Antimalarial activity of extract and norbergenin derivatives from the stem bark of Diospyros sanza-minika A. Chevalier (Ebenaceae)

The methanol extract from the stem bark of Diospyros sanza-minika as well as five norbergenin derivatives isolated from this crude extract were evaluated for their in vitro activity against Plasmodium falciparum K1 and cytotoxicity on MRC-5 cells. 4-O-(3'-methylgalloyl)norbergenin was found to be the most potent compound (IC(50) 0.6 μg/mL; CC(50) 24.7 μg/mL), followed by 4-O-galloylnorbergenin (IC(50) 3.9 μg/mL; CC(50) > 64 μg/mL) and 11-O-p-hydroxy-benzoyl-norbergenin (IC(50) 4.9 μg/mL; CC(50) > 64 μg/mL). Norbergenin and 4-O-syringoylnorbergenin were inactive (IC(50) > 32 μg/mL; CC(50) > 64 μg/mL). The antimalarial activity of the pure constituents and of the methanol extract from the stem bark of Diospyros sanza-minika is reported for the first time. The results provide interesting baseline information for the potential use of the crude extract well as some of the isolated compounds in the search for novel antimalarial compounds.     

Anti-oxidative Activities of Ethanol Extracts from Both Wild Plant and Suspension Cell Cultures of Rheum franzenbachii

Objective To evaluate the content of rhaponticin and anti-oxidative activities of theethanol extracts from both the wild plants and suspension cell cultures of Rheum franzenbachii.Methods Quantitative analysis of rhaponticin was performed by HPLC.The anti-oxidative activities of the ethanol extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl(DPPH)scavenging assays.Results The content of rhaponticin in the roots of the wild plant was 4.36 mg/g,while the content was only 1.59 mg/g in the leaves.The content of rhaponticin in suspension cells cultured on Murashige and Skoog(MS)medium supplemented with 1.0 mg/L 6-benzylaminopurine(6-BAP)and 2.0 mg/L 2,4-dicholorophenoxy acetic acid(2,4-D)was 17.64 mg/g,which increased by 4.05 times compared with the content in the roots of the wild plants.The roots of wild plants displayed the strongest anti-oxidative activity,followed by thesuspension cells 5 and 6,and the scavenging percent was 91.96%,91.23%,and 89.27%,respectively,at the concentration of 100μg/mL.The IC50 values were 2.477,15.644,and 31.415μg/mL,respectively.In particular,the DPPH scavenging activity of the ethanol extracts from the roots of the wild plant was generally comparable to the control of ascorbic acid(VC),and the IC50 value of the extracts was lower than that of VC(2.502μg/mL).Conclusion Rhaponticin production in the cell culture can be modulated and the accumulation can be increased.The roots of the wild plant display the strongest anti-oxidative activity.These results suggest that R.franzenbachii could hold a good potential source for human health.     

Antiplasmodial activity of selected sudanese medicinal plants with emphasis on Acacia nilotica.

Twenty-two plant organs from eleven plants comprising five families were extracted and screened for antiplasmodial activity in vitro against Plasmodium falciparum 3D7 (chloroquine sensitive) and Dd2 (chloroquine resistant and pyrimethamine sensitive). Fifty nine percent of plant extracts from 22 extracts exerted activity on P. falciparum strain 3D7 with an IC(50) less than 50 microg/mL, whereas 43% of plant extracts showed an IC(50) value within 50 microg/mL on Dd2 strains. Plant extracts from Gardenia lutea, Haplophyllum tuberculatum, Cassia tora, Acacia nilotica and Aristolochia bracteolata possessed IC(50) values less than 5 microg/mL on both tested strains. Bioassay guided fractionation of A. nilotica revealed that the ethyl acetate extract possessed the highest activity (IC(50) = 1.5 microg/mL). Fraction 2 (R(f) = 0.75) prepared by preparative chromatography showed the highest activity on P. falciparum (IC(50) = 1.7 microg/mL). Phytochemical analysis indicated that the most active phase contained terpenoids and tannins and was devoid of alkaloids and saponins. The effect of plant extracts on lymphocyte proliferation showed low toxicity to the human cells. This plant has been subjected to long term clinical trials in folk medicine and is a promising plant.     

