Chemical Composition of Five Lamiaceae Essential Oils and Their Insecticidal and Phytotoxic Activity.

The Lamiaceae family is widely distributed worldwide. In this study, we investigated the insecticidal activity of five Lamiaceae essential oils against Thrips flavus Schrank and the phytotoxic activity against Glycine max (L.) Merr., Zea mays L., Portulaca oleracea L., and Echinochloa oryzoides (Ard.) Fritsch. Then, the chemical composition of the five essential oils was analyzed by using gas chromatography-mass spectrometry (GC-MS). The five Lamiaceae essential oils were melissa, basil, rosemary, negundo chastetree, and salvia. The main constituents of the five Lamiaceae essential oils were preliminarily determined to be as follows: α-pinene and 1,8-cineole in the rosemary essential oil; ß-pinene, γ-terpinene, and d-limonene in the negundo chastetree essential oil; ß-cadinene and isolongifolen-5-one in the melissa essential oil; 5-allylguaiacol in the basil essential oil; and isopropyl myristate, linalyl acetate, and linalool in the salvia essential oil. Using a bioassay, it was found that, among the five essential oils, the melissa essential oil exhibited the lowest LC50 value, which was 0.18 mg/mL, and the salvia essential oil exhibited the highest LC50 value, which was 0.42 mg/mL. The control efficacy of the five essential oils significantly increased with time and concentration in pot experiments. The negundo chastetree, basil, rosemary, and salvia essential oils at 900.00 g a.i.·hm-2 showed high control efficacy against T. flavus, with values higher than 90%. Female thrips were attracted to the negundo chastetree essential oil. The five essential oils were also tested for their effects on the germination rate, germination potential, germination index, and shoot length of G. max, Z. mays, P. oleracea, and E. oryzoides. The basil essential oil significantly inhibited the germination of P. oleracea, with germination at a concentration of 1.0 mg/mL being only 11.11 ± 5.09%. This study provides a reference for the development of botanical pesticides to control T. flavus, crops, and weeds.

Structure information analysis and relative content determination of protein and chitin from yellow mealworm larvae using Raman spectroscopy.

Insect protein extract is one of the high-quality protein sources and is frequently viewed as a potential nutrition alternative. However, a more precise method for protein measurement is still needed due to protein overestimation by the Kjeldahl method due to the presence of a large amount of chitin in insects. Therefore, we demonstrated the monitoring of chitin and protein extracted from yellow mealworm larvae through the information on molecular vibration obtained using Raman spectroscopy and infrared (IR) spectroscopy. The NH vibration at 3475 cm-1 is the characteristic peak of chitin in defatted product observed in the Raman spectra. The nitrogen-to-protein conversion factor in protein extracted from larvae by the Raman method was determined based on the NH vibration and found to be 5.66 ± 0.01. We also compared these experimental data to theoretical Raman and IR spectra and determined the possible reasons for why nitrogen elements in chitin affect the determination of protein content. The method of sequentially removing fat and protein could provide more accurate quantification of protein and chitin. Raman spectroscopy is feasible for various types of insects with high chitin content. Compared with the Kjeldahl method, the Raman method is a faster and more accurate measurement method. Moreover, it provides the content of impurities, purity, and structural information.

Recent Advances in the Inhibition of Membrane Lipid Peroxidation by Food-Borne Plant Polyphenols via the Nrf2/GPx4 Pathway.

