Reuven Or

D. Robinson, S. Ritter, L. Zadik-Weiss, H. Ounallah-Saad, N. Abu-Ahmad, R. Kashkoosh, M. Yassin, and R. Or. 2020. “Bridging the accessibility gap of cannabinoid medicine and Arabic culture.” Rambam Maimonides Medical Journal, 11, 1. Publisher's Version Abstract
Arabs are a large minority group in the Israeli society. With the increasing use of medical cannabis throughout Israel due to changing governmental policies, the interactions of the Arab society with medical cannabis becomes of scientific and medical relevance. Recreational cannabis use is considered haram (forbidden) in Islam. However, most religious scholars agree that medical cannabis usage might be justified as zarurat (emergency and life-saving, therefore allowed) use. Obstacles to medical cannabis use within the Arabic population may relate to language barrier and/or cultural barriers. There are few Arabic-speaking web-based medical-cannabis support groups, and little official information about it is available in the Arabic language. In order for the full benefits of medical cannabis to reach the entire Israeli population, a government-sponsored web-based educational program is necessary in Hebrew and Arabic, both of which are among the nation's official languages, thereby contributing to the equalization of health resource accessibility. © 2020 Robinson et al. This is an open-access article. All its content, except where otherwise noted, is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
O. Almogi-Hazan, I. Khuja, S. Ritter, and R. Or. 2020. “The highs and lows of cannabis in cancer treatment and bone marrow transplantation.” Rambam Maimonides Medical Journal, 11, 1. Publisher's Version Abstract
In the last decade, we have observed an increased public and scientific interest in the clinical applications of medical cannabis. Currently, the application of cannabinoids in cancer patients is mainly due to their analgesic and anti-emetic effects. The direct effects of phyto-cannabinoids on cancer cells are under intensive research, and the data remain somewhat inconsistent. Although anti-proliferative properties were observed in vitro, conclusive data from animal models and clinical trials are lacking. Since immunotherapy of malignant diseases and bone marrow transplantation are integral approaches in hemato-oncology, the immuno-modulatory characteristic of cannabinoids is a fundamental aspect for consideration. The effect of cannabinoids on the immune system is presently under investigation, and some evidence for its immunoregulatory properties has been shown. In addition, the interaction of cannabinoids and classical cytotoxic agents is a subject for further investigation. Here we discuss the current knowledge of cannabinoid-based treatments in preclinical models and the limited data in oncological patients. Particularly, we address the possible contradiction between the direct anti-tumor and the immune-modulatory effects of cannabinoids. Better understanding of the mechanism of cannabinoids influence is essential to design therapies that will allow cannabinoids to be incorporated into the clinic. © 2020 Gonen and Amital. This is an open-access article. All its content, except where otherwise noted, is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
O. Almogi-Hazan and R. Or. 2020. “Cannabis, the endocannabinoid system and immunity—the journey from the bedside to the bench and back.” International Journal of Molecular Sciences, 21, 12, Pp. 1-17. Publisher's Version Abstract
The Cannabis plant contains numerous components, including cannabinoids and other active molecules. The phyto-cannabinoid activity is mediated by the endocannabinoid system. Cannabinoids affect the nervous system and play significant roles in the regulation of the immune system. While Cannabis is not yet registered as a drug, the potential of cannabinoid-based medicines for the treatment of various conditions has led many countries to authorize their clinical use. However, the data from basic and medical research dedicated to medical Cannabis is currently limited. A variety of pathological conditions involve dysregulation of the immune system. For example, in cancer, immune surveillance and cancer immuno-editing result in immune tolerance. On the other hand, in autoimmune diseases increased immune activity causes tissue damage. Immuno-modulating therapies can regulate the immune system and therefore the immune-regulatory properties of cannabinoids, suggest their use in the therapy of immune related disorders. In this contemporary review, we discuss the roles of the endocannabinoid system in immunity and explore the emerging data about the effects of cannabinoids on the immune response in different pathologies. In addition, we discuss the complexities of using cannabinoid-based treatments in each of these conditions. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
S. Ritter, L. Zadik-Weiss, O. Almogi-Hazan, and R. Or. 2020. “Cannabis, one health, and veterinary medicine: Cannabinoids' role in public health, food safety, and translational medicine.” Rambam Maimonides Medical Journal, 11, 1. Publisher's Version Abstract
Public health is connected to cannabis with regard to food, animal feed (feed), and pharmaceuticals. Therefore, the use of phytocannabinoids should be examined from a One Health perspective. Current knowledge on medical cannabis treatment (MCT) does not address sufficiently diseases which are of epidemiological and of zoonotic concern. The use of cannabinoids in veterinary medicine is illegal in most countries, mostly due to lack of evidence-based medicine. To answer the growing need of scientific evidence-based applicable medicine in both human and veterinary medicine, a new approach for the investigation of the therapeutic potential of cannabinoids must be adopted. A model that offers direct study of a specific disease in human and veterinary patients may facilitate development of novel therapies. Therefore, we urge the regulatory authorities-the ministries of health and agriculture (in Israel and worldwide)-to publish guidelines for veterinary use due to its importance to public health, as well as to promote One Health-related preclinical translational medicine studies for the general public health. © 2020 Ritter et al. This is an open-access article. All its content, except where otherwise noted, is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
I. Khuja, Z. Yekhtin, R. Or, and O. Almogi-Hazan. 2019. “Cannabinoids reduce inflammation but inhibit lymphocyte recovery in murine models of bone marrow transplantation.” International Journal of Molecular Sciences, 20, 3. Publisher's Version Abstract
Cannabinoids, the biologically active constituents of Cannabis, have potent neuronal and immunological effects. However, the basic and medical research dedicated to medical cannabis and cannabinoids is limited. The influence of these treatments on hematologic reconstitution and on the development of graft versus host disease (GVHD) after bone marrow transplantation (BMT) is largely unknown. In this research, we compared the influence of D9 tetrahydrocannabinol (THC) and cannabidiol (CBD) on lymphocyte activation in vitro and in murine BMT models. Our in vitro results demonstrate that these treatments decrease activated lymphocyte proliferation and affect cytokine secretion. We also discovered that CBD and THC utilize different receptors to mediate these effects. In vivo, in a syngeneic transplantation model, we demonstrate that all treatments inhibit lymphocyte reconstitution and show the inhibitory role of the cannabinoid receptor type 2 (CB2) on lymphocyte recovery. Although pure cannabinoids exhibited a superior effect in vitro, in an allogeneic (C57BL/6 to BALB/c) BMT mouse model, THC-high and CBD-high cannabis extracts treatment reduced the severity of GVHD and improved survival significantly better than the pure cannabinoids. Our results highlights the complexity of using cannabinoids-based treatments and the need for additional comparative scientific results. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.