中药茯苓抗肿瘤有效组分研究

目的:茯苓及其化学拆分组分抗胃癌细胞SGC-7901和乳腺癌细胞Bcap-37增殖的有效部位的研究。方法:MTT法和血清药理学方法测定茯苓石油醚、乙酸乙酯、多糖、大孔吸附树脂水洗物(WEF)和大孔吸附树脂醇洗物(AEF)五个不同组分对胃癌细胞SGC-7901和乳腺癌细胞Bcap-37增殖的抑制率。结果:茯苓多糖对乳腺癌细胞的半数抑制率IC50为29.29μg/mL,乙酸乙酯为57.84μg/mL,血清药理学实验结果显示茯苓多糖和茯苓乙酸乙酯组分吸光度值与对照组比较有显著性差别(P<0.01),与阳性组比较无显著性差异(P>0.05)。茯苓多糖对胃癌细胞的IC50为25.38μg/mL,乙酸乙酯组分对胃癌细胞的IC50为56.27μg/mL,血清药理学实验结果显示茯苓多糖和茯苓乙酸乙酯组分吸光度值与对照组比较有显著性差别(P<0.01),与阳性组比较无显著性差异(P>0.05)。结论:茯苓抗胃癌和乳腺癌的活性组分一致为茯苓多糖和乙酸乙酯组分,并存在一定的时间和量效关系,为进一步研究茯苓抗肿瘤作用提供科学依据。     

沙煲暗罗根乙醇提取物的抗氧化活性和抗菌活性研究

目的 考察沙煲暗罗根乙醇提取物不同萃取物的抗氧化和抗菌活性.方法 研究沙煲暗罗根乙醇提取物不同萃取物对羟基自由基和DPPH的抗氧化效果,并与Vc对比,找出IC50值;同时研究其抑菌效果,测出最低抑菌浓度.结果 乙酸乙酯萃取物对羟基自由基和DPPH的清除效果最好,IC50值分别为110.8μg/mL和156.5 μg/mL;三氯甲烷萃取物有最好的抑菌效果,对大肠杆菌和枯草芽孢杆菌最小抑菌质量浓度均为20 mg/mL,对金黄色葡萄球菌的最小抑菌质量浓度为40 mg/mL.结论 沙煲暗罗根乙醇提取物中乙酸乙酯萃取物有较好的抗氧化,三氯甲烷萃取物有较好的抑菌活性.     

Antihyperlipidemic Components of Cassia auriculata Aerial Parts: Identification Through In Vitro Studies

Cassia auriculata (Caesalpiniaceae) is a common Asian beverage and medicinal plant widely used in tradition medicine for diabetes, hyperlipidemia and various other disease conditions. Previous studies on crude extracts of C. auriculata have documented the scientific basis for some of its traditional medicinal uses. The present study investigates the antilipase activity of the ethanol extract of the aerial parts along with the previously isolated compounds (kaempferol‐3‐O‐rutinoside, rutin, kaempferol, quercetin and luteolin). The crude extract displayed inhibitory activity against pancreatic lipase with IC₅₀ of 6.0 ± 1.0 µg/mL. The most active antilipase compound was kaempferol‐3‐O‐rutinoside with IC₅₀ value (2.9 ± 0.50 μM) only about twice weaker than the standard antilipase drug, orlistat (IC₅₀ = 1.45 ± 0.26 μM). Luteolin, quercetin and rutin were found to be weak pancreatic lipase inhibitors (IC₅₀ over 100 μM), whereas kaempferol showed no activity up to 250 μM. The antihyperlipidemic effect of C. auriculata could be attributed to direct lipase inhibitory effect of the plant constituents. Copyright © 2012 John Wiley & Sons, Ltd.     

Anti-plasmodial activity of some Kenyan medicinal plant extracts singly and in combination with chloroquine

Sixty organic and aqueous extracts of eleven plants used for the control of malaria by local communities in Kisii District, Kenya were screened for in vitro anti-plasmodial activity. The plants selection was based on existing ethnobotanical information and interviews with local communities. The extracts were tested against chloroquine sensitive and resistant laboratory adapted strains of Plasmodium falciparum. The study revealed that 63.6% of the plants were active (IC50 < or = 100 microg/mL). Extracts of four plants, Ekebergia capensis, Stephania abyssinica, Ajuga remota and Clerodendrum myricoides gave IC50 values below 30 microg/mL against both chloroquine sensitive and resistant P. falciparum strains. Combination of extracts of E. capensis and C. myricoides with chloroquine against the multi-drug resistant P. falciparum isolate (V1/S) revealed synergistic effect. The plants which showed activity may be useful as sources for novel anti-plasmodial compounds.     

