John M. Anticancer effects of thymoquinone in head and neck squamous cell carcinoma: A scoping review

Objective

Thymoquinone (TQ), the active constituent of Nigella sativa, has been shown to have anticancer effects in head and neck squamous cell carcinoma (HNSCC). This review aims to outline the properties of TQ, the known drivers in HNSCC formation, and summarize the anticancer effects of TQ in SCC.

Data Sources

Three databases (PubMed, Embase, and Google Scholar) were queried for the key words "thymoquinone squamous cell carcinoma."

Review Methods

Publications that were not original research and publications that did not have full-text available for review were excluded.

Results

Sixteen research articles met the inclusion criteria. Our review demonstrates that TQ-induced cytotoxicity is associated with increased expression and activity of the tumor suppressor p53, proapoptotic proteins Bax and caspases, as well as decreased expression and activity of antiapoptotic proteins Bcl-2 and Mdm2. Additionally, TQ modulates cell-survival pathways such as the PI3k/Akt pathway. TQ synergizes with therapeutics including cisplatin and radiation. Early TQ administration may prevent carcinogenesis via upregulation of antioxidant enzymes, and TQ administration in the presence of cancer can result in disease mitigation via induction of oxidative stress.

Conclusion

TQ acts as an upregulator of proapoptotic pathways and downregulator of antiapoptotic pathways, modulates the oxidative stress balance in tumor development, and works synergistically alongside other chemotherapeutics to increase cytotoxicity. TQ has the potential to prevent carcinogenesis in patients who are at high-risk for SCC and adjuvant treatment for SCC patients undergoing conventional treatments. Future studies should aim to identify specific populations in which TQ's effects would be the most beneficial.

Level of Evidence

Not available.

Herbal Honey Preparations of Curcuma Xanthorriza and Black Cumin Protect against Carcinogenesis through Antioxidant and Immunomodulatory Activities in Sprague Dawley (SD) Rats Induced with Dimethylbenz(a)anthracene

BACKGROUND

Traditionally, Curcuma xanthorriza (CX), black cumin seed (BC), and honey have been used by the Indonesian people as medicinal ingredients to treat various health symptoms. CX extracts and BC have been proven in the laboratory as chemopreventive agents, antioxidants, and immunomodulators. In this study, we developed CX extract, BC oil, and honey into herbal honey preparations (CXBCH) and hypothesized that the preparations show chemopreventive activity. The purpose of the study was to determine the CXBCH potential as chemopreventive, antioxidant, and immunomodulatory.

METHOD

In this experimental laboratory research, antioxidant, immunomodulatory, and cytotoxic activities were tested on human mammary cancer cell lines (T47D cells) while the chemopreventive activity of the CXBCH preparations on Sprague Dawley (SD) rats induced with dimethylbenzene(a)anthracene (DMBA).

RESULTS

CXBCH preparations demonstrated immunomodulatory, antioxidant, and cytotoxic activities in T47D, Hela, and HTB-183 cells and in DMBA-induced SD rats, as the preparations inhibited tumor nodule formation, increased the number of CD4, CD8 and CD4CD25 cells, and glutathione-S-transferase (GST) activity, and decreased serum NO levels.

CONCLUSIONS

CXBCH preparations display chemopreventive, antioxidant, and immunomodulatory properties.

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.

Nutritional Value and Preventive Role of Nigella sativa L. and Its Main Component Thymoquinone in Cancer: An Evidenced-Based Review of Preclinical and Clinical Studies

In recent times, scientific attention has been paid to different foods and their bioactive components for the ability to inhibit the onset and progress of different types of cancer. Nigella sativa extract, powder and seed oil and its main components, thymoquinone and α-hederin, have showed potent anticancer and chemosensitizing effects against various types of cancer, such as liver, colon, breast, renal, cervical, lung, ovarian, pancreatic, prostate and skin tumors, through the modulation of various molecular signaling pathways. Herein, the purpose of this review was to highlight the anticancer activity of Nigella sativa and it constitutes, focusing on different in vitro, in vivo and clinical studies and projects, in order to underline their antiproliferative, proapoptotic, cytotoxic and antimetastatic effects. Particular attention has been also given to the synergistic effect of Nigella sativa and it constitutes with chemotherapeutic drugs, and to the synthesized analogs of thymoquinone that seem to enhance the chemo-sensitizing potential. This review could be a useful step towards new research on N. sativa and cancer, to include this plant in the dietary treatments in support to conventional therapies, for the best achievement of therapeutic goals.

Tinospora cordifolia extract prevents cadmium-induced oxidative stress and hepatotoxicity in experimental rats

Background

Cadmium (Cd) pollution is of serious concern due to its toxic effects in both humans and animals. The study investigates the protective effect of Tinospora cordifolia stem methanolic extract (TCME) on Cd induced hepatotoxicity.

Objective(s)

The objective of the study was to explore the hepatoprotective effects of T. cordifolia extract.

