Insecticidal activities of tea saponin against diamondback moth,Plutella xylostella and aphid,Aphis craccivora

Insecticidal activities of tea saponin were evaluated against larvae of diamondback moth, Plutella xylostella (L.) and aphid, Aphis craccivora Koch. In residual toxicity assay, saponin was found more effective against second instar larvae of P. xylostella (LC₅₀=2106.32?mg L¹) and A. craccivora (LC₅₀?=?540.79?mg L^?1) after 96?h as compared to positive control. In repellent activity study, saponin at 4000?mg?L^?1 showed higher repellence (48.57%) to third instar larvae of P. xylostella. However, feeding preference index (PI) of saponin was less in higher concentration (0.63) against third instar larvae of P. xylostella.     

Volatile,non-volatile composition and insecticidal activity of Eupatorium adenophorum Spreng against diamondback moth,Plutella xylostella (L.), and aphid,Aphis craccivora Koch

Essential oil (EO) from aerial parts of Eupatorium adenophorum Spreng was extracted by steam distillation and characterized by Gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). α-epi-cadinenol (16.63%), O-cymene (13.54%), bornyl acetate (7.70%), β-phellandrene (7.46%), and σ-2-carene (5.77%) were the major terpenoids. The EO showed promising toxicity (median lethal concentration, LC₅₀?=?3176.54?mg?L^?1) and repellent activity (median repellent concentration, RC₅₀?=?2070.99?mg L^?1) to larvae of Plutella xylostella within 24?h. Among fractions, hexane fraction was more effective to P. xylostella (LC₅₀?=?5056.74?mg L^?1), whereas methanol fraction to Aphis craccivora (LC₅₀?=?1175.83?mg L^?1).     

Hypoglycemic effect of aqueous extract of Parthenium hysterophorus L. in normal and alloxan induced diabetic rats

Objectives:

To study the effects of Parthenium hysterophorus L. flower on serum glucose level in normal and alloxan induced diabetic rats.

Materials and Methods:

Albino rats were divided into six groups of six animals each, three groups of normal animals receiving different treatments consisting of vehicle, aqueous extract of Parthenium hysterophorus L. flower (100 mg/kg) and the standard antidiabetic drug, glibenclamide (0.5 mg/kg). The same treatment was given to the other three groups comprising alloxan induced diabetic animals. Fasting blood glucose level was estimated using the glucose oxidase method in normal and alloxan induced diabetic rats, before and 2 h after the administration of drugs.

Results:

Parthenium hysterophorus L. showed significant reduction in blood glucose level in the diabetic (P<0.01) rats. However, the reduction in blood glucose level with aqueous extract was less than with the standard drug glibenclamide. The extract showed less hypoglycemic effect in fasted normal rats, (P<0.05).

Conclusion:

The study reveals that the active fraction of Parthenium hysterophorus L. flower extract is very promising for developing standardized phytomedicine for diabetes mellitus.     

Characterization and Toxicity of Crude Toxins Produced by Cordyceps fumosorosea against Bemisia tabaci (Gennadius) and Aphis craccivora (Koch)

Cordyceps fumosorosea, an insect pathogenic fungus, produces different toxins/secondary metabolites which can act as pest control agents. This study reports the extraction and characterization of crude mycelial extracts of C. fumosorosea isolate SP502 along with their bio-efficacy against Bemisia tabaci and Aphis craccivora. Fourier transform infrared spectroscopy, liquid chromatography, mass spectrometery and nuclear magnetic resonance analysis of C. fumosorosea isolate SP502 extracts showed the presence of five major compounds—Trichodermin, 5-Methylmellein, Brevianamide F, Enniatin and Beauvericin—which all may potentially be involved in insecticidal activity. The HPLC analysis of C. fumosorosea mycelial extracts and Beauvericin standard showed similar chromatographic peaks, with the content of Beauvericin in the crude toxin being calculated as 0.66 mg/ml. The median lethal concentrations of C. fumosorosea mycelial extracts towards first, second, third and fourth instar nymphs of A. craccivora were 46.35, 54.55, 68.94, and 81.92 µg/mL, respectively. The median lethal concentrations of C. fumosorosea mycelial extracts towards first, second, third and fourth instar nymphs of B. tabaci were 62.67, 72.84, 77.40, and 94.40 µg/mL, respectively. Our results demonstrate that bioactive compounds produced by C. fumosorosea isolate SP502 have insecticidal properties and could, therefore, be developed into biopesticides for the management of B. tabaci and A. craccivora.     

Chemical composition of essential oil and oleoresins of Zingiber officinale and toxicity of extracts/essential oil against diamondback moth (Plutella xylostella)

Abstract

Essential oil (EO) of ginger and oleoresins isolated from extraction solvents by GC–MS. Zingiberene was the major constituent in all the samples, and ethanol could extract the maximum quantity (21.2%) from the dried de-oiled cake (EDD) followed by EO (20.3%) as compared to oleoresins. Hydro-distilled EO contains higher oxygenated monoterpenes (22.4%) than oleoresins. EDD showed more toxicity to larvae of Plutella xylostella (LC₅₀?=?4957.9?mg L^?1) after 96?h and was followed by EDW (LC₅₀?=?5067.6?mg L^?1) and EF (LC₅₀?=?6631.2?mg L^?1). EO also showed promising efficacy (LC₅₀?=?5875.9?mg L^?1) and repellency (97.1%) against P. xylostella.     

