Dietary Triterpene Research Articles

Effects of Lupeol on Estrogen and Androgen Receptor-Positive Breast and Prostate Cancer Cells

Background: Different reports have shown that prostate and breast cancers are the most common cancers worldwide. Lupeol, a dietary triterpene, provides various beneficial effects including anti-cancer properties. The current study aims to investigate the anti-proliferative and antioxidant effects of lupeol, in line with the effects of lupeol on the expression of estrogen and androgen receptors in breast (MCF-7) and prostate (LNCaP) cancer cell lines. Methods: MCF-7 and LNCaP cells were incubated with increasing concentrations of the lupeol (1, 10, and 100 µM) for 24h. The cytotoxicity of the lupeol was assessed by MTT and Neutral Red assays. Moreover, TAC (total antioxidant capacity), and gene expression of androgen and estrogen receptors were measured by spectrophotometric and qPCR methods, respectively. Overall, 17 beta-estradiol (E2) (9 nM) and dehydroepiandrosterone (DHEA) (5 µM) were selected as positive controls. Results: The highest concentration of the lupeol induced cytotoxic effects on MCF-7 and LNCaP cells. Various levels of lupeol at specified time intervals increased TAC levels in comparison with the control group. Moreover, the expression levels of estrogen receptors (α and β) and androgen receptors were negatively affected by lupeol. Conclusion: The findings of our study indicate that lupeol could serve as a promising, and accessible multi-functional anti-tumor agent against hormone-positive breast and prostate cancers.

Screening of lupeol, mangiferin and β-carotene contents in pulp of mango (Mangifera indica L.) varieties at edible ripe stage

Mango fruits are an amazing source of numerous bioactive phytonutrients like lupeol (a novel anti-inflammatory and anticancer dietary triterpene), mangiferin (an antidiabetic, anti-HIV, anticancer, immunomodulatory and anti-inflammatory agent) and β-carotene (a significant carotenoid that functions as a precursor to vitamin A, the conscientious reason for our vision). In the present study, ripe pulp of 23 mango varieties was examined for their contents of lupeol, mangiferin and β-carotene using high performance liquid chromatography-photodiode array detector (HPLC-PAD). Mulgoa had the highest lupeol concentration, measuring 42.52 µg/g and Langra stands second with 36.33 µg/g followed by Pairi (33.56 µg/g), Sensation (28.69 µg/g) and Dashehari with 28.22 µg/g. Mangiferin content was highest in variety Arunika (49.58 µg/g) followed by Ambika (34.80 µg/g), Dashehari (33.31 µg/g), Sensation (29.66 µg/g) and Neelum (27.93 µg/g). Sensation's mature pulp has the highest quantity of β-carotene (109.58 µg/g), followed by Kesar (96.87 µg/g), Dashehari (82.13 µg/g), Mulgoa (79.99 µg/g), Arunika (74.26 µg/g), and Amrapali (70.12 µg/g). The pulp of Dashehari, Sensation, Mulgoa, Arunika, Kesar and Amrapali possessed good to moderate amount of these nutraceuticals and are beneficial for consumption at ripe stage. This study has showed the importance of nutraceutical components present in mango; meanwhile it also encourages mango growers to grow these varieties for better profitability.

Retraction Note to: Lupeol enhances inhibitory effect of 5-fluorouracil on human gastric carcinoma cells.

Lupeol, a dietary triterpene present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including cancer-preventive and anti-cancer effects in vitro and in vivo. Here, we investigated the anti-cancer efficacy and adjuvant chemotherapy action of lupeol in gastric cancer (GC) cells (SGC7901 and BGC823) and explored the underlying mechanisms. Cells were treated with lupeol and/or 5-fluorouracil (5-Fu) and subjected to cell viability, colony formation, apoptosis, western blot, semiquantitative RT-PCR, and xenograft tumorigenicity assay. Our results showed that lupeol and 5-Fu inhibited the proliferation of SGC7901 and BGC823 cells, and combination treatment with lupeol and 5-Fu resulted in a combination index < 1, indicating a synergistic effect. Co-treatment with lupeol and 5-Fu induced apoptosis through up-regulating the expressions of Bax and p53 and down-regulating the expressions of survivin and Bcl-2. Furthermore, co-treatment displayed more efficient inhibition of tumor weight and volume on BGC823 xenograft mouse model than single-agent treatment with 5-Fu or lupeol. Taken together, our findings highlight that lupeol sensitizes GC to 5-Fu treatment, and combination treatment with lupeol and 5-Fu would be a promising therapeutic strategy for human GC treatment.

