Aqueous solubility and degradation kinetics of the phytochemical anticancer thymoquinone; probing the effects of solvents, pH and light

Effect of Crosslinking Agents on Chitosan Hydrogel Carriers for Drug Loading and Release for Targeted Drug Delivery

Numerous studies report on chitosan hydrogels in different forms, such as films, porous structures, nanoparticles, and microspheres, for biomedical applications; however, this study concentrates on their modifications with different crosslinking agents and observes their effects on drug loading and releasing capacities. Linear chitosan, along with chitosans crosslinked with two major crosslinkers, i.e., genipin and disulfide, are used to formulate three different hydrogel systems. The crosslinking process is heavily impacted by temperature and pH conditions. Three different drugs, i.e., thymoquinone, gefitinib, and erlotinib, are loaded to the hydrogels in de-ionized water solutions and released in phosphate-buffered solutions; thus, a total of nine combinations are studied and analyzed for their drug loading and releasing capabilities with ultraviolet-visible (UV-Vis) spectroscopy. This study finds that thymoquinone shows the lowest loading efficacy compared to the two other drugs in all three systems. Gefitinib shows stable loading and releasing regardless of crosslinking system, and the genipin-crosslinked system shows stable loading and releasing with all three drug molecules. These experimental results agree well with the findings of our previously published results conducted with molecular dynamics simulations.

Thymoquinone alleviates cisplatin-induced kidney damage by reducing apoptosis in a rat model

Purpose

The aim of the study was to compare the ameliorating effects of thymoquinone at various dosages on cisplatin-induced renal toxicity, and to investigate its effects on cisplatin-induced nephrocyte apoptosis via the mitochondrial pathway in a rat model.

Methods

A rat model of cisplatin-induced renal damage was established, with thymoquinone treatment groups (receiving 1, 3, 5, 10, or 20 mg/kg of thymoquinone). We determined serum creatinine (Cr) and blood urea nitrogen (BUN), measured the expression of the anti-apoptotic protein Bcl-2, the pro-apoptotic protein Bax, caspase-3, kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) in renal tissue. Additionally, we observed pathological changes in renal tissue and performed paller score for renal tubule injury.

Results

Relative to the control, the cisplatin group exhibited significantly elevated Bax, caspase-3, NGAL and KIM-1 expression, elevated serum Cr and BUN concentrations and significantly reduced Bcl-2 expression (P < 0.05). Histopathological examination of cisplatin-treated group revealed vacuolar degeneration, tubular epithelial cell swelling, and an absence of brush margins on renal tubules. Paller score was significantly elevated in the cisplatin group relative to the normal control group. Thymoquinone dose-dependently ameliorated these effects.

Conclusion

Thymoquinone at 1-20 mg/kg improved cisplatin-induced renal dysfunction in rats. This protective effect is related to the inhibition of mitochondria-mediated apoptosis.

HPLC method for the determination of thymoquinone in growth cell medium

BACKGROUND

Preclinical drug testing requires in vitro and in vivo assessments that are vital for studying drug pharmacokinetics and toxicity. Distinct factors that play an important role in drug screening, such as hydrophobicity, solubility of the substance and serum protein binding can be challenging by inducing result inconsistencies. Hence, establishing accurate methods to quantify drug concentrations in cell cultures becomes pivotal for reliable and reproducible results important for in vivo dosing predictions.

OBJECTIVE

This research focuses on developing an optimized analytical approach via high-pressure liquid chromatography (HPLC) to determine thymoquinone (TQ) levels in monolayer cell cultures.

METHODS

The method's validation adheres to the International Council for Harmonisation (ICH) guideline M10, ensuring its acceptance and applicability. Using an HPLC system with a Diode Array Detector (DAD), the study fine-tuned various parameters to achieve an efficient separation of TQ. Validation covered specificity, sensitivity, matrix effects, linearity, precision, and accuracy, alongside assessing TQ stability in RPMI-1640 medium.

RESULTS

The HPLC method exhibited remarkable TQ specificity, free from interfering peaks at the analyte retention. Sensitivity analysis at the lower limit of quantification (LLOQ) revealed 5.68% %CV and 98.37% % mean accuracy. Matrix effect evaluation showcased accuracy within 85-115%. Linearity spanned in the concentration range of 2-10 μM with a correlation coefficient (r2) of 0.9993. Precision and accuracy were aligned with acceptance criteria. The proposed method was found to be greener in terms of usage of persistent, bioaccumulative, and toxic chemicals and solvents, corrosive samples, and waste production.

CONCLUSION

The developed HPLC-DAD method emerges as specific, accurate, sensitive, and reliable for TQ determination in cell cultures. It ensures robust TQ quantification, enhancing precise in vitro assessments and dependable dosing predictions for in vivo studies. Further research is advocated to investigate TQ's stability across diverse environmental conditions.

Thymoquinone: A Promising Therapeutic Agent for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and is responsible for approximately one million deaths each year. The current standard of care is surgical resection of the lesion and chemotherapy with 5-fluorouracil (5-FU). However, of concern is the increasing incidence in an increasingly younger patient population and the ability of CRC cells to develop resistance to 5-FU. In this review, we discuss the effects of thymoquinone (TQ), one of the main bioactive components of Nigella sativa seeds, on CRC, with a particular focus on the use of TQ in combination therapy with other chemotherapeutic agents. TQ exhibits anti-CRC activity by inducing a proapoptotic effect and inhibiting proliferation, primarily through its effect on the regulation of signaling pathways crucial for tumor progression and oxidative stress. TQ can be used synergistically with chemotherapeutic agents to enhance their anticancer effects and to influence the expression of signaling pathways and other genes important in cancer development. These data appear to be most relevant for co-treatment with 5-FU. We believe that TQ is a suitable candidate for consideration in the chemoprevention and adjuvant therapy for CRC, but further studies, including clinical trials, are needed to confirm its safety and efficacy in the treatment of cancer.

Solid lipid nanoparticles of lutein with improved dissolution behavior and oral absorption

The present study aimed to develop solid lipid nanoparticles of lutein (SLN/LT) with improved dissolution behavior and oral absorption. SLN/LT were prepared by a flash nanoprecipitation method using a multi-inlet vortex mixer, and their physicochemical, photochemical, and pharmacokinetic properties were evaluated. The mean particle size of SLN/LT re-dispersed in water was 237 nm, and small spherical particles with no significant aggregation were observed. LT significantly generated singlet oxygen upon exposure to pseudo-sunlight (250 W/m2, 1 h), suggesting its high photoreactivity. The remaining LT in LT solution, crystalline LT, and SLN/LT after irradiation with pseudo-sunlight (250 W/m2, 2 h) were 56.3, 86.7, and 101%, respectively. SLN/LT showed improved dissolution behavior of LT in simulated intestinal fluid, and the dissolved amounts of LT at 2 h were at least 50 times higher than that of crystalline LT. Orally administered SLN/LT (100 mg-LT/kg) exhibited enhanced oral absorption of LT, as evidenced by a relative bioavailability of 3.7 to crystalline LT in rats. SLN/LT may be a promising dosage form for orally available LT supplements, possibly leading to enhanced nutritional functions of LT.

Effects of roasting and ultrasound-assisted enzymatic treatment of Nigella sativa L. seeds on thymoquinone in the oil and antioxidant activity of defatted seed meal

BACKGROUND

Black cumin seeds (black seed; BS) contain various bioactive compounds, such as thymoquinone (TQ). Roasting and ultrasound-assisted enzymatic treatment (UAET) as pre-treatments can increase the phytochemical content in the BS oil. This study aimed to investigate the effects of pre-treatments on the TQ content and the yield of the BS oil and to profile the composition of defatted BS meal (DBSM), followed by evaluating antioxidant properties of the DBSM.

RESULTS

The extraction yield of crude oil from BS was not affected by the roasting time. The highest extraction yield (47.8 ± 0.4%) was obtained with UAET cellulase-pH 5 (enzyme concentration of 100%). Roasting decreased the TQ content of the oil, while the UAET cellulase-pH 5 treatment with an enzyme concentration of 100% yielded the highest TQ (125.1 ± 2.7 μg mL-1 ). Additionally, the UAET cellulase-pH 5 treatment increased total phenolics and flavonoids of DBSM by approximately two-fold, compared to roasting or ultrasound treatment (UT) alone. Principal component analysis revealed that the UAET method might be more suitable for extracting BS oil with higher TQ content than roasting and UT.

