Phytotoxic activity of Cleome arabica L. and its principal discovered active compounds

The aim of this study was to assess the phytotoxic potential of Cleome arabica L, as well as to isolate the main bioactive compounds. Phytotoxicity was evaluated on germination and seedling growth of Lactuca sativa, Raphanus sativus, Peganum harmala and Silybum marianum, through testing aqueous and organic extracts of different C. arabica organs (roots, shoots, siliquae and seeds). Results showed that siliquae methanol extract caused the greatest negative effect on lettuce germination and growth. For the bioactive subfractions (petroleum ether, ethyl acetate and methanol–water), the ethyl acetate induced highly significant reduction, showing 100% inhibition of lettuce growth at 6 g/L. The bioactive ethyl acetate subfraction was chromatographed and subjected to NMR techniques. Based on bio-guided chromatographic fractionation, five bioactive allelochemical compounds were isolated from ethyl acetate extract of siliquae of C. arabica. The most inhibitory compound on lettuce seedling growth was elucidated as 11-α-acetylbrachy-carpone-22(23)-ene.     

Inhibition of Rust Diseases of Cereals by Metabolic Products of Verticillium chlamydosporium

Verticillium chlamydosporium produced in submers culture several antifungal and/or phytotoxic compounds which were detected in a bioassay by using the pathogen-host system Puccinia coronata and oat seedlings. The antifungal compounds were also tested against P. recondita on wheat and P. sorghi on corn seedlings. The production of the active metabolic compounds highly depended on the nutrient solution (peptone-Czapek [PC] and malt extract [ME]) and on the fermentation times. Cell-free filtrates of PC-cultures of the fungus were highly phytotoxic; the fungitoxic and phytotoxic compounds were heat-labile and dialyzable. The ethyl acetate extracts of the PC-culture filtrates contained only the antifungal active substances. The antifungal compounds in ME-culture filtrates proved to be heat-stable, could be dialyzed and extracted with ethyl acetate. Ethyl acetate extracts of PC- and ME-culture filtrates at concentrations of 500 μg/ml reduced rust disease incidence by up to 80 % compared to the control treatment. Further studies with extracts of ME-culture filtrates displayed a distinct protective but no systemic activity. The extract interfered with the development of several infection structures of the rust fungi, mostly with the growth of germ tubes as well as with the formation of the aappressoria and haustorial mother cells. Three rust-active fractions were obtained by preparative layer chromatography on silica gel. One of these fractions exhibited phytotoxic activity. The most active antifungal fraction is identical with the macrolid antibiotic monorden which caused a desorientated spiral growth in P. coronata germlings on oat leaves.     

<Emphasis Type="Italic">Artemisia arborescens</Emphasis> L. leaf litter: phytotoxic activity and phytochemical characterization

Artemisia arborescens L. is a perennial fast-growing Mediterranean shrub, which releases abundant leaf litter upon soil surface throughout the year. The paper aimed to both evaluate the phytotoxic potential and identify major compounds occurring in the plant leaf litter. Following methanolic maceration of the leaf litter, the crude extract was then sequentially extracted with hexane, chloroform and ethyl acetate through a bio-guided fractionation method. The phytotoxic potential of the methanolic extract and its solvent fractions was assessed in vitro on germination and root growth of two sensitive (Lactuca sativa L., Raphanus sativus L.) and native (Amaranthus retroflexus L., Cynodon dactylon (L.) Pers.) species. Moreover, the most active fractions were chemically characterized by GC–MS and HPTLC analysis. In all species, the physiological processes were highly inhibited by both the methanolic extract and its solvent fractions. Several classes of biologically active phytochemicals such as terpenoids, fatty acids, lignans and phenolic compounds were identified in all fractions. Artemisia arborescens leaf litter could be considered an important source of biologically active phytochemicals, which may have a significant allelopathic impact towards neighbouring species once released into the environment.     

