Anticholinesterse and antioxidant investigations of crude extracts,subsequent fractions,saponins and flavonoids of atriplex laciniata L.: potential effectiveness in Alzheimer’s and other neurological disorders

Background

Atriplex laciniata L. was investigated for phenolic, flavonoid contents, antioxidant, anticholinesterase activities, in an attempt to explore its effectiveness in Alzheimer’s and other neurological disorders. Plant crude methanolic extract (Al.MeF), subsequent fractions; n-hexane (Al.HxF), chloroform (Al.CfF), ethyl acetate (Al.EaF), aqueous (Al.WtF), Saponins (Al.SPF) and Flavonoids (Al.FLVF) were investigated for DPPH, ABTS and H₂O₂ free radical scavenging activities. Further these extracts were subjected to acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities using Ellman’s assay. Phenolic and Flavonoid contents were determined and expressed in mg Gallic acid GAE/g and Rutin RTE/g of samples respectively.

Results

In DPPH free radicals scavenging assay, Al.FLVF, Al.SPF and Al.MeF showed highest activity causing 89.41 ± 0.55, 83.37 ± 0.34 and 83.37 ± 0.34% inhibition of free radicals respectively at 1 mg/mL concentration. IC₅₀ for these fractions were 33, 83 and 82 μg/mL respectively. Similarly, plant extracts showed high ABTS scavenging potential, i.e. Al.FLVF (90.34 ± 0.55), Al.CfF (83.42 ± 0.57), Al.MeF (81.49 ± 0.60) with IC₅₀ of 30, 190 and 70 μg/ml respectively. further, H₂O₂ percent scavenging was highly appraised in Al.FLVF (91.29 ± 0.53, IC₅₀ 75), Al.SPF (85.35 ± 0.61, IC₅₀ 70) and Al.EaF (83.48 ± 0.67, IC₅₀ 270 μg/mL). All fractions exhibited concentration dependent AChE inhibitory activity as; Al.FLVF, 88.31 ± 0.57 (IC₅₀ 70 μg/mL), Al.SPF, 84.36 ± 0.64 (IC₅₀ 90 μg/mL), Al.MeF, 78.65 ± 0.70 (IC₅₀ 280 μg/mL), Al.EaF, 77.45 ± 0.46 (IC₅₀ 270 μg/mL) and Al.WtF 72.44 ± 0.58 (IC₅₀ 263 μg/mL) at 1 mg/mL. Likewise the percent BChE inhibitory activity was most obvious in Al.FLVF 85.46 ± 0.62 (IC₅₀ 100 μg/mL), Al.CfF 83.49 ± 0.46 (IC₅₀ 160 μg/mL), Al.MeF 82.68 ± 0.60 (IC₅₀ 220 μg/mL) and Al.SPF 80.37 ± 0.54 (IC₅₀ 120 μg/mL).

Conclusions

These results stipulate that A. laciniata is enriched with phenolic and flavonoid contents that possess significant antioxidant and anticholinestrase effects. This provide pharmacological basis for the presence of compounds that may be effective in Alzheimer’s and other neurological disorders.     

Phytochemical and toxicological investigations of crude methanolic extracts,subsequent fractions and crude saponins of Isodon rugosus

Background

Isodon rugosus is used traditionally in the management of hypertension, rheumatism, tooth-ache and pyrexia. Present study was arranged to investigate I. rugosus for phytoconstituents, phytotoxic and cytotoxic activities to explore its toxicological, pharmacological potentials and to rationalize its ethnomedicinal uses. Briefly, qualitative phytochemical analysis of the plant extracts were carried out for the existence of alkaloids, flavonoids, saponins, oils, glycosides, anthraquinones, terpenoids, sterols and tannins. Plant crude methanolic extract (Ir.Cr), its subsequent fractions; n-hexane (Ir.Hex), chloroform (Ir.Chf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq) and saponins (Ir.Sp) in different concentrations were tested for phytotoxic and cytotoxic activities using radish seeds and brine shrimps (Artemia salina) respectively. The phytotoxic activity was determined by percent root length inhibition (RLI) and percent seeds germination inhibition (SGI) while the cytotoxicity was obtained with percent lethality of the brine shrimps.

Results

Ir.Cr was tested positive for the presence of alkaloids, glycosides, flavonoids, oils, terpenoids, saponins, tannins and anthraquinones. Among different fractions Ir.Sp, Ir.Chf, Ir.EtAc, and Ir.Cr were most effective causing 93.55, 89.32, 81.32 and 58.68% inhibition of seeds in phytotoxicity assay, with IC₅₀ values of 0.1, 0.1, 0.1 and 52 μg/ml respectively. Similarly, among all the tested samples, Ir.Sp exhibited the highest phytotoxic effect causing 91.33% root length inhibition with IC₅₀ of 0.1 μg/ml. Ir.Sp and Ir.Chf were most effective against brine shrimps showing 92.23 and 76.67% lethality with LC₅₀ values of 10 and 12 μg/ml respectively.

