Like most cutting edge medical technology, human stem cell research raises a number of difficult and important ethical issues and concerns, requiring potential benefits to be balanced against the need to protect the rights and welfare of citizens. Much of the debate involves research using embryonic stem (ES) cells, which in turns revolves around the moral status of the human embryo, and the level of respect and protection that should be accorded. This is an especially sensitive issue in pluralistic societies where different, if not conflicting, cultural and religious perspectives exist. Another contentious issue as far as the derivation of ES cells is concerned is the intent involved in producing the embryos, specifically whether it is ethically permissible to allowing embryos to be made solely for the purpose of research. These and several other relevant ethical issues will be discussed, including a comparison of guidelines and positions adopted in different countries.
For years, clinical studies involving human volunteers and several known pre-clinical in vivo models (i.e., mice, guinea pigs) have demonstrated their reliability in evaluating the effectiveness of a number of depigmenting agents. Although these models have great advantages, they also suffer from several drawbacks, especially involving ethical issues regarding experimentation. At present, a new depigmenting model using zebrafish has been proposed and demonstrated. The application of this model for screening and studying the depigmenting activity of many bioactive compounds has been given great attention in genetics, medicinal chemistry and even the cosmetic industry. Depigmenting studies using this model have been recognized as noteworthy approaches to investigating the antimelanogenic activity of bioactive compounds in vivo. This article details the current knowledge of zebrafish pigmentation and its reliability as a model for the screening and development of depigmenting agents. Several methods to quantify the antimelanogenic activity of bioactive compounds in this model, such as phenotype-based screening, melanin content, tyrosinase inhibitory activity, other related proteins and transcription genes, are reviewed. Depigmenting activity of several bioactive compounds which have been reported towards this model are compared in terms of their molecular structure and possible mode of actions. This includes patented materials with regard to the application of zebrafish as a depigmenting model, in order to give an insight of its intellectual value. At the end of this article, some limitations are highlighted and several recommendations are suggested for improvement of future studies.
The sources of embryos for Embryonic Stem Cell Research (ESCR) include surplus embryos from infertility treatments, and research embryos which are created solely for an ESCR purpose. The latter raises more ethical concerns. In a multi-religious country like Malaysia, ethical discussions on the permissibility of ESCR with regard to the use surplus and research embryos are diversified. Malaysia has formulated guidelines influenced by the national fatwa ruling which allows the use of surplus embryos in ESCR. Input from other main religions is yet to be documented. In light of this, this study addresses (i) the ethical viewpoints of Buddhist, Hindu and Catholic leaders on the permissibility of using surplus and research embryos; and (ii) the moral standpoints of religious leaders towards attaining a consensus on the practice of ESCR in Malaysia. Responses from the religious leaders were obtained via semi-structured, face-to-face interviews. The findings show that generally the Buddhist and Hindu leaders approve the use of surplus embryos. Their responses on the creation of research embryos for ESCR are varied. Meanwhile, the Catholic leaders distinctively objected to ESCR regardless of the embryo sources, referring to it as the destruction of life. Taking into account the diverse views, this study explores the response of the religious leaders for a general consensus wherever possible. The ethical discourse surrounding ESCR in a multi-religious setting offers new perspective, which needs to be explored in a broader global community.