Lipid peroxidation (LP) leads to changes in the fluidity and permeability of cell membranes, affecting normal cellular function and potentially triggering apoptosis or necrosis. This process is closely correlated with the onset of many diseases. Evidence suggests that the phenolic hydroxyl groups in food-borne plant polyphenols (FPPs) make them effective antioxidants capable of preventing diseases triggered by cell membrane LP. Proper dietary intake of FPPs can attenuate cellular oxidative stress, especially damage to cell membrane phospholipids, by activating the Nrf2/GPx4 pathway. Nuclear factor E2-related factor 2 (Nrf2) is an oxidative stress antagonist. The signaling pathway regulated by Nrf2 is a defense transduction pathway of the organism against external stimuli such as reactive oxygen species and exogenous chemicals. Glutathione peroxidase 4 (GPx4), under the regulation of Nrf2, is the only enzyme that reduces cell membrane lipid peroxides with specificity, thus playing a pivotal role in regulating cellular ferroptosis and counteracting oxidative stress. This study explored the Nrf2/GPx4 pathway mechanism, antioxidant activity of FPPs, and mechanism of LP. It also highlighted the bioprotective properties of FPPs against LP and its associated mechanisms, including (i) activation of the Nrf2/GPx4 pathway, with GPx4 potentially serving as a central target protein, (ii) regulation of antioxidant enzyme activities, leading to a reduction in the production of ROS and other peroxides, and (iii) antioxidant effects on LP and downstream phospholipid structure. In conclusion, FPPs play a crucial role as natural antioxidants in preventing LP. However, further in-depth analysis of FPPs coregulation of multiple signaling pathways is required, and the combined effects of these mechanisms need further evaluation in experimental models. Human trials could provide valuable insights into new directions for research and application.

Se site targeted-two circles antioxidant in GPx4-like catalytic peroxide degradation by polyphenols (-)-epigallocatechin gallate and genistein using SERS.

A Se site targeted-two circles antioxidant of polyphenols EGCG and genistein in glutathione peroxidase 4 (GPx4)-like catalytic peroxide H2O2 and cumene hydroperoxide degradation was demonstrated by surface-enhanced Raman scattering (SERS). Se atom's active center is presenting a 'low-oxidation' and a 'high-oxidation' catalytic cycle. The former is oxidized to selenenic acid (SeO-) with a Raman bond at 619/ 610 cm-1 assigned to the νO - Se by the hydroperoxide substrate at 544/ 551 cm-1 assigned to ωHSeC decreased. Under oxidative stress, the enzyme shifted to 'high-oxidation' catalytic cycle, in which GPx4 shuttles between R-SeO- and R-SeOO- with a Raman intensity of bond at 840/ 860 cm-1 assigned to νO[bond, double bond]Se. EGCG could act as a reducing agent both in H2O2 and Cu-OOH degradation, while, genistein can only reduce Cu-OOH, because it binds more readily to the selenium site in GPx4 than EGCG with a closer proximity, therefore may affect its simultaneous binding to coenzymes.

Finite element modeling and analysis of effect of preexisting cervical degenerative disease on the spinal cord during flexion and extension.

Recent studies have emphasized the importance of dynamic activity in the development of myelopathy. However, current knowledge of how degenerative factors affect the spinal cord during motion is still limited. This study aimed to investigate the effect of various types of preexisting herniated cervical disc and the ligamentum flavum ossification on the spinal cord during cervical flexion and extension. A detailed dynamic fluid-structure interaction finite element model of the cervical spine with the spinal cord was developed and validated. The changes of von Mises stress and maximum principal strain within the spinal cord in the period of normal, hyperflexion, and hyperextension were investigated, considering various types and grades of disc herniation and ossification of the ligamentum flavum. The flexion and extension of the cervical spine with spinal canal encroachment induced high stress and strain inside the spinal cord, and this effect was also amplified by increased canal encroachments and cervical hypermobility. The spinal cord might evade lateral encroachment, leading to a reduction in the maximum stress and principal strain within the spinal cord in local-type herniation. Although the impact was limited in the case of diffuse type, the maximum stress tended to appear in the white matter near the encroachment site while compression from both ventral and dorsal was essential to make maximum stress appear in the grey matter. The existence of canal encroachment can reduce the safe range for spinal cord activities, and hypermobility activities may induce spinal cord injury. Besides, the ligamentum flavum plays an important role in the development of central canal syndrome.Significance. This model will enable researchers to have a better understanding of the influence of cervical degenerative diseases on the spinal cord during extension and flexion.

