Anticancer and Anti-Metastatic Role of Thymoquinone: Regulation of Oncogenic Signaling Cascades by Thymoquinone

Fabrication of Thymoquinone and Ascorbic Acid-Loaded Spanlastics Gel for Hyperpigmentation: In Vitro Release, Cytotoxicity, and Skin Permeation Studies

Background/Objectives: The demand for a safe compound for hyperpigmentation is continuously increasing. Bioactive compounds such as thymoquinone (TQ) and ascorbic acid (AA) induce inhibition of melanogenesis with a high safety profile. The aim of this study was to design and evaluate spanlastics gel loaded with bioactive agents, TQ and AA, for the management of hyperpigmentation. Methods: Several spanlastics formulations were successfully fabricated and characterized in terms of morphology, vesicle size, zeta potential, and release. Results: The optimized TQ-loaded spanlastic formulation showed an average size of 223.40 ± 3.50 nm, and 133.00 ± 2.80 nm for AA-loaded spanlastic formulation. The optimized spanlastics formulation showed the highest entrapment efficiency (EE%) of 97.18 ± 2.02% and 93.08 ± 1.95%, for TQ and AA, respectively. Additionally, the edge activator concentration had a significant effect (p < 0.05) on EE%; it was found that by increasing the amount of EA, the EE% increases. Following that, the optimal spanlastics fomulation loaded with TQ and AA were incorporated into gel and explored for appearance, pH, spreadability, stability, rheology, in vitro release, ex vivo permeation study, and MTT cytotoxicity. The formulated spanlastics gel (R-1) has a pH of 5.53. Additionally, R-1 gel was significantly (p < 0.05) more spreadable than control gel, and exhibited a shear thinning behavior. Most importantly, ex vivo skin deposition studies confirmed superior skin deposition of TQ and AA from spanlastic gels. Additionally, results indicated that tyrosinase inhibition was primarily due to TQ. When comparing TQ alone with the TQ-AA combination, inhibition ranged from 18.35 to 42.73% and 24.28 to 42.53%, respectively. Both TQ spanlastics and the TQ-AA combination showed a concentration-dependent inhibition of tyrosinase. Conclusions: Spanlastic gel might represent a promising carrier for the dermal delivery of TQ and AA for the management of hyperpigmentation conditions.

Phytochemical Targeting of Nerve Growth Factor by Thymoquinone and Cuscutin: A Molecular Dynamics Simulation Study

Background Nerve growth factor (NGF) is a novel target of pain therapeutics for oral cancer, and it plays a main role in the nociception of chronic pain. Surgery, along with chemotherapy or radiotherapy, is the gold standard for treating patients, but the side effects are significant as well. Newer effective interventions with natural phytochemicals could improve patient compliance and enhance the quality of life among patients with oral cancer. A literature search revealed a positive correlation between NGF and oral cancer pain. Nigella sativa (N. sativa) and Cuscuta reflexa (C. reflexa) have proven anticancer effects, but their activity with NGF is unexplored. Aims and objectives We aimed to identify the potential phytochemicals in N. sativa and C. reflexa. We also checked the NGF-blocking activity of the phytochemicals. Molecular docking and molecular dynamic (MD) simulations evaluated the binding energy and stability between the NGF protein and selected phytochemical ligands. Materials and methods We obtained protein NGF structure from UniProt (ID: 4EDX, P01138, Beta-nerve growth factor), ligand (thymoquinone) structure using PubChem ID: 10281, and ligand (cuscutin) structure using PubChem ID: 66065. Maestro protein (Schrödinger Inc., Mannheim, Germany) was used for molecular docking. Desmond Simulation Package (Schrödinger Inc., Mannheim, Germany) was used to model MD for 100 nanoseconds (ns). We have assessed the interaction between the protein and ligands by root mean square deviation (RMSD) values.  Results The interaction of thymoquinone and cuscutin with NGF was assessed. While interacting with thymoquinone, there was mild fluctuation from 0.6 Å to 2.5 Å up to 80 ns and ended up at 4.8 Å up to 100 ns. While interacting with cuscutin, mild fluctuation was seen from 0.8 Å to 4.8 Å till 90 ns and ended at 6.4 Å up to 100 ns. We found a stable interaction between our drug combination and the NGF receptor. Conclusion We have identified a stable interaction between thymoquinone, cuscutin, and NGF by our MD simulations. Hence, it could be used as an NGF inhibitor for pain relief and to control tumor progression. Further in vitro and in vivo evaluations of this novel drug combination with phytochemicals will help us understand their biological activities and potential clinical applications in oral cancer therapeutics.

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.

Gut microbiota: key facilitator in metastasis of colorectal cancer

Colorectal cancer (CRC) ranks third in terms of incidence among all kinds of cancer. The main cause of death is metastasis. Recent studies have shown that the gut microbiota could facilitate cancer metastasis by promoting cancer cells proliferation, invasion, dissemination, and survival. Multiple mechanisms have been implicated, such as RNA-mediated targeting effects, activation of tumor signaling cascades, secretion of microbiota-derived functional substances, regulation of mRNA methylation, facilitated immune evasion, increased intravasation of cancer cells, and remodeling of tumor microenvironment (TME). The understanding of CRC metastasis was further deepened by the mechanisms mentioned above. In this review, the mechanisms by which the gut microbiota participates in the process of CRC metastasis were reviewed as followed based on recent studies.

Tubulin degradation: Principles, agents, and applications

The microtubule system plays an important role in the mitosis and growth of eukaryotic cells, and it is considered as an appealing and highly successful molecular target for cancer treatment. In fact, microtubule targeting agents, such as paclitaxel and vinblastine, have been approved by FDA for tumor therapy, which have achieved significant therapeutic effects and sales performance. At present, microtubule targeting agents mainly include microtubule-destabilizing agents, microtubule-stabilizing agents, and a few tubulin degradation agents. Although there are few reports about tubulin degradation agents at present, tubulin degradation agents show great potential in overcoming multidrug resistance and reducing neurotoxicity. In addition, some natural drugs could specifically degrade tubulin in tumor cells, but have no effect in normal cells, thus showing a good biosafety profile. Therefore, tubulin degradation agents might exhibit a better application. Currently, some small molecules have been designed to promote tubulin degradation with potent antiproliferative activities, showing the potential for cancer treatment. In this work, we reviewed the reports on tubulin degradation, and focused on the degradation mechanism and important functional groups of chemically synthesized compounds, hoping to provide help for the degradation design of tubulin.