CONCLUSION

Compared to roasting or UT, using ultrasound along with cellulase could improve the oil yield and TQ in the oil from BS and obtain the DBSM with higher phenolics, flavonoids, and antioxidant activity. © 2023 Society of Chemical Industry.

Thymoquinone-loaded lipid nanocapsules with promising anticancer activity for colorectal cancer

Colorectal cancer (CRC) is the third most common worldwide. Depending on its stage, chemotherapy is usually given after surgery when CRC has already metastasized to other organs like the liver or lungs. Unfortunately, the current antineoplastics used for CRC therapies involve toxicity and side effects due to their lack of site-specificity. To overcome the drawbacks of heavy chemotherapy, this study proposes to assess the efficacy of thymoquinone (TQ), a bioactive constituent of black seeds (Nigella sativa), as an antiproliferative and pro-apoptotic agent on an experimental CRC model in mice. TQ was encapsulated in lipid nanocapsules (LNCs), used as nanocarriers, in order to increase its specificity and cell absorption. TQ-loaded LNCs (TQ-LNCs) have a diameter of 58.3 ± 3.7 nm and 87.7 ± 4.5% TQ encapsulation efficiency. In turn, in vivo studies showed that the intratumoral administration of TQ-LNCs decreased the tumor size in colorectal cancer bearing mice compared to the control group. TQ-LNCs were more effective than free TQ for inducing tumor cell death. These results highlight the potential of TQ entrapped in LNCs as an anticancer agent for CRC treatment.

Mechanism of the antidiabetic action of Nigella sativa and Thymoquinone: a review

Introduction

Long used in traditional medicine, Nigella sativa (NS; Ranunculaceae) has shown significant efficacy as an adjuvant therapy for diabetes mellitus (DM) management by improving glucose tolerance, decreasing hepatic gluconeogenesis, normalizing blood sugar and lipid imbalance, and stimulating insulin secretion from pancreatic cells. In this review, the pharmacological and pharmacokinetic properties of NS as a herbal diabetes medication are examined in depth, demonstrating how it counteracts oxidative stress and the onset and progression of DM.

Methods

This literature review drew on databases such as Google Scholar and PubMed and various gray literature sources using search terms like the etiology of diabetes, conventional versus herbal therapy, subclinical pharmacology, pharmacokinetics, physiology, behavior, and clinical outcomes.

Results

The efficiency and safety of NS in diabetes, notably its thymoquinone (TQ) rich volatile oil, have drawn great attention from researchers in recent years; the specific therapeutic dose has eluded determination so far. TQ has anti-diabetic, anti-inflammatory, antioxidant, and immunomodulatory properties but has not proved druggable. DM's intimate link with oxidative stress, makes NS therapy relevant since it is a potent antioxidant that energizes the cell's endogenous arsenal of antioxidant enzymes. NS attenuates insulin resistance, enhances insulin signaling, suppresses cyclooxygenase-2, upregulates insulin-like growth factor-1, and prevents endothelial dysfunction in DM.

Conclusion

The interaction of NS with mainstream drugs, gut microbiota, and probiotics opens new possibilities for innovative therapies. Despite its strong potential to treat DM, NS and TQ must be examined in more inclusive clinical studies targeting underrepresented patient populations.

Co-administration of Thymoquinone and Propolis in Liposomal Formulations as a Potential Approach for Treatment of Acetic Acid-Induced Ulcerative Colitis: Physiological and Histopathological Analysis

A severe form of autoimmune-mediated inflammatory bowel disease (IBD) is termed as ulcerative colitis (UC) which ultimately results in significant mucosal damage and ulceration. Herbal remedies may be employed as an alternative for treatment of UC instead of conventional medications such as Sulfasalazine. Promising natural remedies for the treatment of IBD, including colitis, are propolis extract (PP) and thymoquinone (TQ). This study is aimed at assessing the potential of liposomal formulations of TQ and Egyptian PP in combination therapy on improving their therapeutic efficacy against ulcerative colitis in order to maximize the potential of their beneficial clinical effects. Clinical, biochemical, and histological evaluations of colonic mucosal damage and inflammation were evaluated. The results exhibited a significant increase in tissue MDA, TNFα, and nitrite levels with activation of caspase-3 in the acetic acid-induced colitis group, which is predominantly downregulated in the treatment groups. The prepared formulations of TQ and PP revealed liposomal vesicles in a nanoscale size (192 ± 20.3 and 98.2 ± 20.3 nm, respectively) and accepted stability indicated with a zeta potential of 19.3 ± 0.11 and 17.1 ± 0.25 mV, respectively. They showed an entrapment efficiency of 85.3 ± 12.6% and 69.3 ± 11.8%, respectively. At comparable doses, combination therapy with thymoquinone liposomes and propolis liposomes considerably outperformed free TQ and free PP in reducing inflammation of UC as shown in the present study by clinical, biochemical, and histological evaluations.

Anticancer activity of thymoquinone against breast cancer cells: Mechanisms of action and delivery approaches

The rising incidence of breast cancer has been a significant source of concern in the medical community. Regarding the adverse effects and consequences of current treatments, cancers' health, and socio-economical aspects have become more complicated, leaving research aimed at improved or new treatments on top priority. Medicinal herbs contain multitarget compounds that can control cancer development and advancement. Owing to Nigella Sativa's elements, it can treat many disorders. Thymoquinone (TQ) is a natural chemical derived from the black seeds of Nigella sativa Linn proved to have anti-cancer and anti-inflammatory properties. TQ interferes in a broad spectrum of tumorigenic procedures and inhibits carcinogenesis, malignant development, invasion, migration, and angiogenesis owing to its multitargeting ability. It effectively facilitates miR-34a up-regulation, regulates the p53-dependent pathway, and suppresses Rac1 expression. TQ promotes apoptosis and controls the expression of pro- and anti-apoptotic genes. It has also been shown to diminish the phosphorylation of NF-B and IKK and decrease the metastasis and ERK1/2 and PI3K activity. We discuss TQ's cytotoxic effects for breast cancer treatment with a deep look at the relevant stimulatory or inhibitory signaling pathways. This review discusses the various forms of polymeric and non-polymeric nanocarriers (NC) and the encapsulation of TQ for increasing oral bioavailability and enhanced in vitro and in vivo efficacy of TQ-combined treatment with different chemotherapeutic agents against various breast cancer cell lines. This study can be useful to a broad scientific community, comprising pharmaceutical and biological scientists, as well as clinical investigators.

Characterization of Thymoquinone-Sulfobutylether-β-Cyclodextrin Inclusion Complex for Anticancer Applications

Thymoquinone (TQ) is a quinone derived from the black seed Nigella sativa and has been extensively studied in pharmaceutical and nutraceutical research due to its therapeutic potential and pharmacological properties. Although the chemopreventive and potential anticancer effects of TQ have been reported, its limited solubility and poor delivery remain the major limitations. In this study, we aimed to characterize the inclusion complexes of TQ with Sulfobutylether-β-cyclodextrin (SBE-β-CD) at four different temperatures (293-318 K). Additionally, we compared the antiproliferative activity of TQ alone to TQ complexed with SBE-β-CD on six different cancer cell lines, including colon, breast, and liver cancer cells (HCT-116, HT-29, MDA-MB-231, MCF-7, SK-BR-3, and HepG2), using an MTT assay. We calculated the thermodynamic parameters (ΔH, ΔS, and ΔG) using the van't Holf equation. The inclusion complexes were characterized by X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), and molecular dynamics using the PM6 model. Our findings revealed that the solubility of TQ was improved by ≥60 folds, allowing TQ to penetrate completely into the cavity of SBE-β-CD. The IC₅₀ values of TQ/SBE-β-CD ranged from 0.1 ± 0.01 µg/mL against SK-BR-3 human breast cancer cells to 1.2 ± 0.16 µg/mL against HCT-116 human colorectal cancer cells, depending on the cell line. In comparison, the IC₅₀ values of TQ alone ranged from 0.2 ± 0.01 µg/mL to 4.7 ± 0.21 µg/mL. Overall, our results suggest that SBE-β-CD can enhance the anticancer effect of TQ by increasing its solubility and bioavailability and cellular uptake. However, further studies are necessary to fully understand the underlying mechanisms and potential side effects of using SBE-β-CD as a drug delivery system for TQ.

