Glioblastoma multiforme (GBM) is the most malignant and aggressive primary brain tumor in adults. Despite concerted efforts to improve current therapies, the prognosis of glioblastoma remains very poor. Alantolactone, a sesquiterpene lactone compound, has been reported to exhibit antifungal, antibacteria, antihelminthic, and anticancer properties. In this study, we found that alantolactone effectively inhibits growth and triggers apoptosis in glioblastoma cells in a time‐ and dose‐dependent manner. The alantolactone‐induced apoptosis was found to be associated with glutathione (GSH) depletion, reactive oxygen species (ROS) generation, mitochondrial transmembrane potential dissipation, cardiolipin oxidation, upregulation of p53 and Bax, downregulation of Bcl‐2, cytochrome c release, activation of caspases (caspase 9 and 3), and cleavage of poly (ADP‐ribose) polymerase. This alantolactone‐induced apoptosis and GSH depletion were effectively inhibited or abrogated by a thiol antioxidant, N‐acetyl‐L‐cysteine, whereas other antioxidant (polyethylene glycol (PEG)‐catalase and PEG‐superoxide‐dismutase) did not prevent apoptosis and GSH depletion. Alantolactone treatment inhibited the translocation of NF‐κB into nucleus; however, NF‐κB inhibitor, SN50 failed to potentiate alantolactone‐induced apoptosis indicating that alantolactone induces NF‐κB‐independent apoptosis in glioma cells. These findings suggest that the sensitivity of tumor cells to alantolactone appears to results from GSH depletion and ROS production. Furthermore, our in vivo toxicity study demonstrated that alantolactone did not induce significant hepatotoxicity and nephrotoxicity in mice. Therefore, alantolactone may become a potential lead compound for future development of antiglioma therapy. © © 2012 IUBMB Life, 64(9): 783–794, 2012

Signal transducer and activator of transcription 3 (STAT3) constitutively expresses in human liver cancer cells and has been implicated in apoptosis resistance and tumorigenesis. Alantolactone, a sesquiterpene lactone, has been shown to possess anticancer activities in various cancer cell lines. In our previous report, we showed that alantolactone induced apoptosis in U87 glioblastoma cells via GSH depletion and ROS generation. However, the molecular mechanism of GSH depletion remained unexplored. The present study was conducted to envisage the molecular mechanism of alantolactone-induced apoptosis in HepG2 cells by focusing on the molecular mechanism of GSH depletion and its effect on STAT3 activation. We found that alantolactone induced apoptosis in HepG2 cells in a dose-dependent manner. This alantolactone-induced apoptosis was found to be associated with GSH depletion, inhibition of STAT3 activation, ROS generation, mitochondrial transmembrane potential dissipation, and increased Bax/Bcl-2 ratio and caspase-3 activation. This alantolactone-induced apoptosis and GSH depletion were effectively inhibited or abrogated by a thiol antioxidant, N-acetyl-L-cysteine (NAC). The data demonstrate clearly that intracellular GSH plays a central role in alantolactone-induced apoptosis in HepG2 cells. Thus, alantolactone may become a lead chemotherapeutic candidate for the treatment of liver cancer.

Cancer is the second leading cause of deaths worldwide. Despite concerted efforts to improve the current therapies, the prognosis of cancer remains dismal. Highly selective or specific blocking of only one of the signaling pathways has been associated with limited or sporadic responses. Using targeted agents to inhibit multiple signaling pathways has emerged as a new paradigm for anticancer treatment. Icariside II, a flavonol glycoside, is one of the major components of Traditional Chinese Medicine Herba epimedii and possesses multiple biological and pharmacological properties including anti-inflammatory, anti-osteoporosis, anti-oxidant, anti-aging, and anticancer activities. Recently, the anticancer activity of Icariside II has been extensively investigated. Here, in this review, our aim is to give our perspective on the current status of Icariside II, and discuss its natural sources, anticancer activity, molecular targets and the mechanisms of action with specific emphasis on apoptosis pathways which may help the further design and conduct of preclinical and clinical trials.Icariside II has been found to induce apoptosis in various human cancer cell lines of different origin by targeting multiple signaling pathways including STAT3, PI3K/AKT, MAPK/ERK, COX-2/PGE2 and β-Catenin which are frequently deregulated in cancers, suggesting that this collective activity rather than just a single effect may play an important role in developing Icariside II into a potential lead compound for anticancer therapy. This review suggests that Icariside II provides a novel opportunity for treatment of cancers, but additional investigations and clinical trials are still required to fully understand the mechanism of therapeutic effects to further validate it in anti-tumor therapy.