Retraction Note to: Lupeol inhibits proliferation and induces apoptosis of human pancreatic cancer PCNA-1 cells through AKT/ERK pathways.

Lupeol, a dietary triterpene, present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anti-cancer activities both in vitro and in vivo. However, the precise mechanism involved remains largely unknown. The present study is conducted to investigate the anti-cancer activity and the underlying mechanisms of lupeol on human pancreatic cancer proliferating cell nuclear antigen 1 (PCNA-1) cells in vitro and in vivo. Lupeol significantly inhibited the proliferation of the cells in dose- and time-dependent manners and induced apoptosis as well as cell cycle arrest in G0/G1 phase by upregulating P21 and P27 and downregulating cyclin D1. The expression of apoptosis-related proteins in cells was evaluated by western blot analysis, and we found that lupeol induced cell apoptosis by decreasing the levels of p-AKT and p-ERK. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of lupeol in PCNA-1 cells, demonstrating the important role of AKT in this process. More importantly, our in vivo studies showed that administration of lupeol decreased tumor growth in a dose-dependent manner. Immunohistochemistry analysis demonstrated the downregulation of p-AKT and p-ERK in tumor tissues following lupeol treatment, consistent with the in vitro results. Therefore, these findings indicate that lupeol can inhibit cell proliferation and induce apoptosis as well as cell cycle arrest of PCNA-1 cells and might offer a therapeutic potential advantage for human pancreatic cancer chemoprevention or chemotherapy.

Corrigendum to "Lupeol, a Dietary Triterpene, Enhances Wound Healing in Streptozotocin-Induced Hyperglycemic Rats with Modulatory Effects on Inflammation, Oxidative Stress, and Angiogenesis".

[This corrects the article DOI: 10.1155/2019/3182627.].

Lupeol, a Dietary Triterpene, Enhances Wound Healing in Streptozotocin-Induced Hyperglycemic Rats with Modulatory Effects on Inflammation, Oxidative Stress, and Angiogenesis.

Impaired wound healing is a debilitating complication of diabetes that leads to significant morbidity, particularly foot ulcers. Natural products have shown to be effective in treating skin wounds. Lupeol is known to stimulate angiogenesis, fibroblast proliferation, and expressions of cytokines and growth factors involved in wound healing. The study is performed to evaluate the wound healing activity of lupeol in streptozotocin-induced hyperglycemic rats by macroscopical, histological, immunohistochemical, immunoenzymatic, and molecular methods. Percentage of wound closure and contraction was increased in the lupeol-treated group when compared to the Lanette group. Histopathological observation revealed decreased inflammatory cell infiltration and increased proliferation of fibroblasts, vascularization, and deposition of collagen fibers after lupeol treatment. Immunohistochemical analyses showed decreased intensity of NF-κB and increased intensity of FGF-2, TGF-β1, and collagen III. ELISA results revealed downregulated IL-6 levels and upregulated IL-10 levels in response to lupeol. The mRNA expression levels of Hif-1α, Sod-2, and Ho-1 were significantly increased in response to lupeol as compared to Lanette whereas Nf-κb and Vegf-A levels were decreased in relation to insulin and lupeol treatment. These findings indicate that lupeol possesses wound healing potential in hyperglycemic conditions and may be useful as a treatment for chronic wounds in diabetic patients.

In-vitro assessment of CYP3A4 and CYPC29 inhibition potential of Lupeol using human liver microsomes

Background: Lupeol is a dietary triterpene, possesses numerous biological activities. Lupeol is currently under development for chemotherapy and chemoprevention. The aim of present study was to determine the potential inhibitory effect of Lupeol on cytochrome P450 (CYP3A4 and CYP2C9 isozymes) activities in human liver microsomes (HLM).&#x0D; Methods: The inhibition studies were conducted using testosterone 6β-hydroxylase (CYP3A4), and diclofenac 4’-Hydroxylase (CYP2C9) activity assay using positive control Ketoconazole and Sulphaphenazole, respectively. Inhibition study was performed by incubating lupeol (0 to 20 μM) with human liver microsomes, and the metabolite formation was analyzed by liquid chromatography-Tandem Mass Spectrometry (LC-MS/MS).&#x0D; Results: Luepol did not inhibit CYP3A4 and CYP2C9 isozymes mediated activities in human liver microsomes up to a maximum tested concentration of 20µM based on solubility under tested invitro conditions.&#x0D; Conclusions: Lupeol is not an inhibitor of the CYP3A4 and CYP2C9 isozymes. IC50 is greater than highest tested concentration as well as physiological concentration, where effect was measured with confidence. Therefore, clinically relevant pharmacokinetic herb-drug interactions are unlikely to occur between Lupeol and co-administered substrates of these CYP isozymes. Looking at the spectrum of biological activities and CYP inhibition potential of Lupeol; Lupeol can be used as adjuvant/ chemotherapy agent/ chemopreventive agent in therapy.&#x0D; Keywords: Lupeol, HLM, CYP3A4 and CYP2C9, Inhibition, herb–drug interactions