Antioxidant and anticancer potential of ethyl acetate extract of bark and flower of Tecoma stans (Linn) and In Silico studies on phytoligands against Bcl2 and VEGFR2 factors

This study was designed to appraise the antioxidant and anticancer competence of solvent extracts of Tecoma stans (Linn) and analyze the phytoligands interaction against Bcl2 VEGFR2 through in silico studies. The phytochemical analysis revealed that the ethyl acetate extract contains more number of pharmaceutically valuable phytochemicals than other solvent extracts. Among the various phytochemicals, flavonoid was found as a predominant component, and UV-Vis- spectrophotometer analysis initially confirmed it. Hence, the column chromatogram was performed to purify the flavonoid, and High-performance liquid chromatography (HPLC) was performed. It revealed that the flavonoid enriched fraction by compared with standard flavonoid molecules. About 84.69% and 80.43% of antioxidant activity were found from ethyl acetate extract of bark and flower at the dosage of 80 μg mL^-1 with the IC₅₀ value of 47.24 and 43.40 μg mL^-1, respectively. In a dose-dependent mode, the ethyl acetate extract of bark and flower showed cytotoxicity against breast cancer cell line MCF 7 (Michigan Cancer Foundation-7) as up to 81.38% and 80.94% of cytotoxicity respectively. Furthermore, the IC₅₀ was found as 208.507 μg mL^-1 and 207.38 μg mL^-1 for bark and flower extract correspondingly. About 10 medicinal valued flavonoid components were identified from bark (6) and flower (4) ethyl acetate extract through LC-MS analysis. Out of 10 components, the 3,5-O-dicaffeoylquinic acid (ΔG -8.8) and Isorhamnetin-3-O-rutinoside (ΔG -8.3) had the competence to interact with Bcl2 (B-Cell Lymphoma 2) and VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) respectively with more energy. Hence, these results confirm that the ethyl acetate extract of bark and flower of T. stans has significant medicinal potential and could be used as antioxidant and anticancer agent after some animal performance study.

The anti-leukemic activity of a luteolin-apigenin enriched fraction from an edible and ethnomedicinal plant, Elsholtzia stachyodes, is exerted through an ER stress/autophagy/cell cycle arrest/ apoptotic cell death signaling axis

BACKGROUND

Elsholtzia is a genus in the family Lamiaceae, and some species in this genus are commonly used for food and in ethnomedicinal formulations by some ethnic groups of China and Thailand. Despite their apparent utility, few studies have been conducted to evaluate their potential as sources of medicinally active agents.

PURPOSE

We aimed to investigate the cytotoxicity of ethanolic extracts from three selected edible plant species of the genus Elsholtzia and the most promising extract was further characterized for the bioactive constituents and signaling mechanisms associated with the anti-leukemic activity.

MATERIALS AND METHODS

Ethanolic extracts were screened for cytotoxicity using flow cytometry. HPLC and LC-MS were used to analyze the chemical constituents of the most potent fraction from E. stachyodes. The relevant mechanism of action was assessed by western blot and multispectral imaging flow cytometry (MIFC).

RESULTS

The most potent anti-leukemic activity was observed with the ethanolic extract from E. stachyodes. Luteolin and apigenin were characterized as the major constituents in the fraction from E. stachyodes. Mechanistically, the luteolin-apigenin enriched fraction (LAEF) induced the UPR, increased autophagic flux, induced cell cycle arrest and apoptotic cell death. LAEF showed significantly less cytotoxicity towards peripheral blood mononuclear cells (PBMCs) as compared to leukemia cell lines.

CONCLUSION

This study is the first to report E. stachyodes as a new source of luteolin and apigenin which are capable of triggering leukemic cell death. This could lead to a novel strategy against leukemia using ethnomedicinal plant extracts as an alternative or supplemental anti-cancer agent.

Evaluation of Conventional and Hyaluronic Acid-Coated Thymoquinone Liposomes in an In Vitro Model of Dry Eye

Dry eye disease (DED) is a common ocular disorder characterized by an inadequate lubrication of the eye by tears leading to inflammation and the alteration of the ocular surface. Current treatments are often limited due to their side effects and ineffectiveness. Thymoquinone (TQ) is a natural compound present in the essential oil of Nigella sativa L., with anti-inflammatory and antioxidant activities. In this study, conventional and hyaluronic acid-coated liposomes were developed to improve TQ activity at ocular level. In the present study, the cytoprotective effects of TQ or TQ liposomes were assessed against oxidative and inflammatory processes in human corneal epithelial cells (HCE-2). Hyperosmolarity conditions (450 mOsm) were used as a model of DED. Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and tumor necrosis factor (TNFα) were quantified by quantitative real-time polymerase chain reaction (RT-qPCR); COX-2 and Phospho-NF-κB p65 (p-p65) by Western blotting (WB). Moreover, the mitochondrial reactive oxygen species (mtROS) levels were measured by MitoSOX assay. The hyperosmotic treatment induced a significant increase of the proinflammatory genes and proteins expression that were significantly decreased in the liposomes-treated cells. The coincubation with hyaluronic acid-coated liposomes significantly reverted the increase of mtROS production, evidently stimulated by the hyperosmotic stress. Our data suggest that TQ-loaded liposomes have potential as a therapeutic agent in dry eye disease, improving the TQ efficacy.

In Vitro and In Vivo Investigation of a Dual-Targeted Nanoemulsion Gel for the Amelioration of Psoriasis

Psoriasis, due to its unique pathological manifestations and the limited success of existing therapeutic modalities, demands dedicated domain research. Our group has developed nanotherapeutics consisting of bioactives such as Thymoquinone (TQ) and Fulvic acid (FA), which have been successfully incorporated into a Nanoemulsion gel (NEG), taking kalonji oil as oil phase. The composition is aimed at ameliorating psoriasis with better therapeutic outcomes. TQ is a natural bio-active that has been linked to anti-psoriatic actions. FA has anti-inflammatory actions due to its free radical and oxidant-scavenging activity. Our previous publication reports the formulation development of the NEG, where we overcame the pharmaco-technical limitations of combining the above two natural bioactives. In vitro evaluation of the optimized NEG was carried out, which showed an enhanced dissolution rate and skin permeation of TQ. This work furthers the pharmaceutical progression of dual-targeted synergistic NEG to treat psoriasis. A suitable animal model, BALB/c mice, has been used to conduct the in vivo studies, which revealed the effective anti-psoriatic action of TQ. Molecular docking studies corroborated the results and revealed a good binding affinity for both the targets of TNF-α (Tumor necrosis factor) and IL-6 (Interlukin-6). Tissue uptake by Confocal laser scanning microscopy (CLSM), a skin interaction study of the gel formulation, and an antioxidant free radical scavenging assay (1-1 Diphenyl-2-picrylhydrazyl DPPH) were also carried out. It was concluded that the NEG may be effective in treating psoriasis with minimal side effects.

COVID-19 and Thymoquinone: Clinical Benefits, Cure, and Challenges

In today’s world, the outbreak of the coronavirus disease 2019 (COVID-19) has spread throughout the world, causing severe acute respiratory syndrome (SARS) and several associated complications in various organs (heart, liver, kidney, and gastrointestinal tract), as well as significant multiple organ dysfunction, shock, and even death. In order to overcome the serious complications associated with this pandemic virus and to prevent SARS-CoV-2 entry into the host cell, it is necessary to repurpose currently available drugs with a broad medicinal application as soon as they become available. There are several therapeutics under investigation for improving the overall prognosis of COVID-19 patients, but none of them has demonstrated clinical efficacy to date, which is disappointing. It is in this pattern that Nigella sativa seeds manifest their extensive therapeutic effects, which have been reported to be particularly effective in the treatment of skin diseases, jaundice, and gastrointestinal problems. One important component of these seeds is thymoquinone (TQ), which has a wide range of beneficial properties, including antioxidant and anti-inflammatory properties, as well as antibacterial and parasitic properties, in addition to anticarcinogenic, antiallergic, and antiviral properties. This comprehensive review discussed the possibility of an emerging natural drug with a wide range of medical applications; the use of TQ to overcome the complications of COVID-19 infection; and the challenges that are impeding the commercialization of this promising phytochemical compound. TQ is recommended as a highly effective weapon in the fight against the novel coronavirus because of its dual antiviral action, in addition to its capacity to lessen the possibility of SARS-CoV-2 penetration into cells. However, future clinical trials are required to confirm the role of TQ in overcoming the complications of COVID-19 infection.

