Nanoparticles' Perspective in Skin Tissue Engineering: Current Concepts and Future Outlook.

Nanotechnology seems to provide solutions to the unresolved complications in skin tissue engineering. According to the broad function of nanoparticles, this review article is intended to build a perspective for future success in skin tissue engineering. In the present review, recent studies were reviewed, and essential benefits and challenging issues regarding the application of nanoparticles in skin tissue engineering were summarized. Previous studies indicated that nanoparticles can play essential roles in the improvement of engineered skin. Bio-inspired design of an engineered skin structure first needs to understand the native tissue and mimic that in laboratory conditions. Moreover, a fundamental comprehension of the nanoparticles and their related effects on the final structure can guide researchers in recruiting appropriate nanoparticles. Attention to essential details, including the designation of nanoparticle type according to the scaffold, how to prepare the nanoparticles, and what concentration to use, is critical for the application of nanoparticles to become a reality. In conclusion, nanoparticles were applied to promote scaffold characteristics and angiogenesis, improve cell behavior, provide antimicrobial conditions, and cell tracking.

Indirect co-culture of islet cells in 3D biocompatible collagen/laminin scaffold with angiomiRs transfected mesenchymal stem cells.

Diabetes is an autoimmune disease in which the pancreatic islets produce insufficient insulin. One of the treatment strategies is islet isolation, which may damage these cells as they lack vasculature. Biocompatible scaffolds are one of the efficient techniques for dealing with this issue. The current study is aimed to determine the effect of transfected BM-MSCS with angiomiR-126 and -210 on the survival and functionality of islets loaded into a 3D scaffold via laminin (LMN). AngiomiRs/Poly Ethylenimine polyplexes were transfected into bone marrow-mesenchymal stem cells (BM-MSCs), followed by 3-day indirect co-culturing with islets laden in collagen (Col)-based hydrogel scaffolds containing LMN. Islet proliferation and viability were significantly increased in LMN-containing scaffolds, particularly in the miRNA-126 treated group. Insulin gene expression was superior in Col scaffolds, especially, in the BM-MSCs/miRNA-126 treated group. VEGF was upregulated in the LMN-containing scaffolds in both miRNA-treated groups, specifically in the miRNA-210, leading to VEGF secretion. MiRNAs' target genes showed no downregulation in LMN-free scaffolds; while a drastic downregulation was seen in the LMN-containing scaffolds. The highest insulin secretion was recorded in the Oxidized dextran (Odex)/ColLMN+ group with miRNA-126. LMN-containing biocompatible scaffolds, once combined with angiomiRs and their downstream effectors, promote islets survival and restore function, leading to enhanced angiogenesis and glycemic status.

Severe Acute Respiratory Syndrome Coronavirus Type 2: Insight Into Challenges for Cell Therapy.

Coronavirus disease 2019 has affected more than 4 million people throughout the world since December 2019. It seems this infection has been the most insidious virus of the coronavirus family. This virus causes severe respiratory failure and symptoms in patients and can result in death. Designing a restrict protocol to deal with infections from severe acute respiratory syndrome coronavirus type 2 is critical in cell therapy institutes. In this review, we present the important aspects related to this virus in cell therapy protocols.

Effectiveness of islet transplantation in diabetes mellitus type 1: a systematic review of the recent evidences.

INTRODUCTION: Islet transplantation has been introduced as a promising approach for the treatment of diabetes mellitus type 1. Despite many efforts to achieve a perfect treatment, further investigation is still needed to eliminate limitations and challenging issues. The objective of the present systematic review is to evaluate the efficacy of islet transplantation in diabetes mellitus type 1. EVIDENCE ACQUISITION: We conducted a systematic review on the results of clinical studies on islet cell transplantation between January 2015 and November 2021. The Search strategy was designed and conducted in PubMed, Cochrane, Scopus, and Web of Science. EVIDENCE SYNTHESIS: Studies have indicated that islet transplantation can reduce the daily insulin requirement as well as improving metabolic stability in diabetic patients. Even in some patients, insulin independence was achieved during the first year of transplantation. CONCLUSIONS: Findings show that islet transplantation has a potential to become a promising treatment for diabetes mellitus type 1. In this regard, to obtain a trustworthy result, it is essential to design clinical studies (RCTs) with large sample size and long follow-up (cohort studies) to achieve a comprehensive and accurate appraisal of islet transplantation.

