Squalene Stimulates a Key Innate Immune Cell to Foster Wound Healing and Tissue Repair

The Role of Moisturizer Containing Anti-inflammatory on Skin Hydration in Mild-Moderate Atopic Dermatitis Patients

Atopic dermatitis (AD) is a chronic, inflammatory skin condition characterized by eczema lesions and dry, itchy skin. Recent guidelines for the management of AD emphasize the importance of using moisturizers in the management of AD. This study is a double-blind clinical trial to determine the effectiveness of moisturizers containing anti-inflammatory ingredients compared with moisturizers without anti-inflammatory ingredients for skin hydration in mild to moderate adult AD patients for 14 days at the Dermatology and Venereology Outpatient Clinic at Dr. Soetomo General Academic Hospital. There was a significant difference (p < 0.05) at the baseline and day 14 skin hydration values in the experiment group with anti-inflammatory ingredients (35.97 ± 6.04-66.06 ± 15.84) and the control group without anti-inflammatory ingredients (40.74 ± 10.94-56.12 ± 8.34). After comparison, there was a significant difference (p < 0.05) in the skin hydration value between the experiment group and the control group on the 14th day. There was also a significant difference in the improvement of skin hydration outcomes between both groups (p < 0.05). The severity of the disease using Scoring Atopic Dermatitis (SCORAD) showed a significant difference (p < 0.05) between the experiment group and the control group after 2 weeks of intervention. The addition of anti-inflammatory ingredients in the moisturizer, namely, shea butter, bacterial lysate, allantoin, bisabolol, Phragmites kharka extract, Poria cocos, and Mirabilis jalapa in a moisturizer containing occlusive (dimethicone), humectants (glycerin, saccharide, butylene glycol, and hyaluronic acid), and emollient (shea butter and squalane) was shown to be significantly better in improving skin hydration in patients with mild to moderate AD.

Explicating the multifunctional roles of tocotrienol and squalene in promoting skin health

The skin is the largest organ in the integumentary system, protecting against various external threats, including ultraviolet exposure, heat, infections, dehydration and mechanical injuries. Skin disorders can arise from various causes, including allergic reactions or breaches in the skin barrier, which allow microorganisms or chemicals to penetrate the sweat ducts. These conditions encompass a wide range of issues, including acne, xerosis (dry skin), fungal infections, atopic dermatitis (eczema) and psoriasis. Collectively, these ailments affect a significant portion of the global population, impacting approximately one-third of people worldwide. Additionally, oxidative stress induced by ageing and prolonged exposure to ultraviolet rays can manifest in visible alterations such as pigmentation, wrinkling and dehydration. Recent investigations have underscored the potential of natural antioxidant compounds in safeguarding skin health and combating ageing-related changes. Tocotrienols, a subgroup of vitamin E, have garnered significant attention owing to their antioxidant and anti-inflammatory properties. Significant amounts of tocotrienols can be found in rice bran, olive, oats and hazelnuts. Similarly, squalene, predominantly sourced from fish liver oils such as those from sharks, has been used as an emollient in cosmetic formulations. This article offers a comprehensive review of existing literature elucidating the dermatological benefits associated with tocotrienols and squalene, emphasising their roles as antioxidants, anti-inflammatories, skin barrier protection and facilitators of wound healing. Moreover, it sheds light on contemporary research findings suggesting these compounds' therapeutic promise in managing and ameliorating various skin conditions.

Utilizing the sublingual form of squalene in COVID-19 patients: a randomized clinical trial

In this study, the efficacy of sublingual squalene in decreasing the mortality rate among patients with COVID-19 was investigated. Squalene was extracted from pumpkin seed oil with a novel method. Then, the microemulsion form of squalene was prepared for sublingual usage. In the clinical study, among 850 admitted patients, 602 eligible COVID-19 patients were divided in two groups of control (N = 301) and cases (N = 301) between Nov 2021 and Jan 2022. Groups were statistically the same in terms of age, sex, BMI, lymphocyte count on 1st admission day, hypertension, chronic kidney disease, chronic respiratory disease, immunosuppressive disease, and required standard treatments. The treatment group received five drops of sublingual squalene every 4 h for 5 days plus standard treatment, while the control group received only standard treatment. Patients were followed up for 30 days after discharge from the hospital. The sublingual form of squalene in the microemulsion form was associated with a significant decrease in the mortality rate (p < 0.001), in which 285 (94.7%) cases were alive after one month while 245 (81.4%) controls were alive after 1 month of discharge from the hospital. In addition, squalene appears to be effective in preventing re-hospitalization due to COVID-19 (p < 0.001), with 141 of controls (46.8%) versus 58 cases (19.3%). This study suggests sublingual squalene in the microemulsion as an effective drug for reducing mortality and re-hospitalization rates in COVID-19 patients.Trial Registration Number: IRCT20200927048848N3.