Materials and methods

Rats were administered orally with Cd (5 mg/kg) and TCME (100 mg/kg) for 28 days. At the end of the treatment period, serum and liver tissues homogenates were subjected to biochemical analysis.

Results

Cd treated rats showed increased activities of the serum marker enzymes of liver damage such as AST and ALT along with increased levels of LPO and protein carbonyl content in liver tissues. Cd treatment also leads to decreased activities of endogenous antioxidants (SOD, CAT, GSH, GPx and GST), membrane ATPases (Na⁺K⁺ATPase, Ca²⁺ATPase and Mg²⁺K⁺ATPase) and the tissue glycoprotein levels (hexose, fucose, hexosamine and sialic acid). Histological analysis revealed vacuolar degeneration of hepatocytes with focal necrosis upon Cd administration. TCME co-treatment restored the biochemical and histological alterations caused by Cd intoxication to near normal levels.

Conclusion

The results of the present investigation reveal the hepatoprotective nature of T.cordifolia against Cd induced hepatotoxicity.

Thymoquinone: A novel strategy to combat cancer: A review

The higher consumption of fruit, herbs, spices, and vegetables is well known and practical strategy to cure human cancers owing to their presence of bioactive compounds. Among these, Nigella sativa is a promising source of bioactive compounds including thymoquinone, monoterpenes, p-cymene and α-piene etc. Thymoquinone has been found effective to inhibit the different cancer stages such as proliferation, migration and invasion. It also acts as anticancer agent against different human cancers such as breast, pancreatic, prostate, blood, oral, bone, head and neck, cervical, liver and lung. It significantly mediated miR-34a up-regulation, enhanced the levels of miR-34a through p53, and down controlled Rac1 expression. Thymoquinone induces apoptosis, regulates the levels of pro- and anti- apoptotic genes. It also has been known to lower the phosphorylation of NF-κB and IKKα/β and reduces the metastasis as well as also lowered the ERK1/2 and PI3K activities. Thymoquinone inhibits the metastasis through activation of JNK and p38. The present review article highlights the anticancer perspectives of thymoquinone in human by various pathways and use of this compound as diet based therapy has proven new pharmacological agent against several types of cancers.

Hesperetin on Cell Surface Glycoconjugates Abnormalities and Immunohistochemical Staining with Cytokeratin in 7,12 Dimethylbenz(a)anthracene Induced Hamster Buccal Pouch Carcinogenesis

Hesperetin, a naturally occurring citrus flavanone of the bioactive substance, possesses different pharmacological and biochemical activities including anti-cancer and anti-oxidants effect. The aim of the study to investigate that hesperetin on abnormalities of glycoconjugates (protein bound hexose, hexosamine, total sialic acid and fucose), histology (PAS staining) and immunoexpression of cytokeratin during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch (HBP) carcinogenesis. Oral tumors were developed in the buccal pouches of male golden Syrian hamsters by topical application of 0.5% DMBA thrice a week for 10 weeks and developed morphological alterations depicted as hyperplasia, dysplasia and well-differentiated squamous cell carcinoma formation with noticeable abnormalities of glycoconjugates and cytokeratin. The protective effect of hesperetin against DMBA was evaluated by assessing immunohistochemical expression, histological sections of buccal tissues and the levels of glycoconjugates in the buccal mucosa and plasma were analyzed. Hesperetin administrated orally at a dose of 20 mg/kg b.w. to hamsters treated with DMBA, significantly reduced the status of glycoconjugates and cytokeratin to the near normal range. Overall findings accomplished that hesperetin protects cell surface glycoconjugates abnormalities in DMBA induced HBP carcinogenesis.

Cytotoxicity of thymoquinone alone or in combination with cisplatin (CDDP) against oral squamous cell carcinoma in vitro

Cisplatin (CDDP) is potent anticancer agent used for several tumor types. Thymoquinone (TQ) is naturally occurring compound drawing great attention as anticancer and chemomodulator for chemotherapies. Herein, we studied the potential cytotoxicity of thymoquinone, CDDP and their combination against human oral squamous cell carcinoma cell in contrast to normal oral epithelial cells. CDDP similarly killed both head and neck squamous cell carcinoma cells (UMSCC-14C) and normal oral epithelial cells (OEC). TQ alone exerted considerable cytotoxicity against UMSCC-14C cells; while it induced weaker killing effect against normal oral epithelial cells (OEC). Equitoxic combination of TQ and CDDP showed additive to synergistic interaction against both UMSCC-14C and OEC cells. TQ alone increased apoptotic cell fraction in UMSCC-14C cells, as early as after 6 hours. In addition, prolonged exposure of UMSCC-14C to TQ alone resulted in 96.7 ± 1.6% total apoptosis which was increased after combination with CDDP to 99.3 ± 1.2% in UMSCC-14C cells. On the other hand, TQ induced marginal increase in the apoptosis in OEC and even decreased the apoptosis induced by CDDP alone. Finally, apoptosis induction results were confirmed by the change in the expression levels of p53, Bcl-2 and Caspase-9 proteins in both UMSCC-14c and OEC cells.

