You are looking at 161 - 170 of 5,639 items for :

  • Biology and Life Sciences x
  • All content x
Clear All

A study was conducted to evaluate the antioxidant enzymes activity, proximate and nutritional composition of four medicinal plants, which may contribute to folk pharmacological use in the treatment of different diseases. Plant samples were extracted and antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO) and ascorbate peroxide (APX) activity were estimated. Medicinal plants were also analysed for moisture, ash, protein, fibre, carbohydrate, and fats contents. Plant samples were wet digested and mineral composition in terms of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) was determined. The results revealed that antioxidant activity, proximate and nutritional composition differs significantly among tested medicinal plants extract. The leaves of medicinal plants showed more proximate composition (moisture contents, crude protein, fats contents), nutrient accumulation (N, P, K, Ca, Mg and Na), and antioxidant enzymes (POD, PPO, and APX activity). Among medicinal plants, Tribulus terrestris L. showed the highest amount of crude protein, crude fibre, gross energy, and N and Ca contents. Maximum K, Mg, Na contents, POD, PPO and APX activity was observed in Cenchrus ciliaris L. The ash, fats, phosphorus and SOD activity was more in Euphorbia hirta L. While, Cyperus rotundus L. produced maximum carbohydrates concentration among the tested plants. It is concluded that the target medicinal species had emerged as a good source of the antioxidant and nutritive source, which could play an important role in human nutrition. The extracts of these plants parts can be used in the synthesis of mineral and antioxidant-containing drugs and medicines. This study will provide a baseline for the pharmacology industry.

Restricted access

The genus Hypericum (Hypericaceae) consists of 484 species from 36 sections with worldwide distribution in different areas. Turkey is considered as hot spot for diversity of Hypericum genus. Despite numerous publications, Hypericum species still attracted considerable scientific interest due to pharmaceutically relevant secondary metabolites: naphthodianthrones, acylphloroglucinol derivatives, phenolic acids, flavonoid glycosides, biflavonoids, and some other valuable constituents. Phytochemical investigations carried out on different Hypericum species provided highly heterogeneous results. The content of bioactive compounds varies significantly due to many internal and external factors, including plant organs, phenological stage, genetic profile, environmental abiotic and biotic factors, such as growing site, light, temperature, radiation, soil drought and salinity, pathogens, and herbivores attack. The variations in content of bioactive compounds in plants are regarded as the main problem in the standardization of Hypericum-derived pharmaceuticals and dietary supplements. The review discusses the main factors contributing to the variations of bioactive compounds and what kind of modulations can increase quality of Hypericum raw material.

Restricted access

Genotype selection based on multiple traits in multi-years is frequently influenced by unpredictable rainfed conditions. The main objective of the study was to apply the new methodology of genotype by yield*trait (GYT) biplot for genotype selection and trait profiles in durum wheat genotypes based on multi-traits and multi-year data under rainfed conditions of Iran. A superiority index was applied based on GYT table for ranking of genotypes by the mean of all traits. The GYT biplot ranked the genotypes based on their levels in combining yield with other key traits. Grain yield was combined with target traits and showed the strengths and weaknesses of each genotype. Based on GYT-biplots the relationships among the studied traits were not repeatable across years, but they facilitated visual genotype comparisons and selection. The breeding lines G13, G10 and G15 ranked as the best in combination of the morph-physiological traits i.e., SPAD-reading, early heading, flag-leaf length and number of grain per spike with grain yield under rainfed conditions. The results indicate that there is a potential for simultaneous improvement of some characteristics of durum wheat under rainfed conditions. The GYT biplot was a useful tool for exploring the combination of yield with traits and trait profiles of the durum genotypes to obtain high genetic gains in the durum breeding programs.

Restricted access

Guettarda sierrae, a new species from the NE coastal fringe of Cuba, is described and compared with other species of the genus occurring in Cuba. Aspects of its distribution and conservation status are discussed. A lectotype for Guettarda undulata, a Cuban species related to Guettarda sierrae, is proposed herein.

Restricted access

Background and aims

High light causes disturbances in photosynthetic phosphorylation or damage to the photosystem II (PSII) structure or even assimilation tissues. The value of the red/far-red ratio (R/FR) provides the plant with information on the environmental light conditions, regulating, among others, photosynthetic activity and pigment composition of the plant. The response of the photosynthetic apparatus of the sporotrophophylls and nest leaves of Platycerium bifurcatum, grown for 6 months at the low or high R/FR ratio, were studied. Later, the plants were transferred to high light (1,200 μmol quantum · m−2 · s−1).


Changes in PSII photochemical activity were determined based on non-destructive methods of chlorophyll a fluorescence kinetics analysis. The measurement of radiation reflectance from the leaves allowed to determine the content of selected pigments related to the photosynthesis process and to assess changes in the Photochemical Reflectance Index. The calculation of reflectance difference and sensitivity analysis was used to identify so-called “stress-sensitive wavelengths”.

Results and discussion

Plant growth at high R/FR ratio prepares photosynthetic apparatus of ferns to high light and enables more efficient conversion of absorbed photons. The increase in the amount of photoprotective compounds allows the protection against photoinhibition in the sporotrophophyll leaves that play key roles in plant nutrition and reproduction.

Restricted access

Humans have lost their vitamin C-synthesizing capacities during evolution. Therefore, the uptake of this essential compound from external sources is mandatory in order to prevent vitamin C-deficient conditions resulting in severe morbidities such as scurvy. The potent antioxidant, immunomodulatory, and antiinfectious effects of vitamin C are known since the 1930s. We here (i) review the impact of vitamin C on innate and adaptive immune functions, (ii) provide an overview of its antimicrobial, antibacterial, antiviral, antiparasitic, and antifungal properties, and finally, (iii) discuss vitamin C as an adjunct treatment option for the combat of human infections by bacteria, particularly by emerging multidrug-resistant species.