Effects of myeloid immune cells on the metabolic process of biomimetic bone regeneration

AIMS

As the process of bone regeneration is preceded by an inflammatory response, the immune system has long been considered important for fracture healing. Despite many studies on the contribution of immune cells to bone-related diseases, the role of immune cells in the regeneration therapy of lost bone is not well understood. In addition, various types of cells are involved in the clinical bone regeneration environment, but most of the osteo-biology studies are conducted in an osteoblast-only environment.

MATERIALS AND METHODS

Here, we investigated the effects of macrophages and dendritic cells on osteogenic differentiation in a co-culture environment involving human periosteal cell-derived osteoblasts, human monocyte-derived osteoclasts, and myeloid-derived cells. In addition, the cluster of myeloid immune cells involved in the clinical bone regeneration process was analyzed through bone defect rat modeling.

KEY FINDINGS

We found that specific types of myeloid cells and related cytokines increased osteogenic differentiation. These results were confirmed in experiments using myeloid cells originating from human primitive peripheral blood mononuclear cells and by measuring the colonization of macrophages and dendritic cells in an in vivo bone defect environment. In addition, Next generation sequencing (NGS) analysis was performed through RNA sequencing for osteogenesis caused by macrophages and dendritic cells in vitro, which implemented a clinical bone regeneration environment. The results of these experiments suggest that the role of M2 macrophages or dendritic cells is markedly increased during osteogenic differentiation. Therefore, we propose that the exchange of bioactive factors between macrophages and dendritic cells during the bone formation metabolic process is a crucial step of tissue regeneration rather than limited to the initial inflammatory response.

SIGNIFICANCE

This study indicates that M2 macrophages, among myeloid cells, can be mediators that play a vital role in the effective bone regeneration process and shows the potential as a useful next-generation advanced cell therapy for bone regeneration treatment.

Crosstalk between cholesterol metabolism and psoriatic inflammation

Psoriasis is a chronic autoinflammatory skin disease associated with multiple comorbidities, with a prevalence ranging from 2 to 3% in the general population. Decades of preclinical and clinical studies have revealed that alterations in cholesterol and lipid metabolism are strongly associated with psoriasis. Cytokines (tumor necrosis factor-α (TNF-α), interleukin (IL)-17), which are important in the pathogenesis of psoriasis, have been shown to affect cholesterol and lipid metabolism. Cholesterol metabolites and metabolic enzymes, on the other hand, influence not only the biofunction of keratinocytes (a primary type of cell in the epidermis) in psoriasis, but also the immune response and inflammation. However, the relationship between cholesterol metabolism and psoriasis has not been thoroughly reviewed. This review mainly focuses on cholesterol metabolism disturbances in psoriasis and their crosstalk with psoriatic inflammation.

A Bio-Therapeutically Squalene

Although the skin tissue on our bodies is a well-organized structure with high biomechanical properties like tensile strength and friction, we have all experienced various types of wounds throughout our lives owing to numerous etiological factors. In the general population, it is a substantial source of morbidity. For instance, in the case of burnt skin tissue, self-healing is in fact a large and challenging barrier to tissue regeneration. Squalene is a bioactive triterpene that occurs naturally and plays a key role in the process of making sterols. The most well-known source of squalene is shark liver oil. Vegetable oils may contain squalene in a range of concentrations. They have been extracted using a variety of techniques, including supercritical carbon dioxide, microwave, ultrasonic, cold press, and traditional Soxhlet extractions. In vitro and in animal models, these substances have been demonstrated to have anticancer, antioxidant, drug carrier, detoxifier, skin moisturising, and emollient effects.