Lupeol inhibits LPS-induced neuroinflammation in cerebellar cultures and induces neuroprotection associated to the modulation of astrocyte response and expression of neurotrophic and inflammatory factors

In the central nervous system (CNS), neuroinflammation, especially that modulated by the cell response of astrocytes and microglia, is associated with damage to neurons in neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease and, Multiple Sclerosis. Lupeol is a dietary triterpene that has demonstrated biological activities as antioxidant. This study investigated the anti-inflammatory and neuroprotective effects of lupeol in an in vitro model of neuroinflammation in primary cerebellar cultures. Cultures were obtained from 6-day-old Wistar rats, subjected to inflammatory damage with lipopolysaccharide (LPS, 1 μg/mL) and treated with lupeol (0.1 μM). We observed, after a 48-hour treatment, through Fluorjade-B staining and immunocytochemistry (ICQ) for βIII-tubulin, that lupeol induced neuroprotection in cultures submitted to inflammatory damage. On the other hand, through ICQ for GFAP, it was possible to observe that lupeol modulated the astrocyte morphology for Bergmann glia-like phenotype and, especially for velate astrocyte-like phenotype, both phenotypes associated with the neuroprotective profile. Moreover, RT-qPCR analysis showed that lupeol induced the down-regulation of the mRNA expression for proinflammatory markers TNF, iNOS and NLRP3, as well as the production of nitric oxide (method of Greiss), which were up-regulated by LPS, and also induced up-regulation of the mRNA expression for arginase and IL-6 mRNA. In addition, lupeol induced up-regulation of mRNA expression for neurotrophins GDNF and NGF and also for the sonic hedgehog–Gli pathway. Together, these results lead to the conclusion that lupeol inhibits neuroinflammation in cerebellar cultures and induces neuroprotection associated with the modulation of astrocyte response and expression of neurotrophic and inflammatory factors.

Absorption and distribution of lupeol in CD-1 mice evaluated by UPLC-APCI+ -MS/MS.

Lupeol is a dietary triterpene that shows limited water solubility, which affects its bioavailability. It is well known that poor oral bioavailability is one of the major causes of therapeutic variability. Lupeol has been reported to have multiple biological activities; however, there are no reports about its bioavailability. Therefore, the objective of this research was to evaluate the systemic bioavailability of lupeol. An experimental strategy with three groups of female CD-1 strain mice was proposed (control, olive oil and lupeol in olive oil), at six experimental times (0.5, 2, 4, 8, 12 and 24 h) with four animals per experimental point. Mice were sacrificed for organs, urine, feces and blood collection. Lupeol was extracted from samples and analyzed by UPLC-APCI+ -MS/MS, obtaining the pharmacokinetics parameters time to peak concentration 6.444 ± 0.851 h and peak concentration 8.071 ± 2.930 μg/mL. Study of direct digestion and absorption in various organs showed important concentrations of lupeol at earlier post-administration times (stomach, 137.25 ± 19.94 ng/mg and small intestine, 99.00 ± 12.99 ng/mg). The main excretion route was fecal, with a peak at 12 h post-administration (163.28 ± 9.83 μg/mg). Absorption of lupeol by the animals was better than expected despite its nonpolar nature (extent of absorption F = 0.645 ± 0.0581).