Calamintha nepeta L. (Savi) as source of phytotoxic compounds: bio-guided fractionation in identifying biological active molecules

Calamintha nepeta L. (Savi), known as Lesser Catmint, is a Mediterranean species belonging to the Labiatae family, considered an important source of natural compounds. Since little is known about phytotoxic potential of Lesser Catmint, the bio-guided fractionation method was employed to isolate and identify some compounds, prerequisite for their possible future use in weed management. Leaves and stems of catmint were extracted with methanol and fractionated using n-hexane, chloroform, ethyl acetate and n-butanol, solvents with different polarity. The potential phytotoxicity of the methanolic extract and its fractions, evaluated by ED₅₀ values comparison, was assayed in vitro on seed germination and root growth of lettuce (Lactuca sativa L.). Germination and root growth of lettuce were strongly inhibited by catmint methanolic extract and its fractions, showing the following hierarchy of phytotoxicity for both physiological processes: ethyl acetate ≥ n-hexane > chloroform ≥ n-butanol. In the most active fraction, analyzed by HPLC, 5 poliphenols, gallic, vanillic, syringic, p-coumaric and ferulic acids, were identified and quantified. Whereas, the n-hexane fraction was a mixture of 32 chemicals, mainly composed of terpenoids and fatty acids, as analyzed by gas chromatography–mass spectrometry (GC–MS). Further, GC analysis allowed to quantify 5 compounds: camphor, trans-caryophyllene, menthol, farnesene and pulegone. Furthermore, both fractions inhibited seed germination and root growth of two of the most common weeds, Amaranthus retroflexus and Echinochloa crus-galli. The results confirmed the phytotoxic activity of C. nepeta L. (Savi) due to the presence of different molecule classes with biological activity and their potential future application as bio-herbicides.     

Phytotoxic effect of bioactive compounds isolated from Myrcia tomentosa (Myrtaceae) leaves

The aim of this study was to assess the phytotoxic potential of leaves of Myrcia tomentosa, as well as to isolate and identify the main bioactive compounds. The results for the coleoptile and phytotoxicity bioassays indicated the ethyl acetate extract for the phytochemistry study, owing to the high activity and the maintenance of the activity at lower concentrations. This extract was chromatographed and subjected to ¹H NMR and ¹³C NMR. Two major active compounds were isolated from the ethyl acetate extract of leaves of M. tomentosa: avicularin and juglanin. The fractions where these compounds were isolated showed potent inhibition of coleoptile growth. This paper is the first report on the presence of the flavonoids avicularin and juglanin in species of Myrtaceae from Neotropical savanna and provides a basis for future studies on the bioprospecting of M. tomentosa.     

Hautriwaic acid as one of the hepatoprotective constituent of Dodonaea viscosa

It is widely known that hepatitis and its complications such as cirrhosis or hepatocellular carcinoma are one of the major health problems of the world especially since no specific treatment is available. In the present study we investigated the hepatoprotective potential of the methanolic extract of the whole plant of Dodonaea viscosa and its ethyl acetate, aqueous, butanol and n-hexane fractions against carbon tetrachloride (CCl₄) induced hepatoxicity in rats. Hepatoprotection was assessed in terms of reduction in serum enzymes (ALT, AST, and ALP) that occur after CCl₄ injury, and by histopathology and immunohistochemistry. The methanolic extract reduced the serum enzyme level (ALT, AST, and ALP) down to control levels despite CCl₄ treatment. It also reduced the CCl₄-induced damaged area to 0% as assessed by histopathology. The CD68+ macrophages were also reduced in number around the central vein area by the methanolic extract. These hepatoprotective effects were better than the positive control silymarin. Similar hepatoprotective activities were found with the ethyl acetate, and aqueous fractions of the methanolic extract. The butanol and n-hexane fractions showed elevated levels of ALT, AST and ALP as compared to the positive control silymarin. Histopathology showed ∼30% damage to the liver cells with the butanol and n-hexane fractions which still showed some protective activity compared to the CCl₄ treated control. HPLC fingerprinting suggested that hautriwaic acid present in the methanolic extract and its ethyl acetate, and aqueous fractions may be responsible for this hepatoprotective activity of Dodonaea viscosa which was confirmed by in vivo experiments.     

