Olive Leaf Disease Detection via Wavelet Transform and Feature Fusion of Pre-Trained Deep Learning Models

Olive trees are susceptible to a variety of diseases that can cause significant crop damage and economic losses.Early detection of these diseases is essential for effective management.We propose a novel transformed wavelet,feature-fused,pre-trained deep learning model for detecting olive leaf diseases.The proposed model combines wavelet transforms with pre-trained deep-learning models to extract discriminative features from olive leaf images.The model has four main phases:preprocessing using data augmentation,three-level wavelet transformation,learning using pre-trained deep learning models,and a fused deep learning model.In the preprocessing phase,the image dataset is augmented using techniques such as resizing,rescaling,flipping,rotation,zooming,and contrasting.In wavelet transformation,the augmented images are decomposed into three frequency levels.Three pre-trained deep learning models,EfficientNet-B7,DenseNet-201,and ResNet-152-V2,are used in the learning phase.The models were trained using the approximate images of the third-level sub-band of the wavelet transform.In the fused phase,the fused model consists of a merge layer,three dense layers,and two dropout layers.The proposed model was evaluated using a dataset of images of healthy and infected olive leaves.It achieved an accuracy of 99.72%in the diagnosis of olive leaf diseases,which exceeds the accuracy of other methods reported in the literature.This finding suggests that our proposed method is a promising tool for the early detection of olive leaf diseases.

Olive leaf extract inhibits lead poisoning-induced brain injury

Olive leaves have an antioxidant capacity, and olive leaf extract can protect the blood, spleen and hippocampus in lead-poisoned mice. However, little is known about the effects of olive leaf extract on lead-induced brain injury. This study was designed to determine whether olive leaf extract can inhibit lead-induced brain injury, and whether this effect is associated with antioxidant capacity. First, we established a mouse model of lead poisoning by continuous intragastric administration of lead acetate for 30 days. Two hours after successful model establishment, lead-poisoned mice were given olive leaf extract at doses of 250, 500 or 1 000 mg/kg daily by intragastric administration for 50 days. Under the transmission electron microscope, olive leaf extract attenuated neuronal and capillary injury and reduced damage to organelles and the matrix around the capillaries in the frontal lobe of the cerebral cortex in the lead-poisoned mice. Olive leaf extract at a dose of 1 000 mg/kg had the greatest protective effect. Spectrophotometry showed that olive leaf extract significantly in- creased the activities of superoxide dismutase, catalase, alkaline phosphatase and acid phes- phatase, while it reduced malondialdehyde content, in a dose-dependent manner. Furthermore, immunohistochemical staining revealed that olive leaf extract dose-dependently decreased Bax protein expression in the cerebral cortex of lead-poisoned mice. Our findings indicate that olive leaf extract can inhibit lead-induced brain injury by increasing antioxidant capacity and reducing apop- tosis.

Hydroxytyrosol and olive leaf extract exert cardioprotective effects by inhibiting GRP78 and CHOP expression

Myocardial infarction triggers massive biochemical changes, even cardiac cell death. Endoplasmic reticulum stress is involved in the pathology of myocardial infarction-mediated apoptosis. In the present study, myocardial cell line H9c2 cells were treated with cobalt chloride（CoCl_2） to induce hypoxia. Isoproterenol was used for two successive days to induce myocardial infarction in SD rats. The cardioprotective effect of olive leaf extract（OLE） and its main constituent hydroxytyrosol and the underlying mechanisms were evaluated. The results showed that hydroxytyrosol markedly protected H9c2 cells against CoCl2-induced apoptosis. Hydroxytyrosol could reduce the mRNA and protein expression of GRP78 and CHOP induced by CoCl2 in vitro. In vivo, the decreased ejection fraction and fractional shortening, increased heart weight/body ratio, the formation of infarction, disordered cardiac muscle fibers and infiltration of inflammatory cells induced by isoproterenol could be significantly ameliorated by pretreatment with OLE for a month. Similarly, OLE could also reverse the increase of GRP78 and CHOP expression induced by isoproterenol. Therefore, OLE and hydroxytyrosol exert a cardioprotective effect through endoplasmic reticulum stress, which could be a new target for the prevention and treatment of cardiovascular diseases.

Oleuropein from Olive Leaf Extract as Natural Antioxidant of Frozen Hamburger

Oxidation is one of the major causes of hamburger deterioration. Antioxidants are used to minimize oxidation process. There is a growing interest in the substitution of synthetic food antioxidants by natural ones from vegetable sources. In meat industry, sodium erythorbate is antioxidant that is usually used and is an example of chemical antioxidant. Effect of olive leaf extract rich in olenropein on the quality of frozen hamburger was investigated. The objective of this study was to evaluate the usage of oleuropein from olive leaf extract as natural antioxidant in frozen hamburger stored at -12 ℃ compared with sodium erythorbate. Results suggested that olive leaf extracts might be useful to the meat industry as an efficient alternative to synthetic antioxidants by retarding oxidation of hamburger compared with sodium erythorbate 0.5% of olenropein and 0.5% of sodium erythorbate are the best concentrations to be used in frozen hamburger.

