β-2-himachalen-6-ol: A novel anticancer sesquiterpene unique to the Lebanese wild carrot

The Wild Carrot (Daucus carota): A Phytochemical and Pharmacological Review

Daucus carota L., a member of the Apiaceae family, comprises 13 subspecies, with one being cultivated (D. carota L. ssp. sativus (Hoffm.) Arcang.) and the remaining being wild. Traditionally, the wild carrot has been recognized for its antilithic, diuretic, carminative, antiseptic, and anti-inflammatory properties and has been employed in the treatment of urinary calculus, cystitis, gout, prostatitis, and cancer. While extensive literature is available on the phytochemical, pharmacological, and therapeutic evaluations of the cultivated carrot, limited information has been published on the wild carrot. A thorough search was conducted on the phytochemical composition, folk-medicine uses, and pharmacological properties of wild carrot subspecies (Daucus carota L. ssp. carota). Various electronic databases were consulted, and the literature spanning from 1927 to early 2023 was reviewed. Thirteen wild Daucus carota subspecies were analyzed, revealing over 310 compounds, including terpenoids, phenylpropenoids, flavonoids, and phenolic acids, with 40 constituting more than 3% of the composition. This review also highlights the antioxidant, anticancer, antipyretic, analgesic, antibacterial, antifungal, hypolipidemic, and hepato- and gastroprotective properties of wild carrot subspecies. Existing in vitro and in vivo studies support their traditional uses in treating infections, inflammation, and cancer. However, further research on other subspecies is required to confirm additional applications. Well-designed preclinical and clinical trials are still necessary to establish the safety and efficacy of wild Daucus carota for human use.

Cynaropicrin disrupts tubulin and c-Myc-related signaling and induces parthanatos-type cell death in multiple myeloma

The majority of blood malignancies is incurable and has unforeseeable remitting-relapsing paths in response to different treatments. Cynaropicrin, a natural sesquiterpene lactone from the edible parts of the artichoke plant, has gained increased attention as a chemotherapeutic agent. In this study, we investigated the effects of cynaropicrin against multiple myeloma (MM) cells in vitro and assessed its in vivo effectiveness in a xenograft tumor zebrafish model. We showed that cynaropicrin exerted potent cytotoxicity against a panel of nine MM cell lines and two leukemia cell lines with AMO1 being the most sensitive cell line (IC50 = 1.8 ± 0.3 µM). Cynaropicrin (0.8, 1.9, 3.6 µM) dose-dependently reduced c-Myc expression and transcriptional activity in AMO1 cells that was associated with significant downregulation of STAT3, AKT, and ERK1/2. Cell cycle analysis showed that cynaropicrin treatment arrested AMO1 cells in the G2M phase along with an increase in the sub-G0G1 phase after 24 h. With prolonged treatment times, cells accumulated more in the sub-G0G1 phase, implying cell death. Using confocal microscopy, we revealed that cynaropicrin disrupted the microtubule network in U2OS cells stably expressing α-tubulin-GFP. Furthermore, we revealed that cynaropicrin promoted DNA damage in AMO1 cells leading to PAR polymer production by PARP1 hyperactivation, resulting in AIF translocation from the mitochondria to the nucleus and subsequently to a novel form of cell death, parthanatos. Finally, we demonstrated that cynaropicrin (5, 10 µM) significantly reduced tumor growth in a T-cell acute lymphoblastic leukemia (T-ALL) xenograft zebrafish model. Taken together, these results demonstrate that cynaropicrin causes potent inhibition of hematopoietic tumor cells in vitro and in vivo.

Himachalol induces apoptosis in B16-F10 murine melanoma cells and protects against skin carcinogenesis

ETHNOPHARMACOLOGICAL RELEVANCE

Cedrus libani A. Rich (C. libani) is majestic evergreen Mediterranean conifer growing in the mountains of Lebanon. The ethnobotanical and traditional uses of cedar wood oil traces back to ancient times for the treatment of various ailments including cancer. Previous work in our laboratories revealed that himachalol (7-HC), a major sesquiterpene isolated from C. libani, possesses potent cytotoxic activity against various human cancer cell lines as well as promising anti-inflammatory effect in isolated rat monocytes.