Advances in research on the relationship between thymoquinone and pancreatic cancer

Pancreatic cancer has one of the worst prognoses among the most common cancers in the world. Its characteristics include a high rate of metastasis and chemotherapeutic resistance, which present major challenges to the medical community. The potential anticancer effects of thymoquinone (TQ), which is the main bioactive compound of the black seeds of the Nigella sativa plant, have recently received widespread attention for their potential use in treating pancreatic cancer. TQ can inhibit cell proliferation, promote cancer cell apoptosis, inhibit cell invasion and metastasis, enhance chemotherapeutic sensitivity, inhibit angiogenesis, and exert anti-inflammatory effects. These anticancer effects predominantly involve the nuclear factor (NF)-κB, phosphoinositide 3 kinase (PI3K)/Akt, Notch, transforming growth factor (TGF)-β, c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) signaling pathways as well as the regulation of the cell cycle, matrix metallopeptidase (MMP)-9 expression, and pyruvate kinase isozyme type M2 (PKM2) activity. TQ regulates the occurrence and development of pancreatic cancer at multiple levels and through multiple targets that communicate with each other. In this review, we summarize and discuss the analogs and carriers of TQ that have been developed in recent years. Given its multilevel anticancer effects, TQ may become a new therapeutic drug for treating pancreatic cancer in the future. This review presents a brief introduction to the research that has been conducted on TQ in relation to pancreatic cancer to provide a theoretical basis for future studies on the topic.

Self-nanoemulsifying drug delivery system (SNEDDS) mediated improved oral bioavailability of thymoquinone: optimization, characterization, pharmacokinetic, and hepatotoxicity studies

Thymoquinone (TQ) is an antioxidant, anti-inflammatory, and hepatoprotective compound obtained from the black seed oil of Nigella sativa. However, high hydrophobicity, instability at higher pH levels, photosensitivity, and low oral bioavailability hinder its delivery to the target tissues. A self-nanoemulsifying drug delivery system (SNEDDS) was fabricated using the microemulsification technique to address these issues. Its physicochemical properties, thermodynamic stability studies, drug release kinetics, in vivo pharmacokinetics, and hepatoprotective activity were evaluated. The droplet size was in the nano-range (< 90 nm). Zeta potential was measured to be -11.35 mV, signifying the high stability of the oil droplets. In vivo pharmacokinetic evaluation showed a fourfold increase in the bioavailability of TQ-SNEDDS over pure TQ. Furthermore, in a PCM-induced animal model, TQ-SNEDDS demonstrated significant (p < 0.05) hepatoprotective activity compared to pure TQ and silymarin. Reduction in liver biomarker enzymes and histopathological examinations of liver sections further supported the results. In this study, SNEDDS was demonstrated to be an improved oral delivery method for TQ, since it potentiates hepatotoxicity and enhances bioavailability.

Oleic acid-based vesicular nanocarriers for topical delivery of the natural drug thymoquinone: Improvement of anti-inflammatory activity

The topical administration of a drug compound remains the first choice for the treatment of many local skin ailments. Many skin diseases can be treated by applying the active formulation directly to the skin, but unfortunately some drugs are unable to overcome the stratum corneum and exert their pharmacological action. An example is thymoquinone, a naturally derived drug obtained from Nigella sativa L. and potentially effective in the treatment of inflammatory and oxidative skin conditions. Since its physico-chemical properties are not suitable for overcoming the stratum corneum, we wanted to circumvent the problem by proposing new lipid-based nanovesicles called "oleoethosomes", made up of naturally derived ingredients, for its delivery. Among several formulations of oleoethosomes, the sample made up of 2% (w/w) oleic acid:PL90G 1:1 (molar ratio), and ethanol 15% showed the best physico-chemical characteristics and above all it showed the capacity to contain a suitable amount of thymoquinone (2 mg/ml). The formulation was tested in vitro on stratum corneum and viable epidermis membranes confirming its ability to induce the passage of thymoquinone through the human stratum corneum and to act as a permeation enhancer. In fact, it showed thymoquinone permeation values of 22.63 ± 1.49% regarding the applied drug amount. Oleoethosomes were compared with oleosomes, another kind of naturally derived nanosystems but free of ethanol. The experimental data confirmed that ethanol was an important component that enhanced the activity of the oleoethosomes when tested on the skin of healthy volunteers. The thymoquinone-loaded oleoethosome treatment demonstrated a significantly greater extent of anti-inflammatory activity than the treatment with thymoquinone-loaded oleosomes or the conventional dosage form of the drug. These in vivo results confirmed the synergic effect between oleic acid and ethanol on the lipid and protein compartments of the outermost skin layer, thus promoting a greater penetration capacity.

Nanogels as Potential Delivery Vehicles in Improving the Therapeutic Efficacy of Phytopharmaceuticals

Nanogel is a promising drug delivery approach to improve the pharmacokinetics and pharmacodynamic prospect of phytopharmaceuticals. In the present review, phytopharmaceuticals with astonishing therapeutic utilities are being explored. However, their in vivo delivery is challenging, owing to poor biopharmaceutical attributes that impact their drug release profile, skin penetration, and the reach of optimal therapeutic concentrations to the target site. Nanogel and its advanced version in the form of nanoemulgel (oil-in-water nanoemulsion integrated gel matrix) offer better therapeutic prospects than other conventional counterparts for improving the biopharmaceutical attributes and thus therapeutic efficacy of phytopharmaceuticals. Nanoemulgel-loaded phytopharmaceuticals could substantially improve permeation behavior across skin barriers, subsequently enhancing the delivery and therapeutic effectiveness of the bioactive compound. Furthermore, the thixotropic characteristics of polymeric hydrogel utilized in the fabrication of nanogel/nanoemulgel-based drug delivery systems have also imparted improvements in the biopharmaceutical attributes of loaded phytopharmaceuticals. This formulation approach is about to be rife in the coming decades. Thus, the current review throws light on the recent studies demonstrating the role of nanogels in enhancing the delivery of bioactive compounds for treating various disease conditions and the challenges faced in their clinical translation.

Therapeutic significance of thymoquinone-loaded chitosan nanoparticles on streptozotocin/nicotinamide-induced diabetic rats: In vitro and in vivo functional analysis

To overcome the low bioavailability of lipophilic free thymoquinone (TQ), this study aims to evaluate a novel oral formula of TQ-loaded chitosan nanoparticles (TQ-CsNPs) for the effective treatment of diabetes. The XRD, FTIR, FESEM, HRTEM, and dynamic light scattering were all conducted on the prepared formula. The release pattern of TQ, cytotoxicity against MRC-5 cell line (human lung fibroblast cells), and antidiabetic activity on streptozotocin/nicotinamide (STZ/NA) rat model of diabetes were investigated. The results confirmed the formation of TQ-CsNPs with an entrapment efficiency of 75.7 ± 6.52 %, a mean Zetasizer distribution of 84.25 nm, and an average particle size of about 50 nm. After 24 h, the percentage of free TQ-cumulative release was approximately 35.8 %, whereas TQ-CsNPs showed a sustained release pattern of 78.5 %. The investigated formula was not toxic to normal lung cells, and more efficient in ameliorating the altered glycemia, dyslipidemia, inflammation, and oxidative stress induced by STZ/NA than free TQ, blank CsNPs, and metformin-HCl (as a reference drug). Additionally, TQ-CsNPs restored the normal pancreatic islets' configuration and morphometry, suggesting a potent insulinotropic action. In conclusion, the antidiabetic efficacy of TQ was improved by engaging TQ with CsNPs as an excellent nanoplatform to enhance the oral bioavailability of TQ.