Toxicity and phytochemical profile of essential oil from Iranian Achillea mellifolium L. against Tetranychus urticae Koch (Acari: Tetranychidae)

Chemical composition of Achillea mellifolium essential oil was investigated by gas chromatography-mass spectrometry and its acaricidal activity was estimated using leaf dipping and fumigation bioassays against Tetranychus urticae. Terpenic compounds, such as piperitone (12.79%), ρ-cymene (10.60%), bornyl acetate (8.58%) and p-menth-2-en-1-ol (8.35%) were identified as main components. The essential oil has potential toxicity on T. urticae and a correlation between log concentration and mite mortality in both bioassays has been achieved. The findings indicated that the essential oil of A. mellifolium as a well-known medicinal plant may be useful in the search of effective natural material as Acaricide.     

Antioxidant activities of bark extract from mangroves, Bruguiera cylindrica (L.) Blume and Ceriops decandra Perr

Objectives:

The antioxidant activities of two Indian mangrove plants, Bruguiera cylindrica and Ceriops decandra, were investigated.

Materials and Methods:

Total phenolics and total flavonoid contents of the mangroves were determined using folin-ciocalteu reagent method and aluminium chloride method, respectively. Antioxidant capacity was assessed by the following methods: 1,1-diphenyl-2-picryl hydroxyl (DPPH.) quenching assay; 2,2’- azinobis-3-ethylbenzothiozoline-6-sulfonic acid (ABTS.⁺) cation decolorization test; scavenging capacity towards hydroxyl ion radicals (.OH); reductive capacity; and antihemolytic activity.

Results:

The mangroves yielded 233.3 ± 0.062 and 283.31 ± 0.04 mg gallic acid equivalent/g phenolic contents and 11.6 ± 0.12 and 15.1 ± 0.02 mg quercetin equivalent/g flavonoid contents. The methanol extracts of both mangroves exhibited high antiradical activity against DPPH., ABTS.⁺, and .OH radicals. The reductive capacity of the extracts increased with increasing concentration of samples. The extracts also inhibited H₂O₂ induced hemolysis in cow blood erythrocytes. The antioxidant activities were found stronger than that of the reference standard, butylated hydroxy toluene (BHT). The antioxidant activity of mangrove plants was correlated with total phenolics and flavonoid contents.

Conclusion:

Both plants can be considered as good sources of natural antioxidants for medicinal uses. Further studies are necessary to isolate active principles responsible for the overall antioxidant activity of the extracts.     

Evaluation of the effects of Olea europaea L. subsp. africana (Mill.) P.S. Green (Oleaceae) leaf methanol extract against castor oil‐induced diarrhoea in mice

Objectives Olea europaea L. subsp. africana (Mill.) P.S. Green is widely used in South Africa by traditional medicine practitioners to treat diarrhoea. However, little is known scientifically about this South African species in the treatment of diarrhoea. The main aim of the study therefore was to investigate the antidiarrhoeal effect of the leaf methanol extract of the plant species in mice. Methods The antidiarrhoeal activity of the leaf methanol extract of O. europaea subsp. africana was studied using a castor oil‐induced diarrhoeal test. The antipropulsive activity of the plant extract was also investigated using the charcoal meal transit test. Standard methods were used to investigate the acute toxicity and effect of O. europaea subsp. africana on castor oil‐induced intraluminal fluid accumulation. Results Leaf methanol extract of O. europaea subsp. africana and loperamide, a standard antidiarrhoeal drug, significantly reduced the number of diarrhoeal episodes induced by castor oil, significantly decreased the stool mass, significantly delayed the onset of the diarrhoea and protected the animals against castor oil‐induced diarrhoea. Both O. europaea subsp. africana and loperamide significantly decreased the gastrointestinal transit of charcoal meal and castor oil‐induced intraluminal fluid accumulation in mice. The LD50 value was found to be 3475 mg/kg (p.o.). Conclusions The results obtained suggest that the leaf methanol extract of O. europaea subsp. africana has an antidiarrhoeal property and that, given orally, it may be non‐toxic and/or safe in mice.     

Chemical composition, and antioxidant and antimicrobial activities of three hazelnut (Corylus avellana L.) cultivars.