AIM OF THE STUDY

The present study aims to elucidate the mechanism of action behind the cytotoxic activity of 7-HC against murine melanoma cells (B16F-10) and evaluates its chemopreventive effect against chemically-induced skin carcinogenesis in mice.

MATERIALS AND METHODS

7-HC was extracted and purified from Cedrus libani wood. Cell viability was evaluated using WST-1 kit. Cell cycle analysis and apoptosis were assessed by Flow cytometry using propidium iodide (PI) and fluorescein Isothiocyanate (FITC)-conjugated Annexin V/PI staining respectively. Apoptosis related protein were quantified using western blot. The chemopreventive activity of 7-HC was evaluated for 20 weeks using a DMBA/TPA induced skin carcinogenesis model in Balb/c mice.

RESULTS

7-HC displayed a potent anti-proliferative activity against the melanoma cells with an IC50 of 8.8 μg/ml and 7.3 μg/ml at 24 and 48 h, respectively. Co-treatment with Cisplatin did not show any synergistic or additive effect on cell viability. Flow cytometry analysis using PI revealed that 7-HC treatment (5 and 10 μg/ml) induces the accumulation of cells in the sub-G1 phase and causes a decline in cell populations in the S and G2/M phases. Annexin/PI staining also reveals that 7-HC treatment significantly increases the percentage of cells undergoing early and late apoptosis. Western blot analysis shows that 7-HC treatment decreases the level of the anti-apoptotic protein Bcl-2 and increases the level of the pro-apoptotic protein Bax. A reduction in the level of phosphorylated Erk and Akt was also observed. 7-HC via topical (2.5%), intraperitoneal (10, 25 and 50 mg/kg) or gavage (50 mg/kg) treatment revealed a significant decrease in papilloma volume with no adverse effect on liver and kidney function.

CONCLUSIONS

The present study demonstrates that 7-HC treatment protects against chemically-induced skin carcinogenesis, promotes cell cycle arrest and induces apoptosis partially through an inhibition of both the MAPK/Erk and PI3K/Akt pathways.

In Vitro and In Vivo Evaluation of the Anticancer and Anti-inflammatory Activities of 2-Himachelen-7-ol isolated from Cedrus Libani

Cedrus libani is a majestic evergreen tree native to the Mediterranean mountains of Lebanon, Syria and Turkey. In this study, the tree heart wood was extracted using hexane to produce C. libani oil extract (CLOE) as a dark oil. GCMS analysis of CLOE identified up to 30 compounds whereby 2-himachalen-7-ol (7-HC) was the most abundant (40%). 7-HC was isolated using column chromatography and the identity of the white crystalline solid was confirmed via NMR spectroscopy and X-Ray Crystallography. 7-HC demonstrated potent cytotoxic activity against several human cancer cell lines including brain (SF-268, IC₅₀ 8.1 μg/mL) and colon (HT-29, IC₅₀ 10.1 μg/mL; Caco-2, IC₅₀ 9.9 μg/mL) with ovarian (Sk-OV-3, IC₅₀ > 50 μg/mL) cells being the most resistant. However, while HT-29 displayed resistance to Cisplatin, 7-HC was 8–10 folds more potent. Co-treatment with 7-HC and Cisplatin showed a significant synergistic anti-proliferative effect against SF-268, HT-29 and Caco-2 cells. 7-HC also exhibited significant anti-inflammatory effect in formalin-induced paw edema in rats. Western blot analysis revealed that 7-HC displayed dose dependent inhibition of LPS-induced COX-2 protein expression in isolated rat monocytes. The present study demonstrates that 7-HC possesses promising anticancer and anti-inflammatory activities, and may serve as a lead molecule in cancer therapy.