The biomechanical effect of different types of ossification of the ligamentum flavum on the spinal cord during cervical dynamic activities.

Ossification of the ligamentum flavum (OLF) is thought to be an influential etiology of myelopathy, as thickened ligamentum flavum causes the stenosis of the vertebral canal, which could subsequently compress the spinal cord. Unfortunately, there was little information available on the effects of cervical OLF on spinal cord compression, such as the relationship between the progression of cervical OLF and nervous system symptoms during dynamic cervical spine activities. In this research, a finite element model of C1-C7 including the spinal cord featured by dynamic fluid-structure interaction was reconstructed and utilized to analyze how different types of cervical OLF affect principal strain and stress distribution in spinal cord during spinal activities towards six directions. For patients with cervical OLF, cervical extension induces higher stress within the spinal cord among all directions. From the perspective of biomechanics, extension leads to stress concentration in the lateral corticospinal tracts or the posterior of gray matter. Low energy damage to the spinal cord would be caused by the high and fluctuating stresses during cervical movements to the affected side for patients with unilateral OLF at lower grades.

Effect of Different Types of Ossification of the Posterior Longitudinal Ligament on the Dynamic Biomechanical Response of the Spinal Cord: A Finite Element Analysis.

Ossification of the posterior longitudinal ligament (OPLL) has been identified as an important cause of cervical myelopathy. However, the biomechanical mechanism between the OPLL type and the clinical characteristics of myelopathy remains unclear. The aim of this study was to evaluate the effect of different types of OPLL on the dynamic biomechanical response of the spinal cord. A three-dimensional finite element model of the fluid-structure interaction of the cervical spine with spinal cord was established and validated. The spinal cord stress and strain, cervical range of motion (ROM) in different types of OPLL models were predicted during dynamic flexion and extension activity. Different types of OPLL models showed varying degrees of increase in stress and strain under the process of flexion and extension, and there was a surge toward the end of extension. Larger spinal cord stress was observed in segmental OPLL. For continuous and mixed types of OPLL, the adjacent segments of OPLL showed a dramatic increase in ROM, while the ROM of affected segments was limited. As a dynamic factor, flexion and extension of the cervical spine play an amplifying role in OPLL-related myelopathy, while appropriate spine motion is safe and permitted. Segmental OPLL patients are more concerned about the spinal cord injury induced by large stress, and patients with continuous OPLL should be noted to progressive injuries of adjacent level.

Preliminary Study on Insecticidal Potential and Chemical Composition of Five Rutaceae Essential Oils against Thrips flavus (Thysanoptera: Thripidae).

To meet the demand for novel pest management strategies to combat the development of insecticide resistance, plant essential oils may be a promising alternative source. This study investigated the insecticidal activity of five essential oils from the Rutaceae plant family against Thrips flavus Schrank (Thysanoptera: Thripidae) under laboratory conditions. The plant essential oils were citrus oil (Citrus reticulata Blanco), Chuan-shan pepper oil (Zanthoxylum piasezkii Maxim.), zanthoxylum oil (Zanthoxylum bungeanum Maxim.), pomelo peel oil (Citrus maxima (Burm.) Merr.) and orange leaf oil (Citrus sinensis (L.) Osbeck). Among the essential oils evaluated, orange leaf oil (LC50 = 0.26 g/L), zanthoxylum oil (LC50 = 0.27 g/L), and pomelo peel oil (LC50 = 0.44 g/L) resulted in a higher gastric toxicity under laboratory conditions. The results of the pot experiment also showed that orange leaf oil (93.06 ± 3.67% at 540.00 g a.i.·hm-2, 97.22 ± 1.39% at 720 g a.i.·hm-2, 100.00% at 900.00 g a.i.·hm-2) zanthoxylum oil (98.73 ± 1.27% at 900 g a.i.·hm-2), and pomelo peel oil (100.00% at 900 g a.i.·hm-2) exhibited a higher control efficacy, being the most effective against T. flavus after 7 days of treatment. The essential oil components were then identified by gas chromatography-mass spectrometry (GC-MS). The insecticidal activity of orange leaf oil, pomelo peel oil, and zanthoxylum oil could be attributed to their main constituents, such as methyl jasmonate (50.92%), D-limonene (76.96%), and linalool (52.32%), respectively. In the olfactory test, adult T. flavus were attracted by zanthoxylum oil and Chuan-shan pepper oil. We speculated that linalool might be the key signaling compound that attracts T. flavus. These results showed that orange leaf oil, zanthoxylum oil, and pomelo peel oil exhibited insecticidal activities under controlled conditions. They can be implemented as effective and low-toxicity botanical insecticides and synergistic agents against T. flavus.

