Dendropanoxide Alleviates Thioacetamide-induced Hepatic Fibrosis via Inhibition of ROS Production and Inflammation in BALB/C Mice.

Hepatic fibrosis results from overproduction and excessive accumulation of extracellular matrix (ECM) proteins in hepatocytes. Although the beneficial effects of dendropanoxide (DPx) isolated from Dendropanax morbifera have been studied, its role as an anti-fibrotic agent remains elucidated. We investigated the protective effect of DPx in BALB/C mice that received thioacetamide (TAA) intraperitoneally for 6 weeks. Later DPx (20 mg/kg/day) or silymarin (50 mg/kg/day) was administered daily for 6 weeks, followed by biochemical and histological analyses of each group. Hematoxylin and eosin staining of the livers showed TAA-induced hepatic fibrosis, which was significantly reduced in the DPx group. DPx treatment significantly decreased TAA-induced hyperlipidemia as evidenced by the decreased AST, ALT, ALP, γ-GTP and serum TG concentrations and reduced the activities of catalase (CAT) and superoxide dismutase (SOD) activity. ELISA revealed reduced levels of total glutathione (GSH), malondialdehyde (MDA) and Inflammatory factors (IL-6, IL-1ß, and TNF-α). Immunostaining showed reduced in collagen-1, α-SMA, and TGF-ß1 expression and western blotting showed reduced levels of the apoptotic proteins, TGF-ß1, p-Smad2/3, and Smad4. RT-qPCR and Western blotting revealed modifications in SIRT1, SIRT3 and SIRT4. Thus, DPx exerted a protective effect against TAA-induced hepatic fibrosis in the male BALB/C mouse model by inhibiting oxidative stress, inflammation, and apoptosis via TGF-ß1/Smads signaling.

Erigeron annuus Extract Alleviates Insulin Resistance via Regulating the Expression of Mitochondrial Damage and Endoplasmic Reticulum Stress-Related Genes.

Diabetes is a prevalent and debilitating metabolic disorder affecting a large population worldwide. The condition is characterized by insulin resistance and impaired function of pancreatic ß-cells, leading to elevated blood glucose levels. In this study, the antidiabetic effects of Erigeron annuus extract (EAE) on zebrafish with damaged pancreatic islets caused by insulin resistance were investigated. The study utilized the zebrafish model to monitor live pancreatic islets. RNA sequencing was also conducted to determine the mechanism by which EAE exerts its antidiabetic effect. The results showed that EAE was effective in recovering reduced islets in excess insulin-induced zebrafish. The effective concentration at 50% (EC50) of EAE was determined to be 0.54 µg/mL, while the lethal concentration at 50% (LC50) was calculated as 202.5 µg/mL. RNA sequencing indicated that the mode of action of EAE is related to its ability to induce mitochondrial damage and suppress endoplasmic reticulum stress. The findings of this study demonstrate the efficacy and therapeutic potential of EAE in treating insulin resistance in zebrafish. The results suggest that EAE may offer a promising approach for the management of diabetes by reducing mitochondrial damage and suppressing endoplasmic reticulum stress. Further research is required to establish the clinical application of EAE in diabetic patients.

Amelioration of Sensorineural Hearing Loss through Regulation of Trpv1, Cacna1h, and Ngf Gene Expression by a Combination of Cuscutae Semen and Rehmanniae Radix Preparata.

