Benzyl benzoate 25% application

Scabies is a common skin infestation with a high prevalence in populations with low socioeconomic conditions. The topical application of benzyl benzoate (BB) is effective due to its neurotoxic effects on mites; however, its efficacy remains inconsistent and ambiguous across studies. In contrast, topical permethrin 5% has emerged as one of the most widely prescribed treatments for scabies, attributed to its relatively high efficacy. Recently, several studies have evaluated the effectiveness of topical permethrin, highlighting the need for a comprehensive synthesis of evidence. Therefore, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the efficacy of topical permethrin compared to BB in treating scabies. A systematic search of Scopus, PubMed, Web of Science (WOS), and Cochrane Central was performed from inception until January 2025 to identify RCTs comparing the effectiveness of topical permethrin and BB. The primary outcomes were clinical cure rates of scabies lesions and pruritus. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model for dichotomous data. All statistical analyses were conducted using STATA 18MP (StataCorp LLC, College Station, USA). A total of seven RCTs, including 783 patients, met the inclusion criteria. Topical permethrin demonstrated significantly higher clinical cure rates for both scabies lesions and pruritus in the first week of treatment, with improvements of 30% and 23%, respectively (RR = 1.30; 95% CI: 1.11-1.53; p < 0.001 for scabies lesions, and RR = 1.23; 95% CI: 1.04-1.47; p = 0.02 for pruritus), compared to BB. However, no significant differences were observed between the two treatments in subsequent follow-up assessments. In conclusion, topical permethrin provides a superior and faster improvement in the treatment of scabies compared to BB within the first week of therapy, with no significant difference in later assessment durations, highlighting the superiority of permethrin is time-dependent. Further high-quality RCTs with long-term follow-up are warranted to confirm these findings and evaluate sustained efficacy.

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Background/objectives Oral ivermectin and topical benzyl benzoate are two common treatment options for scabies, but there is ongoing discussion regarding their relative safety and efficacy. A thorough synthesis of the available evidence is required to inform treatment decisions because of the clinical debate caused by the contradictory findings from current randomized controlled trials (RCTs). Methods A systematic review and meta-analysis were conducted on evidence retrieved from PubMed, Scopus, Web of Science, and CENTRAL for RCTs up to August 2025. The primary outcome was the cure rate. Secondary outcomes included pruritus improvement and the incidence of adverse events. Stata MP v. 18 was used to pool outcomes. Results Ten RCTs involving 1,105 patients were included. Cure rates showed no significant difference between ivermectin and benzyl benzoate at 1 week (RR: 1.07, 95% CI [0.88, 1.30], p = 0.51), 2–4 weeks (RR: 0.99, 95% CI [0.88, 1.12], p = 0.91), or after more than 4 weeks (RR: 1.16, 95% CI [0.95, 1.43], p = 0.15). The overall pooled result confirmed no difference (RR: 1.04, 95% CI [0.95, 1.14], p = 0.37). For pruritus, no significant differences were observed at 1 week (RR: 1.07, 95% CI [0.80, 1.43], p = 0.66), 2–4 weeks (RR: 1.19, 95% CI [0.97, 1.46], p = 0.09), or beyond 4 weeks (RR: 1.10, 95% CI [0.89, 1.37], p = 0.38); overall RR: 1.13, 95% CI [0.99, 1.29], p = 0.07. Ivermectin showed significantly fewer adverse events (RR: 0.27, 95% CI [0.16, 0.46], p &amp;lt; 0.001), particularly less burning/stinging (RR: 0.07, 95% CI [0.02, 0.20], p &amp;lt; 0.001). Gastrointestinal (GI) events were not significantly different (RR: 1.47, 95% CI [0.67, 3.22], p = 0.34). Conclusion Oral ivermectin and topical benzyl benzoate exhibit comparable efficacy for the treatment of scabies. However, ivermectin’s significantly better safety and tolerability, combined with the practical advantage of oral administration, establish it as a valuable and often preferable therapeutic choice. Systematic review registration CRD420251143937.