Conclusions

It may be inferred from the current investigations that I. rugosus contains different secondary metabolites and is a potential source for the isolation of natural anticancer and herbicidal drug molecules. Different fractions exhibited phytotoxic and cytotoxic activities, thus providing pharmacological basis for ethnomedicinal uses of this plant.     

Investigations of anticholinestrase and antioxidant potentials of methanolic extract,subsequent fractions,crude saponins and flavonoids isolated from Isodon rugosus

Background

Based on the ethnomedicinal uses and the effective outcomes of natural products in various diseases, this study was designed to evaluate Isodon rugosus as possible remedy in oxidative stress, alzheimer’s and other neurodegenerative diseases. Acetylecholinestrase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of crude methanolic extract (Ir.Cr), resultant fractions (n-hexane (Ir.Hex), chloroform (Ir.Cf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq)), flavonoids (Ir.Flv) and crude saponins (Ir.Sp) of I. rugosus were investigated using Ellman’s spectrophotometric method. Antioxidant potential of I. rugosus was determined using DPPH, H₂O₂ and ABTS free radicals scavenging assays. Total phenolic and flavonoids contents of plant extracts were determined and expressed in mg GAE/g dry weight and mg RTE/g of dry sample respectively.

Results

Among different fractions Ir.Flv and Ir.Cf exhibited highest inhibitory activity against AChE (87.44 ± 0.51, 83.73 ± 0.64%) and BChE (82.53 ± 0.71, 88.55 ± 0.77%) enzymes at 1 mg/ml with IC₅₀ values of 45, 50 for AChE and 40, 70 μg/ml for BChE respectively. Activity of these fractions were comparable to galanthamine causing 96.00 ± 0.30 and 88.61 ± 0.43% inhibition of AChE and BChE at 1 mg/ml concentration with IC₅₀ values of 20 and 47 μg/ml respectively. In antioxidant assays, Ir.Flv, Ir.Cf, and Ir.EtAc demonstrated highest radicals scavenging activities in DPPH and H₂O₂ assays which were comparable to ascorbic acid. Ir.Flv was found most potent with IC₅₀ of 19 and 24 μg/ml against DPPH and H₂O₂ radicals respectively. Whereas antioxidant activates of plant samples against ABTS free radicals was moderate. Ir.Cf, Ir.EtAc and Ir.Cr showed high phenolic and flavonoid contents and concentrations of these compounds in different fractions correlated well to their antioxidant and anticholinestrase activities.

Conclusion

It may be inferred from the current investigations that the Ir.Sp, Ir.Flv and various fractions of I. rugosus are good sources of anticholinesterase and antioxidant compounds. Different fractions can be subjected to activity guided isolation of bioactive compounds effective in neurological disorders.     

In vitro antioxidant capacity and free radical scavenging evaluation of active metabolite constituents of Newbouldia laevis ethanolic leaf extract

Background

The aim of the present study was to evaluate the in vitro antioxidant and free radical scavenging capacity of bioactive metabolites present in Newbouldia laevis leaf extract.

Results

Chromatographic and spectrophotometric methods were used in the study and modified where necessary in the study. Bioactivity of the extract was determined at 10 μg/ml, 50 μg/ml, 100 μg/ml, 200 μg/ml and 400 μg/ml concentrations expressed in % inhibition. The yield of the ethanolic leaf extract of N.laevis was 30.3 g (9.93%). Evaluation of bioactive metabolic constituents gave high levels of ascorbic acid (515.53 ± 12 IU/100 g [25.7 mg/100 g]), vitamin E (26.46 ± 1.08 IU/100 g), saponins (6.2 ± 0.10), alkaloids (2.20 ± 0.03), cardiac glycosides(1.48 ± 0.22), amino acids and steroids (8.01 ± 0.04) measured in mg/100 g dry weight; moderate levels of vitamin A (188.28 ± 6.19 IU/100 g), tannins (0.09 ± 0.30), terpenoids (3.42 ± 0.67); low level of flavonoids (1.01 ± 0.34 mg/100 g) and absence of cyanogenic glycosides, carboxylic acids and aldehydes/ketones. The extracts percentage inhibition of DPPH, hydroxyl radical (OH^.), superoxide anion (O₂^.-), iron chelating, nitric oxide radical (NO), peroxynitrite (ONOO⁻), singlet oxygen (¹O₂), hypochlorous acid (HOCl), lipid peroxidation (LPO) and FRAP showed a concentration-dependent antioxidant activity with no significant difference with the controls. Though, IC₅₀ of the extract showed significant difference only in singlet oxygen (¹O₂) and iron chelating activity when compared with the controls.

