Apoptosis and antimigration induction in human skin cancer cells by rhodomyrtone.

Rhodomyrtone is a bioactive compound extracted from Rhodomyrtus tomentosa leaves. It has been used as a traditional herb medicine for many years. Rhodomyrtone exhibits antibacterial activity, anti-inflammatory and antioxidant activities. However, the anticancer activity of rhodomyrtone has not been previously reported. The present study investigated the anticancer effect of rhomyrtone on human epidermoid carcinoma A431 cells. The cytotoxic and antiproliferative effects of rhodomyrtone on A431 cells were investigated by an MTT assay. Cell morphological alterations and apoptotic cells were observed with Hoechst 33342 staining following rhodomyrtone treatment. Flow cytometry and western blotting were performed to detect cell cycle and apoptosis induction. The results demonstrated that rhodomyrtone inhibited proliferation of A431 cells in a dose-dependent manner with IC50 value of 8.04±0.11 µg/ml. The results also indicated that rhodomyrtone increased chromatin condensation, nuclear fragmentation and apoptotic bodies in treated A431 cells in a time-dependent manner. Apoptosis was also induced through the activation of caspase-7 and poly (ADP-Ribose) polymerase cleavage. Flow cytometry analysis revealed that rhodomyrtone induced cell cycle arrest at the G1 phase. Notably, the non-toxic concentration of rhodomyrtone markedly inhibited A431 cell migration in a dose- and time-dependent manner. These finding suggested that rhodomyrtone may be used as an anticancer agent for human skin cancer.

p38 inhibitor inhibits the apoptosis of cowanin-treated human colorectal adenocarcinoma cells.

Colorectal cancer, which is the third most common type of cancer diagnosed in both men and women, is the leading cause of cancer-related deaths worldwide. Cowanin is a pure compound extracted from Garcinia cowa Roxb., a tree species present in Thailand, Malaysia and Myanmar. The crude extract has been demonstrated to have antitumor activity, inflammation induction, antibacterial activity, anti-inflammatory activity and antimalarial activity. In the present study, the effects of cowanin on apoptosis induction and on the apoptosis-related and mitogen-activated protein kinase (MAPK) pathways were investigated in the LoVo human colorectal cancer cell line. The cytotoxicity of cowanin in LoVo cells was determined by MTT assay. Hoechst 33342 and JC­1 staining were used to determine nuclear morphological changes and mitochondrial membrane potential, respectively. The expression levels of BCL2 apoptosis regulator (Bcl­2) family, MAPK and AKT serine/threonine kinase 1 (Akt) pathway proteins following cowanin treatment were determined by western blot analysis. The results demonstrated that cowanin inhibited cell proliferation and induced cell death via the apoptosis pathway. Cowanin treatment increased BCL2 associated X (Bax) and decreased Bcl­2 expression. In addition, cowanin activated caspase­9, -7 and poly-ADP-ribose-polymerase expression. Furthermore, cowanin decreased the levels of phosphorylated extracellular signal-regulated kinase (p­ERK), p­Akt, p­3­phosphoinositide­dependent protein kinase­1, while it increased p­p38 expression, thus resulting in the induction of apoptosis. In conclusion, cowanin inhibited cell proliferation and induced apoptosis of LoVo cells via the MAPK and Akt signaling pathways. Notably, inhibition of p38 by using a p38 inhibitor (SB203580) prevented the cowanin-induced apoptosis in LoVo cells. These results suggested that cowanin may be a potential candidate for the treatment of colorectal cancer and provided important information on the molecular mechanisms underlying its antitumor activity.

Mechanism of apoptosis induction associated with ERK1/2 upregulation via goniothalamin in melanoma cells.