Immune Cell-Derived Extracellular Vesicles in the Face of Pathogenic Infections.

Extracellular Vesicles (EVs) are a collection of vesicles released from cells that play an important role in intercellular communication. Microbial infections are known as one of the major problems in the medical field. Considering the increasing resistance of strains to routine drug treatments, the need for new therapies seems to be more than ever. Recent studies have shown that the EVs released from immune cells during microbial infections had anti-microbial effects or were able to induce neighbouring cells to display anti-microbial effects. This mini-review aimed to explore the latest studies on immune cell-derived EVs in viral, bacterial, fungal, and parasitic infections. Review of the literature demonstrated that specific cargos in EVs were involved in the fight against pathogenic infections. Additionally, the transport of appropriate bioactive molecules including miRNAs, mRNAs, and proteins via EVs could mediate the anti-microbial process. Thus, it could be a proof-of-principle that therapeutic approaches based on EVs derived from immune cells could offer a promising path forward, which is still in early stages and needs further assessments.

Susceptibility to Metabolic Diseases in COVID-19: To be or Not to be an Issue.

Despite the passage of more than 17 months from the beginning of the COVID-19 pandemic, challenges regarding the disease and its related complications still continue in recovered patients. Thus, various studies are underway to assay the long-term effects of COVID-19. Some patients, especially those with severe symptoms, experience susceptibility to a range of diseases and substantial organ dysfunction after recovery. Although COVID-19 primarily affects the lungs, multiple reports exist on the effect of this infection on the kidneys, cardiovascular system, and gastrointestinal tract. Studies have also indicated the increased risk of severe COVID-19 in patients with diabetes. On the other hand, COVID-19 may predispose patients to diabetes, as the most common metabolic disease. Recent studies have shown that Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) binds to Angiotensin-Converting Enzyme 2 (ACE2) receptors, which are expressed in the tissues and organs involved in regulating the metabolic status including pancreas, adipose tissue, gastrointestinal tract, and kidneys. Therefore, SARS-CoV-2 may result in metabolic disturbance. However, there are still many unknowns about SARS-CoV-2, which are required to be explored in basic studies. In this context, special attention to molecular pathways is warranted for understanding the pathogenesis of the disease and achieving therapeutic opportunities. Hence, the present review aims to focus on the molecular mechanisms associated with the susceptibility to metabolic diseases amongst patients recovered from COVID-19.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: Promising Treatment for COVID-19 Pandemic.

The pandemic of severe acute respiratory syndrome coronavirus-2 infection has prompted the urgent need for novel therapeutic approaches, especially for patients in critically severe conditions. To date, the pathogenesis of COVID-19 is not completely understood, and finding an effective new drug is still inconclusive. Mesenchymal stromal cell-derived extracellular vesicles contain large amounts of proteins, messenger RNA, and microRNAs that act as vehicles that transfer the cargo between cells. These nanotherapeutic materials exert anti-inflammatory effects on the immune system, which are necessary for subsidence of acute inflammation and promotion of tissue repair and regeneration. Therefore, the consideration of mesenchymal stromal cell-derived extracellular vesicles as a new, safe, and effective therapeutic approach in the treatment of COVID-19 pneumonia is suggested.

The potential of the incorporated collagen microspheres in alginate hydrogel as an engineered three-dimensional microenvironment to attenuate apoptosis in human pancreatic islets.

BACKGROUND: Tissue engineering is considered as a promising tool for remodeling the native cells microenvironment. In the present study, the effect of alginate hydrogel and collagen microspheres integrated with extracellular matrix components were evaluated in the decrement of apoptosis in human pancreatic islets. MATERIALS/METHODS: For three-dimensional culture, the islets were encapsulated in collagen microspheres, containing laminin and collagen IV and embedded in alginate scaffold for one week. After that the islets were examined in terms of viability, apoptosis, genes and proteins expression including BAX, BCL2, active caspase-3, and insulin. Moreover, the islets function was evaluated through glucose-induced insulin and C-peptide secretion assay. In order to evaluate the structure of the scaffolds and the morphology of the pancreatic islets in three-dimensional microenvironments, we performed scanning electron microscopy. RESULTS: Our findings showed that the designed hydrogel scaffolds significantly improved the islets viability using the reduction of activated caspase-3 and TUNEL positive cells. CONCLUSIONS: The reconstruction of the destructed matrix with alginate hydrogels and collagen microspheres might be an effective step to promote the culture of the islets.