Antibacterial and cytotoxic activities of extracts from (Tunisian)Rhamnus alaternus (Rhamnaceae)

The petroleum ether, chloroformic, ethyl acetate, methanolic, Total Oligomers Flavonoids (TOF) enriched extracts, water extract as well as its fractions A₁, A₂, A₃ obtained from aerial parts ofRhamnus alaternus, a Tunisian-Mediterranean medicinal species, were investigated for the contents of phenolic compounds, cytotoxic activity against the K562 human chronic myelogenous leukaemia cell line and L1210 leukaemia murine cells and for antibacterial activity against Gram positive and Gram negative bacterial reference strains. A pronounced cytotoxic effect on both the cell lines was shown in the TOF, ethyl acetate, methanolic, aqueous extracts and A₂ fraction, with respectively IC₅₀ values 75, 232, 298, 606 and 571 μg/ml on K562 cells and 198, 176, 767, 560 and 614 μg/ml on L1210 cell line. Significant activity against bacterial reference strains:Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella enteritidis andSalmonella typhimurium was shown with ethyl acetate, TOF extracts and A2 fraction. The antimicrobial and cytotoxic activities showed byR. alatemus depended on the chemical composition of the tested extracts.     

Antimicrobial activity of extracts and fractions of Euphorbia lateriflora (Schum. and Thonn) on microbial isolates of the urinary tract

Euphorbia lateriflora is used in ethnomedicine for treating several conditions, including genital and urinary tract infections (UTI). Although ethnobotanical claims support its use in therapy, there is limited evidence on its effect on UTI, even though UTI remains a public health problem in Nigeria especially due to increasing antimicrobial resistance. We investigated the activity of E. lateriflora extracts and fractions on bacterial and fungal isolates from symptomatic urinary tract infections and vaginosis respectively. Qualitative phytochemical screening was conducted on dried pulverised leaves. Successive gradient extraction was carried out with the aid of a soxhlet extractor with n-Hexane, ethyl acetate and methanol respectively. Bioactivity guided fractionation was conducted on the ethyl acetate extract using Vacuum Liquid Chromatography. Antimicrobial susceptibility testing by disc diffusion was conducted on test isolates. Antimicrobial susceptibility of isolates to extracts and fractions was done using the agar well diffusion technique. Minimum Inhibitory Concentrations (MIC) and Minimum Biocidal Concentrations (MBC) were determined by agar and broth dilutions respectively. Time-kill assay of the ethyl acetate extract was conducted using the viable count technique. Phytochemicals present include saponins, tannins and flavonoids. The majority of isolates used in this study were multidrug resistant. Extracts and fractions of E. lateriflora produced appreciable zones of inhibition on both antibiotic susceptible and resistant bacteria with MICs of 6.25 mg/mL and MBC ranging from 6.25–50 mg/mL. Bactericidal activity of the ethyl acetate extract was concentration and time dependent with 100% kill at 25 mg/mL after 6 h for E. coli and 2 h for C. albicans. Euphorbia lateriflora contains phytochemicals which possess antimicrobial activity on antibiotic resistant bacteria and has potential in the development of chemotherapeutics for bacterial and fungal infections.     

Insecticidal activity of five Chinese medicinal plants against Plutella xylostella L. larvae

Twenty-five extracts of five Chinese medicinal plant species were screened for insecticidal activity against the diamondback moth, Plutella xylostella L., larvae by a leaf dipping bioassay method. The ethyl acetate, ethanol, and acetone extracts of Veratrum nigrum L. root and rhizome, the ethyl acetate extract of Phytolacca americana L. root, and the petroleum ether extract of Pseudolarix kaempferi Gord. root bark were effective against P. xylostella. Among them, the ethyl acetate extract of V. nigrum showed the strongest insecticidal activity against the second and third instar larvae of P. xylostella, with LC₅₀ values of 225 and 335 ppm, respectively. The other extracts gave little or no insecticidal activity against P. xylostella. These results indicated that V. nigrum may be a promising naturally occurring agent for P. xylostella larval control, and that the organic solvent used for plant extraction can affect its insecticidal activity.     

