Dietary Supplement Products Research Articles

A Survey of Melatonin in Dietary Supplement Products Sold in the United States.

In the United States, melatonin products are widely available as dietary supplements. During the past few decades, melatonin products have gained popularity primarily as a sleep aid, with a variety of product forms available for different age groups of consumers. Recent reports have highlighted a rise in melatonin ingestion among children reported to poison control centers. The increased use of melatonin-containing products, the diversity in product forms, and reported label discrepancies has emphasized the need for additional research to better understand the marketplace. This work aims to measure melatonin content in products sold as dietary supplements and marketed for children, evaluate method performance across different product categories, and determine if product form has an impact on melatonin stability. One hundred ten (110) dietary supplement products labeled to contain melatonin and marketed towards children were purchased and analyzed using a targeted LC-MS/MS method validated for the qualitative determination of serotonin and quantification of melatonin, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), and N1-acetyl-5-methoxykynuramine (AMK). Melatonin was identified in 108 of 110 products (98%) with a median concentration of 1.2 mg/g (range: 0.017-130 mg/g) or 1.7 mg/serving (range: 0.042-50 mg/serving). Further, in the tested products, melatonin content ranged from 0% to 667% of the label declaration. This study provides evidence to inform safety assessments and investigate potential factors that may influence reported concentrations, such as product stability and matrix influences.

DSHEA 1994 – Celebrating 30 Years of Dietary Supplement Regulation in the United States

The Dietary Supplement Health and Education Act (DSHEA) of 1994 defined the FDA’s statutory authority to regulate dietary supplement products as a category of food in the United States. As we celebrate 30 years post-DSHEA, it is important to reflect on its significance for public health, influence on the continuously evolving and expanding product category, the current regulatory framework, and potential opportunities or modernizing oversight to ensure a strong and well-regulated marketplace. An estimated three-fourths of U.S. consumers report use of dietary supplements, and the product market has grown substantially since the passage of DSHEA, from approximately 4,000 products in 1994 to 80,000+ present day. This growth represents a current $60 billion domestic and $200 billion international market for dietary supplements. Scientists, public health officials, health care providers, patients, consumer advocacy organizations, and the U.S. Food and Drug Administration have all called for reform to what has been described as ‘outdated’ regulation of dietary supplements. Advancing at an even faster rate is published scientific evidence in the space. This special issue of the Journal of Dietary Supplements comprises a collection of articles authored by academicians, legal scholars, representatives of U.S. government agencies, and industry scientists that critically examine the successes, challenges, and opportunities for improving specific aspects of DSHEA and domestic health policy. This editorial provides historical context and milestones of dietary supplement regulation in the U.S. post-DSHEA and offers an overview of the research contained within the special issue. Advancing toward a more transparent and safer marketplace requires trustworthy supply chains, increased adherence to quality standards, additional labeling requirements, and enhancement of post-market surveillance. This special issue seeks to contribute to the broader understanding of dietary supplement regulation and its future direction.

Cytoprotection against Cadmium by Nrf2-Activating Dietary Phytochemicals

In context with previous work by others, the present findings indicate that rosemary-based dietary supplement products like PB123 might promote beneficial responses against environmental cadmium exposure.

Dietary Supplement and Prescription Omega-3 Fatty Acid Products Use among Iraqi Consumers in Kirkuk City

Dietary Supplement and Prescription Omega-3 Fatty Acid Products Use among Iraqi Consumers in Kirkuk City

Simultaneous determination of picroside I and picroside II in dietary supplements by high performance liquid chromatography with PDA detector

Picroside I and picroside II are two compounds found in the Picrorhiza Kurroa plant, which have anti-cirrhosis, antioxidant, anti-inflammatory, fever, and asthma effects, etc. They are included in the ingredients of many dietary supplement products that help protect the liver and bile, prevent oxidation, etc. Therefore, determining the content of these two active ingredients in dietary supplements is necessary to evaluate product quality. In this study, highperformance liquid chromatography (HPLC-PDA) was used to simultaneously determine picroside I and picroside II in dietary supplements. The analytes in the samples were extracted with methanol for 60 min using a horizontal shaking technique. The extract was then filtered and determined by the HPLC–PDA method with the following conditions: C18 Column (250 mm x 4.6 mm; 5 µm) and a corresponding pre-column (3.9 mm x 5 mm; 5 µm), the mobile phase consists of a solvent mixture of acetonitrile and water according to the gradient program, detection wavelength 265 nm. The method has good specificity, the calibration curve of picroside I and picroside II has a linear coefficient R2 > 0.9999 and the repeatability and recovery meet the AOAC requirements. The method limits of detection (MDL) for these two substances were 4.3 mg/kg and 3.2 mg/kg, respectively. The method was applied to simultaneously determine picroside I and picroside II in 30 different dietary supplement products. The results detected analytes in 3 samples positive with picroside I and picroside II concentrations ranging from 98.8 to 148 mg/kg.