Hazelnut (Corylus avellana L.) is a very popular dry fruit in the world being consumed in different form and presentations. In the present work, three hazelnut cultivars (cv. Daviana, Fertille de Coutard and M. Bollwiller) produced in Portugal, were characterized in respect to their chemical composition, antioxidant potential and antimicrobial activity. The samples were analysed for proximate constituents (moisture, fat, crude protein, ash), nutritional value and fatty acids profile by GC/FID. Antioxidant potential was accessed by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and beta-carotene linoleate model system. Their antimicrobial capacity was also checked against Gram positive (Bacillus cereus, B. subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Results showed that the main constituent of fruits was fat ranging from 56% to 61%, being the nutritional value around 650 kcal per 100 g of fruits. Oleic was the major fatty acid varying between 80.67% in cv. F. Coutard and 82.63% in cv. Daviana, followed by linoleic, palmitic, and stearic acids. Aqueous hazelnut extract presented antioxidant activity in a concentration-dependent way, in general with similar behaviour for all cultivars. Hazelnut extracts revealed a high antimicrobial activity against Gram positive bacteria (MIC 0.1 mg/mL) showing a good bioactivity of these fruits.     

Phytochemical and antioxidant characterization,cytogenotoxicity and antigenotoxicity of the fractions of the ethanolic extract of in Poincianella bracteosa (Tul.) L.P. Queiroz

ABSTRACT

Poincianella bracteosa

has been widely used in folk medicine to treat catarrhal infections, diarrhea, and anemia; however, phytochemical and toxicogenetic data are still lacking. The objective of this study was to examine the phytochemical and antioxidant characteristics as well as assess cytogenotoxicity and antigenotoxicity in hexane (HF), ether (EF) and ethyl acetate (AF) fractions of P. bracteosa leaves using Allium cepa bioassay. Phytochemical analysis revealed the presence of saponins and phenolic groups. EF fraction contained a higher content of total phenolics (441.23 ± 1.82 mg GAE/g), while HF fraction showed a higher content of total flavonoids (84.77 ± 5.33 mg QE/g). Higher antioxidant activity was observed in EF (EC₅₀ 25.06 ± 0.07 µg/ml). Cytotoxic effect was verified for all fractions, but no chromosomal alterations were observed in the A. cepa assay. With respect to antigenotoxicity, the protective effect of EF and AF fractions was attributed to as evidenced by the modulation of mutagenic action of methyl methanesulfonate (MMS), mainly by inhibiting the development of micronuclei. Among the fractions, EF was considered the most promising, as it exhibited higher antioxidant activity, was not genotoxic, exerted protective activity against the damage induced by MMS and also presented cytotoxic activity, a desired quality in the search for natural anticarcinogenic compounds.     

Cytotoxic and apoptogenic effect of Swietenia mahagoni (L.) Jacq. leaf extract in human leukemic cell lines U937, K562 and HL-60

The apoptogenic activity of Swietenia mahagoni leaf extract (SMLE) was investigated against three human leukemic cell lines – U937, K562 and HL-60. SMLE inhibited cell growth and metabolic activity of the leukemic cells and showed characteristic features of apoptosis. Flow-cytometric analysis showed that SMLE arrested U937 and K562 cell populations in the G2-M phase and the HL-60 cell population in the G1 phase of cell cycle. SMLE induced apoptosis was found to be mediated through mitochondrial intrinsic pathway involving the release of cytochrome c into the cytosol and activation of caspase-9 and caspase-3. Two flavonoids, catechin and quercetin-3-O-glucoside, isolated from SMLE, were found to inhibit the growth and metabolic activity of U937, K562 and HL-60 cells at much lower concentrations thus indicating that these two flavonoids might be the active ingredients responsible for the anti-leukemic activity of SMLE.     

Studies on cytotoxic, hydroxyl radical scavenging and topoisomerase inhibitory activities of extracts of Tabernaemontana divaricata (L.) R.Br. ex Roem. and Schult

In the present investigation, the cytotoxic, hydroxyl radical scavenging and topoisomerase inhibition activities of Tabernaemontana divaricata (Apocynaceae) were evaluated. The extracts from leaves of the plant were prepared with different solvents viz. chloroform, methanol, ethyl acetate and hexane. In, in vitro cytotoxicity assay, with cell lines viz HCT-15 (Colon), HT-29 (Colon), 502713 (Colon), MCF-7 (Breast), PC- 3 (Prostrate), it was observed that the ethyl acetate extract was effective against only one colon cell line (502713) at the lowest dose i.e. 10 micro g/ml, whereas the chloroform extract was effective against all the three colon cancer cell lines, at 30 microg/ ml. In order to evaluate the mechanism of cytotoxicity of these extracts, they were assessed for their ability to scavenge hydroxyl radicals in plasmid nicking assay with pBR322. It was observed that all the extracts effectively inhibited the unwinding of supercoiled DNA except hexane extract, which showed the least effect. Since the expression of topo enzymes is linked with cell proliferation so the extracts were also checked for topo I and topo II inhibitory activities. It was noticed that ethyl acetate extract selectively showed inhibition of topo II in topoisomerase II relaxation assay.     

Antioxidant activities of the essential oils and methanol extracts from myrtle (Myrtus communis var. italica L.) leaf,stem and flower

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of α-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50 mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, β-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.