Sensorineural hearing loss (SNHL) is a common condition that results from the loss of function of hair cells, which are responsible for converting sound into electrical signals within the cochlea and auditory nerve. Despite the prevalence of SNHL, a universally effective treatment has yet to be approved. To address this absence, the present study aimed to investigate the potential therapeutic effects of TS, a combination of Cuscutae Semen and Rehmanniae Radix Preparata. To this end, both in vitro and in vivo experiments were performed to evaluate the efficacy of TS with respect to SNHL. The results showed that TS was able to protect against ototoxic neomycin-induced damage in both HEI-OC1 cells and otic hair cells in zebrafish. Furthermore, in images obtained using scanning electron microscopy (SEM), an increase in the number of kinocilia, which was prompted by the TS treatment, was observed in the zebrafish larvae. In a noise-induced hearing loss (NIHL) mouse model, TS improved hearing thresholds as determined by the auditory brainstem response (ABR) test. Additionally, TS was found to regulate several genes related to hearing loss, including Trpv1, Cacna1h, and Ngf, as determined by quantitative real-time polymerase chain reaction (RT-PCR) analysis. In conclusion, the findings of this study suggest that TS holds promise as a potential treatment for sensorineural hearing loss. Further research is necessary to confirm these results and evaluate the safety and efficacy of TS in a clinical setting.

Ameliorative Effects of Flavonoids from Platycodon grandiflorus Aerial Parts on Alloxan-Induced Pancreatic Islet Damage in Zebrafish.

Platycodon grandiflorus (balloon flower), used as a food reserve as well as in traditional herbal medicine, is known for its multiple beneficial effects. In particular, this plant is widely used as a vegetable in Republic of Korea. We examined the ameliorative effects of P. grandiflorus on alloxan-induced pancreatic islet damage in zebrafish. The aerial part treatment led to a significant recovery in pancreatic islet size and glucose uptake. The efficacy of the aerial part was more potent than that of the root. Eight flavonoids (1-8) were isolated from the aerial part. Structures of two new flavone glycosides, designated dorajiside I (1) and II (2), were elucidated to be luteolin 7-O-α-L-rhamno-pyranosyl (1 → 2)-(6-O-acetyl)-ß-D-glucopyranoside and apigenin 7-O-α-L-rhamnopyranosyl (1 → 2)-(6-O-acetyl)-ß-D-glucopyranoside, respectively, by spectroscopic analysis. Compounds 1, 3, 4 and 6-8 yielded the recovery of injured pancreatic islets in zebrafish. Among them, compound 7 blocked KATP channels in pancreatic ß-cells. Furthermore, compounds 3, 4, 6 and 7 showed significant changes with respect to the mRNA expression of GCK, GCKR, GLIS3 and CDKN2B compared to alloxan-induced zebrafish. In conclusion, the aerial part of P. grandiflorus and its constituents conferred a regenerative effect on injured pancreatic islets.

Anticancer effects of the HDAC inhibitor, 3ß,6ß­dihydroxyurs­12­en­27­oic acid, in MCF­7 breast cancer cells via the inhibition of Akt/mTOR pathways.

Astilbe chinensis (A. chinensis) is a perennial herb that is used to treat chronic bronchitis and pain. The anticancer activity of 3ß,6ß­dihydroxyurs­12­en­27­oic acid (ACT­3), a major component isolated from A. chinensis, has not yet been investigated in detail. The purpose of the present study was to investigate the histone deacetylase (HDAC) inhibitory and anticancer activities of ACT­3 compared with suberoylanilide hydroxamic acid (SAHA) in MCF­7 human breast cancer cells. The purity of ACT­3 was determined using high­performance liquid chromatography. In the present study, the effects of ACT­3 on anticancer effects of MCF­7 cells were determined by measuring the level of apoptotic cell death and cell cycle regulator using flow cytometry analysis and western blot analysis, respectively. The effects of ACT­3 on HDAC enzyme activity were measured using assay kits. ACT­3 and SAHA increased the levels of acetylated histone H3 and reduced the levels of HDAC1 and HDAC3 in MCF­7 cells. ACT­3 significantly decreased the cell viability in a concentration­dependent manner and induced different morphological changes at high concentrations. ACT­3 and SAHA significantly inhibited the colony formation in MCF­7 cells. ACT­3 inhibited total HDAC activity in a dose­dependent manner. ACT­3 significantly reduced the expression levels of cyclin D1 and cyclin­dependent kinase 4, and upregulated the expression levels of p21WAF1 and p53. A significant increase in the G1 phase cell population was observed in MCF­7 cells and ACT­3 induced apoptosis by reducing the ratio of B­cell lymphoma­2 (Bcl­2)/Bcl­2­associated X (Bax) and releasing cleaved caspase 9. Additionally, ACT­3 significantly increased autophagic cell death by inhibiting the serine­threonine kinase/mammalian target of the rapamycin pathway. Autophagy induction was confirmed via acridine orange staining. ACT­3 significantly increased the pERK1/2 and p21 in MCF­7 cells. Thus, the activated ERK pathway played an important role in cell cycle arrest and apoptosis via ERK­dependent induction of p21 in MCF­7 cells. These data indicated that ACT­3 can be used as a promising anticancer agent to overcome the limitations and reduce the side effects of conventional anticancer drugs.

