β-Pinene moderates Cr(VI) phytotoxicity by quenching reactive oxygen species and altering antioxidant machinery in maize

From imbalance to impairment: the central role of reactive oxygen species in oxidative stress-induced disorders and therapeutic exploration

Increased production and buildup of reactive oxygen species (ROS) can lead to various health issues, including metabolic problems, cancers, and neurological conditions. Our bodies counteract ROS with biological antioxidants such as SOD, CAT, and GPx, which help prevent cellular damage. However, if there is an imbalance between ROS and these antioxidants, it can result in oxidative stress. This can cause genetic and epigenetic changes at the molecular level. This review delves into how ROS plays a role in disorders caused by oxidative stress. We also look at animal models used for researching ROS pathways. This study offers insights into the mechanism, pathology, epigenetic changes, and animal models to assist in drug development and disease understanding.

Comparison of antibacterial and antioxidant potentials of pure and nanoemulsified Nepeta pogonosperma essential oil

The current study aimed to investigate the antiradical and antibacterial potential of pure and its nanoemulsified (NNE) Nepeta pogonosperma essential oil (PNE). Antimicrobial activity of the essential oil against two Gram-positive (E. faecalis and B. cereus) and two Gram-negative (M. catarrhalis and K. pneumonia) food-related pathogens during 60-day storage was investigated based on disc diffusion, minimum inhibition concentration (MIC), and minimum bactericidal concentration (MBC). The chemical compounds of Nepeta essential oil were estimated by GC/MS. The physical properties of the nanoemulsion including polydispersity index (PDI), mean particle diameter, and viscosity were also determined. 4aα,7α,7aβ-Nepetalactone (46.31%), 1,8-cineole (23.13%), and (Z)-α-bisabolene (4.01%) were the main compounds of this essential oil. The Nepeta nanoemulsion had a mean droplet diameter of 254.07 nm, PDI of 0.281, and viscosity of 0.887 cP. NNE had stability for up to 60 days. The PNE showed a higher IC₅₀ value than NNE (p < .05). During storage, the antiradical performance of both PNE and NNE was decreased (p < .05). However, emulsification was successful to control this decreasing trend. E. faecalis was the most susceptible bacteria to PNE and NNE, while the lowest inhibition zone was obtained for K. pneumoniae. At the first time, the antibacterial effect of PNE was more than NNE. However, over time nanoemulsion became more successful in maintaining its antibacterial effect. Overall, the incorporation of Nepeta pogonosperma essential oil into a nanoemulsion system can be a promising system to maintain the bioactivity of the essential oil for a longer time.

Stress-Induced Volatile Emissions and Signalling in Inter-Plant Communication

The sessile plant has developed mechanisms to survive the “rough and tumble” of its natural surroundings, aided by its evolved innate immune system. Precise perception and rapid response to stress stimuli confer a fitness edge to the plant against its competitors, guaranteeing greater chances of survival and productivity. Plants can “eavesdrop” on volatile chemical cues from their stressed neighbours and have adapted to use these airborne signals to prepare for impending danger without having to experience the actual stress themselves. The role of volatile organic compounds (VOCs) in plant–plant communication has gained significant attention over the past decade, particularly with regard to the potential of VOCs to prime non-stressed plants for more robust defence responses to future stress challenges. The ecological relevance of such interactions under various environmental stresses has been much debated, and there is a nascent understanding of the mechanisms involved. This review discusses the significance of VOC-mediated inter-plant interactions under both biotic and abiotic stresses and highlights the potential to manipulate outcomes in agricultural systems for sustainable crop protection via enhanced defence. The need to integrate physiological, biochemical, and molecular approaches in understanding the underlying mechanisms and signalling pathways involved in volatile signalling is emphasised.

