Sesamol induces cytotoxicity via mitochondrial apoptosis in SCC-25 cells.

Sesamol is the main constituent of sesame seed oil and is obtained from Sesamum indicum. Oral squamous cell carcinoma (OSCC) is one of the most common neoplasms affecting the oral cavity. In this study, we investigated the cytotoxic potentials of sesamol on human oral squamous carcinoma (SCC-25) cells. Human oral squamous carcinoma cells were treated with different concentrations (62.5, 125, and 250 µM/mL) of sesamol for 24 h. Cytotoxicity was analyzed by 3- (4, 5- dimethylthiazol -2- yl) -2, 5-diphenyltetrazolium bromide (MTT) assay. Intracellular reactive oxygen species (ROS) expression was investigated by dichloro-dihydro-fluorescein diacetate assay. Apoptosis-related morphology was analyzed by acridine orange/ethidium bromide staining. Caspase-9 expression was analyzed by confocal microscopic double immunofluorescence staining. Mitochondrial apoptosis-related markers are analyzed using qPCR. Sesamol treatment caused a significant cytotoxic effect in OSCC cells. Sesamol-induced cytotoxic effect was associated with intracellular ROS generation. Sesamol treatments induced a significant increase in the early and late apoptotic cells. This treatment also induced caspase-9 expression in OSCC cells. Sesamol treatments caused downregulation of Harvey rat sarcoma viral oncogene homolog (HRAS) expression at protein and gene levels. Sesamol treatment modulates intrinsic apoptotic marker gene expression in OSCC cells. Overall results confirm the anti-cancer potential of sesamol and it seems to be a promising candidate for OSCC.

Ethanolic Extract of Lagerstroemia Speciosa (L.) Pers., Induces Apoptosis and Cell Cycle Arrest in HepG2 Cells.

Lagerstroemia speciosa (L.) Pers., (Lythraceae) also called Banaba is a native plant of southeast Asia and is widely used in traditional medicinal system. Herbal tea from banaba leaves are used to reduce weight and diabetes. We investigated the cytotoxic potentials of ethanolic banaba leaves extract (EBLE) against human hepatocellular carcinoma (HepG2) cell line. Lagerstroemia speciosa leaves were extracted and obtained from M/s. Quimico Herbal Extract Manufacturer, Bengaluru, India, and it contains 20% corosolic acid. Cells were treated with 50, 100, and 150 µg/ml of EBLE for 24 h, and cytotoxicity was evaluated by MTT assay. Apoptosis-related morphology was investigated by DAPI nuclear staining. Protein and gene expressions of p-Akt, FOXO1, p53, MDM2, p21, p27, CDK4, cyclin D1, and E1 were evaluated through Western blotting and qPCR. EBLE treatments caused significant, concentration-dependent cytotoxicity. DAPI staining and flow cytometry studies showed chromatin condensation, increased apoptotic cell population and cell cycle arrest at subG0/G1 phase upon EBLE treatments respectively. Furthermore, EBLE treatments significantly increased the expressions of p53, p21, p27, FOXO1, while p-Akt, MDM2, CDK4, cyclin D1, and E1 expressions were downregulated. These findings suggested that EBLE induces G1-phase of cell cycle arrest and apoptosis in HepG2 cells. EBLE may serve as a therapeutic agent against hepatocellular carcinoma.

Carbamazepine, a Histone Deacetylase Inhibitor Induces Apoptosis in Human Colon Adenocarcinoma Cell Line HT-29.