Physiological and cellular mechanisms of natural herbicide resource from Aglaia odorata Lour. on bioassay plants

A bioassay-guided fractionation of the allelochemicals of the ethyl acetate fraction extracted from Aglaia odorata led to isolation of a bisamide, odorine. The growth inhibitory effects of odorine and ethyl acetate fraction were studied for comparison on Echinochloa crus-galli. Odorine and ethyl acetate fraction of A. odorata could inhibit the germination and seedling growth of E. crus-galli, with ethyl acetate fraction being more potent. Thus, ethyl acetate fraction was selected for further experiment, E. crus-galli seeds were studied the effects of the ethyl acetate fraction from A. odorata leaves in wettable powder formulation on imbibition and ??-amylase activity. It was found that treated seeds showed lower imbibition and ??-amylase activity. The results of cytogenetic bioassay in Allium cepa roots showed that ethyl acetate fraction inhibited cell mitosis and induced mitotic abnormalities resulting from its action on chromatin organization and mitotic spindle in the exposed roots.     

Enzyme inhibition and radical scavenging activities of aerial parts of Paeonia emodi Wall. (Paeoniaceae)

The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and α-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against α-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the α-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.     

Feeding deterrence,larvicidal and haemolymph protein profiles of an Indian traditional medicinal plant Alangium salviifolium (L.F.) Wangerin on cluster caterpillar,Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

Different organic solvent crude extracts from the leaves of Alangium salviifolium (L.F.) Wangerin, were tested for their feeding deterrence, larvicidal activity and protein concentrations on the fourth instar larvae of Spodoptera litura L. under laboratory conditions. Treatments were given through two different host plant leaves such as brinjal and castor. The bioassay was carried out at different concentrations viz., 0.625, 1.25, 2.5 and 5%. The maximum antifeedant activity in brinjal (52.0%) and castor (29.97%) leaf discs was recorded in ethyl acetate extract as compared with hexane and chloroform extracts at 5% concentration. The result of larvicidal activity revealed that the maximum larval mortality was registered in brinjal leaves (65.81%) and castor with (57.48%) in ethyl acetate extract as compared to hexane and chloroform extracts at 5% concentration. The ethyl acetate extract of A. salviifolium contained alkaloids, diterpenoids, and saponins. The treatment also reduced haemolymph protein concentration after 48 h.     

Acaricidal activity of Aloe vera L. leaf extracts against Tetranychus cinnabarinus (Boisduval) (Acarina: Tetranychidae)

Four different extracts of Aloe vera L. leaves were evaluated for acaricidal activity against female adults of carmine spider mite, Tetranychus cinnabarinus (Boisduval), by slide-dip bioassay. At 72 h after treatment, the acetone extract showed the strongest acaricidal activity with LC₅₀ value of 90 ppm. The LC₅₀ values for ethyl acetate, water, and ethanol extracts were 113, 340, and 391 ppm, respectively. The acetone extract was fractionated using a silica gel column. Among the twenty-two fractions obtained the fifth, tenth, eleventh, twelfth, fifteenth, and seventeenth fractions showed strong acaricidal activity, causing 80.39 to 92.16% mortality at 72 h after treatment. The tenth and eleventh fractions had the strong activity, with LC₅₀ values of 44 ppm and 33 ppm, respectively. The results suggested that A. vera has a great potential for development as a botanical acaricide for T. cinnabarinus control.     

栎属7种植物种子的发芽抑制物质研究

运用系统溶剂法和生物测定法,以栎属7种植物种子为材料,研究了其种皮、胚(胚及周围部分子叶)和子叶(远离胚端2/3子叶)1.0 g/mL和0.5 g/mL浓度甲醇等浸提液以及各有机相对白菜种子萌发的影响。结果表明:栓皮栎、锐齿栎、蒙古栎、沼生栎和麻栎甲醇浸提液均能显著降低白菜种子发芽率、根长和苗高,且对发芽率的抑制作用逐渐降低;夏栎和房山栎甲醇浸提液对白菜种子发芽率没有显著影响,但对根长和苗高有一定的抑制作用;种子不同部位甲醇浸提液的抑制作用表现为胚>子叶>种皮,且甲醇高浓度浸提液的抑制作用大于低浓度的抑制作用;甲醇相对白菜种子发芽率、苗高或根长的抑制作用最强,其次是乙酸乙酯相,其它溶剂相萃取液的抑制作用不明显。栎属种子甲醇浸提液及各有机相对白菜种子苗高和根长的抑制作用强于对发芽率的影响,说明栎属种子中所含抑制物质主要是限制自身根和芽的生长,可能是造成延迟萌发和出苗不整齐的原因。     

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.     