Molecular effects of hesperetin, a citrus flavanone on7,12-dimethylbenz(a)anthracene induced buccal pouch squamous cell carcinoma in golden Syrian hamsters

In recent years, researchers have been focused on citrus flavanone, a naturally occurring bioactive substance of hesperetin. To investigate the molecular mechanism based chemopreventive efficacy of hesperetin on 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch (HBP) squamous cell carcinoma (SCC). The oral tumour was provoked by painted with 0.5% DMBA on left buccal pouch thrice a week for 10 consecutive weeks developed well-differentiated SCC and tumour formation was 100% in DMBA alone. We evaluated the chemopreventive potential of hesperetin by assessing the lipid peroxidation (LPO) by-products, status of enzymatic, non-enzymatic antioxidants, detoxifying agents etc. Moreover, modulating expression of apoptotic and cell proliferation markers were observed in HBP SCC experimental hamsters. Oral administration of hesperetin (20 mg/kg b.w.) to DMBA painted hamsters significantly reversed the stages of oral SCC. Our findings indicate that hesperetin possesses a chemopreventive effect in DMBA-induced oral SCC by exerting anti-carcinogenic property.

Thymoquinone as a Potential Adjuvant Therapy for Cancer Treatment: Evidence from Preclinical Studies

Thymoquinone (TQ), the main bioactive component of Nigella sativa, has been found to exhibit anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Moreover, TQ can specifically sensitize tumor cells toward conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells. In this review, we summarized the adjuvant potential of TQ as observed in various in vitro and in vivo animal models and discussed the pharmacological properties of TQ to rationalize its supplementary role in potentiating the efficacy of standard therapeutic modalities namely surgery, radiotherapy, chemotherapy, and immunotherapy. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical levels to delineate its implied utility as a novel complementary adjuvant therapy for cancer treatment.

Nigella sativa and its active constituent thymoquinone in oral health

In this review, we summarized published reports that investigated the role of Nigella sativa (NS) and its active constituent, thymoquinone (TQ) in oral health and disease management. The literature studies were preliminary and scanty, but the results revealed that black seed plants have a potential therapeutic effect for oral and dental diseases. Such results are encouraging for the incorporation of these plants in dental therapeutics and hygiene products. However, further detailed preclinical and clinical studies at the cellular and molecular levels are required to investigate the mechanisms of action of NS and its constituents, particularly TQ.

Mechanistic perspectives on cancer chemoprevention/chemotherapeutic effects of thymoquinone

The bioactive natural products (plant secondary metabolites) are widely known to possess therapeutic value for the prevention and treatment of various chronic diseases including cancer. Thymoquinone (2-methyl-5-isopropyl-1,4-benzoquinone; TQ), a monoterpene present in black cumin seeds, exhibits pleiotropic pharmacological activities including antioxidant, anti-inflammatory, antidiabetic and antitumor effects. TQ inhibits experimental carcinogenesis in a wide range of animal models and has been shown to arrest the growth of various cancer cells in culture as well as xenograft tumors in vivo. The mechanistic basis of anticancer effects of TQ includes the inhibition of carcinogen metabolizing enzyme activity and oxidative damage of cellular macromolecules, attenuation of inflammation, induction of cell cycle arrest and apoptosis in tumor cells, blockade of tumor angiogenesis, and suppression of migration, invasion and metastasis of cancer cells. TQ shows synergistic and/or potentiating anticancer effects when combined with clinically used chemotherapeutic agents. At the molecular level, TQ targets various components of intracellular signaling pathways, particularly a variety of upstream kinases and transcription factors, which are aberrantly activated during the course of tumorigenesis.

Effects of red mold dioscorea on oral carcinogenesis in DMBA-induced hamster animal model

Monascus-fermented products offer valuable therapeutic benefits and have been extensively used for centuries in East Asia. Dioscorea has been proved to have anti-cancer effect. The aim of this study is to investigate the anti-tumor ability of the ethanol extract of red mold dioscorea (RMDE) on 7,12-dimethyl-1,2-benz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. We induced oral squamous cell carcinoma (OSCC) in the buccal pouch of male Syrian golden hamsters by painting with 0.5% DMBA three times a week for 14 weeks. From 9 to 14 weeks, a dose of 50, 100, and 200 mg RMDE per kg body weight were painting with the hamsters for 6 weeks on days alternate to the DMBA application. The results demonstrated that RMDE decreased nitric oxide (NO), reactive oxygen species (ROS), and prostaglandin E(2) (PGE(2)) overexpression in hamster buccal pouches in the DMBA treatment group and increased p53, serum tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) to significantly stimulate caspase-8 and -3 activities, indicating that RMDE reduced oxidative damage causing by DMBA and induced apoptosis in oral cancer cells. Therefore, RMDE may have therapeutic potentials against OSCC.