Thymoquinone anticancer activity is enhanced when combined with royal jelly in human breast cancer

Abstract

BACKGROUND Breast cancer is the most common cause of the majority of cancer-related deaths in women, among which triple-negative breast cancer is the most aggressive type of breast cancer diagnosed with limited treatment options. Thymoquinone (TQ), the main bioactive constituent of Nigella sativa , has been extensively studied as a potent anticancer molecule against various types of cancers. Honeybee products such as the royal jelly (RJ), the nutritive secretion fed to honeybee queens, exhibit a variety of biological activities besides its anticancer effect. However, the anticancer activity of the combination of TQ and RJ against breast cancer is still unknown. AIM To investigate cytotoxicity of RJ in FHs 74 Int cells and the anticancer effects of TQ, RJ, and their combinations in the MDA-MB-231 cell line. METHODS Cells were treated with TQ, RJ, and their combinations for 24 h. Using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, we determined the half-maximal inhibitory concentration of TQ. Trypan blue and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were then performed to assess the cell viability in response to different treatment conditions. Cell death and cycle regulation were investigated using propidium iodide deoxyribonucleic acid staining followed by flow cytometry in response to a single dose of TQ, RJ, and their combination. Immunostaining for cleaved caspase 3 and Ki67 expression was used to determine apoptosis induction and changes in cell proliferation. RESULTS TQ alone inhibited cell viability in a dose-dependent manner at concentrations below and above the half-maximal inhibitory concentration. RJ exhibited relatively nontoxic effects against MDA-MB-231 cells and FHs 74 Int small intestinal cells at concentrations below 5 µg/mL. High doses of RJ (200 µg/mL) had greater toxicity against MDA-MB-231 cells. Interestingly, the inhibition of cell viability was most pronounced in response to 15 µmol/L TQ and 5 µg/mL RJ. A dose of 15 µmol/L TQ caused a significant increase in the PreG1 population, while a more pronounced effect on cell viability inhibition and PreG1 increase was observed in response to TQ and RJ combinations. TQ was the main inducer of caspase 3-dependent apoptosis when applied alone and in combination with RJ. In contrast, no significant regulation of Ki67 expression was observed, indicating that the decrease in cell viability was due to apoptosis induction rather than to inhibition of cell proliferation. CONCLUSION This study is the first to report enhanced anticancer effects of TQ and RJ combination against MDA-MB-231 breast cancer cells, which could confer an advantage for cancer therapy.

Royal Jelly: Beneficial Properties and Synergistic Effects with Chemotherapeutic Drugs with Particular Emphasis in Anticancer Strategies

“…Moubarak et al demonstrated that the administration of RJ at a dose of 5 µg/mL combined with thymoquinone at the concentration 10 µmol/L for 24 h could reveal the remarkable induction of the caspase-3 apoptotic pathway and the death of human breast cancer cells MDA-MB-231. These findings were reproduced in different cell lines with similar effects and without any cytotoxic changes to normal human small intestinal cells [ 14 ].…”

“…Based on the global cancer records (GLOBOCAN) published in 2020, it was approximated that more than 19 million new cancer patients are to be reported from 185 countries and with 36 cancer-types [ 55 ]. Equally worrisome is the predicted record of an average 33 million new cases by the year 2040, as stated by the World Health Organization [ 14 , 56 ]. As per the complicity of cancer formation and progression, multi-composite synergistic pharmacological solutions and drug reorientation were suggested by Nogales et al, 2021 [ 57 ].…”

“…Certain RJ mechanisms of action have been observed with commercially available drugs such as cyclophosphamide, 5-fluorouracil (5-FU), thymoquinone, cisplatin, temozolomide, Interferon alpha (HulFN-αN3), and GE132 plus (a nutraceutical supplement). RJ can reduce the genotoxicity and DNA damage when used with cyclophosphamide, or even decrease the cell viability and IC 50 with 5-fluorouracil [ 12 , 13 ], and it can also enhance the entrance of the cells into the apoptotic cycle with Thymoquinone or cisplatin [ 14 , 15 ]. The synergistic effect extends to decrease cell proliferation when combined with GE132, HulFN-αN3, and Temozolomide, increasing the efficacy of these drugs [ 16 , 17 , 18 ].…”

“…They can cause polypharmacy with expected and unexpected drug-drug interactions, exposing the patient’s health to higher risks [ 16 ]. To minimize the unwanted side effects, natural products were introduced which exhibited a synergetic effect that can diminish the undesirable side effects, improve the efficacy of the drugs, and maintain the quality of life for cancer patients [ 14 ].…”

Combination Anticancer Therapies Using Selected Phytochemicals

“…Similar to many chemotherapeutic agents, TQ can significantly enhance the effect of other natural products. TQ and royal jelly (RJ) together enhanced the anticancer activity of both against MDA-MB-231 breast cancer cells [ 172 ]. Moreover, in breast adenocarcinoma, a combination of (50 and 100 µM) TQ and (450 µM) ferulic acid required the use of lower doses of both to suppress the proliferation of cultured MDA-MB 231cells [ 173 ].…”