Salicylic acid 52% / Trichloroacetic acid 21% in Glycerol

Background: Acanthosis nigricans (AN) is a skin disorder marked by darkening and thickening of the skin, often linked to metabolic abnormalities. This systematic review of randomized controlled trials (RCTs) assesses the comparative effectiveness and tolerability of different topical treatment options of AN, aiming to determine the most suitable therapeutic strategies. Methods: = 268) assessed topical urea (10-20%), tretinoin (0.025-0.05%), salicylic acid (10%), and chemical peels such as glycolic acid (35-70%) and trichloroacetic acid (15%) over 8 weeks to 2 months, primarily on the neck and axilla. Outcomes included melanin and erythema indices (M/E), ANASI/ANSC scores, Investigator's and Participant's Global Evaluation (IGE/PGE), and adverse events. Results: Urea demonstrated significant efficacy in reducing erythema, particularly at higher concentrations (20%), with mild adverse events such as stinging or irritation. Tretinoin was the most effective for reducing dark pigmentation, especially on the neck, and patients were more satisfied with it than with glycolic acid. Salicylic acid (10%) gave results similar to urea, with only mild side effects like dryness or peeling. Trichloroacetic acid (15%) peel was more effective than glycolic acid (35%) peel, both in skin improvement and patient satisfaction after 8 weeks. Overall, side effects with all treatments were mild and went away on their own. Conclusion: Both urea and tretinoin are effective treatments for AN, choice of therapy should be individualized tretinoin for predominant hyperpigmentation, urea for erythema or lower irritation tolerance, salicylic acid as a tolerable alternative, and TCA peel when stronger procedural options are suitable glycolic peel showed more modest effects. Systematic review registration: Prospero registration number: (CRD42023444441); https://www.crd.york.ac.uk/PROSPERO/view/CRD42023444441.

Abstract licence: CC BY

Low temperature (LT) restricts the growth and development of pitaya, therefore mitigating these detrimental LT-induced effects is of significant agricultural and economic importance in subtropical regions. This study investigated the effects of exogenous salicylic acid (SA, 2 mM) on the antioxidant system, fatty acid components, degree of unsaturation, and fatty acid desaturases (FADs) gene expression in pitaya seedlings ('Taiwan No. 6') under LT stress. LT stress increased reactive oxygen species (ROS), malondialdehyde (MDA), and relative electrical conductivity (REC), causing visible chilling injury (CI = 0.63). Crucially, LT also elevated saturated fatty acids (C12:0, C16:0, C18:0, C22:0) and decreased unsaturated fatty acids (C16:1, C18:2). This reduced the unsaturation ratio (UFA/SFA) and double bond index (DBI), compromising membrane stability and increasing permeability. However, SA application effectively mitigated these effects. SA improved peroxidase (POD) and catalase (CAT) activities, scavenging ROS and preventing oxidative damage. Crucially, SA upregulated the expression of genes encoding stearoyl-ACP desaturase (SAD) and fatty acid desaturases (FAD) enzymes, such as HuSAD2, HuFAD2, HuFAD4, HuFAD6. Consequently, SA increased unsaturated fatty acid proportions (C16:1, C18:2), UFA/SFA, and DBI. This restored membrane stability and integrity, lowered MDA, REC, and markedly reduced CI (to 0.38). This study demonstrates, for the first time in pitaya, that exogenous SA enhances cold resistance by activating antioxidant systems and regulating HuSADs and HuFADs gene expression to maintain membrane fatty acid unsaturation.

Abstract licence: CC BY-NC-ND

Low temperature is a major abiotic stressor that limits the distribution of various fruit tree species worldwide. In this study, the effects of chitosan-salicylic acid nanocomposite (CS-SA NCs) treatment were evaluated on antioxidant enzyme activity, the antioxidant pool, and membrane stability indices in the grapevine cultivar 'Flame seedless' under cold stress conditions. Prolonged exposure to cold, compared to the control, led to a reduction in maximum fluorescence (Fm), variable fluorescence (Fv), the ratio of photochemical to non-photochemical use of light energy in photosystem II (Fv/F0), and the ratio of variable fluorescence to maximum fluorescence (Fv/Fm). Levels of chlorophylls, carotenoids, total soluble protein content, antioxidant enzyme activity, ascorbate, and glutathione activity significantly decreased with increasing cold stress duration. Electrolyte leakage, malondialdehyde, and hydrogen peroxide content increased by 75%, 60%, and 80%, respectively, after 16 hours of cold stress compared to the control. Nanocomposite treatment significantly enhanced antioxidant activity and stabilized membranes under cold stress by reducing electrolyte leakage and malondialdehyde release. Overall, CS-SA NCs act as a biological stimulant and can be effectively used to improve the physiological and biochemical responses of grapevines under cold stress. Further research is needed to gain a comparative understanding of various physiological responses, which will help guide the application of this nanocomposite in extension services and field production systems.