The Effects of β-Pinene, a Pine Needle Oil Monoterpene, on Adenovirus Type 3

The mechanisms of the inhibitory action of β-pinene, a pine needle oil monoterpene, on human adenovirus type 3 were studied using cytopathic inhibition test, MTT test, atomic force and laser confocal microscopy. β-Pinene inhibited the viruses stronger that the reference antiviral medication ribavirin (p<0.05). Inhibition of viral cytopathic effect (CPE) increased with increasing the concentration of β-pinene, which attested to direct elimination of adenovirus type 3. During viral reproduction phase, β-pinene significantly inhibited proliferation of adenovirus type 3. Typical signs of adenoviral CPE as cell swelling and rounding were less pronounced in comparison with the control (ribavirin treatment). In addition, elevation of β-pinene concentration significantly increased the cell survival rate (p<0.05). Laser confocal microscopy showed that fluorescence intensity in the β-pinene group was significantly lower than in the control group (p<0.01), which was consistent with the results of MTT test, thereby providing additional arguments that β-pinene affects the virus during the absorption phase. Thus, β-pinene directly inactivates adenovirus type 3 and impedes its invasion into the cells, but produces no protective effects on cells. Understanding the mode of action of such monoterpenes as β-pinene is of great importance for the development of new antiviral drugs.

The pinene scaffold: its occurrence, chemistry, synthetic utility, and pharmacological importance

This review provides insight into the utility of pinene in the synthetic building block and as reagent in asymmetric synthesis.

β-Pinene alleviates arsenic (As)-induced oxidative stress by modulating enzymatic antioxidant activities in roots of Oryza sativa

Rice (Oryza sativa L.) is a highly consumed staple crop worldwide, but abiotic/heavy metal stresses acting on the plant cause reduction in yield and quality, thereby impacting global food security. In the present study, we examined the effect of β-pinene against Arsenic (As)-induced oxidative damage vis-à-vis regulation of activities of enzymatic antioxidants in roots of O. sativa. Effect of As (50 μM), β-pinene (10 μM; β-10) and As + β-10 treatments on root length, shoot length, As accumulation, lipid peroxidation (as malondialdehyde [MDA] content), hydrogen peroxide (H₂O₂) accumulation, and activities of lipoxygenase (LOX) and enzymatic antioxidants such as ascorbate peroxidase (APX), guaiacol peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT) was determined. Exposure of As caused a decline in root and shoot length, and enhancement in As accumulation, lipid peroxidation, and activities of enzymatic antioxidants. However, supplementation of β-10 (i.e., As + β-10 treatments) led to an increase in root and shoot length. Treatment with As + β-10 resulted in a decline in As accumulation, H₂O₂ content, and MDA content; however, the effect on LOX activity was non-significant, as compared to control. Similarly, with As + β-10 treatment a reduction in the activities of APX, GPX, GR, SOD, and CAT was observed as compared with As-alone treatment. Pearson's correlation matrix exhibited strong negative correlation between reactive oxygen species (ROS) and root/shoot length, whereas a strong positive correlation was observed between antioxidant enzymes and ROS. The present study demonstrated that β-pinene significantly ameliorates As-induced oxidative stress and provides tolerance to O. sativa against As-induced toxicity, and thus offer an option of As-mitigation using environment friendly natural plant products. However, to gain insights into the function of β-pinene in modulating As-induced oxidative damage in plants, further field investigations and exploration of its mechanism of action are needed.

Amelioration potential of β-pinene on Cr(VI)-induced toxicity on morphology, physiology and ultrastructure of maize

Heavy metals' amassment in the soil environment is a threat to crop and agricultural sustainability and consequentially the global food security. For achieving enhancement of crop productivity in parallel to reducing chromium (Cr) load onto food chain demands continuous investigation and efforts to develop cost-effective strategies for maximizing crop yield and quality. In this context, we investigated the amelioration of Cr(VI) toxicity through β-pinene in experimental dome simulating natural field conditions. The protective role of β-pinene was determined on physiology, morphology and ultrastructure in Zea mays under Cr(VI) stress (250 and 500 μM). Results exhibited a marked reduction in the overall growth (shoot and root length and dry matter) of Z. mays plants subjected to Cr(VI) stress. Photosynthetic pigments (chlorophyll and carotenoids) were evidently reduced, and there was a loss of membrane integrity. Supplementation of β-pinene (100 μM), however, declined the toxicity induced by Cr(VI). Interestingly, Cr-tolerant abilities were improved in relation to plant growth, photosynthetic pigments and membrane integrity with the combined treatment of Cr(VI) and β-pinene. β-Pinene also reduced the root-mediated uptake of Cr(VI) and translocation to shoots. Moreover, significant ultrastructural damages recorded in roots and shoots under Cr(VI) stress were partially reverted upon addition of β-pinene. Our analyses revealed that β-pinene mitigates Cr(VI) toxicity in Z. mays, either by membrane stabilization or serving as a barrier to the uptake of Cr from soil. Thus, exogenous supply of β-pinene can be an effective alternative to mitigate Cr toxicity in soil. However, it is deemed essential to investigate further the responses throughout the life cycle of the plant on β-pinene supplementation under natural conditions.