The Effects of Persimmon (Diospyros kaki L.f.) Oligosaccharides on Features of the Metabolic Syndrome in Zebrafish.

Metabolic syndrome has become a global health care problem since it is rapidly increasing worldwide. The search for alternative natural supplements may have potential benefits for obesity and diabetes patients. Diospyros kaki fruit extract and its oligosaccharides, including gentiobiose, melibiose, and raffinose, were examined for their anti-insulin resistance and obesity-preventing effect in zebrafish larvae. The results show that D. kaki oligosaccharides improved insulin resistance and high-fat-diet-induced obesity in zebrafish larvae, evidenced by enhanced ß-cell recovery, decreased abdominal size, and reduced the lipid accumulation. The mechanism of the oligosaccharides, molecular docking, and enzyme activities of PTP1B were investigated. Three of the oligosaccharides had a binding interaction with the catalytic active sites of PTP1B, but did not show inhibitory effects in an enzyme assay. The catalytic residues of PTP1B were typically conserved and the cellular penetration of the cell membrane was necessary for the inhibitors. The results of the mechanism of action study indicate that D. kaki fruit extract and its oligosaccharides affected gene expression changes in inflammation- (TNF-α, IL-6, and IL-1ß), lipogenesis- (SREBF1 and FASN), and lipid-lowering (CPT1A)-related genes. Therefore, D. kaki fruit extract and its oligosaccharides may have a great potential for applications in metabolic syndrome drug development and dietary supplements.

Synthesis of π-Extended Heterocycles via Rh(III)-Catalyzed Oxidative Annulation of 5-Aryl Pyrazinones with Alkynes.

The Rh(III)-catalyzed C-H functionalization and subsequent oxidative annulation between 5-aryl pyrazinones and internal alkynes are reported. This protocol provides facile access to a wide range of pyrazinone-linked naphthalenes via the C(sp2)-H alkenylation and subsequent annulation. This transformation is characterized by mild conditions, simplicity, and excellent functional group compatibility. Notably, it is a first report of the utilization of pyrazinones as directing groups in C-H functionalization.

Pine Needle Extract Applicable to Topical Treatment for the Prevention of Human Papillomavirus Infection.

Most cervical cancers are associated with high-risk human papillomavirus (HPV) infection. Currently, cervical cancer treatment entails surgical removal of the lesion, but treatment of infection and preventing tissue damage are issues that still remain to be addressed. Herbal medicine and biological studies have focused on developing antiviral drugs from natural sources. In this study, we analyzed the potential antiviral effects of Pinus densiflora Sieb. et Zucc. leaf extracts against HPV. The pine needle extracts from each organic solvent were analyzed for antiviral activity. The methylene chloride fraction (PN-MC) showed the highest activity against HPV pseudovirus (PV). The PN-MC extract was more effective before, rather than after treatment, and therefore represents a prophylactic intervention. Mice were pre-treated with PN-MC via genital application or oral administration, followed by a genital or subcutaneous challenge with HPV PV, respectively. The HPV challenge results showed that mice treated via genital application exhibited complete protection against HPV. In conclusion, PN-MC represents a potential topical virucide for HPV infection.