Conclusions

The extract is a potential source of antioxidants/free radical scavengers having important metabolites which maybe linked to its ethno-medicinal use.     

In vitro and in silico studies of bis (indol-3-yl) methane derivatives as potential α-glucosidase and α-amylase inhibitors

In this paper, bis (indol-3-yl) methanes (BIMs) were synthesised and evaluated for their inhibitory activity against α-glucosidase and α-amylase. All synthesised compounds showed potential α-glucosidase and α-amylase inhibitory activities. Compounds 5 g (IC₅₀: 7.54 ± 1.10 μM), 5e (IC₅₀: 9.00 ± 0.97 μM), and 5 h (IC₅₀: 9.57 ± 0.62 μM) presented strongest inhibitory activities against α-glucosidase, that were ∼ 30 times stronger than acarbose. Compounds 5 g (IC₅₀: 32.18 ± 1.66 µM), 5 h (IC₅₀: 31.47 ± 1.42 µM), and 5 s (IC₅₀: 30.91 ± 0.86 µM) showed strongest inhibitory activities towards α-amylase, ∼ 2.5 times stronger than acarbose. The mechanisms and docking simulation of the compounds were also studied. Compounds 5 g and 5 h exhibited bifunctional inhibitory activity against these two enzymes. Furthermore, compounds showed no toxicity against 3T3-L1 cells and HepG2 cells.

Highlights

1. A series of bis (indol-3-yl) methanes (BIMs) were synthesised and evaluated inhibitory activities against α-glucosidase and α-amylase.
2. Compound 5g exhibited promising activity (IC₅₀ = 7.54 ± 1.10 μM) against α-glucosidase.
3. Compound 5s exhibited promising activity (IC₅₀ = 30.91 ± 0.86 μM) against α-amylase.
4. In silico studies were performed to confirm the binding interactions of synthetic compounds with the enzyme active site.

     

Flavonoid constituents,cytotoxic and antioxidant activities of Gleditsia triacanthos L. leaves

Gleditsia triacanthos L. is a deciduous tree belonging to the family Fabaceae. It possesses important biological activities as anti-mutagenic, anticancer, cytotoxic and treating rheumatoid arthritis. The total ethanol extract (EtOHE) and successive extracts (petroleum ether, chloroform, ethyl acetate, and aqueous ethanol) were prepared from the leaves. Eight flavone glycosides and two flavone aglycones named vicenin-I (1), vitexin (2), isovitexin (3), orientin (4), isoorientin (5), luteolin-7-O-ß-glucopyranoside (6), luteolin-7-O-ß-galactopyranoside (7), apigenin-7-O-ß-glucopyranoside (8), luteolin (9) and apigenin (10) were isolated from the aqueous ethanol extract of G. triacanthos L. leaves. Potent cytotoxic activity of the EtOHE extract was observed against the liver (IC₅₀ = 1.68 μg), breast (IC₅₀ = 0.74 μg), cervix (IC₅₀ = 1.28 μg), larynx (IC₅₀ = 0.67 μg) and colon (IC₅₀ = 2.50 μg) cancer cell lines. Cytotoxic activity of compounds 2, 4, 6 and 8 against, the liver, breast and colon cancer cell lines was also proved. Evaluation of the in-vivo antioxidant activity of the EtOHE and successive extracts revealed that the highest activity was exhibited by 100 mg of EtOHE (97.89% potency) as compared with vitamin E (100% potency). Compound 6 showed 91.8% free radical scavenging activity.     

Anti-inflammatory components of the Vietnamese starfish Protoreaster nodosus

Background

In the present study, we examined the inhibitory effects of a methanolic extract, dichloromethane fraction, water layer, and polyhydroxylated sterols (1–4) isolated from the Vietnamese starfish Protoreaster nodosus on pro-inflammatory cytokine (IL-12 p40, IL-6, and TNF-α) production in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) using enzyme-linked immunosorbent assays (ELISA).