Incorporation of VEGF-and bFGF-loaded alginate oxide particles in acellular collagen-alginate composite hydrogel to promote angiogenesis.

BACKGROUND: The use of growth factors in tissue engineering is often challenging due to their instability and short half-life. The delivery of growth factors with nanocarriers can eliminate these problems. In the present study, we introduced an alginate oxide particle in acellular collagen-alginate composite hydrogel platform for the immobilization and controlled release of VEGF and bFGF to promote angiogenesis. METHODS: The particles were prepared by the oxidation of sodium alginate. Then, they were embedded in collagen-alginate hydrogel. Cytocompatibility of the construct with the human umbilical vein endothelial cells was analyzed through a live/dead assay and scanning electron microscopy. In vitro evaluation of VEGF and bFGF Release Kinetics was done. Moreover, the function of the constructs was confirmed through the chick chorioallantoic membrane assay. RESULTS: The engineered constructs maintained the human umbilical vein endothelial cells viability, which indicates the non-toxicity of the tested constructs. The presence of VEGF-loaded particles could improve the Total Branching Points in the chick chorioallantoic membrane assay. In this regard, Total Branching Points was significantly improved in the VEGF group compared to the control group (p = 0.010) and FGF group (p = 0.023). CONCLUSION: The results demonstrated the potential role of these particles in regenerative medicine to improve angiogenesis.

Stem Cell-Derived Exosome as Potential Therapeutics for Microbial Diseases.

Exosomes, as the smallest extracellular vesicles that carry a cargo of nucleic acids, lipids, and proteins and mediate intercellular communication, have attracted much attention in diagnosis and treatment in the field of medicine. The contents of exosomes vary depending on the cell type and physiological conditions. Among exosomes derived from several cell types, stem cell-derived exosomes (stem cell-Exo) are increasingly being explored due to their immunomodulatory properties, regenerative capacity, anti-inflammatory and anti-microbial functions. Administration of stem cell-Exo, as a cell-free therapy for various diseases, has gained great promise. Indeed, the advantages of exosomes secreted from stem cells outweigh those of their parent cells owing to their small size, high stability, less immunogenicity, no risk of tumorigenesis, and easier condition for storage. Recently, the use of stem cell-Exo has been proposed in the field of microbial diseases. Pathogens including bacteria, viruses, fungi, and parasites can cause various diseases in humans with acute and chronic complications, sometimes resulting in mortality. On the other hand, treatments based on antibiotics and other chemical compounds have many side effects and the strains become resistant to drugs in some cases. Hence, this review aimed to highlight the effect of stem cell-derived extracellular vesicles including stem cell-Exo on microbial diseases. Although most published studies are preclinical, the avenue of clinical application of stem cell-Exo is under way to reach clinical applications. The challenges ahead of this cell-free treatment that might be applied as a therapeutic alternative to stem cells for translation from bench to bed were emphasized, as well.

Hypoxia-Preconditioned Wharton's Jelly-Derived Mesenchymal Stem Cells Mitigate Stress-Induced Apoptosis and Ameliorate Human Islet Survival and Function in Direct Contact Coculture System.

Protection of isolated pancreatic islets against hypoxic and oxidative damage-induced apoptosis is essential during a pretransplantation culture period. A beneficial approach to maintain viable and functional islets is the coculture period with mesenchymal stem cells (MSCs). Hypoxia preconditioning of MSCs (Hpc-MSCs) for a short time stimulates the expression and secretion of antiapoptotic, antioxidant, and prosurvival factors. The aim of the present study was to evaluate the survival and function of human islets cocultured with Hpc-MSCs. Wharton's jelly-derived MSCs were subjected to hypoxia (5% O2: Hpc) or normoxia (20% O2: Nc) for 24 hours and then cocultured with isolated human islets in direct and indirect systems. Assays of viability and apoptosis, along with the production of reactive oxygen species (ROS), hypoxia-inducible factor 1-alpha (HIF-1α), apoptotic pathway markers, and vascular endothelial growth factor (VEGF) in the islets, were performed. Insulin and C-peptide secretions as islet function were also evaluated. Hpc-MSCs and Nc-MSCs significantly reduced the ROS production and HIF-1α protein aggregation, as well as downregulation of proapoptotic proteins and upregulation of antiapoptotic marker along with increment of VEGF secretion in the cocultured islet. However, the Hpc-MSCs groups were better than Nc-MSCs cocultured islets. Hpc-MSCs in both direct and indirect coculture systems improved the islet survival, while promotion of function was only significant in the direct cocultured cells. Hpc potentiated the cytoprotective and insulinotropic effects of MSCs on human islets through reducing stressful markers, inhibiting apoptosis pathway, enhancing prosurvival factors, and promoting insulin secretion, especially in direct coculture system, suggesting the effective strategy to ameliorate the islet quality for better transplantation outcomes.