Chemotherapeutic potiential of Lupeol and its analogue (oxime) on human mammary cancer cell line (MCF-7)

Lupeol, a dietary triterpene, present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anti-cancer activities both in vitro.The present study is conducted to investigate the anticancer activity and the underlying mechanisms of Lupeol analogue (oxime) on human mammary cancer (MCF-7).MTT assay showed that the lupeol analogue had marked cytotoxic activity in MCF-7 cancer cells.We observed increased levels of Antioxidants (ABTS, DPPH,Superoxide anions radical scavenging activity,Hydroxyl radical scavenging activity) in MCF-7 cell line, because of anti oxidant mechanism of lupeol analogue (oxime) .We observed the higher concentrations ( 20,30,40,50 and 70 µM/mL) of lupeol analogue treatment significantly showed increased cytotoxicity in MCF-7 cells. The IC50 value was found to be 40 µM/mL of lupeol analogue (oxime) could greatly inhibit the cell growth. So, we have chosen at 40 and 320 µM/mL concentration of lupeol analogue (oxime) for further experiments. We observed increased levels of Lipid peroxidation and decreased levels of Antioxidants (SOD,CAT,GPx,GSH) in MCF-7 cell line because of the pro oxidant mechanism of lupeol analogue (oxime) . These observations revealed the cytotoxic potential of lupeol, which could be attributed to their prooxidant property on the MCF-7 cells. It is evident from the observation made in the present study that the lupeol analogue (oxime)has potential anticancer effect compared to Lupeol.

Anti-obese and Anti-hyperglycemic Effects of Dietary Triterpene Alcohols and Sterols from Rice Bran Oil

Anti-obese and Anti-hyperglycemic Effects of Dietary Triterpene Alcohols and Sterols from Rice Bran Oil

Lupeol Induces Apoptosis and Cell Cycle Arrest of Human Osteosarcoma Cells Through PI3K/AKT/mTOR Pathway.

Lupeol, a dietary triterpene present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anticancer effect in vitro and in vivo However, the activity of lupeol against osteosarcoma remains unclear. The present study is conducted to investigate the anticancer activity and the underlying mechanisms of lupeol on human osteosarcoma cells (MNNG/HOS and MG-63) in vitro and in vivo MNNG/HOS and MG-63 cells were treated by lupeol and subjected to methyl thiazolyl tetrazolium analysis, Hoechst staining, annexin V/propidium iodide double staining, cell cycle analysis, and Western blot analysis. In addition, MNNG/HOS xenograft tumors were established in female nude BALB/c mice, and lupeol was intravenously administered to evaluate the anticancer capacity in vivo Our results showed that lupeol induced apoptosis as well as cell cycle arrest in G0/G1 phase of MNNG/HOS and MG-63 cells in a dose-dependent manner in vitro Furthermore, the protein expression levels of phospho-phosphatidylinositol 3-kinase (p-PI3K), phospho-protein kinase B (p-AKT), p-p70S6K, and cyclin D1 were significantly downregulated, whereas the expression levels of p21 and p27 were upregulated. These protein interactions may play a pivotal role in the regulation of apoptosis and cell cycle arrest. More importantly, our in vivo studies showed that administration of lupeol decreased tumor growth in a dose-dependent manner and has no significant effect on the function of liver and kidney. Taken together, our findings indicated that lupeol can induce apoptosis as well as cell cycle arrest of human osteosarcoma cells through phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway and might offer a promising new approach in the effective treatment of osteosarcoma.

Lupeol enhances inhibitory effect of 5-fluorouracil on human gastric carcinoma cells.

Lupeol, a dietary triterpene present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including cancer-preventive and anti-cancer effects in vitro and in vivo. Here, we investigated the anti-cancer efficacy and adjuvant chemotherapy action of lupeol in gastric cancer (GC) cells (SGC7901 and BGC823) and explored the underlying mechanisms. Cells were treated with lupeol and/or 5-fluorouracil (5-Fu) and subjected to cell viability, colony formation, apoptosis, western blot, semiquantitative RT-PCR, and xenograft tumorigenicity assay. Our results showed that lupeol and 5-Fu inhibited the proliferation of SGC7901 and BGC823 cells, and combination treatment with lupeol and 5-Fu resulted in a combination index < 1, indicating a synergistic effect. Co-treatment with lupeol and 5-Fu induced apoptosis through up-regulating the expressions of Bax and p53 and down-regulating the expressions of survivin and Bcl-2. Furthermore, co-treatment displayed more efficient inhibition of tumor weight and volume on BGC823 xenograft mouse model than single-agent treatment with 5-Fu or lupeol. Taken together, our findings highlight that lupeol sensitizes GC to 5-Fu treatment, and combination treatment with lupeol and 5-Fu would be a promising therapeutic strategy for human GC treatment.