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BACKGROUND: Scabies is a pruritic parasitic infestation of the skin. High-income countries have reported an increasing incidence over the last few years. Studies have indicated a reduction in the sensitivity of scabies mites to the standard treatment of choice, topical permethrin 5%. OBJECTIVES: To evaluate in a head-to-head manner the efficacy of two topical scabicides [permethrin 5% and benzyl benzoate 25% (BB)] in the treatment of scabies using the same administration modality; and to address potential confounding factors such as incorrectly performed treatment and hygiene measures. METHODS: In total, 110 patients with dermoscopy-verified scabies infestation were enrolled and randomized into two equally sized groups in a double-blinded manner. Fifty-five received topical permethrin 5% and 55 received topical BB 25%, both for daily use over a period of three consecutive days. Treatment outcome was evaluated by dermoscopy at a 3-week follow-up visit. RESULTS: Treatment resulted in a dermoscopy-verified cure rate of 27% in the permethrin group and 87% in the BB group. The tolerability and safety profile of permethrin 5% cream was excellent, while the BB emulsion produced a burning sensation in 43% of patients. CONCLUSIONS: Topical permethrin demonstrated a lack of efficacy in the majority of scabies cases, whereas BB demonstrated an excellent cure rate and reasonable tolerability. Considering the reduced sensitivity of scabies mites to permethrin 5%, our results suggest that BB is an appropriate first-line therapy in the treatment of scabies.

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Tribolium castaneum is a damaging pest of stored grains, causing significant losses and secreting lethal quinones, which render the grains unfit for human consumption. Chemical insecticides are the most commonly used approach for control; however, they create insecticide resistance and affect the health of humans, animals, and the environment. As a result, it is critical to find an environmentally friendly pest-management strategy. In this study, two naturally occurring chemicals, benzyl alcohol (BA) and benzoyl benzoate (BB), were investigated for insecticidal activity against T. castaneum using different assays (impregnated-paper, contact toxicity, fumigant, and repellency assays). The results showed that BA had a significant insecticidal effect, with the LC50 achieved at a lower concentration in the direct-contact toxicity test (1.77%) than in the impregnated-paper assay (2.63%). BB showed significant effects in the direct-contact toxicity test, with an LC50 of 3.114%, and a lower toxicity in the impregnated-paper assay, with an LC50 of 11.75%. Furthermore, BA exhibited significant fumigant toxicity against T. castaneum, with an LC50 of 6.72 µL/L, whereas BB exhibited modest fumigant toxicity, with an LC50 of 464 µL/L. Additionally, at different concentrations (0.18, 0.09, 0.045, and 0.0225 µL/cm2), BA and BB both showed a notable and potent repelling effect. BA and BB significantly inhibited acetylcholinesterase, reduced glutathione (GSH), and increased malondialdehyde (MDA) in treated T. castaneum. This is the first report of BA insecticidal activity against the red flour beetle. Also, the outcomes of various assays demonstrated that the application of BA induces a potent bio-insecticidal effect. BA may be a promising eco-friendly alternative to control T. castaneum due to its safety and authorization by the EFSA (European Food Safety Authority).

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Salicylic acid (SA) biosynthesis in plants occurs via the isochorismate synthase (ICS) and phenylalanine ammonia-lyase (PAL) pathways. The critical steps from benzyl-CoA to SA in the PAL-mediated pathway remain unknown. To probe benzenoid metabolism, we generated CRISPR/Cas9-mediated knockouts of benzaldehyde synthase in poplar. These plants produce less benzyl benzoate, benzyl salicylate and SA, yet accumulate more benzoic acid. We show that HSR203J encodes a carboxylesterase that specifically hydrolyzes benzyl salicylate. Virus-induced gene silencing (VIGS) of HSR203J in Nicotiana benthamiana led to reduced benzyl salicylate hydrolysis to SA. Based on these data, we propose a biosynthesis model and provide evidence that benzoyl-CoA is esterified to benzyl benzoate and converted to benzyl salicylate, which then releases SA. In addition, we identified a pathogen-induced cytochrome P450 encoded by HSR515 as a putative benzyl benzoate 2-hydroxylase. VIGS-mediated suppression of HSR515 in N. benthamiana reduced the conversion of benzyl benzoate to SA. Phylogenetic analyses indicated that Brassicaceae genomes do not contain HSR203J and HSR515 orthologs, whereas these genes are present in other vascular plants. These findings represent an important advance in our understanding of SA biosynthesis and identify missing steps in the PAL-mediated SA biosynthetic pathway.

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