Photocytotoxic Effects of Strobilanthes crispus Extracts Towards Human Skin Squamous Carcinoma

Event Abstract Back to Event Photocytotoxic effects of Strobilanthes crispus extracts towards human skin squamous carcinoma Shi-Yun Lim1, Chui-Fung Loke1*, Sheri-Ann Tan1, Tze-Ven Poh1, Wan Z. Saad2, Saila Ismail2 and Khatijah Yusoff2 1 Tunku Abdul Rahman University College, Department of Bioscience, Faculty of Applied Sciences, Malaysia 2 Putra Malaysia University, Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Malaysia Background The killing mechanism by potential photosensitizing chlorophyll-metabolites from Strobilanthes crispus in human skin squamous carcinoma (A431) cells was investigated. The investigation focused on the mechanisms of cell death by the mitochondrial pathway involving death receptors/caspase activation; photodamage of Bcl-2 family in photodynamic therapy (PDT) response, as well as the photosensitivity efficacy of the plant-extracts. Methods Cell viability and reactive oxygen species (ROS) generation after PDT were measured using MTT and DCFH-DA assays respectively. Specific morphological and biochemical changes including cell shrinkage, membrane blebbing, DNA fragmentation, and regulation of anti-/pro-apoptotic proteins such as Bcl-2, Bax and caspase-3 were examined. Results No dark toxicity was observed at concentrations up to 500 μg/mL (for crude extract) and 5.0 μg/mL (for sub-fraction containing pheophorbide-a) in A431 cells. Surprisingly, upon 10 min PDT, apoptotic morphologies appeared in S. crispus-treated A431 at concentration more than 2 μg/mL of sub-fraction, while autophagic morphologies occurred in 1 μg/ mL pheophorbide-a-treated A431. The reduction in cellular viability dramatically charting an IC50 of 9.61 μg/mL for crude extract (containing 0.004 μg/mL of pheophorbide-a) and 2.20 μg/mL for sub-fraction (containing 0.001 μg/mL of pheophorbide-a) respectively. However, IC50 of pheophorbide-a (> 90% purity) on A431 upon PDT was 23-fold (0.085 μg/mL) lower than sub-fraction of S. crispus leave extract. ROS increased remarkably with the descending of A431 cell viability upon PDT. The increment of intracellular ROS lead to increase in depolarization of mitochondrial membrane potential in SCF-treated A431 with PDT. Fragmented DNA was observed in the S. crispus sub-fraction-treated A431 after PDT. Western blot analysis indicated the expression of Bax and caspase-3 proteins was upregulated, while Bcl-2 was downregulated upon PDT. Conclusion The results in the present study suggest that S. crispus could be served as a potential source of photosensitizing agent for treatment of cancer via PDT. Acknowledgements This research was financially supported under the Fundamental Research Grant Scheme (Ref: FRGS/1/2016/STG04/TARUC/02/1) by the Ministry of Education Malaysia and was conducted at Tunku Abdul Rahman Univeristy College (TAR UC). Keywords: Strobilanthes cripus, PDT - photodynamic therapy, pheophorbide-a., human skin squamous carcinoma (A431), Photocytotoxic Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Oral Presentation Topic: Cancer Citation: Lim S, Loke C, Tan S, Poh T, Saad WZ, Ismail S and Yusoff K (2019). Photocytotoxic effects of Strobilanthes crispus extracts towards human skin squamous carcinoma. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00032 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. Chui-Fung Loke, Tunku Abdul Rahman University College, Department of Bioscience, Faculty of Applied Sciences, Kuala Lumpur, Kuala Lumpur, 53300, Malaysia, lokecf@tarc.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Shi-Yun Lim Chui-Fung Loke Sheri-Ann Tan Tze-Ven Poh Wan Z Saad Saila Ismail Khatijah Yusoff Google Shi-Yun Lim Chui-Fung Loke Sheri-Ann Tan Tze-Ven Poh Wan Z Saad Saila Ismail Khatijah Yusoff Google Scholar Shi-Yun Lim Chui-Fung Loke Sheri-Ann Tan Tze-Ven Poh Wan Z Saad Saila Ismail Khatijah Yusoff PubMed Shi-Yun Lim Chui-Fung Loke Sheri-Ann Tan Tze-Ven Poh Wan Z Saad Saila Ismail Khatijah Yusoff Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.