Dendropanoxide, a Triterpenoid from Dendropanax morbifera, Ameliorates Hepatic Fibrosis by Inhibiting Activation of Hepatic Stellate Cells through Autophagy Inhibition.

Hepatic fibrosis results from chronic liver damage and is characterized by excessive accumulation of extracellular matrix (ECM). In this study, we showed that dendropanoxide (DPX), isolated from Dendropanax morbifera, had anti-fibrotic effects on hepatic fibrosis by inhibiting hepatic stellate cell (HSC) activation. DPX suppressed mRNA and protein expression of α-SMA, fibronectin, and collagen in activated HSCs. Moreover, DPX (40 mg/kg) treatment significantly lowered levels of liver injury markers (aspartate aminotransferase and alanine transaminase), expression of fibrotic markers, and deposition of ECM in a carbon tetrachloride-induced mouse model. Anti-fibrotic effects of DPX were comparable to those of silymarin in a hepatic fibrosis mouse model. As a possible mechanism of anti-fibrotic effects, we showed that DPX inhibited autophagosome formation (LC3B-II) and degradation of p62, which have important roles in HSC activation. These findings suggest that DPX inhibits HSC activation by inhibiting autophagy and can be utilized in hepatic fibrosis therapy.

Isolation and Characterization of Phenylpropanoid and Lignan Compounds from Peperomia pellucida [L.] Kunth with Estrogenic Activities.

Extracts of Peperomia pellucida [L.] Kunth have previously been demonstrated to have in vivo estrogenic-like effects, thereby functioning as an anti-osteoporotic agent. However, the compounds responsible for these effects have not yet been determined. Therefore, the aim of this study is to isolate and elucidate potential compounds with estrogenic activity. The structures of the isolated compounds were identified using 1D 1H and 13C-NMR and confirmed by 2D FT-NMR. The estrogenic activity was evaluated using the E-SCREEN assay, and a molecular docking study was performed to predict the binding affinity of the isolated compounds to estrogen receptors. In this experiment, we successfully isolated three phenylpropanoids and two lignan derivatives, namely, 6-allyl-5-methoxy-1,3-benzodioxol-4-ol (1), pachypostaudin B (2), pellucidin A (3), dillapiole (4), and apiol (5). Among these compounds, the isolation of 1 and 2 from P. pellucida is reported for the first time in this study. Activity assays clearly showed that the ethyl acetate extract and its fractions, subfractions, and isolated compounds exerted estrogenic activity. Methanol fraction of the ethyl acetate extract produced the highest estrogenic activity, while 1 and 2 had partial agonist activity. Some compounds (derivates of dillapiole and pellucidin A) also had, in addition, anti-estrogenic activity. In the docking study, the estrogenic activities of 1-5 appeared to be mediated by a classical ligand-dependent mechanism as suggested by the binding interaction between the compounds and estrogen receptors; binding occurred on Arg 394 and His 524 of the alpha receptor and Arg 346 and His 475 of the beta receptor. In summary, we reveal that P. pellucida is a promising anti-osteoporotic agent due to its estrogenic activity, and the compounds responsible for this activity were found to be lignan and phenylpropanoid derivatives. The presence of other compounds in either the extract or fraction may contribute to a synergistic effect, as suggested by the higher estrogenic activity of the methanol fraction. Hence, we suggest further research on the osteoporotic activity and safety of the identified compounds, especially regarding their effects on estrogen-responsive organs.

Protective effects of dendropanoxide isolated from Dendropanax morbifera against cisplatin-induced acute kidney injury via the AMPK/mTOR signaling pathway.