Co-delivery of gentiopicroside and thymoquinone using electrospun m-PEG/PVP nanofibers: In-vitro and In vivo studies for antibacterial wound dressing in diabetic rats

Nanofibers (NFs) provide several delivery advantages like their great flexibility and similarity with extracellular matrix (ECM) which qualify them to be the unique model of a wound dressing. NFs could create mats of polymeric matrix loaded with an active agent enhancing its solubility and stability. In our study, Gentiopicroside (GPS) and Thymoquinone (TQ) loaded in NFs polymeric mats composed of coblended polyvinyl pyrrolidine (PVP) and methyl ether Polyethylene glycol (m-PEG) were fabricated via electrospinning technique. A morphological study using Scanning Electron Microscopy (SEM) was performed for all formulae as well as in vitro release study using High-performance Liquid chromatography (HPLC) for sample analysis. The optimized formula (F3) was chosen for further assays using Fourier-Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC). Study of the antibacterial effect, and in vivo healing action for diabetic infected wounds to quantify Tumor necrosis factor-alpha and Cyclooxygenase-2 were also investigated. F3 achieved the highest % cumulative release (99.79 ± 6.47 for GPS and 96.89 ± 6.87 for TQ) at 60 min, and a smaller diameter (200 nm) showing significant anti-bacterial effects with well-organized skin architecture demonstrating great healing signs. Our results revealed that m-PEG/PVP NFs mats loaded with GPS and TQ could be considered an optimal wound care dressing.

Therapeutic implications and clinical manifestations of thymoquinone

Thymoquinone (TQ), a natural phytochemical predominantly found in Nigella sativa, has been investigated for its numerous health benefits. TQ showed anti-cancer, anti-oxidant, and anti-inflammatory properties, validated in various disease models. The anti-cancer potential of TQ is goverened by anti-proliferation, cell cycle arrest, apoptosis induction, ROS production, anti-metastasis and anti-angiogenesis, inhibition of cell migration and invasion action. Additionally, TQ exhibited antitumor activity via the modulation of multiple pathways and molecular targets, including Akt, ERK1/2, STAT3, and NF-κB. The present review highlighted the anticancer potential of TQ . We summarize the anti-cancer, anti-oxidant, and anti-inflammatory properties of TQ, focusing on its molecular targets and its promising action in cancer therapy. We further described the molecular mechanisms by which TQ prevents signaling pathways that mediate cancer progression, invasion, and metastasis.

Non-Volatile and Volatile Bioactives of Salvia officinalis L., Thymus serpyllum L. and Laurus nobilis L. Extracts with Potential Use in the Development of Functional Beverages

Functional beverages based on herbal extracts are highly demanded products due to the presence of bioactives with promising health benefits and interesting and characteristic sensory properties. Mediterranean medicinal and aromatic herbs contain a wide range of bioactives (non-volatile polyphenols, volatile terpenes) that are important constituents of herbal extracts and essential oils. The antioxidant capacity and potential health benefits of these bioactives could be associated with their synergistic effects. Therefore, this study aimed to characterize the non-volatile and volatile bioactives of sage (Salvia officinalis L.), wild thyme (Thymus serpyllum L.) and laurel (Laurus nobilis L.) aqueous extracts and their two- and three-component mixtures as well as their antioxidant capacity. The content of total phenols, flavonoids, hydroxycinnamic acids and flavonols was determined spectrophotometrically. Individual polyphenols were analyzed by LC-MS/MS, the volatiles were analyzed by HS-SPME/GC-MS, and the antioxidant capacity was analyzed by ORAC and DPPH assays. The results showed that aqueous extracts of all examined herbs and their mixtures contained a high content of phenolic compounds ranging from 0.97 to 2.79 g L^-1 of the sample, among which the most common were flavonols. At the same time, mono- and sesquiterpenes were the main volatiles. All extracts showed high antioxidant capacity, especially L. nobilis (781.62 ± 5.19 μmol TE mL^-1 of the sample in the DPPH assay; 1896.10 ± 8.77 μmol TE mL^-1 of the sample in the ORAC assay) and the two-component mixture of L. nobilis and T. serpyllum (679.12 ± 5.19 μmol TE mL^-1 in the DPPH assay; 1913.38 ± 8.77 μmol TE mL^-1 in the ORAC assay). Mixtures of herbal extracts have been shown to possess additive or synergistic effects, consequently contributing to higher antioxidant capacity. Therefore, two-component mixtures of herbal extracts showed promising potential for the production of functional beverages.

An Overview of the Neuropharmacological Potential of Thymoquinone and its Targeted Delivery Prospects for CNS Disorder

At present, people and patients worldwide are relying on the medicinal plant as a therapeutic agent over pharmaceuticals because the medicinal plant is considered safer, especially for chronic disorders. Several medicinal plants and their components are being researched and explored for their possible therapeutic contribution to CNS disorders. Thymoquinone (TQ) is one such molecule. Thymoquinone, one of the constituents of Plant Nigella Sativa, is effective against several neurodegenerative diseases like; Alzheimer's, Depression, Encephalomyelitis, Epilepsy, Ischemia, Parkinson's, and Traumatic. This review article presents the neuropharmacological potential of TQ's, their challenges, and delivery prospects, explicitly focusing on neurological disorders along with their chemistry, pharmacokinetics, and toxicity. Since TQ has some pharmacokinetic challenges, scientists have focused on novel formulations and delivery systems to enhance bioavailability and ultimately increase its therapeutic value. In the present work, the role of nanotechnology in neurodegenerative disease and how it improves bioavailability and delivery of a drug to the site of action has been discussed. There are a few limitations for developing novel drug formulation, including solubility, pH, and compatibility of nanomaterials. Since here we are targeting CNS disorders, the blood-brain barrier (BBB) becomes an additional challenge Hence, the review summarized the novel aspects of delivery and biocompatible nanoparticles-based approaches for targeted drug delivery into CNS, enhancing TQ bioavailability and its neurotherapeutic effects.

Box-Behnken Design (BBD) Application for Optimization of Chromatographic Conditions in RP-HPLC Method Development for the Estimation of Thymoquinone in Nigella sativa Seed Powder

Thymoquinone (THY) is a bioactive compound present in the seed powder of Nigella sativa (NS). This research aims to precisely and accurately estimate THY using high-performance liquid chromatography (HPLC) with a Quality by Design (QbD) application. Box-Behnken design (BBD) was employed to optimize the chromatographic conditions for HPLC method development, taking mobile phase flow rate, pH of the buffer, and λmax as independent variables and retention time and tailing factor as the measured responses. The mobile phase composition was methanol: acetonitrile: buffer (2.2 mM ammonium formate) at the ratio of 35:50:15 v/v/v on a Symmetry® C18 (5 μm, 3.9 × 150 mm) column. In isocratic mode, it had a flow rate 0.9 mL min−1 and eluted analyte was detected at 249 nm. Validation parameters followed the International Council for Harmonization (ICH) guidelines for the new HPLC method. The method was linear over the range 6.25–100 µg mL−1 with a coefficient of determination (r2) of 0.9957. The limit of detection (LOD) and limit of quantification (LOQ) were 2.05 and 6.25 µg mL−1, respectively. The %RSD of system suitability for retention time was 1.42% and for the tailing factor it was 0.695%. In addition, the developed method was precise, accurate, and robust according to ICH criteria. The developed HPLC method is simple, accurate, quick, and robust, and it could be used for the routine analysis of THY in different kinds of formulations.

GSH Protects the Escherichia coli Cells from High Concentrations of Thymoquinone

The aim of the present study was to evaluate the potential protective effect of glutathione (GSH) on Escherichia coli cells grown in a high concentration of thymoquinone (TQ). This quinone, as the main active compound of Nigella sativa seed oil, exhibits a wide range of biological activities. At low concentrations, it acts as an antioxidant, and at high concentrations, an antimicrobial agent. Therefore, any interactions between thymoquinone and glutathione are crucial for cellular defense against oxidative stress. In this study, we found that GSH can conjugate with thymoquinone and its derivatives in vitro, and only fivefold excess of GSH was sufficient to completely deplete TQ and its derivatives. We also carried out studies on cultures of GSH-deficient Escherichia coli strains grown on a minimal medium in the presence of different concentrations of TQ. The strains harboring mutations in gene ΔgshA and ΔgshB were about two- and fourfold more sensitive (256 and 128 µg/mL, respectively) than the wild type. It was also revealed that TQ concentration has an influence on reactive oxygen species (ROS) production in E. coli strains—at the same thymoquinone concentration, the level of ROS was higher in GSH-deficient E. coli strains than in wild type.

