Physiological mechanisms and adaptation strategies of Lactuca sativa L. in response to Olea europaea L. and Ficus carica L. allelochemicals

Agro-industrial wastes of Ficus carica L. and Olea europaea L. represent great sources of bioactive phenolic compounds that would be actively involved in sustainable development. Most of these wastes possess a valuable source of phytotoxic compounds that would be used as potential bioherbicides, but their function and mechanisms of action in cultivated crops remain far to be understood. In this study, we investigate the biochemical and physiological mechanisms of action of fig and olive allelochemicals extracts in lettuce as a model plant for weed species studies. Results revealed that these allelochemicals triggered an oxidative stress through cell membrane damage in lettuce roots and leaves, which was mitigated by various adaptive responses. Therefore, an intricate defense system was implicated by the increase of enzymatic and non-enzymatic antioxidants in lettuce tissues. This adaptive physiological response was highly correlated with the regulation of the phenylpropanoid pathway through the distinguished activation of phenylalanine ammonia-lyase by 98% and phenolic accumulation by 85% under olive and fig leaves aqueous extracts. The outcomes of this study will help understanding the response of cultivated crop to fig and olive phenolic compounds that can be selective in their actions, or the plants can be selective in their responses

Variations in the prevalence of point (pre)hypertension in a Nigerian school-going adolescent population living in a semi-urban and an urban area

<p>Abstract</p> <p>Background</p> <p>Hypertension has been shown to start in early life and to track into adulthood. Detecting adolescents with hypertension and prehypertension will aid early intervention and reduce morbidity and mortality from the disorders. This study reports the point-prevalence of the two disorders in a semi-urban and an urban population of school-going adolescents in Nigeria.</p> <p>Methods</p> <p>A total of 843 adolescents from two places of domicile were studied. Their blood pressures and anthropometric indices were measured using standard protocol. Point-hypertension and point-prehypertension were defined with respect to each subject's gender, age and height. The prevalence of the disorders was calculated and reported age-wise and nutritional status-wise.</p> <p>Results</p> <p>The prevalence of point-prehypertension in the semi-urban area was 22.2% (20.7% for girls and 23.1% for boys) while it was 25.0% (21.8% for girls and 29.2% for boys) in the urban area. The prevalence of point-hypertension was 4.6% (4.1% for girls and 4.8% for boys) in the semi-urban area and 17.5% (18.0% for girls and 16.9% for boys) in the urban area. Point-prehypertension was not detected among the thin subjects of both places of domicile. The prevalence of point-prehypertension was similar in both the urban and semi-urban areas among the subjects who had normal BMI-for-age, and over-weight/obese subjects respectively. From the semi-urban to the urban area, the prevalence of point-hypertension increased approximately 3-folds among thin and normal BMI-for-age subjects, and 10-folds among overweight/obese subjects. Systolic hypertension was more preponderant in both the semi-urban and urban areas.</p> <p>Conclusions</p> <p>The prevalence of both disorders is considerably high in the studied populations. Urgent pediatric public health action is needed to address the situation.</p

How to strengthen a health research system: WHO's review, whose literature and who is providing leadership?

Background Health research is important for the achievement of the Sustainable Development Goals. However, there are many challenges facing health research, including securing sufficient funds, building capacity, producing research findings and using both local and global evidence, and avoiding waste. A WHO initiative addressed these challenges by developing a conceptual framework with four functions to guide the development of national health research systems. Despite some progress, more is needed before health research systems can meet their full potential of improving health systems. The WHO Regional Office for Europe commissioned an evidence synthesis of the systems-level literature. This Opinion piece considers its findings before reflecting on the vast additional literature available on the range of specific health research system functions related to the various challenges. Finally, it considers who should lead research system strengthening. Main text The evidence synthesis identifies two main approaches for strengthening national health research systems, namely implementing comprehensive and coherent strategies and participation in partnerships. The literature describing these approaches at the systems level also provides data on ways to strengthen each of the four functions of governance, securing financing, capacity-building, and production and use of research. Countries effectively implementing strategies include England, Ireland and Rwanda, whereas West Africa experienced effective partnerships. Recommended policy approaches for system strengthening are context specific. The vast literature on each function and the ever-growing evidence-base are illustrated by considering papers in just one key journal, Health Research Policy and Systems, and analysing the contribution of two national studies. A review of the functions of the Iranian system identifies over 200 relevant and mostly national records; an analysis of the creation of the English National Institute for Health Research describes the key leadership role played by the health department. Furthermore, WHO is playing leadership roles in helping coordinate partnerships within and across health research systems that have been attempting to tackle the COVID-19 crisis. Conclusions The evidence synthesis provides a firm basis for decision-making by policy-makers and research leaders looking to strengthen national health research systems within their own national context. It identifies five crucial policy approaches — conducting situation analysis, sustaining a comprehensive strategy, engaging stakeholders, evaluating impacts on health systems, and partnership participation. The vast and ever-growing additional literature could provide further perspectives, including on crucial leadership roles for health ministries.Health Evidence Network Evidence Synthesis; NIH