The aim of this study was to investigate the protective effects of dendropanoxide (DPx) isolated from Dendropanax morbifera against cis-diamminedichloroplatinum (II) (CDDP)-induced nephrotoxicity in NRK-52E cells and in Sprague-Dawley rats. DPx was administered to Sprague-Dawley rats by oral gavage (5 and 10 mg/kg) for 7 consecutive days, 24 h after intraperitoneal injection with CDDP (6 mg/kg). All rats were euthanized 24 h after the last DPx administration, and histopathological damage, acute kidney injury (AKI) biomarkers, inflammatory cytokines, and oxidative damages were evaluated. DPx (5 and 10 µg/mL) was found to protect against CDDP-induced cytotoxicity and apoptotic cell death in NRK-52E cells. CDDP-induced serum blood urea nitrogen (BUN), creatinine (sCr), and pro-inflammatory cytokines levels were significantly ameliorated by DPx in a dose-dependent manner. Furthermore, excretion of kidney injury molecules (KIM-1), selenium binding protein-1 (SBP-1), and neutrophil gelatinase-associated lipocalin (NGAL) in the urine was significantly reduced in response to DPx administration in CDDP-treated rats. Activities of antioxidant enzymes and lipid peroxidation levels were markedly altered in the kidney of CDDP-treated rats in response to DPx administration. Serum pro-inflammatory cytokine levels were dramatically suppressed by DPx in CDDP-treated rats. DPx also restored renal-cell apoptosis via regulation of AMPK/mTOR signaling in CDDP-treated rats. Our results clearly suggest that DPx ameliorates CDDP-induced nephrotoxicity in vitro and in vivo by inhibiting oxidative stress, inflammation, and apoptosis. Overall, our data demonstrates that DPx may serve as a therapeutic agent in patients with solid tumors to prevent CDDP-induced AKI.

Dendropanax morbifera Protects against Renal Fibrosis in Streptozotocin-Induced Diabetic Rats.

The aquatic extract of Dendropanax morbifera (DP) is typically consumed as a beverage in Korea and China and is also used in various traditional medicines. However, the functional role of DP on diabetes-induced renal fibrosis is unclear. Here, the protective effects of DP extract against diabetes-induced renal fibrosis were evaluated. Streptozotocin (STZ, 60 mg/kg) was injected intraperitoneally in rats to induce diabetes. After 5 days, DP extract (25 mg/kg/day) and metformin (50 mg/kg/day) were administered orally to diabetic rats for 28 days. DP administration protected both body and organ weight loss in STZ-treated diabetic rats. Significant improvements in serum blood urea nitrogen (BUN), creatinine, and oxidative stress parameters were observed in diabetic rats by DP administration. DP extract markedly protected diabetic-induced histopathological damages in the kidney and pancreas. A significant reduction was observed in microalbumin, kidney injury molecule-1 (KIM-1), selenium binding protein-1 (SBP1), and pyruvate kinase muscle isozyme M2 (PKM2) levels in the urinary excretion of diabetic rats after the administration of DP extract. The expression of pro-inflammatory cytokines and fibrosis marker levels were significantly reduced in the kidney of diabetic rats. Our results strongly indicate that DP extract exhibits protective activity against diabetes-induced renal fibrosis through ameliorating oxidative stress and inflammation. Therefore, we suggest that DP extract can be used as a preventive agent on the progression of diabetic nephropathy and renal fibrosis.

Effects of ß-Sitosterol from Corn Silk on TGF-ß1-Induced Epithelial-Mesenchymal Transition in Lung Alveolar Epithelial Cells.