Dynamic changes in mechanical properties of the adult rat spinal cord after injury.

Spinal cord injury (SCI), a debilitating medical condition that can cause irreversible loss of neurons and permanent paralysis, currently has no cure. However, regenerative medicine may offer a promising treatment. Given that numerous regenerative strategies aim to deliver cells and materials in the form of tissue-engineered therapies, understanding and characterising the mechanical properties of the spinal cord tissue is very important. In this study, we have systematically characterised the spatiotemporal changes in elastic stiffness (elastic modulus, Pa) and viscosity (drop in peak force, %) of injured rat thoracic spinal cord tissues at distinct time points after crush injury using the indentation technique. Our results demonstrate that in comparison with uninjured spinal cord tissue, the injured tissues exhibited lower stiffness (median 3281 Pa versus 9632 Pa; P < 0.001) but demonstrated elevated viscosity (median 80% versus 57%; P < 0.001) at 3 days postinjury. Between 4 and 6 weeks after SCI, the overall viscoelastic properties of injured tissues returned to baseline values. At 12 weeks after SCI, in comparison with uninjured tissue, the injured spinal cord tissues displayed a significant increase in both elasticity (median 13698 Pa versus 9920 Pa; P < 0.001) and viscosity (median 64% versus 58%; P < 0.001). This work constitutes the first quantitative mapping of spatiotemporal changes in spinal cord tissue elasticity and viscosity in injured rats, providing a mechanical basis of the tissue for future studies on the development of biomaterials for SCI repair. STATEMENT OF SIGNIFICANCE: Spinal cord injury (SCI) is a devastating disease often leading to permanent paralysis. While enormous progress in understanding the molecular pathomechanisms of SCI has been made, the mechanical properties of injured spinal cord tissue have received considerably less attention. This study provides systematic characterization of the biomechanical evolution of rat spinal cord tissue after SCI using a microindentation test method. We find spinal cord tissue behaves significantly softer but more viscous immediately postinjury. As time passes, the lesion site gradually returns to baseline values and then displays pronounced increased viscoelastic properties. As host tissue mechanical properties are a crucial consideration for any biomaterial implanted into central nervous system, our results may have important implications for further studies of SCI repair.

Biomechanical response of lumbar intervertebral disc in daily sitting postures: a poroelastic finite element analysis.

This study aims to establish and validate a poroelastic L4-L5 finite element model to evaluate the effect of different sitting postures and their durations on the mechanical responses of the disc. During the sustained loading conditions, the height loss, fluid loss and von-Mises stress gradually increased, but the intradiscal pressure decreased. The varying rates of aforementioned parameters were more significant at the initial loading stage and less so at the end. The predicted values in the flexed sitting posture were significantly greater than other postures. The extended sitting posture caused an obvious von-Mises stress concentration in the posterior region of the inter-lamellar matrix. From the biomechanical perspective, prolonged sitting may pose a high risk of lumbar disc degeneration, and therefore adjusting the posture properly in the early stage of sitting time may be useful to mitigate that. Additionally, upright sitting is a safer posture, while flexed sitting posture is more harmful.