scholarly journals Warburgia ugandensis Leaf and Bark Extracts: An Alternative to Copper as Fungicide against Downy Mildew in Organic Viticulture?

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2765
Author(s):  
Christian Kraus ◽  
Rada Abou-Ammar ◽  
Andreas Schubert ◽  
Michael Fischer

In organic viticulture, copper-based fungicides are commonly used to suppress Downy Mildew infection, caused by the oomycete Plasmopara viticola. However, the frequent and intensive use of such fungicides leads to accumulation of the heavy metal in soil and nearby waters with adverse effects on the ecosystem. Therefore, alternative, organic fungicides against Downy Mildew are urgently needed to reduce the copper load in vineyards. In this study, the use of Warburgia ugandensis Sprague (Family Canellacea) leaf and bark extracts as potential fungicides against Downy Mildew were evaluated. In vitro (microtiter) and in vivo (leaf discs, seedlings) tests were conducted, as well as field trials to determine the efficacy of the extracts against Downy Mildew. The results revealed an MIC100 of 500 µg/mL for the leaf extract and 5 µg/mL for the bark extract. Furthermore, experiments with leaf discs and seedlings demonstrated a strong protective effect of the extracts for up to 48 h under (semi-) controlled conditions. However, in field trials the efficacy of the extracts distinctly declined, regardless of the extracts’ origin and concentration.

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 535
Author(s):  
Pratik Doshi ◽  
Nisha Nisha ◽  
Ahmed Ibrahim Alrashid Yousif ◽  
Katalin Körösi ◽  
Rita Bán ◽  
...  

Two neem-derived pesticides were examined under in vitro and in vivo conditions to test their efficacy in controlling Plasmopara halstedii pathotype 704, a causal agent of downy mildew in sunflower. All the tested concentrations of neem leaf extract and the highest concentration of commercial neem product significantly reduced the sporangial germination under in vitro conditions. In in vivo experiment, 3-days old pre-treated seedlings with both concentrations of neem leaf extract and the highest concentration of commercial product showed a significant reduction in the infection indicating possible systemic effect of neem. When the seedlings were treated following the infection with P. halstedii (i.e., post-treatment), only the highest concentrations of neem leaf extract and the commercial product showed a significant reduction in the infection indicating curative effect of neem. Possibilities for the control of P. halstedii with neem-derived pesticides are discussed.


2021 ◽  
Vol 28 (1) ◽  
pp. 1-14
Author(s):  
Carine Pedrotti ◽  
Clarissa Franzoi ◽  
Rafael Nicolas Sandi ◽  
Daniel Santos Grohs ◽  
Joséli Schwambach

Downy mildew (Plasmopara viticola) is the primary disease in viticulture worldwide, and your control requires synthetic fungicides applications to avoid quality and yield loss in the grapevines. However, alternatives to reduce synthetic fungicides are needed to ensure the consumer’s health and the environment. Essential oils (EOs) are amongst the most promising natural plant protection alternatives because of their antifungal properties on several crop diseases. The present study objective was to determine the effect of Eucalyptus staigeriana EO in vitro and in vivo against P. viticola. The EO exhibited the highest activity in vitro, inhibiting 90% of the incidence and severity of disease caused by P. viticola in leaves of grapevines in the greenhouse. In the field (in vivo), treatment with EO could not control the disease; however, treatment with EO in consortium with conventional treatment reduced approximately 50% of the incidence and more than 90% of the severity of downy mildew disease in leaves, decreasing the application of synthetic fungicides by 50%.


Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 309
Author(s):  
Olukayode O. Aremu ◽  
Adebola O. Oyedeji ◽  
Opeoluwa O. Oyedeji ◽  
Benedicta N. Nkeh-Chungag ◽  
Constance R. Sewani Rusike

Oxidative stress has gained attention as one of the fundamental mechanisms responsible for the development of hypertension. The present study investigated in vitro and in vivo antioxidant effects of 70% ethanol-water (v/v) leaf and root extracts of T. officinale (TOL and TOR, respectively). Total phenolic and flavonoid content of plant extracts were assessed using Folin Ciocalteau and aluminium chloride colorimetric methods; while, 2,2-diphenyl-1-picrlhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) protocols were used to determine the free radical scavenging and total antioxidant capacities (TAC), respectively. The in vivo total antioxidant capacity and malondialdehyde acid (MDA) levels for lipid peroxidation tests were performed on organ homogenate samples from Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats treated with leaf extract, TOL (500 mg/kg/day) and TOR (500 mg/kg/day) for 21 days. Results showed that compared to TOR, TOL possessed significantly higher (p < 0.01) polyphenol (4.35 ± 0.15 compared to 1.14 ± 0.01) and flavonoid (23.17 ± 0.14 compared to 3 ± 0.05) content; free radical scavenging activity (EC50 0.37 compared to 1.34 mg/mL) and total antioxidant capacities (82.56% compared to 61.54% ABTS, and 156 ± 5.28 compared to 40 ± 0.31 FRAP) and both extracts showed no toxicity (LD50 > 5000 mg/kg). TOL and TOR significantly (p < 0.01) elevated TAC and reduced MDA levels in targets organs. In conclusion, T. officinale leaf extract possesses significant anti-oxidant effects which conferred significant in vivo antioxidant protection against free radical-mediated oxidative stress in L-NAME-induced hypertensive rats.