Biological activity of Xanthium strumarium seed extracts on different cancer cell lines and Aedes caspius,Culex pipiens (Diptera: Culicidae)

Effects of methanol extracts of Xanthium strumarium on different cancer cell lines and on the mortality rates of Aedes caspius, Culex pipiens (Diptera: Culicidae) were investigated. Among the cell lines tested, the Jurkat cell line was the most sensitive to the methanol extract and ethyl acetate fraction, with reported LC₅₀ values of 50.18 and 48.73 μg/ml respectively. Conversely, methanol extracts were not that toxic to the A549 cell line though the toxicity increased on further purification. The percentage of growth inhibition was dose dependent for the methanol extract and ethyl acetate fraction. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The results showed that methanol extracts of plant seeds caused 100% mortality of mosquito larvae at a concentration of 1000 μg/ml after 24 h of treatment. The LC₅₀ and LC₉₀ values of X. strumarium were found to be 531.07 and 905.95 μg/ml against Ae. caspius and 502.32 and 867.63 μg/ml against Cx. Pipiens, respectively. From the investigations, it was concluded that the crude extract of X. strumarium showed a weak potential for controlling the larval instars of Ae. caspius and Cx. pipiens. However, on further purification the extract lost the larvicidal activity. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The ethyl acetate fraction investigated in this study appears to have a weak larvicidal activity but a promising cytotoxic activity. Future studies will include purification and investigation in further detail of the action of X. strumarium on Cancer Cell Lines and mosquitoes.     

Distribution and radical scavenging activity of phenols in Ascophyllum nodosum (Phaeophyceae)

Phlorotannins have been purified and fractionated in the brown alga Ascophyllum nodosum using successively differential extraction, liquid-liquid separation and dialysis. Both the phenol content and the radical scavenging capacity of the resulting fractions were assayed by the Folin-Ciocalteu test and the DPPH method, respectively, whilst purity of the fractions was assessed by ¹H NMR analysis. The purification process resulted in the isolation of six fractions from each crude extract with only minor losses. High levels of phenols, up to 97-99%, were measured in semi-purified fractions containing phlorotannins more than 50 kDa in average molecular size, accounting for more than 95% of the ethyl acetate phenol pool. As a consequence, purity decreased in ethyl acetate fractions together with the molecular size of compounds. The importance of differential extraction based on the polarity of phenols is highlighted by the fact that most of these compounds were found in the ethyl acetate fraction after the first extraction step in 100% methanol, whilst two thirds of phenols extracted by 50% methanol remained in the aqueous phase. The radical scavenging activity of the fractions was correlated with the phenol content and was maximal in complete ethyl acetate fractions and in dialysis concentrates containing molecules more than 50 kDa in size. The specific activity of phenols was found to be maximal for molecules smaller than 2 kDa when isolated from the 100% methanol extract and 1-4 times smaller in the water phase separated from the same extract. The distribution of radical-scavenging potentials in the phenol pool of A. nodosum supports the idea that physiological roles and putative uses of phlorotannins are under the control of a polarity-molecular size complex.     

Hypotensive mechanism of the extracts and artemetin isolated from Achillea millefolium L. (Asteraceae) in rats

Traditional uses of Achillea millefolium L. (Asteraceae) include the treatment of cardiovascular diseases. In the present study, we used anesthetized rats to assess the hypotensive effect of a hydroethanolic extract (HEAM), and its dichloromethane (DCM), ethyl acetate (EA), butanolic (BT), and dichloromethane-2 (DCM-2) fractions, besides the flavonoid artemetin, isolated from A. millefolium. The oral administration of HEAM (100-300 mg/kg), DCM (20 mg/kg), DCM-2 (10-30 mg/kg), but not EA (10 mg/kg) and BT (50 mg/kg) fractions significantly reduced the mean arterial pressure (MAP) of normotensive rats. The phytochemical analysis by NMR ¹H of DCM and DCM-2 fractions revealed high amounts of artemetin, that was isolated and administered by either oral (1.5 mg/kg) or intravenous (0.15-1.5 mg/kg) routes in rats. This flavonoid was able to dose-dependently reduce the MAP, up to 11.47 ± 1.5 mm Hg (1.5 mg/kg, i.v.). To investigate if artemetin-induced hypotension was related to angiotensin-converting enzyme inhibition, we evaluated the influence of this flavonoid on the vascular effects of both angiotensin I and bradykinin. Intravenous injection of artemetin (0.75 mg/kg) significantly reduced the hypertensive response to angiotensin I while increased the average length of bradykinin-induced hypotension. Artemetin (1.5 mg/kg, p.o.) was also able to reduce plasma (about 37%) and vascular (up to 63%) ACE activity in vitro, compared to control group. On the other hand, artemetin did not change angiotensin II-induced hypertension. Our study is the first showing the hypotensive effects induced by the extract and fractions obtained from A. millefollium. In addition, our results disclosed that this effect may be, at least in part, associated with high levels of artemetin and its ability to decrease angiotensin II generation in vivo, by ACE inhibition.     