Abstract licence: CC BY

Salinization of agricultural areas is one of the main abiotic factors responsible for the reduction of seed germination and vigor. In this context, the use of stress attenuators applied to seeds may contribute to mitigating the effects of salinity and improving the physiological and antioxidant performance of seedlings. This study aimed to evaluate the effects of stress attenuators on the tolerance and antioxidant activity of watermelon Citrullus lanatus (Thunb.) Matsum & Nakai cultivars under saline conditions. The study was conducted in two stages. In the first stage, a 3 × 6 factorial scheme was used to evaluate three salinity levels (0, −0.2, and −0.4 MPa) and six watermelon cultivars. In the second stage, in a 2 × 6 factorial scheme, two cultivars (sensitive and tolerant) were subjected to the combination of salinity (−0.4 MPa) and attenuators: hydropriming, gibberellic acid, salicylic acid, and hydrogen peroxide. Physiological and biochemical traits were evaluated, including hydrogen peroxide content, lipid peroxidation, and the activity of the enzymes, superoxide dismutase, catalase, and ascorbate peroxidase. Salinity reduced germination and seedling vigor, with Crimson Sweet, Charleston Gray, and Charleston Super being the most sensitive cultivars, whereas Congo and Omaru exhibited greater tolerance, and Fairfax also showed good performance under saline conditions. The selection of cultivars for the second stage was based not only on physiological tolerance but also on agronomic and commercial relevance, including post-harvest resistance traits. Seed treatment of Crimson Sweet with salicylic acid and hydrogen peroxide increased antioxidant enzyme activity, with increases of up to 103% in ascorbate peroxidase activity, and reduced oxidative damage, with reductions of 44% in hydrogen peroxide and 49% in malondialdehyde levels. In Fairfax, gibberellic acid contributed to osmotic adjustment, promoting increase of up to 76% in total soluble sugars, while pre-germinative treatment with salicylic acid and hydrogen peroxide promoted higher enzyme activity, contributing to the reduction of oxidative stress.

Abstract licence: CC BY

Eucalyptus spp. are the most important timber and pulpwood species in southern China. This tree species is frequently and severely damaged by the leaf-eating pest Buzura suppressaria, which significantly impairs photosynthesis and hinders the healthy and sustainable development of the Eucalyptus industry. To investigate the defensive responses of Eucalyptus urophylla × Eucalyptus grandis to pest (B. suppressaria)-feeding and leaf-clipping stress, this study measured the temporal changes in defense enzyme activities and defense compounds in Eucalyptus under conditions of pest-feeding and leaf-clipping stresses, aiming to provide a theoretical basis for resistance breeding in Eucalyptus. The results show that pest-feeding and leaf-clipping stress groups significantly affected the peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities in Eucalyptus leaves. Within a short period after stress (3 h), POD activity was significantly reached 444.83 U by leaf-clipping stress, whereas it was significantly inhibited (34.83 U) by pest-feeding stress. PPO activity was significantly enhanced to 95.25 U under pest-feeding stress within 3 h, while leaf clipping induced a lower level of PPO activity (58.75 U). PAL activity was significantly induced to 474.38 U by leaf-clipping stress at 3 h, whereas pest-feeding stress resulted in a moderate increase to 238.00 U. Both pest-feeding and leaf-clipping stresses had significant effects on the contents of defense compounds in Eucalyptus leaves. Within a short period (3 h), both leaf-clipping and pest-feeding stresses significantly induced the accumulation of salicylic acid (0.226 μg/g and 0.326 μg/g, respectively), jasmonic acid (0.239 μg/g and 0.278 μg/g, respectively), and tannin (0.581 μg/g and 0.657 μg/g, respectively). The POD activity and salicylic acid content were identified as the primary factors in Eucalyptus responses to pest-feeding and leaf-clipping stresses. In conclusion, biotic (pest-feeding) and abiotic (leaf-clipping) stresses can induce higher activities of related defense enzymes while also promoting the synthesis of greater quantities of defensive chemical compounds, thereby enhancing the resilience to biotic and abiotic stresses in Eucalyptus. This study provides important practical guidance for insect-resistant Eucalyptus breeding and implementing integrated pest management strategies.