Antimicrobial, resistance-modifying effects, antioxidant and free radical scavenging activities of Mezoneuron benthamianum Baill., Securinega virosa Roxb. &Wlld. and Microglossa pyrifolia Lam

Mezoneuron benthamianum, Securinega virosa and Microglossa pyrifolia are used in folk medicine in Ghana for the treatment of dermal infections and wounds. Petroleum spirit, chloroform and ethanol extracts of the plants were tested for antimicrobial activity against a battery of organisms using the agar well diffusion technique and a serial dilution microassay. The resistance modifying activities of these extracts on standard antibiotics against Staphylococcus aureus possessing efflux mechanisms of resistance have also been assessed. A 4-fold potentiation of the activity of norfloxacin was observed for ethanol and chloroform extracts of M. benthamianum and S. virosa, respectively, whilst the petroleum spirit extract resulted in a 2-fold potentiation with minimum inhibitory concentration (MIC) values in the range 8-16 microg/mL. Ethanol extracts of all three species, the petroleum spirit extract of M. benthamianum and the chloroform extracts of M. benthamianum and S. virosa, showed interesting antimicrobial activities. Antioxidant and free radical scavenging activities using DPPH spectrophotometric and TBA lipid peroxidation assays were also conducted. Of the five extracts that showed antioxidant activities, the petroleum spirit and chloroform extracts of M. benthamianum rated most highly by displaying strong free radical scavenging activity with IC50 values of 15.33 and 19.72 microg/mL, respectively. Lipid peroxidation inhibition provided by the same two extracts also produced the lowest IC50 values for all the extracts tested, of 23.15 and 30.36 microg/mL. These findings therefore give some support to the ethnopharmacological use of the plants in the treatment of various skin diseases and wounds, as well as demonstrating the potential of some of the plants as sources of compounds possessing the ability to modulate bacterial multidrug resistance.     

Cytotoxic pentacyclic and tetracyclic aromatic sesquiterpenes from Phomopsis archeri

Three new sesquiterpenes, named phomoarcherins A-C (1-3), and four known compounds, kampanol A (4), R-mevalonolactone, ergosterol, and ergosterol peroxide, were isolated from the endophytic fungus Phomopsis archeri. These structures were established on the basis of spectroscopic evidence. The structure and absolute configuration of 1 were confirmed by X-ray crystallographic analysis of its p-bromobenzoate derivative (1a). Compounds 1-4 showed cytotoxicity against five cholangiocarcinoma cell lines (0.1-19.6 μg/mL), while 1 and 2 exhibited weak cytotoxicity against the KB cell line with IC(50) values of 42.1 and 9.4 μg/mL, respectively. In addition, compound 2 showed antimalarial activity against Plasmodium falciparum with an IC(50) value of 0.79 μg/mL.     

Inhibitory activity on lipid peroxidation of extracts from marine brown alga

Several extracts from marine brown alga Sargassum micracanthum (Kuetzing) Endlicher were screened for their inhibitory activity on lipid peroxidation. In an in vitro study, methanol extract (Sm-M), chloroform/ methanol (3:1) extract and ethyl acetate fraction of Sm-M inhibited lipid peroxidation in rat liver homogenates. The IC(50) values were 0.70, 0.70 and 0.37 micro g/mL, respectively. These inhibitions were stronger than vitamin C and E. These extracts showed reductive activity on DPPH, the IC(50) values were 34, 37 and 11 micro g/mL, respectively. In an in vivo study, Sm-M had the effect on CCl4 induced liver injury in rats and Sm-M (120-1200 mg/kg, p.o.) lowered dose-dependently the level of lipid peroxidation in liver.     

Screening of Indonesian medicinal plant extracts for antibabesial activity and isolation of new quassinoids from Brucea javanica

Boiled extracts derived from 28 Indonesian medicinal plants were screened for their antibabesial activity against Babesia gibsoni in vitro. Of these extracts, the fruit of Brucea javanica was the most active in inhibiting parasite growth at a concentration of 10 microg/mL. Bioassay-guided fractionation of the fruit extract of Br. javanica led to the isolation of two new quassinoids, bruceantinol B and bruceine J, and the structures of these compounds were elucidated on the basis of their spectroscopic data and by chemical transformation to known compounds. In addition, the known quassinoids bruceines A-D, bruceantinol, and yadanziolide A were isolated. Antibabesial activities were also examined in vitro, and bruceine A and bruceantinol were shown to be more potent than diminazene aceturate, a drug (IC50 = 103 ng/mL) used clinically against B. gibsoni, with IC50 values of 4 and 12 ng/mL, respectively.     