Pulmonary fibrosis is a chronic lung disease characterized by abnormal accumulation of the extracellular matrix (ECM). Chronic damage of the alveolar epithelium leads to a process called "epithelial-mesenchymal transition" (EMT) and increases synthesis and deposition of ECM proteins. Therefore, inhibition of EMT might be a promising therapeutic approach for the treatment of pulmonary fibrosis. ß-Sitosterol is one of the most abundant phytosterols in the plant kingdom and the major constituent in corn silk, which is derived from the stigma and style of maize (Zea mays). In this study, we elucidated that ß-sitosterol inhibited transforming growth factor-ß1 (TGF-ß1)-induced EMT and consequently had an antifibrotic effect. ß-Sitosterol (1-10 µg/mL) significantly downregulated the TGF-ß1-induced fibrotic proteins, such as collagen, fibronectin, and α-smooth muscle actin in human alveolar epithelial cells (p < 0.01). After 24 h, relative wound density (RWD) was increased in TGF-ß1 treated group (82.16 ± 5.70) compare to the control group (64.63 ± 2.21), but RWD was decreased in ß-sitosterol cotreated group (10 µg/mL: 71.54 ± 7.39; 20 µg/mL: 65.69 ± 6.42). In addition, the changes of the TGF-ß1-induced morphological shape and protein expression of EMT markers, N-cadherin, vimentin, and E-cadherin, were significantly blocked by ß-sitosterol treatment (p < 0.01). The effects of ß-sitosterol on EMT were found to be associated with the TGF-ß1/Snail pathway, which is regulated by Smad and non-Smad signaling pathways. Taken together, these findings suggest that ß-sitosterol can be used to attenuate pulmonary fibrosis through suppression of EMT by inhibiting the TGF-ß1/Snail pathway.

Protective Effects of Dendropanax morbifera against Cisplatin-Induced Nephrotoxicity without Altering Chemotherapeutic Efficacy.

Use of the chemotherapeutic agent cisplatin (CDDP) in cancer patients is limited by the occurrence of acute kidney injury (AKI); however, no protective therapy is available. We aimed to investigate the renoprotective effects of Dendropanax morbifera water extract (DM) on CDDP-induced AKI. Male Sprague-Dawley rats (six animals/group) received: Vehicle (control); CDDP (6 mg/kg, intraperitoneally (i.p.); DM (25 mg/kg, oral); or DM + CDDP injection. CDDP treatment significantly increased blood urea nitrogen (BUN), serum creatinine (sCr), and pro-inflammatory cytokines (IL-6 and TNF-α), and severely damaged the kidney architecture. Urinary excretion of protein-based AKI biomarkers also increased in the CDDP-treated group. In contrast, DM ameliorated CDDP-induced AKI biomarkers. It markedly protected against CDDP-induced oxidative stress by increasing the activity of endogenous antioxidants and reducing the levels of pro-inflammatory cytokines (IL-6 and TNF-α). The protective effect of DM in the proximal tubules was evident upon histopathological examination. In a tumor xenograft model, administration of DM enhanced the chemotherapeutic activity of CDDP and exhibited renoprotective effects against CDDP-induced nephrotoxicity without altering chemotherapeutic efficacy. Our data demonstrate that DM may be an adjuvant therapy with CDDP in solid tumor patients to preserve renal function.

ß-Peltoboykinolic Acid from Astilbe rubra Attenuates TGF-ß1-Induced Epithelial-to-Mesenchymal Transitions in Lung Alveolar Epithelial Cells.

Epithelial-to-mesenchymal transition (EMT) is increasingly recognized as contributing to the pathogenesis of idiopathic pulmonary fibrosis. Therefore, novel plant-based natural, active compounds have been sought for the treatment of fibrotic EMT. The aim of the present study was to investigate the inhibitory effects of Astilbe rubra on TGF-ß1-induced EMT in lung alveolar epithelial cells (A549). A. rubra was subjected to extraction using 70% ethanol (ARE), and ethanol extracts of the aerial part and that of the rhizome were further partitioned using various solvents. Protein expression and cell motility were investigated to evaluate the inhibitory effects of ARE on EMT. EMT occurred in A549 cells treated with TGF-ß1, but was prevented by co-treatment with ARE. The dichloromethane fractions showed the strongest inhibitory effect on TGF-ß1-induced EMT. ß-Peltoboykinolic acid was isolated from the dichloromethane fractions of A. rubra by activity-oriented isolation. ß-Peltoboykinolic acid not only attenuated TGF-ß1-induced EMT, but also the overproduction of extracellular matrix components including type I collagen and fibronectin. The Smad pathway activated by TGF-ß1 was inhibited by co-treatment with ß-peltoboykinolic acid. Taken together, these results indicate that ß-peltoboykinolic acid from A. rubra and dichloromethane fractions shows potential as an antifibrotic agent in A549 cells treated with TGF-ß1.