Corporate social responsibility (CSR) at the individual level has emerged as an important field of research. However, a more comprehensive understanding of how CSR affects employee work engagement and organizational citizenship behavior (OCB) is still lacking. Based on social exchange theory, we examine the effects of employees’ perceptions of CSR on OCB and work engagement as well as the mediating mechanism of distributive and procedural justice, based on data collected from 350 employees working in the banking sector of Pakistan. Our study suggests that employees’ perceptions of CSR positively predict OCB and work engagement, and that work engagement is positively related to OCB. Both distributive and procedural justice positively mediate the effects of employees’ perceptions of CSR on OCB and work engagement.

BackgroundRepetition and reinforcement have been shown to play a crucial role in the sustainability of the effect of Oral Health Education (OHE) programs. However, its relevance to school-based OHE imparted by different personnel is not depicted by the existing dental literature. The present study was undertaken to determine the effectiveness of the repeated and reinforced OHE (RR-OHE) compared to one-time OHE intervention and to assess its role in school-based OHE imparted by dentist, teachers and peers.MethodsThe study was a cluster randomized controlled trial that involved 935 adolescents aged 10-11 years. Twenty four boys’ and girls’ schools selected at random in two towns of Karachi, Pakistan were randomly assigned to three groups to receive OHE by dentist (DL), teachers (TL) and peer-leaders (PL). The groups received a single OHE session and were evaluated post-intervention and 6 months after. The three groups were then exposed to OHE for 6 months followed by 1 year of no OHE activity. Two further evaluations at 6-month and 12-month intervals were conducted. The data were collected by a self-administered questionnaire preceded by a structured interview and followed by oral examination of participants.ResultsThe adolescents’ oral health knowledge (OHK) in the DL and PL groups increased significantly by a single OHE session compared to their baseline knowledge (p < 0.05) and the increase was sustained over 6 months. Although one-time OHE resulted in a significant improvement in adolescents’ oral health behavior (OHB) related to the prevention of gingivitis in the two groups (p < 0.05), no significant change was observed in their behavior towards prevention of oral cancer. One-time teacher-led OHE was ineffective in improving adolescents’ OHK and OHB. The oral hygiene status (OHS) of the participants in all three groups did not change statistically after one-time OHE. The OHK, OHB and OHS indices increased significantly 6 months after RR-OHE than the initial scores (p < 0.001) irrespective of OHE strategy. Although the OHK scores of the DL and PL groups decreased significantly at 12-month evaluation of RR-OHE (p < 0.05), the said score of the TL group; and OHB and OHS scores of all three groups remained statistically unchanged during this period.ConclusionsThe repetition and reinforcement play a key role in school-based OHE irrespective of educators. The trained teachers and peers can play a complementary role in RR-OHE.

Artemisia argyi is a widely used medicinal plant in China. The present study was designed to identify the bioactive constituents with antiglioma activity from leaves of Artemesia argyi. A bioactivity guided approach based on MTT assay for cells growth inhibition led to the isolation of a flavonoid, “jaceosidin” from ethanol extract of leaves of Artemesia argyi. The growth inhibitory effect of jaceosidin was explored using flow cytometry and Western blot studies. Our results showed that jaceosidin exerts growth inhibitory effect by arresting the cells at G2/M phase and induction of apoptosis. Furthermore, our study revealed that induction of apoptosis was associated with cell cycle arrest at G2/M phase, upregulation of p53 and Bax, decrease in mitochondrial membrane potential, release of cytochrome c, and activation of caspase 3. This mitochondrial-caspase-3-dependent apoptosis pathway was confirmed by pretreatment with caspase 3 inhibitor, Ac-DEVD-CHO. Our findings suggested that jaceosidin induces mitochondrial-caspase-3-dependent apoptosis in U87 cells by arresting the cell cycle at G2/M phase.

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Alantolactone and isoalantolactone, main bioactive compounds that are present in many medicinal plants such as Inula helenium, L. Inula japonica, Aucklandia lappa, Inula racemosa, and Radix inulae, have been found to have various pharmacological actions including anti-inflammatory, antimicrobial, and anticancer properties, with no significant toxicity. Recently, the anticancer activity of alantolactone and isoalantolactone has been extensively investigated. Here, our aim is to review their natural sources and their anticancer activity with specific emphasis on mechanism of actions, by which these compounds act on apoptosis pathways. Based on the literature and also on our previous results, alantolactone and isoalantolactone induce apoptosis by targeting multiple cellular signaling pathways that are frequently deregulated in cancers and suggest that their simultaneous targeting by these compounds could result in efficacious and selective killing of cancer cells. This review suggests that alantolactone and isoalantolactone are potential promising anticancer candidates, but additional studies and clinical trials are required to determine their specific intracellular sites of actions and derivative targets in order to fully understand the mechanisms of therapeutic effects to further validate in cancer chemotherapy.