Assessment of the Biological Activity of a Probiotic Fermented Milk Product with the Addition of Lactobacillus helveticus Cell-Free Supernatant

Products enriched with probiotic microorganisms have proven to possess immunomodulatory, antioxidant, hypo-cholesterolemic, hypotensive, and antimicrobial properties. Biologically active substances, which are by-products of microbial fermentation, have potential applications in various industries. Cell-free supernatants, depending on the microorganisms used and production conditions, can exhibit antimicrobial, antioxidant, bifidogenic, and other biological activities. This paper presents a study on the biological activity of a probiotic fermented milk product, supplemented with 0.01% lyophilized cell-free supernatant from Lactobacillus helveticus. The fermented milk product was developed based on a composition of Lacticaseibacillus rhamnosus F, Lactococcus cremoris CR201, and Propionibacterium shermanii E2. The research evaluated antimicrobial activity, Bifidobacteria growth stimulation, and the content of organic acids, amino acids, and B vitamins. It was found that adding lyophilized cell-free supernatant to the fermented milk product enhanced its biological activity. In particular, the experimental samples showed a threefold increase in vitamin B6 content compared to the control, reaching 22.412 μg/100 g. Additionally, the amino acid content in the experimental samples exhibited a significant increase of more than 100% in the essential amino acid tryptophan compared to the control. Notably, antimicrobial activity increased against several opportunistic strains. The experimental samples also showed a significant increase in lactic and formic acids, which may enhance the product’s inhibitory properties against pathogens. An increase in antioxidant activity was observed, potentially due to the higher content of tryptophan and vitamin B6. The positive effect of adding cell-free supernatant on the growth of Bifidobacteria was also demonstrated. Thus, the findings suggest that this cell-free supernatant can be recommended as an additive in the production of fermented milk products, food additives, dietary supplements, and animal feed.

Assesment of quality of Ginkgo biloba extract and dietary supplements in Vietnam market based on flavonol glycoside content and flavonoid ratio

Ginkgo biloba is one of the oldest medicinal herbs in the world. It is commonly used as a dietary supplement to protect against blood circulation disorders, improve memory, and prevent cognitive decline. Currently, Vietnam and other countries have regulations in place to ensure the quality of Ginkgo biloba extract in their pharmacopoeia. In this study, the quality of 11 raw materials and 120 dietary supplement products containing ginkgo extract was evaluated based on flavonol glycoside content and the ratio of component flavonoids. The results revealed a significant number of unsatisfactory samples, highlighting the need for closer monitoring of quality products to protect consumer rights.

Vegetative reproduction and yield of bear garlic (<i>Allium ursinum</i> L.) in field cultivation

Bear garlic (<i>Allium ursinum</i> L.) and its value for human health have been known for centuries. Its leaves, flowers, and bulbs contain many health-promoting compounds, and can be essential raw materials for the production of food and dietary supplements of natural origin. The purpose of the study was to evaluate the possibility of growing bear garlic in field conditions that differed significantly from those required by this plant, using unconventional treatments: catch crops (phacelia), shade plant (turnip rape), and biopreparations (Bio-Algeen S90 and Kelpak SL). The plowing of phacelia biomass had a beneficial effect on the number of <i>A. ursinum</i> progeny bulbs, the unit weight of bulbs and their yield per unit area, and the leaf yield not only in the first year of cultivation but also in the follow-up. Winter turnip rape applied as a shade crop caused a slight increase in the unit weight of bulbs and their yield in the first and second years of cultivation and in the number of progeny bulbs in the second and third years of cultivation. The cultivation of <i>A. ursinum</i> with turnip rape increased the percentage of garlic root weight and leaf yield. There was a positive effect of the applied biopreparations on the studied traits of <i>A. ursinum</i> bulb yield and leaf yield and on the formation of progeny bulbs in relation to the control object. The analysis of the interaction of the factors of the experiment showed that the combination with the application of the phacelia catch crop and the simultaneous cultivation of the shade crop had the most favorable effect on <i>A. ursinum</i> progeny bulb formation, bulb unit weight, root system development, and leaf yield. In all years of the study, the worst effect was obtained in the control object, i.e., in the cultivation without the catch crop, rapeseed, and application of biopreparations.