Comparative Metabolic Study of Tamarindus indica L.'s Various Organs Based on GC/MS Analysis, In Silico and In Vitro Anti-Inflammatory and Wound Healing Activities

The chemical composition of the n-hexane extract of Tamarindus indica's various organs-bark, leaves, seeds, and fruits (TIB, TIL, TIS, TIF)-was investigated using gas chromatography-mass spectrometry (GC/MS) analysis. A total of 113 metabolites were identified, accounting for 93.07, 83.17, 84.05, and 85.08 % of the total identified components in TIB, TIL, TIS, and TIF, respectively. Lupeol was the most predominant component in TIB and TIL, accounting for 23.61 and 22.78%, respectively. However, n-Docosanoic acid (10.49%) and methyl tricosanoate (7.09%) were present in a high percentage in TIS. However, α-terpinyl acetate (7.36%) and α-muurolene (7.52%) were the major components of TIF n-hexane extract. By applying a principal component analysis (PCA) and hierarchal cluster analysis (HCA) to GC/MS-based metabolites, a clear differentiation of Tamarindus indica organs was achieved. The anti-inflammatory activity was evaluated in vitro on lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. In addition, the wound healing potential for the n-hexane extract of various plant organs was assessed using the in-vitro wound scratch assay using Human Skin Fibroblast cells. The tested extracts showed considerable anti-inflammatory and wound-healing activities. At a concentration of 10 µg/mL, TIL showed the highest nitric oxide (NO) inhibition by 53.97 ± 5.89%. Regarding the wound healing potential, after 24 h, TIB, TIL, TIS, and TIF n-hexane extracts at 10 g/mL reduced the wound width to 1.09 ± 0.04, 1.12 ± 0.18, 1.09 ± 0.28, and 1.41 ± 0.35 mm, respectively, as compared to the control cells (1.37 ± 0.15 mm). These findings showed that the n-hexane extract of T. indica enhanced wound healing by promoting fibroblast migration. Additionally, a docking study was conducted to assess the major identified phytoconstituents' affinity for binding to glycogen synthase kinase 3-β (GSK3-β), matrix metalloproteinases-8 (MMP-8), and nitric oxide synthase (iNOS). Lupeol showed the most favourable binding affinity to GSK3-β and iNOS, equal to -12.5 and -13.7 Kcal/mol, respectively, while methyl tricosanoate showed the highest binding affinity with MMP-8 equal to -13.1 Kcal/mol. Accordingly, the n-hexane extract of T. indica's various organs can be considered a good candidate for the management of wound healing and inflammatory conditions.

Liposomes Loaded with Amaranth Unsaponifiable Matter and Soybean Lunasin Prevented Melanoma Tumor Development Overexpressing Caspase-3 in an In Vivo Model

The objective of this study was to assess the effectiveness of liposomes loaded with soybean lunasin and amaranth unsaponifiable matter (UM + LunLip) as a source of squalene in the prevention of melanoma skin cancer in an allograft mice model. Tumors were induced by transplanting melanoma B16-F10 cells into the mice. The most effective treatments were those including UM + LunLip, with no difference between the lunasin concentrations (15 or 30 mg/kg body weight); however, these treatments were statistically different from the tumor-bearing untreated control (G3) (p < 0.05). The groups treated with topical application showed significant inhibition (68%, p < 0.05) compared to G3. The groups treated with subcutaneous injections showed significant inhibition (up to 99%, p < 0.05) in G3. During tumor development, UM + LunLip treatments under-expressed Ki-67 (0.2-fold compared to G3), glycogen synthase kinase-3β (0.1-fold compared to G3), and overexpressed caspase-3 (30-fold compared to G3). In addition, larger tumors showed larger necrotic areas (38% with respect to the total tumor) (p < 0.0001). In conclusion, the UM + LunLip treatment was effective when applied either subcutaneously or topically in the melanoma tumor-developing groups, as it slowed down cell proliferation and activated apoptosis.

Effect of Olive Pomace Oil on Cardiovascular Health and Associated Pathologies

Background: olive pomace oil (OPO) is a nutritionally relevant fat due to its high oleic acid content (C18:1) and the presence of a wide range of minor bioactive components. Although numerous in vitro and preclinical studies have been developed to study some of its characteristic components, the health effect of prolonged OPO consumption is unknown. Methods: a randomised, blinded, cross-over, controlled clinical trial was carried out in 31 normocholesterolemic and 37 hypercholesterolemic subjects. Participants consumed 45 g/day of OPO or sunflower oil (SO) for 4 weeks, each preceded by a 3-week run-in/wash-out phase with corn oil (CO). Results: regular consumption of OPO and SO had no statistically significant effect on any of the markers related to lipid profile, blood pressure, and endothelial function in both groups, except for eNOS levels, which were close to statistical significance due to the effect of oil (OPO and SO) (p = 0.083). A decrease in visceral fat (p = 0.028) in both groups was observed after OPO intake, accompanied by an increment of leptin (p = 0.017) in the hypercholesterolemic group. Conclusion: reducing visceral fat after prolonged OPO intake might contribute to improve cardiometabolic status, with a potentially positive effect on the vascular tone. Further clinical trials are needed to confirm the present results.