Open access

Higher plant population and nitrogen management is an adopted approach for improving crop productivity from limited land resources. Moreover, higher plant density and nitrogen regimes may increase the risk of stalk lodging, which is a consequence of complex interplant competition of individual organs. Here, we aimed to investigate the dynamic change in morphology, chemical compositions and lignin promoting enzymes of the second basal inter-nodes altering lodging risk controlled by planting density and nitrogen levels. A field trial was conducted at the Mengcheng research station (33°9′44″N, 116°32′56″E), Huaibei plain, Anhui province, China. A randomized complete block design was adopted, in which four plant densities, i.e., 180, 240, 300, and 360 × 104 ha−1 and four N levels, i.e., 0, 180, 240, and 300 kg ha−1 were studied. The two popular wheat varieties AnNong0711 and YanNong19 were cultivated. Results revealed that the culm lodging resistance (CLRI) index of the second basal internodes was positively and significantly correlated with light interception, lignin and cellulose content. The lignin and cellulose contents were significantly and positive correlated to light interception. The increased planting density and nitrogen levels declined the lignin and its related enzymes activities. The variety AnNong0711 showed more resistive response to lodging compared to YanNong19. Overall our study found that increased planting densities and nitrogen regimes resulted in poor physical strength and enzymatic activity which enhanced lodging risk in wheat varieties. The current study demonstrated that stem bending strength of the basal internode was significantly positive correlated to grains per spike. The thousand grain weight and grain yield had a positive and significant relationship with stem bending strength of the basal internode. The results suggested that the variety YanNong19 produces higher grain yield (9298 kg ha−1) at density 240 × 104 plants ha−1, and 180 kg ha−1 nitrogen, while AnNong0711 produced higher grain yield (10178.86 kg ha−1) at density 240 × 104 plants ha−1 and with 240 kg ha−1 nitrogen. Moreover, this combination of nitrogen and planting density enhanced the grain yield with better lodging resistance.

Restricted access

The genetic diversity of 12 Atriplex halimus L. populations collected throughout its natural range in Morocco has been studied by using sequences of nrDNA ITS region. Within-population genetic diversity was high in comparison to others species with similar life histories and ecological traits. Most of genetic variation detected by AMOVA resided within populations (94%), relative to the amount of variation among populations (6%). The level of populations differentiation (FST = 0.06) was low, which corresponds with the high level of gene flow (4.00) revealed between populations. Differentiation among ecological groups of populations accounted only for 1.23% of the total ITS variation, which indicates that climatic conditions did not have an effect of population's structuration or that this differentiation is obviously not related to ITS markers. Furthermore, very low genetic differentiation (FCT = 0.015) was observed between regions (Moroccan populations versus American population). Strangely enough, geographic distances were not correlated to genetic differentiation between the populations (r = 0.06, P = 0.5). The structuration of populations in five groups was not operated according to their bioclimatic type. The data obtained in this assay could play a crucial role to establish efficient strategies for genetic resources conservation and to work out the scheme of breeding programs of Atriplex.

Restricted access
European Journal of Microbiology and Immunology
Authors: Cosme Alvarado-Esquivel, Ángel Osvaldo Alvarado-Félix, and Gustavo Alexis Alvarado-Félix

The epidemiology of Toxocara infection in rural Mexico is largely unknown. Therefore, we sought to determine the seroprevalence of Toxocara infection in rural people in a northern Mexican state. We performed a cross-sectional seroprevalence study of 641 people living in rural Durango State including 282 subjects of the general population, 214 subjects of Huichol ethnicity, and 145 subjects of Mennonite ethnicity. Sera of participants were analyzed for the presence of anti-Toxocara immunoglobulin G (IgG) antibodies using a commercially available enzyme immunoassay. Three (0.5%) of the 641 subjects tested were positive for anti-Toxocara IgG antibodies. Of the 3 Toxocara seropositive subjects, two were females, aged 19 and 39 years, and one was male, aged 59 years. They had contacted with dogs, cleaned cat excrement, consumed unwashed raw fruits, contacted soil, or lived in a house with soil floors. Seroprevalence of Toxocara infection was similar among the 3 groups of population studied: 0.4% for the general population, 0.9% for Huicholes, and 0.0% for Mennonites (P = 0.41). In conclusion, the Toxocara seroprevalence found in subjects in rural Durango is low as compared with those reported in people from rural areas in other countries.

Open access
Cereal Research Communications
Authors: N. Niu, Y.X. Bai, S. Liu, Q.D. Zhu, Y.L. Song, S.C. Ma, L.J. Ma, X.L. Wang, G.S. Zhang, and J.W. Wang

Studies of the pollen abortion mechanism in thermo-sensitive male sterile lines may provide a strong foundation for breeding hybrid wheat and establishing a theoretical basis for marker-assisted selection. To investigate the cause of pollen abortion in Bainong thermo – sensitive male sterile (BNS) lines, we analyzed the properties of pollen grains, changes in the tapetum and microspores in different anther developmental stages, and the distribution and deposition of nutrient substances in microspores. We found that tapetum degraded in the early uninucleate stage in sterile BNS (S-BNS), which was earlier than that of fertile BNS (F-BNS) tapetum. Large amounts of insoluble polysaccharides, lipids, and proteins were deposited until the trinucleate pollen stage in the nutritive cells in F-BNS. At the binucleate stage, the vacuoles disappeared and pollen inclusion increased gradually. At the trinucleate stage, these nutrients would help pollen grains mature and participate in fertilization normally. Therefore, early degradation of the tapetum, which inhibits normal microspore development, and the limited content of nutrient substances in pollen may be the main factors responsible for male sterility in BNS lines.

Restricted access