An Optimum Dose of Olive Leaf Extract Improves Insulin Receptor Substrate-1,Tyrosine Kinase,and Glucose Transporters,While High Doses Have Genotoxic and Apoptotic Effects

Type 2 diabetes is the most common type of diabetes. Conventionally many drugs are used for the treatment of diabetes such as biguanides, sulfonylureas, meglitinides, etc. But the desired effective treatment is still not to be achieved. So researches are going on for the development of effective alternative therapy against diabetes. Olive leaves are traditionally used in the treatment of the disease. However, studies on its mechanism of action are not yet enough. The aim of this study was to investigate whether olive leaf extract (OLE) improves insulin receptor substrate-1 (IRS-1), tyrosine kinase (TK), GLUT-2, and GLUT-4. Oleuropein levels were analyzed from OLE obtained by using four different solvents, and the highest content of methanol extract was selected for the study. Different concentrations of OLE (2.5 to 320 μg/mL) were incubated with hepatocellular carcinoma (HepG2) cells for 24 hours. After incubation, cell viability was assessed based on luminometric ATP cell viability assay kit. Intracellular reactive oxygen species (ROS) generating level was detected using 2,7dichlorodihydrofluorescein-diacetate (H2DCF-DA) fluorescent probes. Apoptosis was evaluated by acridine orange/ethidium bromide double staining method. Genotoxicity was evaluated by alkaline single cell gel electrophoresis assay (Comet Assay). Protein expression levels of IRS-1, TK, GLUT-2, and GLUT-4 were analyzed by western blotting technique from the obtained cell lysates. Although an optimum doses of OLE (10 μg/mL) maximally increased cell proliferation, decreased ROS generation improved IRS-1, TK, GLUT-2, and GLUT-4 protein expression levels (about fivefold), higher doses (10 to 320 μg/mL) markedly decreased the cell viability, increased DNA damage, apoptosis and ROS generation in a concentration-dependent manner. OLE can be used in the treatment of type 2 diabetes. However, in order to find the most effective and non-toxic concentration, dose optimization is required.

Optimization of Extraction Process of Olive Leaves by RSM and Evaluation of Antioxidant Capacity Measurements to the Mixtures

Water extracts prepared from seven varieties of olive leaves native to the Mediterranean area but planted in Sichuan province, P.R. China, namely Frantoiao, Leccio, Ezhi, Picholine, Pendollino, Chenggu and Huaou 9#, were examined for their total phenonic and flavonoid contents, antioxidant capacity. Total phenolic and flavonoid content were measured by Folin-Ciocalteu method and a colorimetric method, respectively. ABTS＋ method and FRAP were used for examining antioxidant activity. Response surface methodology （RSM） was used for optimizing the extract condition. Under the optimum condition, the total phenolic and flavonoid content of aqueous extracts of the dry olive leaves （DOL） ranged from 40.27 to 56.58 mg gallic acid （GAE）/g DOL and 21.59 to 33.72 mg catechin （CE）/g DOL in June, 34.31 to 52.81 mg GAE/g DOL and 17.11 to 23.53 mg CE/g DOL in November. The ABTS＋ method and FRAP ranged from 0.23 to 0.35 mmol trolox （TE）/g DOL and 313.01 to 409.69 μmol Fe2＋/g DOL in June, 0.19 to 0.30 mmol TE/g DOL and 254.69 to 418.10 pmol Fe2＋/g DOL in November. Our results revealed that the total phenolic and flavonoid, or antioxidant capacity of the water extract were higher in June than November. Moreover, it was noticed that the antioxidant activity depends on the flavonoid and phenolic.

Evaluation of Phytochemical, Antimicrobial, and Antioxidant Properties of Wild versus Cultivated Olive Leaves

The relation between Olea europaea subspecies cuspidata and subspecies europaea in Saudi Arabia were investigated for determination of the bioactive compounds in olive leaves. The antioxidant and total phenolic content were demonstrated by HPLC/MS. Also, the antimicrobial agar gel well diffusion activity was done for ethanolic extracts. The study identified a great number of phenolic compounds out of which some anticancer compounds were identified. The content of olive leaves extract differs according to habitat (either wild or cultivated). The ethanolic extract of both types has high phenolic content (21.3 to 22.6 mg GA/gdw) and antioxidant activity (71% to 57%) for wild and cultivated leaf extracts, respectively. The phenolic profiles revealed the presence of plenty of flavonoids and phenolic compounds. The major polyphenol in the extracts is naringenin, which appears at peaks 8 with concentrations of 21.93 and 17.35 μg/mL for cultivated and wild leave respectively, which retention times 14.99 and 14.98. The antimicrobial activity showed that the leaves extract have strong antimicrobial activity against Bacillus subtilis, with the highest inhibition zones (28 and 26 mm) for wild and cultivated leaf extracts, respectively. This is considered as valuable data about the potential for industrial mass production of polyphenol.