Exosomes derived from human mesenchymal stem cells preserve mouse islet survival and insulin secretion function.

Islet cell death and loss of function after isolation and before transplantation is considered a key barrier to successful islet transplantation outcomes. Mesenchymal stem cells (MSCs) have been used to protect isolated islets owing to their paracrine potential partially through the secretion of vascular endothelial growth factor (VEGF). The paracrine functions of MSCs are also mediated, at least in part, by the release of extracellular vesicles including exosomes. In the present study, we examined (i) the effect of exosomes from human MSCs on the survival and function of isolated mouse islets and (ii) whether exosomes contain VEGF and the potential impact of exosomal VEGF on the survival of mouse islets. Isolated mouse islets were cultured for three days with MSC-derived exosomes (MSC-Exo), MSCs, or MSC-conditioned media without exosomes (MSC-CM-without-Exo). We investigated the effects of the exosomes, MSCs, and conditioned media on islet viability, apoptosis and function. Besides the expression of apoptotic and pro-survival genes, the production of human and mouse VEGF proteins was evaluated. The MSCs and MSC-Exo, but not the MSC-CM-without-Exo, significantly decreased the percentage of apoptotic cells and increased islet viability following the downregulation of pro-apoptotic genes and the upregulation of pro-survival factors, as well as the promotion of insulin secretion. Human VEGF was observed in the isolated exosomes, and the gene expression and protein production of mouse VEGF significantly increased in islets cultured with MSC-Exo. MSC-derived exosomes are as efficient as parent MSCs for mitigating cell death and improving islet survival and function. This cytoprotective effect was probably mediated by VEGF transfer, suggesting a pivotal strategy for ameliorating islet transplantation outcomes.

Significant reduction of apoptosis induced via hypoxia and oxidative stress in isolated human islet by resveratrol.

BACKGROUND AND AIMS: Successful islet transplantation as a promising treatment of diabetes type 1 is threatened with the loss of islets during the pre-transplant culture due to hypoxia and oxidative stress-induced apoptosis. Therefore, optimization of culture in order to preserve the islets is a critical point. In this study, we investigated the effect of resveratrol, as a cytoprotective agent, on the cultured human islets. METHODS AND RESULTS: Isolated islets were treated with different concentrations of resveratrol for 24 and 72 h. Islets' viability, apoptosis, apoptosis markers, and insulin and C-peptide secretion, along with the production of reactive oxygen species (ROS), hypoxia inducible factor 1 alpha (HIF-1α), and its target genes in the islets were investigated. Our findings showed that the islets were exposed to hypoxia and oxidative stress after isolation and during culture. This insult induced apoptosis and decreased viability during 72 h. The presence of resveratrol significantly attenuated HIF-1α and ROS production, reduced apoptosis, promoted the VEGF secretion, and increased the insulin and C-peptide secretion. In this regard, resveratrol improved the islet's survival and function in the culture period. CONCLUSIONS: Using resveratrol can attenuate the stressful condition for the islets in the pre-transplant culture and subsequently ameliorate their viability and functionality that lead to successful outcome after clinical transplantation.

Cytoprotective effects of ginsenoside Rd on apoptosis-associated cell death in the isolated human pancreatic islets.

Ginsenoside Rd (GS-Rd), one of the main pharmacologically active components of ginseng, has shown the potential to stabilize mitochondrial membrane integrity and decrease apoptotic death in neuronal and non-neuronal cells. The present study aimed to evaluate the effect of this bioactive molecule on the apoptosis-associated cell death in human pancreatic islets. In this regard human pancreatic islets were isolated and grouped for the treatment with GS-Rd. The isolated islets were treated with different concentrations of GS-Rd. After 24 and 72 h of incubation, the islets were evaluated in terms of viability, BAX, BCL2, and insulin gene expression, BAX, BCL2, and caspase-3 protein expression, apoptosis, and glucose-induced insulin/C-peptide secretion. Our results revealed the islet survival was significantly decreased in the control group after 72 h of incubation. However, GS-Rd inhibited the progress of the islet death in the treated groups. TUNEL staining revealed that the preventive effect of this molecule was caused by the inhibition of apoptosis-associated death. In this regard, the activation of caspase-3 was down-regulated in the presence of GS-Rd. GS-Rd did not exhibit undesirable effects on glucose-induced insulin and C-peptide stimulation secretion. In conclusion, GS-Rd inhibited the progress of death of cultured human pancreatic islets by diminishing the apoptosis of the islet cells.