Liposomes Containing Amaranth Unsaponifiable Matter and Soybean Lunasin Suppress ROS Production in Fibroblasts and Reduced Interleukin Production in Macrophages

Inflammation is a normal response in defense to agents that may cause damage to the human body. When inflammation becomes chronic, reactive oxygen species (ROS) are produced; which could lead to diseases such as cancer. The aim was to assess liposomes' antioxidant and anti-inflammatory capacity loaded with amaranth unsaponifiable matter and soybean lunasin (UM + LunLip) in an in vitro model using fibroblasts and macrophages. To evaluate ROS production, fibroblasts CHON-002 ABAP were added to promote ROS production; and the cells were treated with UM + LunLip. For inflammation markers production, lipopolysaccharides (LPS)-stimulated RAW 264.7 and peritoneal macrophages were treated with empty liposomes (EmLip), liposomes loaded with unsaponifiable matter (UMLip), liposomes loaded with lunasin (LunLip), and UM + LunLip. ROS production was significantly decreased by 77% (p < 0.05) when fibroblasts were treated with UM + LunLip at 2 mg lunasin/mL compared with the control treated with ABAP. Treatment with UMLip was the most effective in reducing tumor necrosis factor-α (71-90%) and interleukin-6 (43-55%, p < 0.001). Both liposomes containing unsaponifiable matter (UMLip and UM + LunLip) were more effective than EmLip or LunLip. In conclusion, amaranth unsaponifiable matter-loaded liposomes are effective in decreasing pro-inflammatory cytokine production.

Evaluation of in vitro and in silico anti-inflammatory potential of some selected medicinal plants of Bangladesh against cyclooxygenase-II enzyme

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants are sources of chemical treasures that can be used in treatment of different diseases, including inflammatory disorders. Traditionally, Heritiera littoralis, Ceriops decandra, Ligustrum sinense, and Polyscias scutellaria are used to treat pain, hepatitis, breast inflammation. The present research was designed to explore phytochemicals from the ethanol extracts of H. littoralis, C. decandra, L. sinense, and P. scutellaria to discern the possible pharmacophore (s) in the treatment of inflammatory disorders.

MATERIAL AND METHODS

The chemical compounds of experimental plants were identified through GC-MS analysis. Furthermore, in-vitro anti-inflammatory activity was assessed in human erythrocytes and an in-silico study was appraised against COX-2.

RESULTS

The experimental extracts totally revealed 77 compounds in GC-MS analysis and all the extracts showed anti-inflammatory activity in in-vitro assays. The most favorable phytochemicals as anti-inflammatory agents were selected via ADMET profiling and molecular docking with specific protein of the COX-2 enzyme. Molecular dynamics simulation (MDS) confirmed the stability of the selected natural compound at the binding site of the protein. Three phytochemicals exhibited the better competitive result than the conventional anti-inflammatory drug naproxen in molecular docking and MDS studies.

CONCLUSION

Both experimental and computational studies have scientifically revealed the folklore uses of the experimental medicinal plants in inflammatory disorders. Overall, N-(2-hydroxycyclohexyl)-4-methylbenzenesulfonamide (PubChem CID: 575170); Benzeneethanamine, 2-fluoro-. beta., 3, 4-trihydroxy-N-isopropyl (PubChem CID: 547892); and 3,5-di-tert-butylphenol (PubChem CID: 70825) could be the potential leads for COX-2 inhibitor for further evaluation of drug-likeliness.