Applications of Capillary Electrophoresis for the Detection of Adulterants in Dietary Supplements.

In recent years, the consumption of dietary supplements, particularly those incorporating plant-based ingredients, has increased greatly, driven by the perception of their natural origins and purported minimal health risks. However, one significant safety concern revolves around the adulteration of dietary supplements, wherein unscrupulous manufacturers may illegally incorporate pharmaceutical substances or their analogs into these products to achieve increased efficiency and bolster sales. This review assesses the role of capillary electrophoresis (CE) in ensuring the quality control of dietary supplement products over the past two decades. This study provides an overview of various applications of CE in analyzing dietary supplements, outlining the typical attributes of natural product analysis using CE. These analyses demonstrate the broad versatility of CE, exemplified by its diverse applications and detection modes. Moreover, the review highlights the growing prominence of CE as a separation technique in quality control, by comparison with more conventional methods like high-performance liquid chromatography (HPLC). Through this exploration, the review elucidates the pivotal role of CE in upholding the integrity and safety of dietary supplements, in connection with a landscape of evolving regulatory challenges and consumer demands.

Determination of Toxic Elements in Botanical Dietary Supplement Ingredient Reference Materials.

The National Institute of Standards and Technology (NIST) has produced over 40 botanical dietary supplement Standard Reference Materials® (SRMs) and reference materials (RMs) with values assigned for chemical markers and/or active compounds. Although environmental accumulation or inadvertent introduction of toxic elements (arsenic, cadmium, lead, and mercury) is a potential source of exposure in botanical dietary supplement products, the majority of the dietary supplement SRMs/RMs do not have values assigned for the four major toxic elements. To determine As, Cd, Pb, and Hg content in the current inventory of NIST botanical dietary supplement SRMs/RMs. Fifteen SRMs/RMs suites of plant part, extract, and finished products [i.e., solid oral dosage form (SODF)] were analyzed for As, Cd, Pb, and Hg using nitric acid microwave-assisted digestion followed by quantification using inductively coupled plasma-mass spectrometry. Results for control samples were in good agreement with certified values indicating that the analyses of 38 individual botanical SRMs/RMs were in control. Characterization of linked plant/extract SRMs/RMs derived from the same source materials demonstrated that while extraction processes can often yield extracts with lower toxic element content for Hg or As, it is also possible for mass fraction levels to remain unchanged or even increase following extraction. The results fill significant knowledge gaps in toxic element content ranges for SRMs/RMs where no NIST assigned values existed, in particular for Hg content and for extract and SODF matrices. With comprehensive toxic element content now available, researchers can better select appropriate dietary supplement SRMs/RMs for use as controls in the analysis of dietary supplement ingredients and products. Results for As, Cd, Pb, and Hg are reported for 38 dietary supplement SRMs/RMs including 6 suites of plant, extract, and SODF and 9 pairs of plant and extract from the same batch of plant material.

Secondary metabolites of soybean seeds variety locus and their spatial arrangement, represented by laser microscopy

The purpose of this study is a detailed metabolomic analysis using tandem mass spectrometry of the soybean variety Locus, selected from the collection of the Federal Scientific Center for Agrobiotechnologies of the Far East named after A. K. Chaika», to identify both the polyphenolic composition of seeds and the determination of other chemical groups in the composition of the seed. Tandem mass spectrometry studies were further supported by visual data obtained for the first time using laser microscopy. The object of the study is the seeds of the soybean variety Locus, grown in 2022 at the field site of the soybean breeding laboratory of the Federal Scientific Center for Agrobiotechnologies of the Far East named after A. K. Chaika», located in the village of Timiryazevsky (near the city of Ussuriysk). Experiments were carried out on a CLSM-800 laser confocal microscope and mass spectrometry of biologically active substances on an amaZon SL ion trap. Laser microscopy made it possible to clarify in detail the spatial distribution of the content of phenolic acids, flavonols and anthocyanins in soybean seeds. The studies were able to convincingly show that soybean polyphenolic substances and, in particular, anthocyanins are spatially localized mainly in the soybean seed coat. High-performance liquid chromatography coupled with ion trap (tandem mass spectrometry) was used to identify target analytes in soybean seed extracts. Using tandem mass spectrometry, the presence of 59 compounds was identified, of which 35 compounds represent the group of polyphenolic compounds. 15 compounds were identified for the first time in soybean extracts of the Locus variety. These are flavones: apigenin, acacetin, cirsimaritin; tetrahydroxyflavone aromadendrin 7-O-rhamnoside; lignan medioresinol; coumarin tomentin and other polyphenolic compounds. The data obtained will help intensify future research on the development and production of new drugs, dietary supplements, food additives and various functional and specialized products containing targeted soybean extracts.