Experimental and Theoretical Insights on Chemopreventive Effect of the Liposomal Thymoquinone Against Benzo[a]pyrene-Induced Lung Cancer in Swiss Albino Mice

Purpose

Thymoquinone (TQ), a phytoconstituent of Nigella sativa seeds, has been studied extensively in various cancer models. However, TQ’s limited water solubility restricts its therapeutic applicability. Our work aims to prepare the novel formulation of TQ and assess its chemopreventive potential in chemically induced lung cancer animal model.

Methods

The polyethylene glycol coated DOPE/CHEMS incorporating TQ-loaded pH-sensitive liposomes (TQPSL) were prepared and characterized. Mice were exposed to benzo[a]pyrene (BaP) thrice a week for 4 weeks to induce lung cancer. TQPSL was administered three times a week for 21 weeks, starting 2 weeks before the first dose of BaP.

Results

The prepared TQPSL revealed 85% entrapment efficiency with 128 nm size and −19.5 mv ζ-potential showing high stability of the formulation. The pretreatment of TQPSL showed the recovery in BaP-modulated relative organ weight of lungs, cancer marker enzymes, and antioxidant enzymes in the serum. The histopathological analysis of the tissues showed that TQPSL protected the malignancy in the lungs. The flow cytometry data revealed the induction of apoptosis and decreased intracellular ROS by TQPSL. Molecular docking was performed to predict the TQ’s affinity for eight possible anticancer drug targets linked to lung cancer etiology. The data assisted to identify the serine/threonine-protein kinase BRAF as the most suitable target of TQ with binding energy −6.8 kcal/mol.

Conclusion

The current findings demonstrated the potential of TQPSL and its possible therapeutic targets of lung cancer. To our knowledge, this is the first research to outline the development of TQ formulation against lung cancer considering its low solubility as well as pulmonary delivery challenges.

Preparation, characterization, and biological activity study of thymoquinone-cucurbit[7]uril inclusion complex

In this study, the formation of a host–guest inclusion complex between cucurbit[7]uril (CB[7]) and thymoquinone (TQ) was investigated in aqueous solution. The formation of a stable inclusion complex, CB[7]–TQ, was confirmed by using different techniques, such as ¹H NMR and UV-visible spectroscopy. The aqueous solubility of TQ was clearly enhanced upon the addition of CB[7], which provided an initial indication for supramolecular complexation. The complexation stoichiometry and the binding constant of the inclusion complex were determined through a combination of two sets of titration methods, including UV-visible and fluorescence displacement titrations. Both methods suggested the formation of a 1 : 1 stoichiometry between CB[7] and TQ with moderate binding affinity of 3 × 10³ M⁻¹. Density functional theory (DFT) calculations were also performed to verify the structure of the resulted host–guest complex and to support the complexation stoichiometry. The theoretical calculations were in agreement with experimental results obtained by ¹H NMR spectroscopy. Most importantly, the cytotoxic effect of the CB[7]–TQ complex was investigated against cancer and normal cell lines. The results showed that the anticancer activity of TQ against MDA-MB-231 cells was enhanced by the complexation with CB[7], while no significant effect was observed in MCF-7 cells. The results also confirmed the low toxicity of the CB[7] host molecule that supports the use of CB[7] as a drug carrier.

The host–guest inclusion complexation of thymoquinone by cucurbit[7]uril in aqueous solution is established, which results in an enhanced biological activity.

Safety, Stability, and Therapeutic Efficacy of Long-Circulating TQ-Incorporated Liposomes: Implication in the Treatment of Lung Cancer

Thymoquinone (TQ), which is one of the main bioactive constituents of Nigella sativa seeds, has demonstrated its potential against various cancer models. The poor solubility of TQ in aqueous solution limits its uses in clinical application. The present study aimed to develop a novel formulation of TQ to increase its bioavailability and therapeutic potential with minimal toxicity. Polyethylene glycol (PEG)-coated DSPC/cholesterol comprising TQ liposomes (PEG-Lip-TQ) were prepared and characterized on various aspects. A computational investigation using molecular docking was used to assess the possible binding interactions of TQ with 12 prospective anticancer drug targets. The in vitro anticancer activity was assessed in A549 and H460 lung cancer cells in a time- and dose-dependent manner, while the oral acute toxicity assay was evaluated in silico as well as in vivo in mice. TQ docked to the Hsp90 target had the lowest binding energy of −6.05 kcal/mol, whereas caspase 3 was recognized as the least likely target for TQ with a binding energy of −1.19 kcal/mol. The results showed 96% EE with 120 nm size, and −10.85 mv, ζ-potential of PEG-Lip-TQ, respectively. The cell cytotoxicity data demonstrated high sensitivity of PEG-Lip-TQ and a several fold decrease in the IC₅₀ while comparing free TQ. The cell cycle analysis showed changes in the distribution of cells with doses. The in vivo data revealed an ~9-fold increase in the LD₅₀ of PEG-Lip-TQ on free TQ as an estimated 775 and 89.5 mg/kg b.w, respectively. This study indicates that the pharmacological and efficacy profile of PEG-lip-TQ is superior to free TQ, which will pave the way for an exploration of the effect of TQ formulation in the treatment of lung cancer in clinical settings.

Thymoquinone: A Review of Pharmacological Importance, Oxidative Stress, COVID-19, and Radiotherapy

Widely consumed worldwide, Nigella sativa (NS) is a medicinal herb commonly used in various alternative medicine systems such as Unani and Tibb, Ayurveda, and Siddha. Recommended for regular use in Tibb-e-Nabwi (Prophetic Medicine), NS is considered one of the most notable forms of healing medicine in Islamic literature. Thymoquinone (TQ), the main component of the essential oil of NS, has been reported to have many properties such as antioxidant, anti-inflammatory, antiviral, and antineoplastic. Its chemical structure indicates antiviral potential against many viruses, including the hepatitis C virus, human immunodeficiency virus, and other coronavirus diseases. Interestingly, molecular docking studies have demonstrated that TQ can potentially inhibit the development of the coronavirus disease 2019 (COVID-19) by binding to the receptor site on the transmembrane serine proteinase 2 (the activator enzyme that attaches the virus to the cell). In addition, TQ has been shown to be effective against cancer cells due to its inhibitory effect by binding to the different regions of MDM2, according to the proposed molecular docking study. Detailed in this review is the origin of TQ, its significance in alternative medicine, pharmacological value, potential as a cancer anti-proliferative agent, use against the coronavirus disease 2019 (COVID-19), and treatment of other diseases.

Evaluation of the increase of the thymoquinone permeability formulated in polymeric micelles: In vitro test and in vivo toxicity assessment in Zebrafish embryos

Thymoquinone (TQ) is a natural compound present in the essential oil and in the fixed oil of Nigella sativa L. Like many natural substances, it is characterized by poor aqueous solubility and low stability which limit its bioavailability. Soluplus®-Solutol® HS15 polymeric micelles (TQ-MP) were developed to increase the permeability of TQ with particular attention to overcoming intestinal barrier and the blood brain barrier, for possible oral and parenteral administration. The optimized micelles have dimensions < 100 nm and PdI < 0.2 indicating that the formulation was homogeneous as confirmed also by TEM experiments. EE% was 92.4 ± 0.3%. Stability studies showed a stable formulation following subsequent dilutions and in the gastric-intestinal media. In vitro studies have revealed that the carrier enhances the permeability of TQ in the intestine and in the blood-brain barrier using Parallel Artificial Membrane Permeability Assay (PAMPA) assay and cellular tests with Caco-2 cells and hCMEC/D3 monolayer cells. Up-take study, cell viability and cytotoxicity studies were also conducted. Fluorescent micelles (FITC-MP), were also optimized to perform in vitro up-take study in Caco-2 cells and to study their toxicity in Zebrafish model. The toxicity was evaluated on three lines of Zebrafish: wild type, transgenic line Tg(Myl7:EGFP) in which cardiomyocytes are marked with green fluorescence protein and Tg(flk1-GFP) line which expresses GFP under the control of the vascular endothelial growth factor receptor 2 (vegfr2) promoter.