The present study aimed to investigate the effect of goniothalamin on apoptosis induction in the A375 melanoma cell line. Melanoma is a type of skin cancer with increased prevalence and no potential standard treatment. Goniothalamin is a plant, bioactive styrly-lactone, which has various bioactivities including anti-microbial, anti-inflammatory and anti-cancer. Apoptosis induction by goniothalamin has been studied in numerous cancer cell lines, however not in the melanoma cell line A375. The results of the MTT assay demonstrated that goniothalamin induced anti-proliferation in a dose dependent manner. Hoechst staining assay demonstrated that goniothalamin induced chromatin condensation and apoptotic bodies in A375 treated cells, and JC-1 staining revealed that goniothalamin induced mitochondrial membrane dysfunction in A375 cells. In addition, goniothalamin decreased the level of anti-apoptotic proteins myeloid cell leukemia 1, B cell lymphoma (Bcl)-2 and Bcl-extra large, whereas it increased the level of pro-apoptotic proteins, Bcl-2 Associated X, apoptosis regulator, t-BID and Bim in A375 treated cells. In addition, goniothalamin also increased active caspase-9, -7 and cleaved-poly (ADP-ribose) polymerase expression in A375 treated cells. Furthermore, phosphorylated (p)-pyruvate dehydrogenase kinase (PDK) 1 (Ser241) and p-RAC-alpha serine/threonine-protein kinase (Akt; Ser473) were decreased, however c-Jun and p-extracellular signal-regulated kinase (ERK)1/2 were increased upon goniothalamin treatment. These results suggest that goniothalamin has an effect, as anti-proliferation and apoptosis induction in A375 cells were associated with upregulated p-ERK1/2, c-Jun and downregulated p-PDK1 (Ser241), p-Akt (Ser473) in A375 cells. Therefore, goniothalamin may be a potential candidate for anti-cancer drug development for melanoma treatment.

Goniothalamin enhances TRAIL-induced apoptosis in colorectal cancer cells through DR5 upregulation and cFLIP downregulation.

The combination of TNF-related apoptosis-inducing ligand (TRAIL) and bioactive compound to enhance apoptosis in TRAIL-resistant cancer is one of cancer treatment strategies. TRAIL possesses the unique capacity to selectively induce apoptosis in cancer cells both in vitro and in vivo with little effect on normal cells. Recent studies have reported that there are many TRAIL-resistant cancers. Thus, bioactive compounds that enhance cytotoxicity of TRAIL would be potential candidates for cancer therapeutic application. This study evaluated the cytotoxic and apoptosis induction upon combined treatment of TRAIL and goniothalamin, the natural styryl-lactone compound extracted from plant Goniothalamus spp., in LoVo cells. The results showed that a combination of goniothalamin and TRAIL enhanced caspase-dependent apoptosis induction in LoVo cells via both death receptor- and mitochondrial-mediated apoptosis pathways. In addition, goniothalamin enhanced TRAIL-induced apoptosis through increased death receptor DR5 expression and decreased anti-apoptotic regulator cFLIP. Interestingly, goniothalamin increased translocation of DR5 to cell surface and consequently contributed to the enhancement of TRAIL-induced apoptosis. In conclusion, this is the first report showing the combined treatment of goniothalamin and TRAIL was able to effectively enhance TRAIL-mediated apoptosis induction in TRAIL-refractory colorectal cancer, LoVo cells. Therefore, this study may offer a strategic cancer treatment against TRAIL-resistant cancers.

Apoptotic induction of skin cancer cell death by plant extracts.

OBJECTIVE: The aim of the present study was to investigate the effects of plant extracts on cancer apoptotic induction. MATERIAL AND METHOD: Human epidermoid carcinoma A431 cell line, obtained from the American Type Culture Collection (ATCC, Manassas, VA), was maintained in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) at 37 degrees C, 5% carbon dioxide (CO2). Plant extract solutions were obtained from S & J international enterprises public company limited. These plant extracts include 50% hydroglycol extracts from Etlingera elatior (Jack) R.M.Smith (torch ginger; EE), Rosa damascene (damask rose; DR) and Rafflesia kerrii Meijer (bua phut; RM). The cell viability, time and dose dependency were determined by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. A431 cells were treated with the plant extracts and stained with Hoechst 33342 fluorescent staining dye. RESULTS: Cell viability was demonstrated by the inhibitory concentration 50% (IC50). The anti-proliferative effects were shown to be dependent on time and dose. Typical characteristics of apoptosis which are cell morphological changes and chromatin condensation were clearly observed. CONCLUSION: The plant extracts was shown to be effective for anti-proliferation and induction of apoptosis cell death in skin cancer cells. Therefore, mechanisms underlying the cell death and its potential use for treatment of skin cancer will be further studied.

The correlation of parathyroid hormone and heart rate variability in CAPD patients.

