Biological effects of essential oils and extracts
Z. tahami; S.M. Hosseini; A. Valizadeh Ghalebeig
Abstract
To evaluate the effects of a mixture from Cinnamomum cassia (L.) J.Presl, Mentha pulegium L., and Capsicum annuum L. extracts on the relative weight of visceral and gastrointestinal organs, gastrointestinal tract acidity, blood parameters, and tibia characteristics of Ross 308 broilers, an experiment ...
Read More
To evaluate the effects of a mixture from Cinnamomum cassia (L.) J.Presl, Mentha pulegium L., and Capsicum annuum L. extracts on the relative weight of visceral and gastrointestinal organs, gastrointestinal tract acidity, blood parameters, and tibia characteristics of Ross 308 broilers, an experiment was conducted in a completely randomized design with five treatments, four replications, and eight chickens per replication. The experimental treatments included basal diet (BD), BD+500 mg kg-1 oxytetracycline, BD+50 mg kg-1 mixed extract, BD+100 mg kg-1 mixed extract, and BD+200 mg kg-1 mixed extract. After 42 days of raising the broilers with the mixed extract, the sampling was performed to evaluate the desired traits. The results showed that the consumption of 100 mg kg-1 mixed extract increased the pancreas and heart weight, relative length of ileum and jejunum, and relative weight and length of tibia and reduced the acidity of duodenum and jejunum compared to the control (p < /em><0.05). The results showed that the experimental treatments did not affect the concentration of blood elements of broilers, but the amount of magnesium and phosphorus in tibia was affected by 50 and 100 mg kg-1 mixed extract (p < /em><0.05). Based on the findings of this study, it could be concluded that the use of 100 mg kg-1 mixed extract improved the performance of broilers by increasing the relative length and weight of gastrointestinal organs and reducing the acidity of gastrointestinal tract.
Biological effects of essential oils and extracts
M. Ajamhassani
Abstract
< p >The lethal and physiological effects of plant secondary metabolites on a wide range of pest insects have been proved. These compounds, while having a direct effect on the target pest, are low risk to humans and the environment, and this has led to their advantage over chemicals. In this study, ...
Read More
< p >The lethal and physiological effects of plant secondary metabolites on a wide range of pest insects have been proved. These compounds, while having a direct effect on the target pest, are low risk to humans and the environment, and this has led to their advantage over chemicals. In this study, the lethal effect of Ferula assa-foetida L. and Aloysia citriodora Palau ethanolic extracts was determined on the third instar larvae of Ephestia kuehniella. The larval mortality was directly related to increasing the extracts concentration. The activity of some digestive enzymes in the gastrointestinal tract and the changes in hemocytes were also studied in the third instar larvae treated with the extracts. First, sublethal concentration of plant ethanolic extracts was calculated. The larvae then fed the diet contaminated by the lethal concentration of 25% (LC25) of the extracts (40 and 30 ppm for F. assa-foetida and A. citriodora,respectively). The control group consisted of larvae that fed the diet contaminated with diluted ethanol. The results indicated that both extracts significantly reduced the activity of trypsin and chymotrypsin enzymes. F. assa-foetida extract significantly reduced the activity of lipase and beta-glucosidase enzymes compared to the control, but the effect of A. citriodora extract on the activity of these two enzymes was in a statistical group with the control. The extracts had no significant effects on the alpha-glucosidase enzyme activity. The immune activity of larvae was also stimulated by changes in the number of blood cells affected by both extracts. The total number of cells and granulocytes of hemolymph showed a significant increase after 12 hours of feeding in the both extracts treatments, but gradually decreased until 24 hours that was still higher than the control group. The plasmatocytes showed a significant increase in the A. citriodora extract treatment after 12 hours,but in the F. assa-foetida extract treatment, this increase was significant after 24 hours. Understanding the intractions of plant extracts with the insect physiological characteristics such as the physiology of digestive and blood circulatory systems can lead to the possibility of appropriate use of these factors in the target pest control and be used in the pests management programs.
S. Salehi; M. Mohammadi Sharif; A. Hadizadeh
Abstract
The study of the plant compounds efficacy for pest control is one of the expanding researches in most agricultural systems. In this research, the efficacy of aqueous and ethanolic extracts of four plants including dwarf elder (Sambucus ebulus L.), common nettle (Urtica dioica L.), blackberry (Rubus fructicosus ...