Synergistic Effect of Squalene and Hydroxytyrosol on Highly Invasive MDA-MB-231 Breast Cancer Cells

Several studies relate Mediterranean diet and virgin olive oil (VOO) intake with lower risk of several chronic diseases, including breast cancer. Many of them described antitumor properties of isolated minor compounds present in VOO, but beneficial properties of VOO arise from the effects of all its compounds acting together. The aim of the present study was to test the antitumor effects of two minor compounds from VOO (hydroxytyrosol (HT) and squalene (SQ)) on highly metastatic human breast tumor cells (MDA-MB-231) when acting in combination. Both isolated compounds were previously analyzed without showing any antitumoral effect on highly invasive MDA-MB-231 breast cancer cells, but the present results show that HT at 100 µM, combined with different concentrations of SQ, could exert antitumor effects. When they are combined, HT and SQ are able to inhibit cell proliferation, promoting apoptosis and DNA damage in metastatic breast cancer cells. Therefore, our results suggest that the health-promoting properties of VOO may be due, at least in part, to the combined action of these two minor compounds.

Evaluating the efficacy of extracted squalene from seed oil in the form of microemulsion for the treatment of COVID-19: A clinical study

This study investigates the effect of the nanostructure of squalene in the form of microemulsion on COVID‐19 patients. In this blinded clinical trial, a comparison was made between the efficacy of squalene treatment and controls. A total of 30 COVID‐19 patients admitted to the emergency department, and the infection ward was equally allocated to case (n = 15) and control (n = 15) groups according to their age and underlying diseases. The baseline characteristics of subjects, including age, gender, time of treatment onset, underlying condition, white blood cells count, and lymphocyte count were similar (p < 0.05). Baseline laboratory tests and computed tomography (CT) scans were performed for the study groups. The treatment group received 5 mg of intravenous squalene twice a day and standard treatment for 6 days, while controls received only standard treatment. After 6 days of treatment, clinical and CT scan changes were evaluated and compared in intervention and control groups. The need for oxygen therapy (p = 0.020), 2 days of no fever (p = 0.025), cough alleviation (p = 0.010), and lung high‐resolution computed tomography improvement (p = 0.033) were significantly different between cases and controls within 7 days of admission. No adverse effects were observed in the treatment group. Our data suggest that squalene could be considered as a potential treatment for COVID‐19, and further studies are required to confirm the results.

The Next-Generation of Combination Cancer Immunotherapy: Epigenetic Immunomodulators Transmogrify Immune Training to Enhance Immunotherapy

Cancer immunotherapy harnesses the immune system by targeting tumor cells that express antigens recognized by immune system cells, thus leading to tumor rejection. These tumor-associated antigens include tumor-specific shared antigens, differentiation antigens, protein products of mutated genes and rearrangements unique to tumor cells, overexpressed tissue-specific antigens, and exogenous viral proteins. However, the development of effective therapeutic approaches has proven difficult, mainly because these tumor antigens are shielded, and cells primarily express self-derived antigens. Despite innovative and notable advances in immunotherapy, challenges associated with variable patient response rates and efficacy on select tumors minimize the overall effectiveness of immunotherapy. Variations observed in response rates to immunotherapy are due to multiple factors, including adaptative resistance, competency, and a diversity of individual immune systems, including cancer stem cells in the tumor microenvironment, composition of the gut microbiota, and broad limitations of current immunotherapeutic approaches. New approaches are positioned to improve the immune response and increase the efficacy of immunotherapies, highlighting the challenges that the current global COVID-19 pandemic places on the present state of immunotherapy.

Antibacterial and Anti-Inflammatory Potential of Polyherbal Formulation Used in Chronic Wound Healing

Objective

Polyherbal formulations Jathyadi Thailam and Jatyadi Ghritam (JT) are used in Indian traditional medicine for diabetic chronic wounds, fistula, fissure, eczema, and burn management. We aimed to investigate the antibacterial and anti-inflammatory properties of crude hexane and ethanol extracts of JT formulations.

Methods

Antibacterial activity of JT extracts was tested to estimate minimum inhibitory concentrations (MICs) against nine reference bacterial strains, including one methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) Pseudomonas aeruginosa, and clinical strains of methicillin-susceptible S.aureus (MSSA), all involved in diabetic foot infection. The anti-inflammatory activity of plant extracts was evaluated in LPS-treated macrophage cells by measuring the mRNA levels and secretion of inflammatory mediators.