Estimating the burden of selected non-communicable diseases in Africa: a systematic review of the evidence

Background The burden of non-communicable diseases (NCDs) is rapidly increasing globally, and particularly in Africa, where the health focus, until recently, has been on infectious diseases. The response to this growing burden of NCDs in Africa has been affected owing to a poor understanding of the burden of NCDs, and the relative lack of data and low level of research on NCDs in the continent. Recent estimates on the burden of NCDs in Africa have been mostly derived from modelling based on data from other countries imputed into African countries, and not usually based on data originating from Africa itself. In instances where few data were available, estimates have been characterized by extrapolation and over-modelling of the scarce data. It is therefore believed that underestimation of NCDs burden in many parts of Africa cannot be unexpected. With a gradual increase in average life expectancy across Africa, the region now experiencing the fastest rate of urbanization globally, and an increase adoption of unhealthy lifestyles, the burden of NCDs is expected to rise. This thesis will, therefore, be focussing on understanding the prevalence, and/or where there are available data, the incidence, of four major NCDs in Africa, which have contributed highly to the burden of NCDs, not only in Africa, but also globally. Methods I conducted a systematic search of the literature on three main databases (Medline, EMBASE and Global Health) for epidemiological studies on NCDs conducted in Africa. I retained and extracted data from original population-based (cohort or cross sectional), and/or health service records (hospital or registry-based studies) on prevalence and/or incidence rates of four major NCDs in Africa. These include: cardiovascular diseases (hypertension and stroke), diabetes, major cancer types (cervical, breast, prostate, ovary, oesophagus, bladder, Kaposi, liver, stomach, colorectal, lung and non-Hodgkin lymphoma), and chronic respiratory diseases (chronic obstructive pulmonary disease (COPD) and asthma). From extracted crude prevalence and incidence rates, a random effect meta-analysis was conducted and reported for each NCD. An epidemiological model was applied on all extracted data points. The fitted curve explaining the largest proportion of variance (best fit) from the model was further applied. The equation generated from the fitted curve was used to determine the prevalence and cases of the specific NCD in Africa at midpoints of the United Nations (UN) population 5-year age-group population estimates for Africa. Results From the literature search, studies on hypertension had the highest publication output at 7680, 92 of which were selected, spreading across 31 African countries. Cancer had 9762 publications and 39 were selected across 20 countries; diabetes had 3701 publications and 48 were selected across 28 countries; stroke had 1227 publications and 19 were selected across 10 countries; asthma had 790 publications and 45 were selected across 24 countries; and COPD had the lowest output with 243 publications and 13 were selected across 8 countries. From studies reporting prevalence rates, hypertension, with a total sample size of 197734, accounted for 130.2 million cases and a prevalence of 25.9% (23.5, 34.0) in Africa in 2010. This is followed by asthma, with a sample size of 187904, accounting for 58.2 million cases and a prevalence of 6.6% (2.4, 7.9); COPD, with a sample size of 24747, accounting for 26.3 million cases and a prevalence of 13.4% (9.4, 22.1); diabetes, with a sample size of 102517, accounting for 24.5 million cases and a prevalence of 4.0% (2.7, 6.4); and stroke, with a sample size of about 6.3 million, accounting for 1.94 million cases and a prevalence of 317.3 per 100000 population (314.0, 748.2). From studies reporting incidence rates, stroke accounted for 496 thousand new cases in Africa in 2010, with a prevalence of 81.3 per 100000 person years (13.2, 94.9). For the 12 cancer types reviewed, a total of 775 thousand new cases were estimated in Africa in 2010 from registry-based data covering a total population of about 33 million. Among women, cervical cancer and breast cancer had 129 thousand and 81 thousand new cases, with incidence rates of 28.2 (22.1, 34.3) and 17.7 (13.0, 22.4) per 100000 person years, respectively. Among men, prostate cancer and Kaposi sarcoma closely follows with 75 thousand and 74 thousand new cases, with incidence rates of 14.5 (10.9, 18.0) and 14.3 (11.9, 16.7) per 100000 person years, respectively. Conclusion This study suggests the prevalence rates of the four major NCDs reviewed (cardiovascular diseases (hypertension and stroke), diabetes, major cancer types, and chronic respiratory diseases (COPD and asthma) in Africa are high relative to global estimates. Due to the lack of data on many NCDs across the continent, there are still doubts on the true prevalence of these diseases relative to the current African population. There is need for improvement in health information system and overall data management, especially at country level in Africa. Governments of African nations, international organizations, experts and other stakeholders need to invest more on NCDs research, particularly mortality, risk factors, and health determinants to have evidenced-based facts on the drivers of this epidemic in the continent, and prompt better, effective and overall public health response to NCDs in Africa