Author(s):  
Ganiyu Oboh ◽  
Veronica O. Odubanjo ◽  
Fatai Bello ◽  
Ayokunle O. Ademosun ◽  
Sunday I. Oyeleye ◽  
...  

AbstractAvocado pear (The inhibitory effects of extracts on AChE and BChE activities and antioxidant potentials (inhibition of FeThe extracts inhibited AChE and BChE activities and prooxidant-induced TBARS production in a dose-dependent manner, with the seed extract having the highest inhibitory effect and the leaf extract exhibiting higher phenolic content and radical scavenging abilities, but lower Fe chelation ability compared with that of the seed. The phytochemical screening revealed the presence of saponins, alkaloids, and terpenoids in both extracts, whereas the total alkaloid profile was higher in the seed extract than in the leaf extract, as revealed by GC-FID.The anti-cholinesterase and antioxidant activities of avocado leaf and seed could be linked to their phytoconstituents and might be the possible mechanisms underlying their use as a cheap and natural treatment/management of AD. However, these extracts should be further investigated in vivo.


Author(s):  
Bhong Prabha N. ◽  
Naikawade Nilofar. S. ◽  
Mali Pratibha. R. ◽  
Bindu Madhavi. S.

Objectives: The present study designed to evaluate the Antiasthmatic activity of aqueous extract of bark of Eugenia Jambolana (AEEJ) on in vitro and in vivo animal models. Materials and methods: Different in vitro and in vivo animal models was used to study the anti asthmatic activity as isolated goat tracheal chain preparation, Acetylcholine and Histamine induced bronconstriction in guinea pigs, effect of drug extract on histamine release from mast cell was checked by clonidine-induced mast cell degranulation, and milk-induced eosinophilia and leukocytosis. Results: In-vitro study on goat tracheal chain preparation revealed that aqueous extract of Eugenia jambolana (AEEJ)bark exerted antagonistic effect on the histamine induced contraction. (P<0.05) The guinea pigs when exposed to 0.2% histamine aerosol showed signs of progressive dyspnoea leading to convulsions. AEEJ significantly prolonged the latent period of convulsions (PCT) as compared to control following the exposure of histamine (0.2%) aerosol (P<0.01). The observation of present study indicates aqueous extract of Eugenia jambolana shows significant inhibition of milk induced eosinophilia and leukocytosis. Group of animals pretreated with aqueous Eugenia jambolana bark extract showed significant reduction in degranulation of mast cells when challenged with clonidine. The prevention of degranulation process by the aqueous Eugenia jambolana bark extract (P<0.01) indicates a possible stabilizing effect on the mast cells, indicating mast cell stabilizing activity. Conclusions: Thus, AEEJ showed antihistaminic, mast cell stabilizing and protective in guinea pigs against histamine induced PCD, reduced eosinophilia and leukocytosis and hence possesses potential role in the treatment of asthma.


2009 ◽  
Vol 6 (2) ◽  
pp. 227-231 ◽  
Author(s):  
S. A. Adesegun ◽  
A. Fajana ◽  
C. I. Orabueze ◽  
H. A. B. Coker

The antioxidant activities of crude extract ofPhaulopsis fascisepalaleaf were evaluated and compared with α-tocopherol and BHT as synthetic antioxidants and ascorbic acid as natural-based antioxidant.In vitro, we studied its antioxidative activities, radical-scavenging effects, Fe2+-chelating ability and reducing power. The total phenolic content was determined and expressed in gallic acid equivalent. The extract showed variable activities in all of thesein vitrotests. The antioxidant effect ofP. fascisepalawas strongly dose dependent, increased with increasing leaf extract dose and then leveled off with further increase in extract dose. Compared to other antioxidants used in the study, α-Tocopherol, ascorbic acid and BHT,P. fascisepalaleaf extract showed less scavenging effect on α,α,-diphenyl-β-picrylhydrazyl (DPPH) radical and less reducing power on Fe3+/ferricyanide complex but better Fe2+-chelating ability. These results revealed thein vitroantioxidant activity ofP.fascisepala.Further investigations are necessary to verify these activitiesin vivo.