An isocratic HPLC-UV analytical procedure for assessment of glutathione and its related substances

Reduced glutathione (GSH) is an endogenous tripeptide antioxidant which plays a crucial role in a variety of physiological and pathological activities. Although GSH is not present in any FDA-approved drug product, GSH dietary supplement products and compounded GSH drugs are available to patients in the US. Several incidents of toxicity have occurred in recent years due to endotoxin or otherwise contaminated GSH in compounded drugs. Efficient and sensitive analytical methods are needed for assessing and ensuring the quality of GSH substance and associated drug or dietary supplement products. Impurities A (L-cysteinylglycine), B (cysteine), C (oxidized L-glutathione) and D (γ-L-glutamyl-L-cysteine) are the main related impurities for GSH drug substance which have been detected and quantified by capillary electrophoresis and qNMR analytical procedures. However, there are no reported HPLC methods for detecting or quantifying the three main related impurities A, B and D even though numerous HPLC analytical methods have been reported for analyzing GSH and impurity C. In this report, an isocratic HPLC-UV analytical procedure was developed and validated for separating and identifying GSH and related impurities A-D as well as a newly identified degradant, L-pyroglutamic acid (pGlu), within 10 minutes with resolution (RS) more than 3. The LOD and LOQ were determined to be 0.02 % w/w and 0.05 % w/w, respectively, for impurities A-D and pGlu. Importantly, the optimized HPLC analytical procedure for GSH assay does not have interference from impurities A, B and D, providing highly specific results compared to the commonly used iodine titration method. The newly validated analytical procedure was applied to assess different commercial GSH bulk substance samples. The results suggest that the analytical procedure described in this work is suitable for quality assessment of GSH samples.

Secondary metabolites of perilla (<i>Perilla frutescens</i> (L.) Britton) of Far Eastern origin identified by tandem mass spectrometry

Perilla frutescens is a monotypic genus of annual herbaceous plants of dead nettles. The article presents a simultaneous evaluation of the presence of both phenolic compounds in P. frutescens seed extracts and compounds of other chemical classes. It has been confirmed that the seeds of P. frutescens varieties k-130, k-263, k-326 contain a large number of polyphenolic complexes, which are biologically active compounds. The complete metabolomic composition of perilla seed extracts is presented for the first time. The study utilized a tandem mass spectrometry method involving the use of liquid chromatography in parallel with an ion trap. Using tandem mass spectrometry, the presence of 60 compounds was identified, of which 41 compounds represent the group of polyphenolic compounds, as well as 19 compounds of other chemical groups in perilla extracts. The chemical components were identified by comparing their retention index, mass spectra and MS fragmentation with the home library database based on the data from other spectroscopic techniques such as nuclear magnetic resonance, UV-visible spectroscopy and mass spectrometry. Also, 29 chemical compounds were found for the first time, including 16 compounds of polyphenolic group and 13 compounds of other chemical groups. Lignans: syringaresinol and medioresinol; coumarins: umbelliferone and 4-hydroxycoumarin; flavones: luteolin 7-O-glucoside, diosmetin C-hexoside, chrysoeriol C-hexoside C-pentoside; flavanols: ampelopsin, astragalin, etc. were identified in perilla seeds for the first time. The data obtained will help intensify future research on the development and production of new drugs, dietary supplements and various functional, specialized and dietary products containing targeted perilla extracts.

Development of Potential Therapeutic Agents from Black Elderberries (the Fruits of Sambucus nigra L.).