Mes ennemis, les facteurs de risque

International audienceWe have to distinguish between non-modifiable risk factors such as age, gender, heredity, (we cannot fight against these enemies), and modifiable risk factors (avoidable) such as hypertension, smoking, diabetes, and dyslipidemia. Environmental factors, bad diet, sedentary lifestyle, and smoking are the basis of these risk factors. Cardiovascular disease due to these risk factors is clinically silent during a given period, then symptoms occur which can eventually lead to death. Nine risk factors explain the occurrence of 90 % of myocardial infarctions (MI), their correction avoid 80 % of MI. Despite the presence of several studies proving that secondary prevention reduces coronary mortality, the management of cardiovascular risk factors is not optimal. \textcopyright 2021 Elsevier Masson SA

Olive Wastes as a High-Potential by-Product: Variability of Their Phenolic Profiles, Antioxidant and Phytotoxic Properties

The global world olive oil industry produces large amounts of wastes and wastewaters. However, the disposal of these polluting by-products is a significant environmental problem owing to their high polyphenolic compounds. In order to learn possible ways of exploiting this waste, we investigated the phytochemical profiles, the phytotoxicity and the antioxidant activities of olive wastes (leaves, mill wastewater (OMWW) and mill solid waste (OMSW)). Leaf extracts exhibited the highest phytotoxic and antioxidant effects, which are mainly due to its phenolic content. The chromatographic profiles depicted eleven phenolic compounds belonging to secoiridoids, phenyl alcohols, phenolic acids, phenylethanoid glycoside, and flavonoids. Hydroxytyrosol and oleuropein were the main components in leaf methanol and OMWW extracts, respectively, exhibiting an amount of 13.05 and 4.39 mg/g DW. These results will help to demonstrate the possibility of utilizing olive wastes, particularly the leaf, as an inexpensive natural product, in food and agricultural applications. Graphic Abstract: [Figure not available: see fulltext.]

Allelopathic potential and phenolic allelochemicals discrepancies in Ficus carica L. cultivars

The phytotoxic effect of some tree species could act as an ecological filter through chemical production that influences plant growth of other species. Despite this widespread interest, few studies have investigated the allelopathic effect of some Moraceae species, while this mechanism has not been studied in Ficus carica. To address this research, we attempted to identify the allelopathic mechanisms of thirteen local preserved fig cultivars on the germination and seedling growth of common weeds and standard target species. The results stated that all fig extracts displayed significant phytotoxic impact, and the degree of inhibition was appeared to be dependent on the cultivars and target species. In general, leaf extracts were more toxic and significantly influenced the seedling elongations, as compared to twig extracts. It was clearly marked that the germination and growth of weed species were totally affected by leaf aqueous and methanol extracts of cultivars Kahli and Bouhouli, respectively, at 40 g/L and 6 g/L. The phytochemical analysis through high performance liquid chromatography detected similar profile among cultivars but with a significant disparity in phenolic composition. Among the identified compounds, rutin is the major flavonoid compound recorded in cv. Zidi and was highly accumulated in leaf rather than in twig. It was obvious that the different fig cultivars or even their tissues can be characterized and clustered in three groups based on their allelopathic potential and phenolic compounds