Impacts of various mixing approaches towards black seed oil-alginate emulsion attributes

Black seed oil (BSO) contains thymoquinone, an active ingredient that is well-known for its antioxidant property. The bitter taste of BSO makes it challenging for the consumers, mainly children and the elderly, to consume it every day. Thus, BSO is encapsulated in alginate beads in micrometre size to enhance its palatability. This encapsulation was previously established in the lab-scale and the standard mixing method to produce a stable BSO-alginate emulsion used a magnetic stirrer coupled with a sonicator. This mixing method is not suitable for the production of BSO beads at a large scale. Hence, this research aims to investigate the impacts of various mixing methods coupled with sonication towards the BSO-alginate emulsion attributes. Four BSOalginate coarse emulsions were prepared using a magnetic stirrer (MS) as the benchmark, overhead stirrer (OS), homogeniser (H), and overhead stirrer combined with homogeniser (OSH). All the coarse emulsions were then sonicated to produce a nanoemulsion using a flow cell sonicator. The coarse emulsions were characterised in terms of dissolution time while the nanoemulsions were characterised in terms of droplet size, polydispersity index, zeta potential, conductivity and absorbance. These characteristics were statistically compared to the benchmark emulsion characteristics. MS, OS, H, and OSH coarse emulsion formation required 45, 230, 102, and 46 minutes to be produced, respectively. There were significant differences (p <0.05) between the droplet size of OSH (266.53±4.36) nm and MS (285.50±1.15) nm emulsions, indicating that the OSH emulsion was more stable. The absorbance of OSH BSO-alginate nanoemulsion was significantly lower (p <0.05) than the benchmark. In comparison to MS as the benchmark, OSH technique produced a stable emulsion in terms of lower dissolution time, droplet size, zeta potential, and absorbance.

Development and optimization of sitagliptin and dapagliflozin loaded oral self-nanoemulsifying formulation against type 2 diabetes mellitus

Control of hyperglycemia and prevention of glucose reabsorption (glucotoxicity) are important objectives in the management of type 2 diabetes. This study deals with an oral combined dosage form design for two anti-diabetic drugs, sitagliptin and dapagliflozin using self-nanoemulsifying drug delivery systems (SNEDDS). The SNEDDS were developed using naturally obtained bioactive medium-chain/long-chain triglycerides oil, mixed glycerides and nonionic surfactants, and droplet size was measured followed by the test for antioxidant activities. Equilibrium solubility and dynamic dispersion experiments were conducted to achieve the maximum drug loading. The in vitro digestion, in vivo bioavailability, and anti-diabetic effects were studied to compare the representative SNEDDS with marketed product Dapazin^®. The representative SNEDDS containing black seed oil showed excellent self-emulsification performance with transparent appearance. Characterization of the SNEDDS showed nanodroplets of around 50–66.57 nm in size (confirmed by TEM analysis), in addition to the high drug loading capacity without causing any precipitation in the gastro-intestinal tract. The SNEDDS provided higher antioxidant activity compared to the pure drugs. The in vivo pharmacokinetic parameters of SNEDDS showed significant increase in C_max (1.99 ± 0.21 µg mL⁻¹), AUC (17.94 ± 1.25 µg mL⁻¹), and oral absorption (2-fold) of dapagliflozin compared to the commercial product in the rat model. The anti-diabetic studies showed the significant inhibition of glucose level in treated diabetic mice by SNEDDS combined dose compared to the single drug therapy. The combined dose of sitagliptin-dapagliflozin using SNEDDS could be a potential oral pharmaceutical product for the improved treatment of type 2 diabetes mellitus.

Amelioration of polycystic ovary syndrome-related disorders by supplementation of thymoquinone and metformin

Background

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders of reproductive age women with a prevalence of 4-12%. The study aimed to investigate the potential benefit of adding thymoquinone to metformin in alleviating symptoms of polycystic ovarian syndrome. Two hundred seven overweight and obese PCOS patients were divided into two groups. Patients in group A received metformin 500 mg three times daily for 6 months. Patients in group B received a combination of metformin 500 mg and thymoquinone in the form of black cumin oil 500 mg capsules three times daily for 6 months. Follow-up was done after 3 and 6 months from the beginning of the study for evaluation of menstrual cycle pattern, body mass index, waist circumference, hip circumference, and waist:hip ratio, oral glucose tolerance test, glycosylated hemoglobin A1C, superoxide dismutase activity, and malondialdehyde concentration.

Results

Patients who received a combination of black cumin oil capsules and metformin, showed a significant decrease in number of patients suffering from amenorrhea or oligomenorrhea (P = 0.031), significant (P = 0.00) weight reduction (reduced BMI), and body fat redistribution (reduced W/H ratio), regaining oxidative balance with significant increase of SOD activity (P = 0.00) and decrease of MDA concentrations (P = 0.03). Regarding the number of prediabetic patients, there was no statistically significant difference (P = 0.89) when both groups were compared at the end of study period.

Conclusions

Black cumin oil supplementation constitutes a beneficial added value to metformin in ameliorating PCOS-related disorders with resumption of menstrual regularity, weight reduction, change of body fat distribution, and regaining oxidative balance.

Alleviation of prilocaine-induced epileptiform activity and cardiotoxicity by thymoquinone

PURPOSE

This study investigated whether thymoquinone (TQ) could alleviate central nervous system (CNS) and cardiovascular toxicity of prilocaine, a commonly used local anesthetic.

METHODS

Rats were randomized to the following groups: control, prilocaine treated, TQ treated and prilocaine + TQ treated. Electroencephalography and electrocardiography electrodes were placed and trachea was intubated. Mechanical ventilation was initiated, right femoral artery was cannulated for continuous blood pressure measurements and blood-gas sampling while the left femoral vein was cannulated for prilocaine infusion. Markers of myocardial injury, reactive oxygen/nitrogen species (ROS/RNS) generation and total antioxidant capacity (TAC) were assayed by standard kits. Aquaporin-4 (AQP4), nuclear factor(NF)κB-p65 and -p50 subunit in brain tissue were evaluated by histological scoring.

RESULTS

Blood pH and partial oxygen pressure, was significantly decreased after prilocaine infusion. The decrease in blood pH was alleviated in the prilocaine + TQ treated group. Prilocaine produced seizure activity, cardiac arrhythmia and asystole at significantly lower doses compared to prilocaine + TQ treated rats. Thymoquinone administration attenuated levels of myocardial injury induced by prilocaine. Prilocaine treatment caused increased ROS/RNS formation and decreased TAC in heart and brain tissue. Thymoquinone increased heart and brain TAC and decreased ROS/RNS formation in prilocaine treated rats. AQP4, NFκB-p65 and NFκB-p50 expressions were increased in cerebellum, cerebral cortex, choroid plexus and thalamic nucleus in prilocaine treated rats. Thymoquinone, decreased the expression of AQP4, NFκB-p65 and NFκB-p50 in brain tissue in prilocaine + TQ treated rats.

CONCLUSION

Results indicate that TQ could ameliorate prilocaine-induced CNS and cardiovascular toxicity.

Solubility Determination, Hansen Solubility Parameters and Thermodynamic Evaluation of Thymoquinone in (Isopropanol + Water) Compositions

This article studies the solubility, Hansen solubility parameters (HSPs), and thermodynamic behavior of a naturally-derived bioactive thymoquinone (TQ) in different binary combinations of isopropanol (IPA) and water (H₂O). The mole fraction solubilities (x₃) of TQ in various (IPA + H₂O) compositions are measured at 298.2–318.2 K and 0.1 MPa. The HSPs of TQ, neat IPA, neat H₂O, and binary (IPA + H₂O) compositions free of TQ are also determined. The x₃ data of TQ are regressed by van’t Hoff, Apelblat, Yalkowsky–Roseman, Buchowski–Ksiazczak λh, Jouyban–Acree, and Jouyban–Acree–van’t Hoff models. The maximum and minimum x₃ values of TQ are recorded in neat IPA (7.63 × 10⁻² at 318.2 K) and neat H₂O (8.25 × 10⁻⁵ at 298.2 K), respectively. The solubility of TQ is recorded as increasing with the rise in temperature and IPA mass fraction in all (IPA + H₂O) mixtures, including pure IPA and pure H₂O. The HSP of TQ is similar to that of pure IPA, suggesting the great potential of IPA in TQ solubilization. The maximum molecular solute-solvent interactions are found in TQ-IPA compared to TQ-H₂O. A thermodynamic study indicates an endothermic and entropy-driven dissolution of TQ in all (IPA + H₂O) mixtures, including pure IPA and pure H₂O.