Dendropanax morbifera Ameliorates Thioacetamide-Induced Hepatic Fibrosis via TGF-ß1/Smads Pathways.

Hepatic fibrosis, characterized by persistent deposition of extracellular matrix (ECM) proteins, occurs in most types of chronic liver disease. The prevention of liver damage using extract of Dendropanax morbifera has been widely studied, but its molecular mechanism on the therapeutic efficacy of hepatic fibrosis is unclear. The aim of this study was to assess whether aquatic extract (DM) of D. morbifera ameliorates thioacetamide (TAA)-induced hepatic fibrosis. Hepatic fibrosis was induced by an intraperitoneal (i.p.) injection (150 mg/kg, twice per week) of TAA for 6 weeks. DM (50 mg/kg/day) or silymarin (50 mg/kg/day) was administered daily for 6 weeks. DM markedly reduced serum AST, ALT, ALP, and r-GTP in TAA-treated rats. DM significantly ameliorated the total glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activity in TAA-treated rats. In particular, DM significantly reduced expression of α-SMA, type I collagen, vimentin, TGF-ß1 and p-Smad2/3 in hepatic fibrosis rats. The protective effects of DM on progression of hepatic fibrosis were clearly shown by detecting 4-hydroxyproline concentration and histopathological examination in the liver. Therefore, our data suggest that DM dramatically prevented hepatic fibrosis by inhibiting oxidative stress and the TGF-ß1/Smads signaling pathways.

Correction to: Different apoptotic effects of saxifragifolin C in human breast cancer cells.

The authors regret that incorrect western band of Bax (MDA-MB-231) in Fig. 6a (right panel) was mistakenly uploaded in the original publication. The correct Fig. 6a is shown below. This correction does not change the conclusions of this manuscript. The authors would like to apologize for any inconvenience caused.

Plumbagin from a tropical pitcher plant (Nepenthes alata Blanco) induces apoptotic cell death via a p53-dependent pathway in MCF-7 human breast cancer cells.

Plumbagin (5-hydroxy-2-methyl-1,4-naphthaquinone) has displayed antitumor activity in vitro and in animal models; however, the underlying molecular mechanisms have not been fully explored. The aim of this study was to investigate the anticancer effects of plumbagin isolated from Nepenthes alata against MCF-7 breast cancer cells. We examined the cytotoxicity, cell cycle regulation, apoptotic cell death, and generation of intracellular reactive oxygen species (ROS) in MCF-7 cells. Plumbagin exhibited potent cytotoxicity in MCF-7 cells (wild-type p53) compared to that in SK-OV-3 (null-type) human epithelial ovarian cancer cells. Specifically, plumbagin upregulated the expression of p21CIP1/WAF1 in MCF-7 cells, causing cell cycle arrest in the G2/M phase through inhibition of cyclin B1 levels. Plumbagin also significantly increased the ratio of Bax/Bcl-2 and release of cytochrome c, resulting in apoptotic cell death in MCF-7 cells. Furthermore, plumbagin dramatically increased the intracellular ROS level, whereas pretreatment with the ROS scavenger N-acetyl cysteine protected against plumbagin-induced cytotoxicity, suggesting that ROS formation plays a pivotal role in antitumor activity in MCF-7 cells. In mice bearing MCF-7 cell xenografts, plumbagin significantly reduced tumor growth and weight without apparent side effects. We therefore concluded that plumbagin exerts anticancer activity against MCF-7 cells through the generation of intracellular ROS, resulting in the induction of apoptosis via a p53-dependent pathway. This study thus identifies a new anticancer mechanism of plumbagin against p53-dependent breast cancer cells and suggests a novel strategy for overcoming of breast cancer therapy.