Elderberry (Sambucus nigra L.) is a widespread deciduous shrub, of which the fruits (elderberries) are used in the food industry to produce different types of dietary supplement products. These berries have been found to show multiple bioactivities, including antidiabetic, anti-infective, antineoplastic, anti-obesity, and antioxidant activities. An elderberry extract product, Sambucol®, has also been used clinically for the treatment of viral respiratory infections. As the major components, phenolic compounds, such as simple phenolic acids, anthocyanins and other flavonoids, and tannins, show promising pharmacological effects that could account for the bioactivities observed for elderberries. Based on these components, salicylic acid and its acetate derivative, aspirin, have long been used for the treatment of different disorders. Dapagliflozin, an FDA-approved antidiabetic drug, has been developed based on the conclusions obtained from a structure-activity relationship study for a simple hydrolyzable tannin, β-pentagalloylglucoside (β-PGG). Thus, the present review focuses on the development of therapeutic agents from elderberries and their small-molecule secondary metabolites. It is hoped that this contribution will support future investigations on elderberries.

Optimization and validation of a simple extraction method coupled with ICP-MS for the determination of essential and toxic elements in liquid dietary supplement products

This study aimed to develop and validate a fast, easy, cost-effective, and accurate method for determining Mn, Co, Ni, Cr, Cu, Fe, Zn, As, Cd, Hg, Sb, and Pb in liquid dietary supplements using an inductively coupled plasma mass spectrometer (ICP-MS). Two sample preparation methods were compared: microwave acid digestion and direct analysis after dilution. Both methods provided acceptable recovery values (87.7–111 %), with RSD values up to 6.35 %. The microwave digestion method was validated using various certified reference materials (CRMs) and a proficiency test (PT). Additionally, 34 domestic dietary supplements were analyzed using both methods, and the results were similar. Only one sample exceeded the maximum allowable limit for arsenic, which is 150 mg/kg set by the United States Pharmacopeia (USP). Two products had high Fe and Zn levels exceeding the recommended daily allowance (RDA), according to the Food and Drug Administration (FDA). This study demonstrates the effectiveness and advantages of the direct analysis method for measuring essential and toxic elements in liquid dietary supplements. This method promotes green chemistry principles and provides valuable information for ensuring consumer safety and product quality.

A Shotgun Metagenomics Investigation into Labeling Inaccuracies in Widely Sold Probiotic Supplements in the USA.

While probiotics are generally considered safe, concerns persist regarding the accuracy of labels on these supplements and their potential contribution to the spread of antibiotic resistance genes. Given that probiotics are predominantly ingested with a view towards obtaining particular health benefits. The objective of this study is to assess the composition of 50 widely available probiotic supplements in the USA using shotgun metagenome sequencing. The study also determines the potential resistome profile, and the functional characteristics of these products. This study finds that 67% of products does not contain any labeling inaccuracies. Antimicrobial Resistance Genes (ARGs) are identified in several products, particularly Bacillus-based products carrying between 10 and 56 genes. The risk posed by the presence of these ARGs requires further study. Functional analysis reveals differences in metabolic profiles among probiotic supplements, indicating the importance of strain-level selection for personalized probiotics. This study provides updated and comprehensive analysis to evaluate a snapshot of the USA market. The study demonstrates that label inaccuracies occur on approximately one third of popular dietary supplement products sold in the USA, supporting the need for improved approaches to marketing and quality control. Further, the risk of antibiotic resistance, especially in Bacillus-based formulations, should be assessed.

Differences in P-Type and Type 1 Uropathogenic Escherichia coli Urinary Anti-Adhesion Activity of Cranberry Fruit Juice Dry Extract Product and D-Mannose Dietary Supplement

Background Urinary tract infection (UTI) prevention benefits of cranberry intake are clinically validated, especially for women and children. To ensure the benefits of cranberry dietary supplement products, the anti-adhesion activity (AAA) against uropathogenic bacteria is routinely used in in vitro bioassays to determine the activity in whole product formulations, isolated compounds, and ex vivo bioassays to assess urinary activity following intake. D-mannose is another dietary supplement taken for UTI prevention, based on the anti-adhesion mechanism. Objective Compare the relative AAA of cranberry and D-mannose dietary supplements against the most important bacterial types contributing to the pathogenesis of UTI, and consider how certain components potentially induce in vivo activity. Methods The current study used a crossover design to determine ex vivo AAA against both P- and Type 1-fimbriated uropathogenic Escherichia coli of either D-mannose or a cranberry fruit juice dry extract product containing 36 mg of soluble proanthocyanidins (PACs), using bioassays that measure urinary activity following consumption. AAA of extracted cranberry compound fractions and D-mannose were compared in vitro and potential induction mechanisms of urinary AAA explored. Results The cranberry dietary supplement exhibited both P-type and Type 1 in vitro and ex vivo AAA, while D-mannose only prevented Type 1 adhesion. Cranberry also demonstrated more robust and consistent ex vivo urinary AAA than D-mannose over each 1-week study period at different urine collection time points. The means by which the compounds with in vitro activity in each supplement product could potentially induce the AAA in urines was discussed relative to the data. Conclusions Results of the current study provide consumers and healthcare professionals with additional details on the compounds and mechanisms involved in the positive, broad-spectrum AAA of cranberry against both E. coli bacterial types most important in UTIs and uncovers limitations on AAA and effectiveness of D-mannose compared to cranberry.