Read More
The study of the plant compounds efficacy for pest control is one of the expanding researches in most agricultural systems. In this research, the efficacy of aqueous and ethanolic extracts of four plants including dwarf elder (Sambucus ebulus L.), common nettle (Urtica dioica L.), blackberry (Rubus fructicosus Boiss.) and eagle fern (Pteridium aquilinum (L.) Kuhn) was assessed against the adult female of Tetranychus urticae, one of the most important pests of crops and greenhouse plants. The acaricidal effect of the extracts and their long-lasting effectiveness were studied as well as their oviposition deterrent effect. Two experiments included the long-lasting effectiveness (with the concentrations of 0.5, 1 and 1.5 mg/cm2) and oviposition deterrent effect (with the concentrations of 0.4, 0.7 and 1 mg/cm2). The study of extracts was conducted in a completely randomized design. The aqueous extract of blackberry did not have any acaricidal effect on the pest, and this effect varied from 9.2 to 49.8 % for other aqueous extracts. The LC50 values for ethanolic extracts of dwarf elder, common nettle, blackberry, and eagle fern against the adult females of the pest were obtained to be 0.54, 0.82, 0.76 and 0.72 mg/cm2, respectively. The study of long-lasting acaricide effectiveness of the ethanolic extracts showed that the common nettle extract had high long-lasting effectiveness of 48 hours, after which the extracts of blackberry, dwarf elder, and eagle fern were respectively placed. The blackberry ethanolic extract had the highest oviposition inhibitory effect in comparison with other extracts (94% at 1 mg/cm2). The results demonstrated the appropriate efficacy of the ethanolic extracts to control T. urticae pest in comparison with the aqueous ones, and accordingly, evaluating their control capacity under field conditions will provide some practical valuable data. Amongst the ethanolic extracts, dwarf elder displayed the most acaricidal effect.
N. Ghazalbash; M. Abdollahi
Abstract
Root knot nematodes are one of the most important plant parasitic nematodes damaging many crops, particularly vegetables. According to the experiments conducted in greenhouse conditions, the damage of this nematode was estimated to be 56-49 percent, based on dry weight of stem and root. Increasing use ...
Read More
Root knot nematodes are one of the most important plant parasitic nematodes damaging many crops, particularly vegetables. According to the experiments conducted in greenhouse conditions, the damage of this nematode was estimated to be 56-49 percent, based on dry weight of stem and root. Increasing use of pesticides is of concern to specialists in environmental and nutritional sciences so the use of natural substances to control of pests and plant diseases is a priority. This research was aimed to reduce the pesticide use with application of the aqueous extract of two local medicinal plants, Ferulago angulata (Schlecht.) Boiss. and Zataria multiflora Boiss., on root-knot nematode, Meloidogyne javanica, in tomato plants. A factorial experiment was performed with three factors including medicinal plants, plant parts and percentage of plant extract or powder, in a randomized complete block design with four replications. Results showed that the best treatments in terms of the factors associated with root-knot nematode, were flower and stem powder of F. angulata at the rate of 0.2%. The treatments of leaf powder of F. angulata at the rate of 0.1% and stem powder of this plant at the rate of 0.2% were the best treatments with best effect on the plant growth factors. In addition to sufficient effect of leaf powder of this plant on the factors associated with nematodes at the rates of 0.1 and 0.2%, growth factors of tomato plants were not affected.
J. Nazemi Rafih; S. Moharramipour
Abstract
Red flour beetle Tribolium castaneum isa major pest of stored products especially cereal flour depreciating the quantity and quality of the food economically. The application of repellents could be considered as a new control method in storage. In this study repellent activity of extracts from leaf, ...
Read More
Red flour beetle Tribolium castaneum isa major pest of stored products especially cereal flour depreciating the quantity and quality of the food economically. The application of repellents could be considered as a new control method in storage. In this study repellent activity of extracts from leaf, red and white flowers of Nerium oleander, Lavandula officinalis leaves and Ferula assafoetida gum was assayed on T. castaneum. Experiments were conducted in dark condition at 27±1ºC and 70-80% RH. To determine percentage repellency (PR), filter paper disks were impregnated with different concentrations of plant extracts. Each filter paper was divided into two equal parts. Then, each half-disk was separately added by extract dilutions (1.99, 3.98, 11.94, 19.90 and 27.78 μl/cm2) or acetone as control. Each treated half-disk was then attached lengthwise edge-to-edge, to a control half-disk with adhesive tape and placed in a petri dish (8cm diam.). Twenty adult insects were released in the middle of each filter paper, and the insects that settled on each half, were counted after 1 h and then at hourly intervals for 5h. The results showed that the repellency of Ferula gum was significantly higher than that of remaining extracts. The highest PR (98.75%) was observed in the Ferula gum in the concentration of 27.78 μl/cm2. While, the lowest PR (5.5%) was shown in the Lavandula leaf extract in 1.99 μl/cm2. Repellency increased with concentration in all cases, the repellent effect did not decreased with time over the 5-h experimental period.