Protective effect of nobiletin on isolated human islets survival and function against hypoxia and oxidative stress-induced apoptosis.

Islets transplantation, as a treatment of type 1 diabetes, faces challenges, including the loss of islets in the process of isolation and pre-transplantation due to cellular stresses-induced apoptosis. Accordingly, the optimization of culture plays a decisive role in the transplantation success. In this study, we evaluated the effect of nobiletin on the cultured human islets. Isolated human islets were treated by different concentrations of nobiletin and cultured for 24 and 72 hours. Then, the islets viability, apoptosis, insulin and C-peptide secretion, and apoptosis markers were evaluated. Also, the production of reactive oxygen species (ROS), hypoxia inducible factor 1 alpha (HIF-1α), and its target genes in the islets were examined. Our findings showed that the islets were encountered with hypoxia and oxidative stress after isolation and during culture. These insults induced apoptosis and reduced viability during culture period. Moreover, the secretion of insulin and C-peptide decreased. Nobiletin treatments significantly improved the islets survival through reduction of HIF-1α and ROS production and suppression of apoptosis, along with increased islets function. Islet protective effect of nobiletin might be related to its anti-oxidant, anti-apoptotic and insulinotropic properties. Hence, in order to achieve viable and functional islets for clinical transplantation, the application of nobiletin during pre-transplantation period is useful.

Amelioration of the apoptosis-mediated death in isolated human pancreatic islets by minocycline.

Minocycline functions as a therapeutic drug in different diseases because of its cytoprotective properties. In the present study, we examined the potential of minocycline to decrease the islet loss in pre-transplantation culture stage. Pancreatic islets were isolated from the deceased donors and treated by 0, 2, 10, and 20 µM minocycline for 24 and 72 h. After that, the incubated islets were evaluated for viability and function. Apoptosis markers including Bax, Bcl2, and caspase-3 were determined at gene and protein level. On the other hand, TUNEL assay was used to confirm apoptosis. The functionality of the islets was investigated using glucose-induced insulin and c-peptide secretion assay. After 72 h of incubation, the viability of human islet was drastically decreased, whereas supplementation with minocycline inhibited the cells death. In this regard, the expression of Bax and active Caspase-3 was downregulated, whereas the expression of Bcl2 was upregulated. These consequences suggest that pancreatic islets undergo apoptosis in vitro and minocycline can decelerate or inhibit this process. Our findings identified minocycline as a cytoprotective molecule for preventing human islets death in pre-transplantation culture.

Cytoprotective effects of olesoxime on isolated human pancreatic islets in order to attenuate apoptotic pathway.

BACKGROUND AND PURPOSE: Islet transplantation is considered as a promising approach in the treatment of diabetes type 1. In this regard, optimal culture of the pancreatic islets is promising in the success of transplantation. In the present study, the effect of olesoxime, as an antiapoptotic substance, was evaluated on human islet culture. EXPERIMENTAL APPROACH: The pancreatic islets were isolated by mechanical and enzymatic techniques. After overnight recovery, the islets were treated by different concentrations of olesoxime for 24 and 72 h. Then, they were examined in terms of viability, apoptosis, genes and proteins expression including BAX, BCL2, active caspase-3, and insulin. Moreover, the islets function was evaluated through the glucose-induced insulin and C-peptide secretion assay. KEY RESULTS: Our findings showed that the islets increased in apoptosis and the decreased in viability after 72 h; also, insulin and C-peptide secretion reduced. However, in the presence of olesoxime, BAX/BCL2 ratio and the activation of caspase-3 were decreased. Therefore, olesoxime could improve the viability of the islets with the decrease of apoptosis. CONCLUSION: The application of olesoxime can reduce the stressful condition for the islets in vitro and subsequently improve their viability and functionality.

Effect of CYP3A5*1 expression on tacrolimus required dose after liver transplantation: A systematic review and meta-analysis.