2009 ◽  
Vol 3 (2) ◽  
pp. 48-64
Author(s):  
Kadhim M. Ibrahim ◽  
Shaimaa A. Yousir

Several experiments were carried out to study heavy metal tolerance in tissue cultures or whole plants of S. grandiflora., Callus was induced and maintained on modified Murashige and Skoog, 1962 medium (MS) supplemented with (0.5)mg/l benzyl adenine and (2)mg/l 2,4-phenoxy acetic acid . Heavy metals (Cd, Co, Cu, Cr or Zn) were added to the culture medium at different concentrations as contamination agents. In order to asses the effect of these heavy metals on seed germination; seeds were sown in soil contaminated with different concentrations of heavy metals for 3 weeks. Atomic Absorption Spectrophotometer was used for analysis of samples taken from whole plants and callus cultures. Results showed that callus fresh weight decreased with increasing heavy metal concentration in cultural medium. Germination percentages and plant heights increased over time. However, a reduction occurred in these parameters with increasing heavy metal levels. Percentages of metals accumulated in calli were (0.001, 0.011, 0.012 and 0.013%) at (0.0, 0.05, 0.075 and 0.1)mg/l Cd respectively; (0.001, 0.008, 0.016 and 0.006%) at (0.0, 0.1, 0.25 and 0.5)mg/l Co respectively; (0.001, 0.020, 0.034 and 0.015%) at (0.0, 0.075, 0.2 and 0.5)mg/l Cu respectively; (0.001, 0.013, 0.012 and 0.010%) at (0.0, 0.25, 0.4 and 0.5)mg/l Cr respectively and (0.027, 0.051, 0.059 and 0.056%) at (0.0 , 0.75, 1.0 and 1.5)mg/l Zn respectively. Percentages of metals accumulated in whole plants were (0.08, 0.55, 1.11, 0.83 and 0.44%) at (0.0, 1.0, 2.0, 3.0 and 4.0)mg/Kg soil Cd respectively; (0.11, 0.22, 0.55, 0.47 and 0.44%) at (0.0, 15.0, 30.0 45.0 and 60.0)mg/Kg soil Co respectively; (0.01, 0.10, 0.57, 0.58 and 0.72%) at (0.0, 25.0, 50.0, 75.0 and 100.0)mg/Kg soil Cu respectively. (0.08, 0.80, 1.28, 1.31 and 0.88%) at (0.0, 25.0, 50.0, 75.0 and 100.0)mg/Kg soil Cr respectively and (0.06, 1.11, 1.20, 1.83 and 2.22%) at (0.0, 100.0, 200.0, 300.0 and 400.0)mg/Kg soil Zn respectively.


2017 ◽  
Vol 12 (2) ◽  
pp. 33-44 ◽  
Author(s):  
Shaimaa Helmy El-Sayed ◽  
Neimat Amer ◽  
Soad Ismail ◽  
Iman Ali ◽  
Enas Rizk ◽  
...  

2018 ◽  
Vol 7 (4) ◽  
pp. 392-398
Author(s):  
B.T Yunana ◽  
◽  
B. B Bukar ◽  
J. C Aguiyi ◽  
◽  
...  

The ethanol extracts of root, bark and leaf of Bridelia ferruginea was investigated for antibacterial activity against clinical isolate of Staphylococcus aureus and Escherichia coli. The extracts had significant antibacterial activity in vitro at concentration of 25 mg/ml, 50 mg/ml, 100 mg/ml and 200 mg/ml and in vivo at dose of 50 mg/kg and 100 mg/kg. The root extract in vitro had the highest zone of inhibition, followed by the bark extract for both Staphylococcus aureus and Escherichia coli. The concentration of 200 mg/ml had the highest zone of inhibition in vitro. The minimum inhibitory concentration (MIC) showed a decreasing inhibitory effect of the plant extracts for both Staphylococcus aureus and Escherichia coli as the concentration decreases with root having 3.125 mg/ml, bark having 6.25 mg/ml and leaf having 25 mg/ml for Staphylococcus aureus and Escherichia coli. Likewise, the minimum bactericidal concentration (MBC) showed decreasing bactericide effects with decrease concentration with root having 12.5 mg/ml, bark having 12.5 mg/ml and leaf having 25 mg/ml for Escherichia coli while root had 6.25mg/ml, bark had 12.5mg/ml and leaf had 25mg/ml for Staphylococcus aureus. The in vivo investigation showed that the root and bark extract exhibited antibacterial activity on both Staphylococcus aureus and Escherichia coli at doses of 100mg/kg and 50mg/kg; the root extract had higher activity than the bark and root/bark combined. The dose of 100 mg/kg had the highest colonies reduction for Staphylococcus aureus and Escherichia coli in vivo. Preliminary phytochemical screening of root, bark and leaves of Bridelia ferruginea revealed the presence of tannins, flavonoids, carbohydrates, cardiac glycoside (root, bark and leaves), saponins (root and bark). The presence of tannins, saponins, flavonoid, cardiac glycoside and carbohydrate in the bark and root extracts of the plant indicates that the bark and root extracts were pharmacological importance


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