β-2-Himachalen-6-ol inhibits 4T1 cells-induced metastatic triple negative breast carcinoma in murine model

β-2-himachalen-6-ol (HC), a major sesquiterpene isolated from the Lebanese wild carrot umbels, was shown to possess remarkable in vitro and in vivo anticancer activities. The present study investigates the anti-metastatic activity of HC post 4T1 breast cancer cells inoculation in a murine model. The effect of HC on 4T1 cell viability was assessed using WST-1 kit, while cell cycle analysis was performed using flow cytometry. Tumor development and metastasis were evaluated by injecting 4T1 cells in the mice mammary gland region followed by either HC or cisplatin treatment. The 6-thioguanine assay was used for the quantification of metastatic cells in the blood. HC treatment caused a dose-dependent decrease in cell viability with IC₅₀ and IC₉₀ values of 7 and 28 μg/mL respectively. Concomitant treatment with cisplatin significantly reduced cell viability when compared to cells treated with cisplatin or HC alone. Flow cytometry revealed a significant increase (p˂0.05) in cell count in the Sub-G1 phase at HC 10 μg/mL, and total DNA fragmentation (p˂0.001) at HC 25 μg/mL. Annexin/PI staining showed early and late apoptotic mode of cell death upon treatment with HC. Histopathological evaluation revealed less incidence of primary and metastatic tumor/inflammation in the HC and cisplatin treated groups. Tumor size and colony-forming units were significantly decreased in the HC treated group. HC treatment induced cell cycle arrest, promoted apoptosis and reduced the incidence of primary and metastatic lesions caused by 4T1 cells. The present findings suggest that HC has an anti-metastatic potential against aggressive types of cancer.

β-2-himachalen-6-ol protects against skin cancer development in vitro and in vivo

Background

Previous studies in our laboratory showed that Daucus carota oil extract (DCOE) possesses remarkable in-vitro anticancer activity and antitumour promoting effect against DMBA/TPA skin carcinogenesis in mice. Chemical analysis of DCOE led to the isolation of the β-2-himachalen-6-ol (HC), major sesquiterpene with a potent anticancer activity against various colon, breast, brain and skin cancer cells. This study investigated the anticancer activity of HC against invasive epidermal squamous cell carcinoma cells and evaluated its effect in a DMBA/TPA skin carcinogenesis Balb/c murine model.

Methods

HaCaT-ras II-4 epidermal squamous cells were treated with HC (1, 5, 10, 25 and 50 μg/ml), and cell viability was evaluated with WST 1 assay kit. Cell cycle analysis was carried out by flow cytometry, and pro/anti-apoptotic proteins were measured using Western blot. The effect of topical and intraperitoneal (IP) treatment with HC in mice was assessed using the DMBA/TPA skin carcinogenesis model. Cisplatin (2.5 mg/kg; IP) was used as a positive control. Papilloma incidence, yield and volume were monitored, and isolated papillomas were assessed for their pro/anti-apoptotic proteins and morphology.

Results

β-2-himachalen-6-ol showed a dose-dependent decrease in cell survival with an IC50 and IC90 of 8 and 30 μg/ml, respectively. Flow cytometry analysis revealed that treatment with 10 μg/ml HC significantly increased the number of cells undergoing late apoptosis (28%), while 25 μg/ml caused a larger cell shift towards late apoptosis (46.6%) and necrosis (39%). A significant decrease in protein levels of p53 and Bcl-2 and a significant increase in p21 and Bax were observed. Also, there was a significant decrease in p-Erk and p-Akt protein levels. The treatment of mice (IP and topical) with HC caused a significant decrease in papilloma yield, incidence and volume. Similar effects were observed with cisplatin treatment, but HC-treated groups exhibited twofold to threefold increase in survival rates. Similar patterns in the pro- and anti-apoptotic proteins were observed in mice treated with HC, except for a significant increase in p53 protein.

Conclusions

In conclusion, HC treatment induced cell cycle arrest (low dose) and promoted apoptosis partly via inhibition of the MAPK/ERK and PI3K/AKT pathways with no significant toxicity to laboratory mice.