Toxicity of black nightshade (Solanum nigrum) extracts on Alternaria brassicicola, causal agent of black leaf spot of Chinese cabbage (Brassica pekinensis)

Root extracts of black nightshade (Solanum nigrum) were analyzed for activity against isolates ABA‐31 and ABA‐104 of Alternaria brassicicola, the causal agent of black leaf spot of Chinese cabbage (Brassica pekinensis). Preliminary results showed that dried root tissues of black nightshade extracted with 70% ethanol contained antifungal properties against A. brassicicola. Ethanol root extracts were used for further fractionations using ethyl acetate, n‐butanol and water. Among the three extracts, the n‐butanol fraction showed the strongest antifungal activity by its suppression of conidial germination of A. brassicicola. The n‐butanol extract of S. nigrum roots was fractionated further into six fractions (I–VI). Among the six fractions tested, fraction V showed a strong inhibitory effect on conidial germination of A. brassicicola and thereby suppressed lesion development of black leaf spot of Chinese cabbage at a concentration of 25 ppm or higher. Nuclear magnetic resonance analysis indicated that fraction V contained a mixture of saponins, and results of further bio‐guided fractionation and bioassay suggested that saponins in fraction V were key chemical components in the control of A. brassicicola. The potential of using black nightshade for developing natural products for the control of fungal plant diseases is discussed.     

Evaluation of anti-nociceptive,anti-inflammatory and antipyretic potential of Mikania cordata (Burm. f.) Robinson in experimental animal model

Mikania cordata is widely used for the treatment of cuts, wounds, and dengue fever in Bangladesh. In the present study, essential oil (12.5, 25 and 50?mg/kg) and two extracts, viz., chloroform and ethyl acetate extracts (200, 400, 800?mg/kg b.w.) were tested for peripheral and central anti-nociceptive activity by acetic acid-induced writhing and hot plate method, respectively. Carrageenan-induced rat paw edema assay and yeast-induced hyperthermia assay were also carried out to evaluate anti-inflammatory and antipyretic properties of oil and extracts, respectively at aforesaid doses. The essential oil (50?mg/kg), chloroform extract (800?mg/kg) and ethyl acetate extract (800?mg/kg) showed potent peripheral anti-nociceptive activity having 47.33%, 29.33% and 16.65% of writhing inhibition, respectively, comparable with standard diclofenac (52.0%). Essential oil (50?mg/kg), chloroform extract (800?mg/kg) and ethyl acetate extract (800?mg/kg) presented promising central anti-nociceptive activity as well having 95.86%, 79.18% and 42.37% elongation of reaction time, respectively, at 90?min after administration of essential oil, ethyl acetate extract and 60?min after administration of chloroform extract. In anti-inflammatory activity screening, the essential oil (50?mg/kg) produced the highest 72.80% edema inhibition at 4?h after administration of carrageenan which was comparable with that of standard phenylbutazoe (87.87%). On the other hand, chloroform extract (800?mg/kg) and ethyl acetate extract (800?mg/kg) showed up to 34.31% and 15.27% of edema inhibition, respectively, at 4?h after administration of carrageenan. In antipyretic assay, the essential oil and chloroform extract displayed a strong antipyretic effect in yeast-induced rats, whereas the ethyl acetate extract had no antipyretic activity. The present study revealed anti-nociceptive, anti-inflammatory and antipyretic potential of M. cordata which could be the therapeutic option against fever, inflammations as well as painful conditions and confirmed the traditional use of M. cordata.