Inflammation and oxidative stress are two interconnected processes that play a role in cancer development and progression. In the present research, we aimed to evaluate the anticancer effect of Pistacia lentiscus L. (PL) essential oil (EO) in vitro against MCF-7 breast cancer cells and in vivo in DMBA-mammary cancer induction on female C57BL/6 mice model as well as to investigate its anti-inflammatory and antioxidant potential as implicated mechanism. Our results revealed a new chemotypes-profile of 39 bio-compounds of PL EO. The main chemotypes were terpenoid and ketone compounds. In vitro, PL EO had a potent anti-proliferative activity against MCF-7 cells. In vivo, PL reduced the tumor number, volume, weight and burden values as compared to the DMBA-positive control group (p<0.05). Histopathology data confirmed the protective effect of PL traduced by the presence of necrosis area. PL EO revealed improvement on inflammatory perturbation in the C-RP levels and the complete blood cell count. Finally, PL improved oxidative disorders of lipid peroxidation, thiol groups, hydrogen peroxide and antioxidant enzymes depletion in plasma and mammary tissues. Also, a potent plasma scavenging capacity has been detected. Our data suggested that PL chemotypes inhibited cell proliferation, exerting a potential protective effect against DMBA-mammary cancer through anti-inflammatory and antioxidant enhancements. Targeting inflammation and oxidative stress may represent a promising strategy for breast cancer prevention and treatment.

Kathryn Bayne, David Bayvel, Judy MacArthur Clark, Gilles Demers, Christophe Joubert, Tsutomu Miki Kurosawa, Ekaterina Rivera, Ouajdi Souilem, Patricia V. Turne

Animals are used for scientific purposes across Africa to benefit humans, animals or the environment. Nonetheless, ethical and regulatory oversight remains limited in many parts of the continent. To strengthen this governance framework, the Pan-African Network for Laboratory Animal Science and Ethics brought together experts from 12 African countries to create an Africa-centric practical guide to facilitate the establishment and appropriate functioning of Institutional Animal Ethics Committees across Africa. The Guidelines are based on universal principles for the care and use of sentient animals for scientific purposes, with consideration of the cultural, religious, political and socio-economic diversity in Africa. They focus on 11 key elements, including responsibilities of institutions and of the Institutional Official; composition of the Committee; its responsibilities, functioning and authority; ethical application and review processes; oversight and monitoring of animal care and use and of training and competence; quality assurance; and the roles of other responsible parties. The intent is for African institutions to adopt and adapt the guidelines, aligning with existing national legislation and standards where relevant, thus ensuring incorporation into practice. More broadly, the Guidelines form an essential component of the growing discourse in Africa regarding moral considerations of, and appropriate standards for, the care and use of animals for scientific purposes. The increased establishment of appropriately functioning animal ethics committees and robust ethical review procedures across Africa will enhance research quality and culture, strengthen societal awareness of animals as sentient beings, improve animal well-being, bolster standards of animal care and use, and contribute to sustainable socio-economic development.

Despite the recognised need for education and training in laboratory animal science (LAS) and ethics in Africa, access to such opportunities has historically been limited. To address this, the Pan-African Network for Laboratory Animal Science and Ethics (PAN-LASE) was established to pioneer a support network for the development of education and training in LAS and ethics across the African continent. In the 4.5 years since the establishment of PAN-LASE, 3635 individuals from 28 African countries have participated in our educational activities. Returning to their home institutions, they have both established and strengthened institutional and regional hubs of knowledge and competence across the continent. Additionally, PAN-LASE supported the development of guidelines for establishment of institutional Animal Ethics Committees, a critical step in the implementation of ethical review processes across the continent, and in enhancing animal welfare and scientific research standards. Key challenges and opportunities for PAN-LASE going forward include the formalisation of the network; the sustainability of education and training programmes; implementation of effective hub-and-spoke models of educational provision; strengthening governance frameworks at institutional, national and regional levels; and the availability of Africa-centric open access educational resources. Our activities are enhancing animal welfare and the quality of animal research undertaken across Africa, enabling African researchers to undertake world-leading research to offer solutions to the challenges facing the continent. The challenges, successes and the lessons learnt from PAN-LASE’s journey are applicable to other low- and middle-income countries across the world seeking to enhance animal welfare, research ethics and ethical review in their own country or region.

This study aims to investigate the anti-cancer, antimicrobial and antioxidant activities of Pistacia lentiscus L. (P. lentiscus) extracts, as well as their phyto-chemical profile. The GC-MS crude chemical profile provided new chemotypes of fixed oil (FO) and essential oil (EO) extracts. Secondary metabolites screened high levels of polyphenols and condensed tannins in EO, while FO had the highest flavonoids content. A potent anti-proliferative activity of both extracts was shown on two human breast cancer cells (EO-IC50 = 5.2 mg/mL MDA-MB-231 cells). The antimicrobial activity showed that only EO was active against six multidrug resistant bacteria (inhibition zone 20-8 mm) and two fungi strains (inhibition zone 3-4 mm). Also, the highest in vitro antioxidant free-radical scavenging ability was in the case of EO (125.5 μg/mL). In vivo P. lentiscus EO provided corrective effect vs the tamoxifen (Txf) induced oxidative damage in liver and kidney in C57BL/6 in female mouse. These findings confirm that EO inhibits cell proliferation, induces bacterial death and has a potential antioxidant activity. KEY WORDS: Phytotherapy, Pistacia lentiscus, Antioxidant, Antimicrobial activity, Breast cancer Bull. Chem. Soc. Ethiop. 2023, 37(6), 1487-1501. DOI: https://dx.doi.org/10.4314/bcse.v37i6.15

The pervasive presence of atmospheric pollution, particularly polycyclic aromatic hydrocarbons such as 7,12-dimethylbenz(a)anthracene, instigates aberrant cellular and tissue conditions, precipitating oxidative damage and inflammatory cascades conducive to the onset of cancer, notably mammary cancer. Given the hepatic metabolism of 7,12-dimethylbenz(a)anthracene, the imperative of employing natural antioxidants becomes apparent. In this study, we delve into the antioxidant and hepato-protective properties of Pistacia lentiscus against 7,12-dimethylbenz(a)anthracene-induced toxicity, alongside exploring its potential anticancer attributes. Our investigations unveil Pistacia lentiscus's anti-proliferative efficacy against human breast cancer cell lines. Notably, 7,12-dimethylbenz(a)anthracene-intoxication escalates body weight, disrupts lipid profiles, and incites serum oxidative damage. Concurrently, hepatic and renal oxidative stress ensue, accompanied by heightened antioxidant enzyme activity in the 7,12-dimethylbenz(a)anthracene-exposed-group compared to controls (p<0.05). Nonetheless, Pistacia lentiscus co-administration rectifies biochemical imbalances, significantly attenuates oxidative stress aberrations, and augments antioxidant enzyme responses (p<0.05). Importantly, histological analysis evinces Pistacia lentiscus's shielding effect against 7,12-dimethylbenz(a)anthracene induced hepatocyte injury and steatosis. Our findings underscore Pistacia lentiscus's robust anti-proliferative, antioxidant, and hepato-protective capacities, mitigating metabolic disturbances, oxidative stress propagation in liver and kidney functions, and potential histological alterations, thereby impeding 7,12-dimethylbenz(a)anthracene-induced mammary cancer initiation. We posit that Pistacia lentiscus may serve as a prophylactic agent against breast cancer instigated by this carcinogen.