Results

The methanolic extract and dichloromethane fraction exerted potent inhibitory effects on the production of all three pro-inflammatory cytokines, with IC₅₀ values ranging from 0.60 ± 0.01 to 26.19 ± 0.64 μg/mL. Four highly pure steroid derivatives (1–4) were isolated from the dichloromethane fraction and water layer of P. nodosus. Potent inhibitory activities were also observed for (25S) 5α-cholestane-3β,4β,6α,7α,8β,15α,16β,26-octol (3) on the production of IL-12 p40 and IL-6 (IC_50s = 3.11 ± 0.08 and 1.35 ± 0.03 μM), and for (25S) 5α-cholestane-3β,6α,8β,15α,16β,26-hexol (1) and (25S) 5α-cholestane-3β,6α,7α,8β,15α,16β,26-heptol (2) on the production of IL-12 p40 (IC_50s = 0.01 ± 0.00 and 1.02 ± 0.01 μM). Moreover, nodososide (4) exhibited moderate inhibitory effects on IL-12 p40 and IL-6 production.

Conclusion

This is the first report of the anti-inflammatory activity from the starfish P. nodosus. The main finding of this study is the identification oxygenated steroid derivatives from P. nodosus with potent anti-inflammatory activities that may be developed as therapeutic agents for inflammatory diseases.     

Antioxidant,inhibition of α-glucosidase and suppression of nitric oxide production in LPS-induced murine macrophages by different fractions of Actinidia arguta stem

In traditional systems of medicine, fruits, leaves, and stems of Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq. have been used to treat various inflammatory diseases. The present study determined the proximate composition, antioxidant, anti-inflammatory, and hypoglycemic potential of A. arguta stem. Phenolic composition of hot water extract and its sub-fractions was determined by Folin–Ciocalteu’s reagent method. In vitro antioxidant activities of the samples were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assays. Anti-inflammatory activity of different fractions was investigated through the inhibition of nitric oxide (NO) production in lipopolysaccharide (1 μg/ml) stimulated RAW 264.7 cells. In addition, inhibition of α-glucosidase activity of hot water extract was determined using p-nitrophenyl-α-d-glucopyranoside (pNPG) as a substrate. Ethyl acetate (557.23 mg GAE/g) fraction contains higher level of total phenolic content. The antioxidant activity evaluated by DPPH radical scavenging assay showed a strong activity for ethyl acetate (IC₅₀ of 14.28 μg/ml) and n-butanol fractions (IC₅₀ of 48.27 μg/ml). Further, ethyl acetate fraction effectively inhibited NO production in RAW 264.7 cells induced by lipopolysaccharide (LPS) than other fractions (nitrite level to 32.14 μM at 200 μg/ml). In addition, hot water extract of A. arguta stem exhibited appreciable inhibitory activity against α-glucosidase enzyme with IC₅₀ of 1.71 mg/ml. The obtained results have important consequence of using A. arguta stem toward the development of effective anti-inflammatory drugs.     

In glucose-limited continuous culture the minimum substrate concentration for growth,smin, is crucial in the competition between the enterobacterium Escherichia coli and Chelatobacter heintzii,an environmentally abundant bacterium

The competition for glucose between Escherichia coli ML30, a typical copiotrophic enterobacterium and Chelatobacter heintzii ATCC29600, an environmentally successful strain, was studied in a carbon-limited culture at low dilution rates. First, as a base for modelling, the kinetic parameters μ_max and K_s were determined for growth with glucose. For both strains, μ_max was determined in batch culture after different precultivation conditions. In the case of C. heintzii, μ_max was virtually independent of precultivation conditions. When inoculated into a glucose-excess batch culture medium from a glucose-limited chemostat run at a dilution rate of 0.075 h⁻¹ C. heintzii grew immediately with a μ_max of 0.17±0.03 h⁻¹. After five transfers in batch culture, μ_max had increased only slightly to 0.18±0.03 h⁻¹. A different pattern was observed in the case of E. coli. Inoculated from a glucose-limited chemostat at D=0.075 h⁻¹ into glucose-excess batch medium E. coli grew only after an acceleration phase of ∼3.5 h with a μ_max of 0.52 h⁻¹. After 120 generations and several transfers into fresh medium, μ_max had increased to 0.80±0.03 h⁻¹. For long-term adapted chemostat-cultivated cells, a K_s for glucose of 15 μg l⁻¹ for C. heintzii, and of 35 μg l⁻¹ for E. coli, respectively, was determined in ¹⁴C-labelled glucose uptake experiments. In competition experiments, the population dynamics of the mixed culture was determined using specific surface antibodies against C. heintzii and a specific 16S rRNA probe for E. coli. C. heintzii outcompeted E. coli in glucose-limited continuous culture at the low dilution rates of 0.05 and 0.075 h⁻¹. Using the determined pure culture parameter values for K_s and μ_max, it was only possible to simulate the population dynamics during competition with an extended form of the Monod model, which includes a finite substrate concentration at zero growth rate (s_min). The values estimated for s_min were dependent on growth rate; at D=0.05 h⁻¹, it was 12.6 and 0 μg l⁻¹ for E. coli and C. heintzii, respectively. To fit the data at D=0.075 h⁻¹, s_min for E. coli had to be raised to 34.9 μg l⁻¹ whereas s_min for C. heintzii remained zero. The results of the mathematical simulation suggest that it is not so much the higher K_s value, which is responsible for the unsuccessful competition of E. coli at low residual glucose concentration, but rather the existence of a significant s_min.     