Screening of New Zealand Plant Extracts for Inhibitory Activity Against HIV-1 Protease

231 Ethanol/aqueous extracts from New Zealand plants were screened for inhibitory activity against HIV-1 protease using fluorogenic and HPLC assays. Among the examined extracts, Pseudotsuga menziesii , Elaeocarpus hookerianus , Pernettya macrostigma and Cassinia leptophylla showed significant inhibition at a concentration of 50 μg/mL in the HPLC confirmation assay. The IC₅₀ values of these extracts to HIV-1 protease on its synthetic peptide substrate were 9.63, 9.74, 27.62 and 60.73 μg/mL, respectively. The derivatives of dihydroquercetin and [5′5′]-bisdihydroquercetin from Pseudotsuga menziesii could be the causative compounds for the inhibition.     

Effect of Mexican medicinal plant used to treat trichomoniasis on Trichomonas vaginalis trophozoites

Crude methanolic extracts from 22 Mexican medicinal plants were screened for antitrichomonal activity against Trichomonas vaginalis, which is the etiological agent of trichomoniasis. Among the plants tested Carica papaya and Cocos nucifera showed the best antitrichomonal activity with IC(50) values of 5.6 and 5.8 microg/ml, respectively. The extracts of Bocconia frutescens, Geranium mexicanum, and Lygodium venustum showed moderate activity with IC(50) values ranging from 30.9 to 60.9 microg/ml. All the other plant extracts were inactive (IC(50)>100 microg/ml). All extracts tested were less active than metronidazole (IC(50) 0.037 microg/ml), an antiprotozoal drug used as positive control. The results of the antiprotozoal screening support the popular uses of five of the plants tested for the treatment of some urogenital tract disorders in Mexican traditional medicine. However, seeds of Carica papaya and aerial parts of Bocconia frutescens should be used in herbal medicine with care to avoid toxicity.     

Antiviral activity of chilean medicinal plant extracts

Chilean flora is a potential source of bioactive compounds, including some with antiviral activity. Ninety aqueous and hydroaloholic extracts from 36 native and introduced plant species were screened for antiviral activity on herpes (HSV-1 and HSV-2) and HIV viruses. Furthermore, the samples were assayed for antimicrobial effect on pathogenic bacteria and a yeast. Plants were selected according to their indication of use for treating symptomatology of possible viral aetiology in Chilean folk medicine. The hydroaloholic extracts of Cassia stipulacea and Escallonia illintia exhibited detectable antiviral effects towards HSV-1 with IC₅₀ values of 80 and 40 μg crude extract/mL, respectively. Samples belonging to Aristotelia chilensis (IC₅₀ of 40 μg/mL), Drymis winteri (IC₅₀ values of 35 and 80μg/mL), Elytropus chilensis and Luma apiculata, with an IC₅₀ value of 100 μg/mL showed activity against HSV-2. None of the extracts showed activity against HIV at extract concentrations which were nontoxic for cells.     

Indiosides G-K: steroidal glycosides with cytotoxic and anti-inflammatory activities from Solanum violaceum

Five new steroidal glycosides (1-5) and nine known compounds were isolated from Solanum violaceum. Indiosides G (1) and H (2) are spirostene saponins with an iso-type F ring, indioside I (3) is a spirostane saponin, and indiosides J (4) and K (5) are unusual furostanol saponins with a deformed F ring. These structures represent rare naturally occurring steroidal skeletons. The structures of the new compounds were elucidated using 1D and 2D spectroscopic techniques and acid hydrolysis. Compounds 2, 3, and 7-9 exhibited cytotoxic activity against six human cancer cell lines (HepG2, Hep3B, A549, Ca9-22, MDA-MB-231, and MCF-7) with IC(50) values of 1.83-8.04 μg/mL. Steroidal saponins 3, 8, and 9 showed inhibitory effects on superoxide anion generation with IC(50) values of 2.84 ± 0.18, 0.62 ± 0.03, and 1.62 ± 0.59 μg/mL, respectively. Saponins 8 and 9 also inhibited elastase release with IC(50) values of 111.05 ± 7.37 and 4.04 ± 0.51 μg/mL, respectively. Structure-activity relationship correlations of these compounds with respect to cytotoxic and anti-inflammatory effects are discussed.     

Effect of Honghua (Flos Carthami) on nitric oxide production in RAW 264.7 cells and α-glucosidase activity

Objective

To study the effects of extracts from Honghua (Flos Carthami) on lipopolysaccharide induced nitric oxide (NO) production in RAW 264.7 cells and the influence of the extracts on yeast α-glucosidase activity. The total flavonoid content of the extracts was also determined.

