mg/kg, p.o.) with LD₅₀ of 1874.83?mg/kg was found to exert significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The crude extract and fractions also exerted prominent activity against both chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ values of 9.31?±?0.46?μg/mL (Pf 3D7) and 3.69?±?0.66?μg/mL (Pf INDO). The crude extract and fractions were not cytotoxic to the two cell lines tested with IC₅₀ values of?>100?μg/mL against both HeLa and HEKS cell lines.

Discussion and conclusion: These results suggest that the husk extract/fractions of Zea mays possesses antimalarial and antiplasmodial activities and these justify its use in ethnomedicine to treat malaria infections.     

Unlocking the in vitro anti-inflammatory and antidiabetic potential of Polygonum maritimum

Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes.

Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L.

Material and methods: Antioxidant activity was determined (up to 1?mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24?h at concentrations up to 100?μg/mL and antidiabetic potential was assessed by α-amylase and α-glucosidase inhibition (up to 10?mg/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS).

Results: The methanol leaf extract had the highest activity against DPPH? (IC₅₀ =?26?μg/mL) and ABTS⁺? (IC₅₀ =?140?μg/mL), FRAP (IC₅₀ =?48?μg/mL) and CCA (IC₅₀ =?770?μg/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC₅₀ =?48?μg/mL). The methanol root (IC₅₀ =?19?μg/mL) and leaf (IC₅₀ =?29?μg/mL) extracts strongly inhibited baker’s yeast α-glucosidase, but LDCM had higher rat’s α-glucosidase inhibition (IC₅₀ =?2527?μg/mL) than acarbose (IC₅₀ =?4638?μg/mL). GC-MS analysis identified β-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities.

Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.     

Evaluation of the cytotoxic potential of a new pentacyclic triterpene from Rhododendron arboreum stem bark

Context: Traditionally, Rhododendron arboreum Sm. (Ericaceae) is a very important medicinal plant having oxytocic, estrogenic, anti-inflammatory, analgesic and hepatoprotective activities; it also inhibits the prostaglandin synthetase.

Objectives: This study determines the cytotoxic potential of 15-oxoursolic acid isolated from R. arboreum against selected human cancer cell lines.

Materials and methods: Extraction from stem bark (5?kg) of R. arboreum was performed with methanol, which was successively partitioned into hexane, dichloromethane and ethyl acetate fractions, respectively. The new antitumor agent [15-oxoursolic acid (1)] was isolated from ethyl acetate fraction through column chromatography. Structure elucidation of new compound was performed through extensive spectroscopy i.e., IR, MS and 1D and 2D NMR. Cytotoxicity of isolated compound was determined at doses 5–100?μM for a period of 72?h on specified human cancer cell lines [renal cell carcinoma (A498), non-small cell lung (NCI-H226), squamous cell carcinoma (H157) and human ovarian carcinoma (MDR-2780AD)].

Results: Structure of isolated compound was characterized as 15-oxoursolic acid on the basis of various extensive spectroscopic techniques. 15-Oxoursolic acid revealed considerable anticancer activity with IC₅₀ values of 2.3?±?0.1?μM, 4.9?±?0.2?μM, 9.2?±?0.2?μM and 10.3?±?0.1?μM against MDR 2780AD, Hep G2, H157 and NCI-H226, respectively, while in the case of A498, the activity was good (IC₅₀ 32.8?±?1.2?μM).

Conclusions: This study highlighted the potential of 15-oxoursolic acid to be further explored as a new lead compound for cancer chemotherapy.     

Phytochemical analysis,antiproliferative and antioxidant activities of Chrozophora tinctoria: a natural dye plant

Context: Chrozophora tinctoria (L.) A. Juss. (Euphorbiaceae) is known as ‘dyer’s-croton’ and used to obtain dye substances. Recently, natural antioxidants and colorants have been of interest because of their safety and therapeutic effects.

Objective: This study investigates the antiproliferative and antioxidant activities of the various extracts and fractions from C. tinctoria and analyzes their phytochemical contents.

Materials and methods: The aerial parts of C. tinctoria were extracted with water, ethyl acetate, n-butanol, and methanol/chloroform. Phenolic compounds and other constituents of the extracts were analyzed by HPLC/TOF-MS. The ethyl acetate extract (EA) was fractionated by flash chromatography. The extracts, fractions, and major phenolic compounds were investigated for their antiproliferative activities on human cervical adenocarcinoma (HeLa) cell line at the concentrations of 5–100?μg/mL by using BrdU ELISA assay during 24?h of incubation. DPPH radical scavenging activities (5–150?μg/mL) and total phenolic contents of the samples were also evaluated.

Results: 4-Hydroxybenzoic acid (268.20?mg/kg), apigenin-7-glucoside (133.34?mg/kg), and gallic acid (68.92?mg/kg) were the major components of EA. CT/E-F6 (IC₅₀?=?64.59?±?0.01?μg/mL) exhibited the highest antiproliferative activity. CT/E-F2 (IC₅₀=?14.0?±?0.0?μg/mL) and some fractions displayed higher radical scavenging activity compared to synthetic antioxidant BHT (IC_50?=_?23.1?±?0.0?μg/mL). Among the main phenolics, gallic acid exhibited the highest antiproliferative and radical scavenging abilities (IC_50?<_?5?μg/mL).

Conclusion: In this study, we have determined the biologically active fractions and their high effects may be attributed to the presence of gallic acid.     

Flavonoids of Calligonum polygonoides and their cytotoxicity

Context Calligonum polygonoides L. subsp. comosum L’ Hér. (Polygonaceae), locally known as “arta”, is a slow-growing small leafless desert shrub.

Objective Isolation, structure elucidation and evaluation of cytotoxic activity of flavonoids from C. polygonoides aerial parts.

Materials and methods Flavonoids in the hydroalcoholic extract of the of C. polygonoides were isolated and purified using column chromatography and preparative HPLC. The structures of the isolated flavonoids were elucidated on the basis of spectroscopic data including 2D NMR techniques. The cytotoxic activity of the isolated flavonoids (6.25, 25, 50 and 100?μg/mL) was evaluated against liver HepG2 and breast MCF-7 cancer cell lines using sulphorhodamine-B assay.

Results A new flavonoid, kaempferol-3-O-β-D-(6″-n-butyl glucuronide) (1), and 13 known flavonoids, quercetin 3-O-β-D-(6″-n-butyl glucuronide) (2), kaempferol-3-O-β-D-(6″-methyl glucuronide) (3), quercetin-3-O-β-D-(6″-methyl glucuronide) (4), quercetin-3-O-glucuronide (5), kaempferol-3-O-glucuronide (6), quercetin-3-O-α-rhamnopyranoside (7), astragalin (8), quercetin-3-O-glucopyranoside (9), taxifolin (10), (+)-catechin (11), dehydrodicatechin A (12), quercetin (13), and kaempferol (14), were isolated from the aerial parts of C. polygonoides. Quercetin showed significant cytotoxic activity against HepG2 and MCF-7 cell lines with IC₅₀ values of 4.88 and 0.87?μg/mL, respectively. Structure–activity relationships were analyzed by comparing IC₅₀ values of several pairs of flavonoids differing in one structural element.

Discussion and conclusion The activity against breast cancer cell lines decreased by glycosylation at C-3. The presence of 2,3-double bond in ring C, carbonyl group at C-4 and 3’,4’-dihydroxy substituents in ring B are essential structural requirements for the cytotoxic activity against breast cancer cells.