Dose-finding evaluation of once-daily treatment with olodaterol,a novel long-acting β2-agonist,in patients with asthma: results of a parallel-group study and a crossover study

Background

Olodaterol is a novel, inhaled long-acting β₂-agonist (LABA) with >24-hour duration of action investigated in asthma and chronic obstructive pulmonary disease.

Methods

Two multicentre studies examined the efficacy and safety of 4 weeks’ once-daily (QD) olodaterol (2, 5, 10 and 20 μg, with background inhaled corticosteroids) in patients with asthma. One randomised, double-blind, parallel-group study (1222.6; 296 patients) administered treatment in the morning. Pulmonary function tests (PFTs) were performed pre-dose (trough) and ≤3 hours post-dose (weeks 1 and 2), and ≤6 hours post-dose after 4 weeks; primary end point was trough forced expiratory volume in 1 second (FEV₁) response (change from baseline mean FEV₁) after 4 weeks. A second randomised, double-blind, placebo- and active-controlled (formoterol 12 μg twice-daily) incomplete-block crossover study (1222.27; 198 patients) administered QD treatments in the evening. PFTs were performed over a 24-hour dosing interval after 4 weeks; primary end point was FEV₁ area under the curve from 0–24 hours (AUC_0–24) response (change from study baseline [mean FEV₁] after 4 weeks).

Results

Study 1222.6 showed a statistically significant increase in trough FEV₁ response with olodaterol 20 μg (0.147 L; 95 % confidence interval [CI]: 0.059, 0.234; p = 0.001) versus placebo, with more limited efficacy and no evidence of dose response compared to placebo across the other olodaterol doses (2, 5 and 10 μg). Study 1222.27 demonstrated increases in FEV₁ AUC_0–24 responses at 4 weeks with all active treatments (p < 0.0001); adjusted mean (95 % CI) differences from placebo were 0.140 (0.097, 0.182), 0.182 (0.140, 0.224), 0.205 (0.163, 0.248) and 0.229 (0.186, 0.272) L for olodaterol 2, 5, 10 and 20 μg, respectively, and 0.169 (0.126, 0.211) for formoterol, providing evidence of increased efficacy with higher olodaterol dose. Olodaterol was generally well tolerated, with a few events associated with known sympathomimetic effects, mainly with 20 μg.

Conclusions

The LABA olodaterol has >24-hour duration of action. In patients with asthma, evidence of bronchodilator efficacy was demonstrated with statistically and clinically significant improvements in the primary end point of trough FEV₁ response measured in clinics over placebo for the highest administered dose of 20 μg in Study 1222.6, and statistically and clinically significant improvements versus placebo in FEV₁ AUC_0–24 responses at 4 weeks for all doses tested in Study 1222.27, which also exhibited a dose response. Bronchodilator efficacy was seen over placebo for all olodaterol doses for morning and evening peak expiratory flow in both studies. All doses were well tolerated.

Trial registrations

{"type":"clinical-trial","attrs":{"text":"NCT00467740","term_id":"NCT00467740"}}NCT00467740 (1222.6) and {"type":"clinical-trial","attrs":{"text":"NCT01013753","term_id":"NCT01013753"}}NCT01013753 (1222.27).

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0249-8) contains supplementary material, which is available to authorized users.     

Assessment of the phytochemical constituents and antioxidant activity of a bloom forming microalgae Euglena tuba

Background

Unstable generation of free radicals in the body are responsible for many degenerative diseases. A bloom forming algae Euglena tuba growing abundantly in the aquatic habitats of Cachar district in the state of Assam in North-East India was analysed for its phytochemical contents, antioxidant activity as well as free radical scavenging potentials.

Results

Based on the ability of the extract in ABTS^•+ radical cation inhibition and Fe³⁺ reducing power, the obtained results revealed the prominent antioxidant activity of the algae, with high correlation coefficient of its TEAC values to the respective phenolic and flavonoid contents. The extract had shown its scavenging activity for different free radicals and 41.89 ± 0.41 μg/ml, 5.83 ± 0.07 μg/ml, 278.46 ± 15.02 μg/ml and 223.25 ± 4.19 μg/ml were determined as the IC₅₀ values for hydroxyl, superoxide, nitric oxide and hypochlorous acid respectively, which are lower than that of the corresponding reference standards. The phytochemical analysis also revealed that the phenolics, flavonoids, alkaloids, tannins and carbohydrates are present in adequate amount in the extract which was confirmed by HPLC analysis.