Methods

Cytotoxicity of the extracts to RAW 264.7 cells was evaluated by the ATPlite™ method. Inhibitory effects of the extracts on NO production were evaluated by Griess assay. Curcumin was used as a positive control. Screening of extracts for potential α-glucosidase inhibitors was done by a fluorometric assay. The assay was based on the hydrolysis of 4-methylumbelliferyl-a-D-glucopyranoside to form the fluorescent product, 4-methylumbellifer-one. Acarbose was used as a positive control. The total flavonoid content was tested using kaempferol as the standard.

Results

There were significant inhibitory effects on NO production when the extracts were 25-100 μg/mL (P<0.05) and curcumin was 2-4 μg/mL (P< 0.001). The extracts showed an inhibitory effect on α-glucosidase activity at the concentrations of 15.6-125 μg/mL with a half maximal (50%) inhibitory concentration (IC50) of (32.8 ± 5.7) μg/mL, compared with the IC₅₀ of acarbose at (1.8±0.4) μg/mL. There was a significant difference between the two IC₅₀ values (P<0.001). The total content of flavonoids per gram of dried herb was 1.14 mg.

Conclusion

Honghua (Flos Carthami) showed inhibitory effects on NO production in activated RAW 264.7 macrophage cells and an inhibitory effect on yeast α-glucosidase. There might be a relationship between these pharmacological effects and its flavonoid content.     

Screening of selected indigenous plants of Cambodia for antiplasmodial activity

The in vitro antiplasmodial activity of 117 aqueous, methanol and dichloromethane extracts derived from different parts of 28 indigenous wild plant species was studied. These plants are commonly used in Cambodian traditional medicine. The plant extracts were tested for in vitro activity against a chloroquine resistant Plasmodium falciparum strain (W2). Nine extracts were moderately active with IC(50) values ranging between 5 and 10 microg/ml, 17 extracts were active with IC(50) values ranging between 1 and 5 microg/ml. These 26 extracts derived from eight plants belong to six families. The most active extracts were dichloromethane and came from Stephania rotunda and Brucea javanica with IC(50) values of 1 microg/ml and a selectivity index > or = 25. It is interesting to note that some aqueous extracts were as active as dichloromethane extracts especially aqueous extracts of Stephania rotunda, Brucea javanica, Phyllanthus urinaria and Eurycoma longifolia with IC(50) values of < or = 4 microg/ml. These results are in agreement with statements of healers on traditional uses of these plants for the treatment of malaria and/or fever. In this study, we report the antiplasmodial potential activity of eight plant species from Cambodia. Among them four are tested for the first time.     

Screening of Korean medicinal plants for lipase inhibitory activity

The pancreatic lipase inhibitory activity of the aqueous ethanol extracts obtained from 19 medicinal plants was evaluated in vitro by a continuous-monitoring pH-Stat technique using tributyrin as a substrate. Of the extracts tested, those of Juniperus communis (bark) and Illicium religiosum (wood) exhibited the strongest activity with an IC50 value of 20.4 and 21.9 microg/mL, respectively.     

Screening of medicinal plants from Iranian traditional medicine for acetylcholinesterase inhibition

To find new herbal compounds with an acetylcholinesterase (AChE) inhibitory effect, this study focused on herbal drugs and resins which have been used in Iranian traditional medicine for the treatment of cognitive disorders. Forty drugs were selected from authoritative written documents of Iranian traditional medicine. Each drug was extracted by accelerated solvent extraction using dichloromethane followed by methanol. The 80 extracts were screened for AChE inhibitory activity by a TLC bioautography method. The inhibiting effect of the 32 most active extracts was measured by a microplate colorimetric assay. Due to the best activity, the seeds of Peganum harmala L. were investigated in detail. From the TLC bioautography assay the alkaloids harmaline and harmine were identified as active compounds. This result was confirmed by means of HPLC‐DAD. The IC₅₀ values were 41.2 μg/mL for the methanol extract, 95.5 μg/mL for the dichloromethane extract, 8.4 μg/mL for harmaline and 10.9 μg/mL for harmine. The concentrations of active compounds in the extracts were determined by a fast and precise HPLC method. As the amounts of harmaline and harmine in the extracts were correlated with the IC₅₀ values of the extracts, it can be concluded that these two alkaloids are responsible for the AChE inhibitory activity of P. harmala. Copyright © 2011 John Wiley & Sons, Ltd.