Abstract licence: CC BY

Salicylic acid enhances cadmium tolerance in plants by modulating antioxidant defenses and promoting cadmium immobilization in cell walls. However, its potential to mitigate cadmium-induced growth inhibition and physiological disturbances in the woody species Cornus alba L. remains unexplored. Cornus alba L. seedlings were used in the pot experiment with four treatments: control (CK); 40 mg·kg−1 cadmium treatment (Cd); 100 µmol·L−1 salicylic acid treatment (SA); and both salicylic acid and cadmium treatment (SACd). The results showed that salicylic acid reduced lipid peroxidation in cell membranes by enhancing root cadmium sequestration and reconfiguring the antioxidant enzyme system, thus demonstrating a synergistic protective effect. By inhibiting cadmium transport to the shoots, it thereby mitigated the cadmium-induced inhibition of photosynthesis and reproductive development. Transcriptome analysis indicated that salicylic acid upregulates key genes in sucrose and starch metabolism pathways (e.g., TPS, GN1_2_3, otsB), leading to enhanced carbon assimilation and energy supply. Furthermore, it upregulates the key terpenoid biosynthesis genes (including HMGR and GGPS), leading to a coordinated modulation of primary and secondary metabolic flux and an increased output of the related pathways. The results reveal a potential mechanism by which salicylic acid alleviates cadmium stress in Cornus alba L., offering new insights into its role in plant heavy metal stress responses.

Abstract licence: CC BY

Plasmopara viticola (Pv), the causal agent of downy mildew, is one of the most damaging pathogens affecting grapevine. Current control strategies largely depend on copper-based fungicides and synthetic chemicals, raising increasing concerns related to environmental sustainability and pathogen resistance. This study evaluated the efficacy of a novel Saccharomyces cerevisiae extract (U) as an inducer of resistance in the grapevine–Pv interaction. Microscopic observations revealed the ability of U to inhibit Pv spread over the leaf. Additionally, biochemical and molecular responses were analyzed in grapevine leaves subjected to four treatments: plants treated only with water (U−/Pv−; i.e., control) or U (U+/Pv−), inoculated with Pv (U−/Pv+), or both treated with U and then inoculated with Pv (U+/Pv+). Fully expanded leaves were sampled at 2-, 5-, 24-, and 72-h post inoculation (hpi). In U+/Pv− leaves, jasmonic, salicylic and abscisic acid (JA, SA, and ABA), as well as hydrogen peroxide (H2O2) increased at 2 hpi (+44, +33, +38%, and 3-fold, respectively), accompanied by upregulation of pr1 (2-fold higher than control, respectively), suggesting the capacity of U to trigger the plant alert system. In U−/Pv+ leaves, peaks of JA and H2O2 occurred at 24 hpi (+40% and 4-fold higher than control), followed by marked ethylene emissions and upregulation of pr1 and pr2 (i.e., genes associated with Pv defense; around 2-fold, averagely) at 72 hpi, confirming the progression of infection. In contrast, U+/Pv+ leaves showed stronger peaks of H2O2 at both 2 and 5 hpi (7-fold and +58%, respectively), together with SA accumulation and upregulation of pr1, pr2, eds1, and chit1b at 72 hpi (more than 2-fold), suggesting a priming effect of U. Overall, U effectively enhanced grapevine defense responses and limited Pv development, highlighting its potential as a sustainable disease management strategy.

Abstract licence: CC BY

Background: Acne vulgaris is a common inflammatory disorder with significant clinical and psychosocial impacts. Medium-depth chemical peels are increasingly used to manage both active acne lesions and atrophic acne scars. This study aimed to quantitatively assess the clinical effectiveness of a novel multimodal medium-depth chemical peel regimen, yellow peel, in improving acne severity and scar depth, as well as skin hydration and sebum production in patients with mild to moderate facial acne. Methods: Twenty patients (17 women and 3 men) aged 20–25 with mild to moderate acne vulgaris underwent two sessions of yellow peel treatment at four-week intervals. The peel protocol combined glycolic acid, salicylic acid, and a multi-acid mask containing retinol, azelaic, phytic, kojic, and salicylic acids. Clinical outcomes were evaluated at baseline, four weeks after the first peel, and two months after the second peel. Assessments included the Investigators Global Assessment (IGA), inflammatory lesion count, 3D scar depth analysis, skin hydration (corneometer), and sebum secretion (sebumeter). Results: Yellow peel treatment significantly reduced acne severity, with an 85% decrease in inflammatory lesion counts and over 20% reduction in scar depth. Skin hydration improved significantly across all facial regions, and sebum secretion decreased substantially, enhancing skin barrier function and seboregulation. Statistical analysis confirmed the treatment’s efficacy with sustained improvements two months post-final peel. Conclusions: The yellow peel protocol is an effective and well-tolerated adjunct therapy for managing mild to moderate acne and atrophic acne scars. By combining exfoliative, anti-inflammatory, antibacterial, sebostatic, and depigmenting agents, this multimodal approach delivers comprehensive skin improvement. Further large-scale, controlled studies are recommended to confirm long-term safety and efficacy.

Abstract licence: CC BY