Conclusions

The results showed that 70% methanol extract of the algae possesses excellent antioxidant and free radical scavenging properties.     

Inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells by stem bark of Ulmus pumila L.

This study was designed to isolate and identify a potent inhibitory compound against nitric oxide (NO) production from the stem bark of Ulmus pumila L. Ethyl acetate fraction of hot water extract registered a higher level of total phenolics (756.93 mg GAE/g) and also showed strong DPPH (IC₅₀ at 5.6 μg/mL) and ABTS (TEAC value 0.9703) radical scavenging activities than other fractions. Crude extract and its fractions significantly decreased nitrite accumulation in LPS-stimulated RAW 264.7 cells indicating that they potentially inhibited the NO production in a concentration dependent manner. Based on higher inhibitory activity, the ethyl acetate fraction was subjected to Sephadex LH-20 column chromatography and yielded seven fractions and all these fractions registered appreciable levels of inhibitory activity on NO production. The most effective fraction F1 was further purified and subjected to ¹H, ¹³C-NMR and mass spectrometry analysis and the compound was identified as icariside E₄. The results suggest that the U. pumila extract and the isolated compound icariside E₄ effectively inhibited the NO production and may be useful in preventing inflammatory diseases mediated by excessive production of NO.     

Extraction of saponins and toxicological profile of Teucrium stocksianum boiss extracts collected from District Swat,Pakistan

Background

The current era is facing challenges in the management of neoplasia and weeds control. The currently available anti-cancer and herbicidal drugs are associated with some serious side effects. Therefore numerous researchers are trying to discover and develop plant based alternative particularly for the rational management of cancer and weed control. Teucrium stocksianum possess antioxidant and analgesic activities. The current study was designed to evaluate crude saponins (CS), methanolic extract and sub-fractions of T. stocksianum for cytotoxic and phytotoxic potentials. CS, methanolic extract and sub-fractions were extracted from powdered plant material using different solvents. Cytotoxic potential of the extracts at a dose of 10, 100 and 1000 μg/ml were evaluated against Brine shrimp’s nauplii. Phytotoxic assay also performed at the same concentration against Lemna minor. Etoposide and Paraquat were used as positive controls in cytotoxic and phytotoxic assays respectively.

Results

The percent yield of crude saponins was (5%). CS demonstrated tremendous brine shrimp lethality showing < 10 μg/ml LC₅₀. The n-hexane (HF) and chloroform fractions (CF) demonstrated excellent cytotoxicity with 80 and 55 μg/ml LC₅₀ respectively. Whereas the methanolic extract (TSME), ethyl acetate (EAF) and aqueous fractions (AF) revealed moderate cytotoxicity showing 620, 860 and 1000 μg/ml LC₅₀ values respectively. In phytotoxic assay profound inhibition was displayed by HF (96.67%) and TSME (95.56%, 30 μg/ml LC₅₀) against the growth of Lemna minor at 1000 μg/ml respectively. Both CF and EAF demonstrated profound phytoxicity (93.33%) respectively at highest concentration (1000 μg/ml), while AF and CS demonstrated weak phytotoxicity with 1350 and 710 μg/ml LC₅₀ values respectively.

Conclusion

Cytotoxicity and phytotoxicity assays indicated that the crude saponins, n-hexane and chloroform fractions of T. stocksianum could play a vital role in the treatment of neoplasia and as potential natural herbicides. Therefore these sub-fractions are recommended for further investigation with the aim to isolate novel anti-cancer and herbicidal compounds.     

Discovery of orally active chalcones as histone lysine specific demethylase 1 inhibitors for the treatment of leukaemia

Histone lysine specific demethylase 1 (LSD1) has emerged as an attractive molecule target for the discovery of potently anticancer drugs to treat leukaemia. In this study, a series of novel chalcone derivatives were designed, synthesised and evaluated for their inhibitory activities against LSD1 in vitro. Among all these compounds, D6 displayed the best LSD1 inhibitory activity with an IC₅₀ value of 0.14 μM. In the cellular level, compound D6 can induce the accumulation of H3K9me1/2 and inhibit cell proliferation by inactivating LSD1. It exhibited the potent antiproliferative activity with IC₅₀ values of 1.10 μM, 3.64 μM, 3.85 μM, 1.87 μM, 0.87 μM and 2.73 μM against HAL-01, KE-37, P30-OHK, SUP-B15, MOLT-4 and LC4-1 cells, respectively. Importantly, compound D6 significantly suppressed MOLT-4 xenograft tumour growth in vivo, indicating its great potential as an orally bioavailable candidate for leukaemia therapy.     