OBJECTIVE: To investigate the correlation of parathyroid hormone (PTH) and cardiac autonomic nervous system (ANS) measured by heart rate variability (HRV) method in continuous ambulatory peritoneal dialysis (CAPD) patients. MATERIAL AND METHOD: Healthy subjects (HS) and two groups of CAPD patients classified by the PTH concentration: high PTH group (H-PTH; PTH = 150-300 pg/ml) and ultra-high PTH group (UH-PTH; PTH > 300 pg/ml) were studied. Time and frequency domains of HRV were analyzed. For the frequency domain, the fast Fourier transform of the total power (TP), low frequency (LF), high frequency (HF), and LF/HF ratio were transformed by natural logarithm (ln). The Pearson's correlation was used to analyze the correlation between lnPTH and the parameters of HRV RESULTS: Time and frequency domains of HS were at highest values whilst LF/HF ratio was the lowest. For UH-PTH CAPD patients, the values of standard deviation of R-R interval (SDNN), root mean square of the difference of R-R interval (RMSSD), lnTP and lnHF were significantly lower whereas lnLF was not significantly different compared to H-PTH. In addition, lnHF was found to have the highest negative correlation value with lnPTH concentration (r = -0.53). CONCLUSION: PTH, a serious uremic toxin, influences the initiation of ANS dysfunction. According to decreased lnHF a decrease in parasympathetic activity was demonstrated in UH-PTH. Consequently, the modality that can stimulate the parasympathetic activity should be considered in CAPD patients who were hyperparathyroidism.

Role of mouse organic anion transporter 3 (mOat3) as a basolateral prostaglandin E2 transport pathway.

Renal organic anion transporters play an important role in the handling of a number of endogenous and exogenous anionic substances in the kidney. In this study, we investigated prostaglandin E(2) (PGE(2)) transport properties and intrarenal localization of mouse organic anion transporter 3 (mOat3). When expressed in Xenopus oocytes, mOat3 mediated the time- and concentration-dependent transport of PGE(2) (K(m): 1.48 microM). PGE(2) transport mediated by mOat3 was trans-stimulated by intracellular glutarate injected into the oocytes. PGE(2) efflux via mOat3 was also trans-stimulated by extracellular glutarate. Thus, mOat3 was shown to mediate the bidirectional transport of PGE(2), partly coupled to the dicarboxylate exchange mechanism. Immunohistochemical study revealed that mOat3 protein was localized at the basolateral membrane of renal proximal and distal tubules. Furthermore, diffuse expression of mOat3, including expression in the basolateral membrane in macula densa (MD) cells, was observed. These results indicate that mOat3 plays an important role as a basolateral transport pathway of PGE(2) in the distal nephron including MD cells that may constitute one of the indispensable steps for renin release and regulation of the tubuloglomerular feedback mechanism.

Mutations in SLC6A19, encoding B0AT1, cause Hartnup disorder.

Hartnup disorder, an autosomal recessive defect named after an English family described in 1956 (ref. 1), results from impaired transport of neutral amino acids across epithelial cells in renal proximal tubules and intestinal mucosa. Symptoms include transient manifestations of pellagra (rashes), cerebellar ataxia and psychosis. Using homozygosity mapping in the original family in whom Hartnup disorder was discovered, we confirmed that the critical region for one causative gene was located on chromosome 5p15 (ref. 3). This region is homologous to the area of mouse chromosome 13 that encodes the sodium-dependent amino acid transporter B(0)AT1 (ref. 4). We isolated the human homolog of B(0)AT1, called SLC6A19, and determined its size and molecular organization. We then identified mutations in SLC6A19 in members of the original family in whom Hartnup disorder was discovered and of three Japanese families. The protein product of SLC6A19, the Hartnup transporter, is expressed primarily in intestine and renal proximal tubule and functions as a neutral amino acid transporter.

Isolation and characterization of thermophilic benzothiophene-degrading Mycobacterium sp.

A bacterial strain, SWU-4, capable of using benzothiophene (BT) as a sole carbon and energy source was isolated from a petroleum-contaminated site in Thailand and identified by 16S rRNA gene sequence analysis to be in the genus of Mycobacterium. The strain was Gram-positive, nonspore former, and grew at 50 degrees C. Colonies of the strain on nutrient agar were rod-shaped, smooth with a convex surface, slightly mucoid, and yellow pigmented. The thermophilic Mycobacterium sp. strain SWU-4 rapidly degraded 2% (w/v) BT at 50 degrees C. Interestingly, this strain was able to degrade a wide variety of organosulfur compounds including thiophene, bromo(alpha)thiophene, and 3-methylthiophene in liquid minimum medium at 50 degrees C, which will be beneficial for industrial applications.