Engineering Fatty Acid Biosynthesis in Microalgae: Recent Progress and Perspectives.

Microalgal lipids hold significant potential for the production of biodiesel and dietary supplements. To enhance their cost-effectiveness and commercial competitiveness, it is imperative to improve microalgal lipid productivity. Metabolic engineering that targets the key enzymes of the fatty acid synthesis pathway, along with transcription factor engineering, are effective strategies for improving lipid productivity in microalgae. This review provides a summary of the advancements made in the past 5 years in engineering the fatty acid biosynthetic pathway in eukaryotic microalgae. Furthermore, this review offers insights into transcriptional regulatory mechanisms and transcription factor engineering aimed at enhancing lipid production in eukaryotic microalgae. Finally, the review discusses the challenges and future perspectives associated with utilizing microalgae for the efficient production of lipids.

Label Accuracy of Weight Loss Dietary Supplements Marketed Online With Military Discounts

Dietary supplements for weight loss, among the most popular supplement products on the market, are promoted not only for losing weight and shedding fat, but also for added benefits of energy and performance, all packed into 1 capsule with multiple combinations of ingredients. Fraudulent marketing of weight loss supplements, some with exaggerated claims, some that are potentially dangerous, and some that contain illegal ingredients, is ever present, especially through online sources, where multiple manufacturers target service members by offering military discounts. To examine whether select dietary supplements marketed online for weight loss from companies advertising military discounts are accurately labeled according to the Supplement Facts listed ingredients, whether they contain any ingredients prohibited for use in the military, and to qualitatively describe the products' label claims. In this case series, 30 dietary supplement products marketed for weight loss were selected and purchased in June 2023 from 12 online companies advertising military discounts. Data were analyzed from July to August 2023. Liquid chromatography-mass spectrometry was used to verify whether products were accurately labeled according to the Supplement Facts listed ingredients and whether they contained any substances on the DoD Prohibited Dietary Supplement Ingredients List. A separate analysis was conducted to describe product label claims by using the Operation Supplement Safety (OPSS) Risk Assessment Scorecard. Of the 30 products tested, analysis showed that 25 had inaccurate labels. Of these, 24 had ingredients listed on the label that were not detected (misbranded); 7 had hidden components not present on the label, some of which would be considered adulterated; and 10 had substances on the DoD Prohibited Dietary Supplement Ingredients List either on or hidden from the label. All products were rated as risky when applying the OPSS Scorecard. In this case series study, the majority of products had inaccurate labels. Some were misbranded, others would be considered adulterated with ingredients not allowed in dietary supplements, and some contained ingredients prohibited for use in the military.

The pathogenicity and regulatory function of temperature-sensitive proteins PscTSP in Pseudofabraea citricarpa under high temperature stress

Citrus fruit rich in beneficial health-promoting nutrients used for functional foods or dietary supplements production. However, its quality and yield were damaged by citrus target spot. Citrus target spot is a low-temperature fungal disease caused by Pseudofabraea citricarpa, resulting in citrus production reductions and economic losses. In this study, transcriptome and gene knockout mutant analyses were performed on the growth and pathogenicity of P. citricarpa under different temperature conditions to quantify the functions of temperature-sensitive proteins (PscTSP). The optimum growth temperature for P. citricarpa strain WZ1 was 20 °C, while it inhibited or stopped growth above 30 °C and stopped growth below 4 °C or above 30 °C. Certain PscTSP-key genes of P. citricarpa were identified under high temperature stress. qRT-PCR analysis confirmed the expression levels of PscTSPs under high temperature stress. PscTSPs were limited by temperature and deletion of the PscTSP-X gene leads to changes in the integrity of citrus cell walls, osmotic regulation, oxidative stress response, calcium regulation, chitin synthesis, and the pathogenicity of P. citricarpa. These results provide insight into the underlying mechanisms of temperature sensitivity and pathogenicity in P. citricarpa, providing a foundation for developing resistance strategies against citrus target spot disease.