Impairment of ATP hydrolysis decreases adenosine A1 receptor tonus favoring cholinergic nerve hyperactivity in the obstructed human urinary bladder

This study was designed to investigate whether reduced adenosine formation linked to deficits in extracellular ATP hydrolysis by NTPDases contributes to detrusor neuromodulatory changes associated with bladder outlet obstruction in men with benign prostatic hyperplasia (BPH). The kinetics of ATP catabolism and adenosine formation as well as the role of P1 receptor agonists on muscle tension and nerve-evoked [³H]ACh release were evaluated in mucosal-denuded detrusor strips from BPH patients (n = 31) and control organ donors (n = 23). The neurogenic release of ATP and [³H]ACh was higher (P < 0.05) in detrusor strips from BPH patients. The extracellular hydrolysis of ATP and, subsequent, adenosine formation was slower (t_1/2 73 vs. 36 min, P < 0.05) in BPH detrusor strips. The A₁ receptor-mediated inhibition of evoked [³H]ACh release by adenosine (100 μM), NECA (1 μM), and R-PIA (0.3 μM) was enhanced in BPH bladders. Relaxation of detrusor contractions induced by acetylcholine required 30-fold higher concentrations of adenosine. Despite VAChT-positive cholinergic nerves exhibiting higher A₁ immunoreactivity in BPH bladders, the endogenous adenosine tonus revealed by adenosine deaminase is missing. Restoration of A₁ inhibition was achieved by favoring (1) ATP hydrolysis with apyrase (2 U mL⁻¹) or (2) extracellular adenosine accumulation with dipyridamole or EHNA, as these drugs inhibit adenosine uptake and deamination, respectively. In conclusion, reduced ATP hydrolysis leads to deficient adenosine formation and A₁ receptor-mediated inhibition of cholinergic nerve activity in the obstructed human bladder. Thus, we propose that pharmacological manipulation of endogenous adenosine levels and/or A₁ receptor activation might be useful to control bladder overactivity in BPH patients.     

Methanol extract from Vietnamese Caesalpinia sappan induces apoptosis in HeLa cells

Background

This study evaluated the cytotoxic activity of extracts from Caesalpinia sappan heartwood against multiple cancer cell lines using an MTT cell viability assay. The cell death though induction of apoptosis was as indicated by DNA fragmentation and caspase-3 enzyme activation.

Results

A methanol extract from C. sappan (MECS) showed cytotoxic activity against several of the cancer cell lines. The most potent activity exhibited by the MECS was against HeLa cells with an IC₅₀ value of 26.5 ± 3.2 μg/mL. Treatment of HeLa cells with various MECS concentrations resulted in growth inhibition and induction of apoptosis, as indicated by DNA fragmentation and caspase-3 enzyme activation.

Conclusion

This study is the first report of the anticancer properties of the heartwood of C. sappan native to Vietnam. Our findings demonstrate that C. sappan heartwood may have beneficial applications in the field of anticancer drug discovery.     

In vivo antipyretic,antiemetic, in vitro membrane stabilization,antimicrobial, and cytotoxic activities of different extracts from Spilanthes paniculata leaves

Background

The study was conducted to evaluate the in vitro antimicrobial activity, cytotoxic, and membrane stabilization activities, and in vivo antiemetic and antipyretic potentials of ethanolic extract, n-hexane and ethyl acetate soluble fractions of Spilanthes paniculata leaves for the first time widely used in the traditional treatments in Bangladesh.

Results

In antipyretic activity assay, a significant reduction (P < 0.05) was observed in the temperature in the mice tested. At dose 400 mg/kg-body weight, the n-hexane soluble fraction showed the effect (36.7 ± 0.63°C ) as like as the standard (dose 150 mg/kg-body weight) after 5 h of administration. Extracts showed significant (P < 0.001) potential when tested for the antiemetic activity compared to the standard, metoclopramide. At dose 50 mg/kg-body weight, the standard showed 67.23% inhibition, whereas n-hexane and ethyl acetate soluble fractions showed 37.53% and 24.93% inhibition of emesis respectively at dose 400 mg/kg-body weight. In antimicrobial activity assay, the n-hexane soluble fraction (400 μg/disc) showed salient activity against the tested organisms. It exerts highest activity against Salmonella typhi (16.9 mm zone of inhibition); besides, crude, and ethyl acetate extracts showed resistance to Bacillus cereus and Bacillus subtilis, and Vibrio cholera respectively. All the extracts were tested for lysis of the erythrocytes. At the concentration of 1mg/ml, ethanol extract, and n-hexane and ethyl acetate soluble fractions significantly inhibited hypotonic solution induced lysis of the human red blood cell (HRBC) (27.406 ± 3.57, 46.034 ± 3.251, and 30.72 ± 5.679% respectively); where standard drug acetylsalicylic acid (concentration 0.1 mg/ml) showed 77.276 ± 0.321% inhibition. In case of heat induced HRBC hemolysis, the plant extracts also showed significant activity (34.21 ± 4.72, 21.81 ± 3.08, and 27.62 ± 8.79% inhibition respectively). In the brine shrimp lethality bioassay, the n-hexane fraction showed potent (LC₅₀ value 48.978 μg/ml) activity, whereas ethyl acetate fraction showed mild (LC₅₀ value 216.77 μg/ml) cytotoxic activity.