Results

The antibacterial activity of JT extracts was higher against Gram (+) bacteria, with the MICs varying from 1.95 to 62.5 mg/mL. Gram (−) bacteria were only susceptible to ethanol extracts of JT. Plant extracts were found to be the most active against the reference and clinical strains of MSSA, MRSA, and biofilm-forming S. epidermidis. JT extracts efficiently inhibited in a dose-dependent manner the mRNA expression and protein secretion of proinflammatory cytokines IL-6 and IL-1β, and chemokines MCP-1 and CXCL10 in LPS-challenged macrophages.

Conclusion

In the present study, we have shown that extracts of JT formulations possess potent antibacterial and anti-inflammatory properties that could be involved in chronic wound healing activity and has the potential to be used as external add-on therapy in the management of multidrug-resistant bacterial infections at the wound.

Targeting the tumor immune microenvironment with "nutraceuticals": From bench to clinical trials

The occurrence of immune effector cells in the tissue microenvironment during neoplastic progression is critical in determining tumor growth outcomes. On the other hand, tumors may also avoid immune system-mediated elimination by recruiting immunosuppressive leukocytes and soluble factors, which coordinate a tumor microenvironment that counteracts the efficiency of the antitumor immune response. Checkpoint inhibitor therapy results have indicated a way forward via activation of the immune system against cancer. Widespread evidence has shown that different compounds in foods, when administered as purified substances, can act as immunomodulators in humans and animals. Although there is no universally accepted definition of nutraceuticals, the term identifies a wide category of natural compounds that may impact health and disease statuses and includes purified substances from natural sources, plant extracts, dietary supplements, vitamins, phytonutrients, and various products with combinations of functional ingredients. In this review, we summarize the current knowledge on the immunomodulatory effects of nutraceuticals with a special focus on the cancer microenvironment, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of nutraceuticals for envisioning future therapies employing nutraceuticals as chemoadjuvants.

Electrospun anti-inflammatory patch loaded with essential oils for wound healing

Wound healing is a complex process that consists of three overlapping phases: inflammation, proliferation, and remodeling. A bacterial infection can increase inflammation and delay this process. Microorganisms are closely related to the innate immune system, such as macrophages and neutrophils, as they can start an inflammatory cascade. Essential oils play an important role in the inhibition and prevention of bacterial growth due to their ability to reduce antimicrobial resistance. The possibility to find a strategy that combines antimicrobial and anti-inflammatory properties is particularly appealing for wound healing. In this work, we showcase a variety of patches based on electrospun polycaprolactone (PCL) nanofibers loaded with natural compounds derived from essential oils, such as thymol (THY) and tyrosol (TYR), to achieve reduced inflammation. In addition, we compared the effect these essential oils have on activated macrophages when incorporated into the PCL patch. Specifically, we demonstrate that PCL-THY resulted in more efficient down-regulation of pro-inflammatory genes related to the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κb) pathway when compared to PCL-TYR and the combination patch containing TYR and THY (i.e., PCL-TYR-THY). Furthermore, PCL-THY displayed low affinity for cell attachment, which may hinder wound adherence and integration. Overall, our results indicate that THY-loaded patches could serve as promising candidates for the fabrication of dressings that incorporate bactericidal and anti-inflammatory properties while simultaneously avoiding the limitations of traditional antibiotic-loaded devices.

Engineering Strategies in Microorganisms for the Enhanced Production of Squalene: Advances, Challenges and Opportunities

The triterpene squalene is a natural compound that has demonstrated an extraordinary diversity of uses in pharmaceutical, nutraceutical, and personal care industries. Emboldened by this range of uses, novel applications that can gain profit from the benefits of squalene as an additive or supplement are expanding, resulting in its increasing demand. Ever since its discovery, the primary source has been the deep-sea shark liver, although recent declines in their populations and justified animal conservation and protection regulations have encouraged researchers to identify a novel route for squalene biosynthesis. This renewed scientific interest has profited from immense developments in synthetic biology, which now allows fine-tuning of a wider range of plants, fungi, and microorganisms for improved squalene production. There are numerous naturally squalene producing species and strains; although they generally do not make commercially viable yields as primary shark liver sources can deliver. The recent advances made toward improving squalene output from natural and engineered species have inspired this review. Accordingly, it will cover in-depth knowledge offered by the studies of the natural sources, and various engineering-based strategies that have been used to drive the improvements in the pathways toward large-scale production. The wide uses of squalene are also discussed, including the notable developments in anti-cancer applications and in augmenting influenza vaccines for greater efficacy.