Usage of Natural Volatile Organic Compounds as Biological Modulators of Disease

Plants produce a wide variety of natural volatile organic compounds (NVOCs), many of which are unique to each species. These compounds serve many purposes, such as fending off herbivores and adapting to changes in temperature and water supply. Interestingly, although NVOCs are synthesized to deter herbivores, many of these compounds have been found to possess several therapeutic qualities, such as promoting nerve stability, enhancing sleep, and suppressing hyperresponsiveness, in addition to acting as antioxidants and anti-inflammatory agents. Therefore, many NVOCs are promising drug candidates for disease treatment and prevention. Given their volatile nature, these compounds can be administered to patients through inhalation, which is often more comfortable and convenient than other administration routes. However, the development of NVOC-based drug candidates requires a careful evaluation of the molecular mechanisms that drive their therapeutic properties to avoid potential adverse effects. Furthermore, even compounds that appear generally safe might have toxic effects depending on their dose, and therefore their toxicological assessment is also critical. In order to enhance the usage of NVOCs this short review focuses not only on the biological activities and therapeutic mode of action of representative NVOCs but also their toxic effects.

Heatwave frequency and seedling death alter stress-specific emissions of volatile organic compounds in Aleppo pine

Biogenic volatile organic compounds (BVOC) play important roles in plant stress responses and can serve as stress indicators. While the impacts of gradual environmental changes on BVOCs have been studied extensively, insights in emission responses to repeated stress and recovery are widely absent. Therefore, we studied the dynamics of shoot gas exchange and BVOC emissions in Pinus halepensis seedlings during an induced moderate drought, two four-day-long heatwaves, and the combination of drought and heatwaves. We found clear stress-specific responses of BVOC emissions. Reductions in acetone emissions with declining soil water content and transpiration stood out as a clear drought indicator. All other measured BVOC emissions responded exponentially to rising temperatures during heat stress (maximum of 43 °C), but monoterpenes and methyl salicylate showed a reduced temperature sensitivity during the second heatwave. We found that these decreases in monoterpene emissions between heatwaves were not reflected by similar declines in their internal storage pools. Because stress intensity was extremely severe, most of the seedlings in the heat-drought treatment died at the end of the second heatwave (dark respiration ceased). Interestingly, BVOC emissions (methanol, monoterpenes, methyl salicylate, and acetaldehyde) differed between dying and surviving seedlings, already well before indications of a reduced vitality became visible in gas exchange dynamics. In summary, we could clearly show that the dynamics of BVOC emissions are sensitive to stress type, stress frequency, and stress severity. Moreover, we found indications that stress-induced seedling mortality was preceded by altered methanol, monoterpene, and acetaldehyde emission dynamics.

Terpenoids, Cannabimimetic Ligands, beyond the Cannabis Plant

Medicinal use of Cannabis sativa L. has an extensive history and it was essential in the discovery of phytocannabinoids, including the Cannabis major psychoactive compound—Δ9-tetrahydrocannabinol (Δ9-THC)—as well as the G-protein-coupled cannabinoid receptors (CBR), named cannabinoid receptor type-1 (CB1R) and cannabinoid receptor type-2 (CB2R), both part of the now known endocannabinoid system (ECS). Cannabinoids is a vast term that defines several compounds that have been characterized in three categories: (i) endogenous, (ii) synthetic, and (iii) phytocannabinoids, and are able to modulate the CBR and ECS. Particularly, phytocannabinoids are natural terpenoids or phenolic compounds derived from Cannabis sativa. However, these terpenoids and phenolic compounds can also be derived from other plants (non-cannabinoids) and still induce cannabinoid-like properties. Cannabimimetic ligands, beyond the Cannabis plant, can act as CBR agonists or antagonists, or ECS enzyme inhibitors, besides being able of playing a role in immune-mediated inflammatory and infectious diseases, neuroinflammatory, neurological, and neurodegenerative diseases, as well as in cancer, and autoimmunity by itself. In this review, we summarize and critically highlight past, present, and future progress on the understanding of the role of cannabinoid-like molecules, mainly terpenes, as prospective therapeutics for different pathological conditions.