We systematically collected eligible data to measure the effect of CYP3A5*1 expression on personalized tacrolimus therapy. Six databases were searched for studies on adult liver transplant recipients and donors of liver graft which reported tacrolimus dose requirement, trough blood concentration, and/or concentration/dose (C/D) ratio in expressers and nonexpressers of CYP3A5*1. Eligible data were pooled by meta-analysis. Sixteen observational studies (1309 recipients, 1044 donors of liver graft) were included in the analyses. Tacrolimus C/D ratio was lower, and the dose was higher in recipient expressers of CYP3A5*1 and/or carriers of expresser liver graft at 1-4 weeks and 2-4, 6, and 12 months post-transplantation. Tacrolimus blood concentration was lower at the first two weeks. Pair expressers were affected by about twofold, and the effect was different between ethnic groups. CYP3A5*1 expression in recipients increased tacrolimus required dose by 0.023 at first, 0.022 at third, and 0.012 mg/kg/day at sixth month. Its expression in graft tissue increased tacrolimus required dose by 0.024 at first, 0.035 at third, and 0.032 mg/kg/day at sixth month. Considering CYP3A5*1 polymorphism can be helpful in individualization of tacrolimus efficient dose prior to administration, and it can remove initial high-risk lag time (over/underdose period before reaching target blood level) at first few days post-transplantation.

Effect of CYP3A5*1 expression on tacrolimus required dose for transplant pediatrics: A systematic review and meta-analysis.

This systematic review was designed to find out optimal tacrolimus dose in pediatrics according to their CYP3A5*1 genotype by performing meta-analysis. PubMed, Scopus, ISI web of Science, ProQuest, Cochrane library, and clinicaltrail.gov were systematically searched to find studies in which tacrolimus dose and/or blood concentration and/or concentration-to-dose (C/D) ratio were determined in genotype groups of CYP3A5*1 in pediatric population. Data were extracted at 14 time points post-transplantation and meta-analysis of mean and SD was performed. In all, 11 studies including 596 pediatric transplant recipients were entered into systematic review and meta-analysis. Analysis of tacrolimus required dose, blood concentration, and C/D ratio in 14 time points post-transplantation resulted in significant differences between expressers and non-expressers of CYP3A5*1. It seems that 0.06 mg/kg/day higher tacrolimus dose in expressers can produce same blood level as non-expressers. Using results of TDM for tacrolimus dose adjustment, it takes about 1 month for patients to reach stable and optimum tacrolimus blood concentration. This is too long time period which increases the risk of immunosuppressive over/under-dose and drug toxicity or organ rejection. Considering our results, defining genetic profile helps to predict the individual required dose more rapidly, actually before beginning of treatment.

Effect of soil application of humic acid on nutrients uptake, essential oil and chemical compositions of garden thyme (Thymus vulgaris L.) under greenhouse conditions.

Humic acid is natural biological organic, which has a high effect on plant growth and quality. However, the mechanisms of the promoting effect of humic acid on the volatile composition were rarely reported. In this study, the effects of soil application of humic acid on the chemical composition and nutrients uptake of Thymus vulgaris were investigated. Treatments comprised 0, 50, 75 and 100 g m-2. Essential oil was extracted by hydrodistillation and analyzed using GC-MS and GC-FID. Essential oil content was enhanced by increase of the humic acid level and its content ranged from 0.8% (control) to 2.0% (75 g m-2). Thirty-two volatile compounds were identified and these compounds were considerably affected by humic acid. The highest percentage of thymol (74.15%), carvacrol (6.20%), p-cymene (4.24%), borneol (3.42%), trans-caryophyllene (1.70%) and cis-sabinene hydrate (1.35%) as major compounds were observed in T. vulgaris under 100 g m-2 humic acid. There was a linear relationship (R2 = 97%) between humic acid levels and thymol as a major compound. The oils were dominated by oxygenated monoterpenes followed by monoterpene hydrocarbons and sesquiterpene hydrocarbons. Based on the path coefficient analysis, the highest direct effects on essential oil content were observed in monoterpene esters (3.465) and oxygenated sesquiterpenes (3.146). The humic acid application also enhanced the uptake of N, P, K, Mg and Fe in garden thyme. The highest N (2.42%), P (0.75%), K (2.63%), Mg (0.23%) and Fe (1436.58 ppm) were observed in medium supplemented with 100 g m-2 humic acid. In all, the utilization of humic acid could positively change nutrients uptake, essential oil content and its major constituents in T. vulgaris.