Conclusions

Our results showed that the n-hexane extract has better effects than the other in all trials. In the context, it can be said that the leaves of S. paniculata possess remarkable pharmacological effects, and justify its folkloric use as antimicrobial, antipyretic, anti-inflammatory, and antiemetic agent. Therefore, further research may be suggested to find possible mode of action of the plant part.     

Pentacycloundecane lactam vs lactone norstatine type protease HIV inhibitors: binding energy calculations and DFT study

Background

Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC₅₀ values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereomers complexed with South African HIV protease (C-SA) was performed. This will enable us to rationalize the considerable difference between inhibitory concentration (IC₅₀) of PCU-lactam-NH-EAIS and PCU-lactone-CO-EAIS peptides.

Results

The PCU-lactam model exhibited more negative calculated binding free energies of solvation than the PCU-lactone model. The same trend was observed for the PCU-peptide inhibitors, which correspond to the experimental activities for the PCU-lactam-NH-EAIS peptide (IC₅₀ = 0.076 μM) and the PCU-lactone-CO-EAIS peptide inhibitors (IC₅₀ = 0.850 μM). Furthermore, a density functional theory (DFT) study on the natural atomic charges of the nitrogen and oxygen atoms of the three PCU-lactam, PCU-lactim and PCU-lactone models were performed using natural bond orbital (NBO) analysis. Electrostatic potential maps were also used to visualize the electron density around electron-rich regions. The asymmetry parameter (η) and quadrupole coupling constant (χ) values of the nitrogen and oxygen nuclei of the model compounds were calculated at the same level of theory. Electronic molecular properties including polarizability and electric dipole moments were also calculated and compared. The Gibbs theoretical free solvation energies of solvation (∆G_solv) were also considered.

Conclusions

A general trend is observed that the lactam species appears to have a larger negative charge distribution around the heteroatoms, larger quadrupole constant, dipole moment and better solvation energy, in comparison to the PCU-lactone model. It can be argued that these characteristics will ensure better eletronic interaction between the lactam and the receptor, corresponding to the observed HIV protease activities in terms of experimental IC₅₀ data.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0115-5) contains supplementary material, which is available to authorized users.     

Cytotoxicity and hepatoprotective attributes of methanolic extract of Rumex vesicarius L.

Background

To evaluate the hepatoprotective potential and invitro cytotoxicity studies of whole plant methanol extract of Rumex vesicarius L. Methanol extract at a dose of 100 mg/kg bw and 200 mg/kg bw were assessed for its hepatoprotective potential against CCl₄-induced hepatotoxicity by monitoring activity levels of SGOT (Serum glutamic oxaloacetic transaminase), SGPT (Serum glutamic pyruvic transaminase), ALP (Alkaline phosphatase), TP (Total protein), TB (Total bilirubin) and SOD (Superoxide dismutase), CAT (Catalase), MDA (Malondialdehyde). The cytotoxicity of the same extract on HepG2 cell lines were also assessed using MTT assay method at the concentration of 62.5, 125, 250, 500 μg/ml.

Results

Pretreatment of animals with whole plant methanol extracts of Rumex vesicarius L. significantly reduced the liver damage and the symptoms of liver injury by restoration of architecture of liver. The biochemical parameters in serum also improved in treated groups compared to the control and standard (silymarin) groups. Histopathological investigation further corroborated these biochemical observations. The cytotoxicity results indicated that the plant extract which were inhibitory to the proliferation of HepG2 cell line with IC50 value of 563.33 ± 0.8 μg/ml were not cytotoxic and appears to be safe.

Conclusions

Rumex vesicarius L. whole plant methanol extract exhibit hepatoprotective activity. However the cytotoxicity in HepG2 is inexplicable and warrants further study.