Thymoquinone, as a Novel Therapeutic Candidate of Cancers

To date, natural products are widely used as pharmaceutical agents for many human diseases and cancers. One of the most popular natural products that have been studied for anticancer properties is thymoquinone (TQ). As a bioactive compound of Nigella sativa, TQ has shown anticancer activities through the inhibition of cell proliferation, migration, and invasion. The anticancer efficacy of TQ is being investigated in several human cancers such as pancreatic cancer, breast cancer, colon cancer, hepatic cancer, cervical cancer, and leukemia. Even though TQ induces apoptosis by regulating the expression of pro- apoptotic and anti-apoptotic genes in many cancers, the TQ effect mechanism on such cancers is not yet fully understood. Therefore, the present review has highlighted the TQ effect mechanisms on several signaling pathways and expression of tumor suppressor genes (TSG). Data from relevant published experimental articles on TQ from 2015 to June 2020 were selected by using Google Scholar and PubMed search engines. The present study investigated the effectiveness of TQ alone or in combination with other anticancer therapeutic agents, such as tyrosine kinase inhibitors on cancers, as a future anticancer therapy nominee by using nanotechnology.

Delivery of Natural Agents by Means of Mesoporous Silica Nanospheres as a Promising Anticancer Strategy

Natural prodrugs derived from different natural origins (e.g., medicinal plants, microbes, animals) have a long history in traditional medicine. They exhibit a broad range of pharmacological activities, including anticancer effects in vitro and in vivo. They have potential as safe, cost-effective treatments with few side effects, but are lacking in solubility, bioavailability, specific targeting and have short half-lives. These are barriers to clinical application. Nanomedicine has the potential to offer solutions to circumvent these limitations and allow the use of natural pro-drugs in cancer therapy. Mesoporous silica nanoparticles (MSNs) of various morphology have attracted considerable attention in the search for targeted drug delivery systems. MSNs are characterized by chemical stability, easy synthesis and functionalization, large surface area, tunable pore sizes and volumes, good biocompatibility, controlled drug release under different conditions, and high drug-loading capacity, enabling multifunctional purposes. In vivo pre-clinical evaluations, a significant majority of results indicate the safety profile of MSNs if they are synthesized in an optimized way. Here, we present an overview of synthesis methods, possible surface functionalization, cellular uptake, biodistribution, toxicity, loading strategies, delivery designs with controlled release, and cancer targeting and discuss the future of anticancer nanotechnology-based natural prodrug delivery systems.

Nigella sativa and Thymoquinone: A Natural Blessing for Periodontal Therapy

Thymoquinone (TQ), the chief active constituent of Nigella sativa (NS), shows very valuable biomedical properties such as antioxidant, antimicrobial, anticancer, anti-inflammatory, antihypertensive, hypoglycemic, antiparasitic and anti-asthmatic effects. Several studies have examined the pharmacological actions of TQ in the treatment of oral diseases but its potential role in periodontal therapy and regeneration is not yet fully defined. The present investigation has been designed to review the scientific studies about the effects of TQ as an adjunct to periodontal treatment to promote healing and periodontal regeneration. Along with clinical experiments, in vitro studies exhibit the beneficial effects of TQ during periodontal therapy. Nevertheless, additional comprehensive clinical and preclinical studies at cellular and molecular levels are essential to examine the particular action mechanisms of Nigella sativa and its elements, particularly TQ, during periodontal treatment or regeneration.

Formulation, Cellular Uptake and Cytotoxicity of Thymoquinone-Loaded PLGA Nanoparticles in Malignant Melanoma Cancer Cells

Introduction

Thymoquinone (TQ) is the main active compound extracted from Nigella sativa a traditional herb with wide therapeutic applications and recognizable anticancer properties. This study aimed to formulate and characterize TQ-nanoparticles using PLGA as a biocompatible coating material (TQ-PLGA NPs) with the evaluation of its therapeutic properties in human melanoma cancer cells.

Methods

The TQ-PLGA NPs were prepared and characterized for size, zeta potential, encapsulation efficiency, and release profile.

Results

The particle size was 147.2 nm, with 22.1 positive zeta potential and 96.8% encapsulation efficiency. The NPs released 45.6% of the encapsulated TQ within 3 h followed by characteristic sustained release over 7 days with a total of 69.7% cumulative release. TQ-PLGA NPs were taken up effectively by the cells in a time-dependent manner up to 24 h. Higher cell toxicity was determined within the first 24 h in melanoma cells due to the rapid release of TQ from the NPs and its low stability in the cell culture media.

Conclusion

TQ-PLGA NPs is a potential anticancer agent taking advantage of the sustained release and tailored size that allows accumulation in the cancer tissue by the enhanced permeability and retention effect. However, stability problems of the active ingredient were address in this study and requires further investigation.

Thymoquinone-Loaded Soluplus®-Solutol® HS15 Mixed Micelles: Preparation, In Vitro Characterization, and Effect on the SH-SY5Y Cell Migration

Thymoquinone (TQ) is the main active ingredient of Nigella sativa essential oil, with remarkable anti-neoplastic activities with anti-invasive and anti-migratory abilities on a variety of cancer cell lines. However, its poor water solubility, high instability in aqueous solution and pharmacokinetic drawbacks limits its use in therapy. Soluplus^® and Solutol^® HS15 were employed as amphiphilic polymers for developing polymeric micelles (SSM). Chemical and physical characterization studies of micelles are reported, in terms of size, homogeneity, zeta potential, critical micelle concentration (CMC), cloud point, encapsulation efficiency (EE%), load capacity (DL), in vitro release, and stability. This study reports for the first time the anti-migratory activity of TQ and TQ loaded in SSM (TQ-SSM) in the SH-SY5Y human neuroblastoma cell line. The inhibitory effect was assessed by the wound-healing assay and compared with that of the unformulated TQ. The optimal TQ-SSM were provided with small size (56.71 ± 1.41 nm) and spherical shape at ratio of 1:4 (Soluplus:Solutol HS15), thus increasing the solubility of about 10-fold in water. The entrapment efficiency and drug loading were 92.4 ± 1.6% and 4.68 ± 0.12, respectively, and the colloidal dispersion are stable during storage for a period of 40 days. The TQ-SSM were also lyophilized to obtain a more workable product and with increased stability. In vitro release study indicated a prolonged release of TQ. In conclusion, the formulation of TQ into SSM allows a bio-enhancement of TQ anti-migration activity, suggesting that TQ-SSM is a better candidate than unformulated TQ to inhibit human SH-SY5Y neuroblastoma cell migration.

An examination of carbopol hydrogel/organogel bigels of thymoquinone prepared by microwave irradiation method

Nigella sativa L. is shown wide spread over the world and contains many useful phytochemicals. Much of the biological activity of the seeds has been shown due to the presence of thymoquinone (TQ). Its poor aqueous solubility of TQ hinders its delivery to target site. The aim of this work was to prepare TQ bigels composed of Carbopol 974 P NF (C974) in PEG 400 (organogel) or C974 in water (hydrogel) with microwave heating method. A novel technique, high speed homogenization followed by microwave heating, was used to prepare organogels. The pH, electrical conductivity, differential scanning calorimetry, rheological properties, and morphological structure of the formulations have been evaluated, and the effect of microwave on drug content and TQ antioxidant activity has been investigated. The bigels of TQ were successfully produced via high-speed homogenization followed by microwave-assisted heating for the first time in this study. Highly lipophilic TQ was successfully dissolved in organogel, and it was not affected from the microwaves. It can be stated that microwave heating is a promising method to obtain C974 organogels and thus bigels with appropriate above indicated investigated physicochemical characteristics. The time and energy consumption could be decreased with microwave-assisted heating, especially for gel preparation in the field of pharmaceuticals.