BACKGROUND AND AIM: Colon cancer ranks fourth and is responsible for causing 10% cancer-related mortality in western countries. Its incidence is rising in many countries due to widespread adoption of the Western diet and lifestyle. Carbamazepine (CBZ) is a FDA-approved antiepileptic drug and a histone deacetylase inhibitor. The aim of this study is to evaluate the cytotoxic potentials of CBZ in human colon cancer cells (HT-29 cells). METHODS: HT-29 cells were treated with 36 and 76 µg/ml of CBZ for 24 h. The cytotoxic effect was evaluated by MTT assay. The intracellular reactive oxygen species (ROS) expression was evaluated through dichloro-dihydro-fluorescein diacetate staining. Morphological changes related to apoptosis were evaluated by dual staining with acridine orange and ethidium bromide. Mitochondrial membrane potential was evaluated by rhodamine 123 staining. Immunofluorescence analysis of caspase 3 was done with confocal microscopy. RESULTS: CBZ caused significant cytotoxicity in HT-29 cells and the effect was concentration dependent. CBZ treatments also caused significant expression of ROS in HT-29 cells. Dual staining showed early and late apoptotic cells and morphological alterations induced by the CBZ. Confocal microscopic studies confirmed the increased caspase 3 expression in CBZ-treated cells. CONCLUSION: CBZ induced apoptosis in HT-29 cell through ROS generation and caspase 3 expression and these results pave the way for further in vivo studies.

Syringic acid triggers reactive oxygen species-mediated cytotoxicity in HepG2 cells.

Hepatocellular carcinoma is the second most common cause of cancer death in the world and its incidence has dramatically increased worldwide in the past two decades. Syringic acid (SA) has been studied for its hepatoprotective, anti-inflammatory, immunomodulatory, free radical scavenging, and antioxidant activities. We aimed to evaluate the cytotoxic effect of SA against human hepatoma HepG2 cell line. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HepG2 cells were treated with SA at concentration ranges of 25, 50, and 100 µM for 24 h. Reactive oxygen species (ROS) expression was investigated by dichlorofluorescein staining assay. Morphological changes of SA-treated HepG2 cells were evaluated by acridine orange (AO) and ethidium bromide (EB) dual staining. Apoptotic marker gene expressions were evaluated by qPCR. SA treatment caused significant cytotoxicity and liberation of ROS in HepG2 cells. AO and EB staining showed membrane blebbing and distortion in SA-treated cells. Apoptotic markers such as caspases 3 and 9, cytochrome c, Apaf-1, Bax, and p53 gene expressions were significantly increased upon SA treatment indicating the possibility of apoptosis induction in HepG2 cells. This treatment also caused significant downregulation of Bcl-2 gene expression. SA has a cytotoxic effect on human HepG2 cell line, and this might be a promising agent in anticancer research.

Silibinin mitigates zidovudine-induced hepatocellular degenerative changes, oxidative stress and hyperlipidaemia in rats.

Prolonged zidovudine (AZT) treatment in HIV-infected and AIDS patients is shown to induce liver toxicity leading to complications. Therapeutic regimen that could encounter this adverse effect is unavailable and management of toxicity is often symptomatic or is limited to withdrawal of therapy. In the present investigation, we evaluated the alleviating properties of silibinin (SBN), a flavanolignan obtained from Silybum marianum against subacute AZT-induced hepatotoxicity and oxidative stress in rats. AZT treatment (50 mg/kg body weight (b.w.) periorally (p.o.), daily for 45 days) caused highly significant increases in alanine transaminase, alkaline phosphatase, argininosuccinic acid lyase and bilirubin in serum. Oxidative stress is shown by a highly significant increase in lipid peroxidase and total carbonyl content and decrease in catalase and protein thiols in the liver tissue. Hyperlipidaemia is indicated by highly significant increase in total lipids and free fatty acid in serum. Evaluation of liver by haematoxylin and eosin staining shows parenchymal cell enlargement, inflammatory changes and increase in sinusoidal spaces. Simultaneous treatment of SBN (100 mg/kg b.w. p.o., daily for 45 days) significantly protected the liver against hepatotoxicity, oxidative stress and hyperlipidaemia induced by AZT, and this alleviating property is attributed to hepatoprotective, membrane-stabilizing, antioxidant and free radical scavenging properties of SBN.