Lupeol inhibits proliferation and induces apoptosis of human pancreatic cancer PCNA-1 cells through AKT/ERK pathways.

Lupeol, a dietary triterpene, present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anti-cancer activities both in vitro and in vivo. However, the precise mechanism involved remains largely unknown. The present study is conducted to investigate the anti-cancer activity and the underlying mechanisms of lupeol on human pancreatic cancer proliferating cell nuclear antigen 1 (PCNA-1) cells in vitro and in vivo. Lupeol significantly inhibited the proliferation of the cells in dose- and time-dependent manners and induced apoptosis as well as cell cycle arrest in G0/G1 phase by upregulating P21 and P27 and downregulating cyclin D1. The expression of apoptosis-related proteins in cells was evaluated by western blot analysis, and we found that lupeol induced cell apoptosis by decreasing the levels of p-AKT and p-ERK. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of lupeol in PCNA-1 cells, demonstrating the important role of AKT in this process. More importantly, our in vivo studies showed that administration of lupeol decreased tumor growth in a dose-dependent manner. Immunohistochemistry analysis demonstrated the downregulation of p-AKT and p-ERK in tumor tissues following lupeol treatment, consistent with the in vitro results. Therefore, these findings indicate that lupeol can inhibit cell proliferation and induce apoptosis as well as cell cycle arrest of PCNA-1 cells and might offer a therapeutic potential advantage for human pancreatic cancer chemoprevention or chemotherapy.

Lupeol induces apoptosis and inhibits invasion in gallbladder carcinoma GBC-SD cells by suppression of EGFR/MMP-9 signaling pathway.

The cytostatic drug from fruits and other plant derived products have acted as a chemotherapeutic agent used in treatment of a wide variety of cancers. Lupeol, a dietary triterpene, present in many fruits and medicinal plants, has been shown to possess many pharmacological properties including anti-cancer effect in both in vitro and in vivo assay systems. However, the cancer proliferative and invasive inhibitory effects and molecular mechanisms on gallbladder carcinoma GBC-SD cells have not been studied. In the present study, GBC-SD cells were treated by lupeol and subjected to methyl thiazolyl tetrazolium analysis, Hoechst 33342 staining, annexin V/propidium iodide double-staining, transwell chamber assay and Western blot analysis. In addition, GBC-SD xenograft tumors were established in male nude BALB/c mice, and lupeol was intravenously administered to evaluate the anti-cancer capacity in vivo. Our results showed that lupeol inhibited the proliferation, migration, invasion and induced apoptosis of GBC-SD cells in a dose-dependent manner in vitro. Furthermore, the expression of p-EGFR, p-AKT and MMP-9 levels were significantly down-regulated. These protein interactions may play a pivotal role in the regulation of apoptosis and invasion. More importantly, our in vivo studies showed that administration of lupeol decreased tumor growth in a dose-dependent manner. Immunohistochemistry analysis demonstrated the down-regulation of p-EGFR and MMP-9 in tumor tissues following lupeol treatment, consistent with the in vitro results. Taken together, our findings indicated that lupeol can induce apoptotic cell death and inhibit the migration as well as invasion of GBC-SD cells. The mechanism may be associated with the suppression of EGFR/MMP-9 signaling. These results might offer a therapeutic potential advantage for human gallbladder carcinoma chemoprevention or chemotherapy.

The dietary terpene lupeol targets colorectal cancer cells with constitutively active Wnt/β-catenin signaling

Aberrant activation of the Wingless-type mouse mammary tumor virus integration site family (Wnt)/β-catenin signaling pathway is the most common modification, and often considered, a hallmark of colorectal cancer (CRC). Typically in this pathway the β-catenin translocates from the cytoplasm to the nucleus, where it functions as a transcription regulator of several genes that support tumor formation and progression. Thus, any agent that could attenuate the translocation of β-catenin could be extremely valuable against CRC, especially the tumors that exhibit constitutively active Wnt/β-catenin signaling. Using human CRC cells that exhibit differential expression of Wnt/β-catenin signaling, we demonstrate that treatment of CRC cells with dietary triterpene lupeol results in a dose-dependent (i) decrease in cell viability, (ii) induction of apoptosis, (iii) decrease in colonogenic potential, (iv) decrease in β-catenin transcriptional activity, and (v) decrease in the expression of Wnt target genes. Most importantly lupeol was observed to inhibit the translocation of β-catenin from the cytoplasm to the nucleus. Importantly, all these effects of lupeol were restricted to cells that harbor constitutively active Wnt/β-catenin signaling while negligible effects were observed in cells that lack constitutively active Wnt/β-catenin signaling. Further, we also demonstrate that inhibition of Wnt signaling in cells with constitutive active Wnt/β-catenin results in loss of lupeol efficacy while inducing Wnt signaling sensitizes the cells to inhibitory effects of lupeol. In summary, our data strongly advocate the efficacy of lupeol against CRC cells that exhibit constitutively active Wnt/β-catenin signaling.

PI3-kinase inhibition synergistically promoted the anti-tumor effect of lupeol in hepatocellular carcinoma

BackgroundLup-20(29)-en-3H-ol (Lupeol), a dietary triterpene, has been shown to possess multiple pharmacological activities including anti-tumor effectsMethodsIn the current study, we noted that low doses of lupeol (<40 μM) promoted the growth of hepatocellular carcinoma (HCC) cells with a significant activation of the PI3-kinase/Akt signaling pathway. We further investigated the combined anti-tumor effect of lupeol and S14161, a newly identified PI3-Kinase inhibitor in vitro and in vivoResultsThe results demonstrated that lupeol and S14161 could exert a synergistic antitumor effect resulting in chemo-sensitization of HCC to low doses of lupeol. Using an in vivo HCC model, we further demonstrated that lupeol and S14161 synergistically inhibited tumor growth without any adverse effects on body weightConclusionOur studies showed that the activation of PI3-kinase/Akt pathway resulted in the tumor-promoting effect with low doses of lupeol. Combining PI3-kinase inhibitor with lupeol could synergistically augment the anti-tumor effect of lupeol and might be an applicable strategy for HCC therapy.

Growth Inhibition and Apoptosis Induced by Lupeol, a Dietary Triterpene, in Human Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC) is the fifth most malignant tumor worldwide and is known to be resistant to conventional chemotherapy. New therapeutic strategies are urgently needed for treating HCC. Lup-20(29)-en-3H-ol (Lupeol), a novel dietary triterpene, is found in fruits, vegetables, and medicinal plants and possesses multiple bio-activities with very low toxicity. In the current study, we investigated its growth-inhibitory effects in HCC cell lines SMMC7721 and HepG2. In the in vitro studies, lupeol treatment alone caused decrease of cell viability in two HCC cell lines in a dose-dependent manner. It also induced apoptosis and caused cell accumulation in S phase. Further analysis revealed the induction of active caspase-3 and poly(ADP-ribose)polymerase (PARP) cleavage by lupeol treatment. In the in vivo studies, nude mice implanted with SMMC7721 cells subcutaneously were treated with lupeol three times a week and tumor development was significantly inhibited. We further investigated the combination anti-tumor effect of lupeol and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in HCC, considering TRAIL treatment alone could not achieve high level of anti-tumor effect. The results demonstrated that lupeol could exert a combinational effect with TRAIL, resulting in chemosensitization of HCC. Our results suggested that lupeol alone or as an adjuvant to therapeutic agents could be developed as a potential agent for treating HCC.

Re: Specific targeting of Wnt/ -catenin signaling in human melanoma cells by a dietary triterpene lupeol: a reply

Re: Specific targeting of Wnt/ -catenin signaling in human melanoma cells by a dietary triterpene lupeol: a reply

Re: Specific targeting of Wnt/ -catenin signaling in human melanoma cells by a dietary triterpene lupeol

Dear Editors, We were surprised during our reading of the recent article by Tarapore et al. (published online on 23 August) regarding the specific targeting of Wnt/beta-catenin signaling in melanoma by dietary lupeol. In the abstract, the authors state that the one-third of melanomas with active Wnt/beta-catenin signaling have a poor prognosis, an assertion that is not supported by the literature (see ref. 1 for review of this topic). In fact, multiple publications have reported just the opposite, namely that the presence of active Wnt/beta-catenin signaling (as measured by nuclear beta-catenin) actually portends an unexpected IMPROVED survival, suggesting that the role of this pathway in melanoma (and other cancers) may be more complex than previously thought. None of these reports are addressed by the authors, and their failure to acknowledge these findings compromises the interpretation of their results in the larger context of what is known about melanoma progression. It is unfortunate that this oversight was not caught by either the authors themselves or the peer reviewers responsible for ensuring the scientific quality of the work.