Plants contain significant amounts of bioactive compounds which have potential benefits to livestock and humans. This study evaluated the phytochemicals of some plant materials that have potential animal nutrition values. In this study, fresh samples (6 samples per each) of four leaves: Siam weed (Chromolaena odorata L.), African basil (Ocimum gratissimum L.), waterleaf (Talinum triangulare Jacq. Willd), and Mexican sunflower (Tithonia diversifolia Hemsl. A. Gray) were air-dried (between 27 and 31 ^oC), oven-dried (at 65 ^oC) or freeze-dried (at -80 ^oC). The leaves were milled in a 1.0 mm sieve and the phytochemical contents of each leaf sample (in triplicates) were quantified. Phytochemicals quantified were flavonoids, tannins, beta carotene, and xanthophylls for each of the leaves. Data were subjected to Analysis of Variance and significant means separated using Duncan Multiple Range Test. Flavonoids, tannins, and xanthophylls were found to be the highest (P < 0.05) in most air-dried leaf samples compared to oven-dried and freeze-dried ones. Flavonoids, tannins, beta carotene, and xanthophylls in the leaves showed that all leaf samples appear to have good potentials to be used as natural feed additives such as egg yolk colourants in laying chicken feeds. In-vivo studies using birds were recommended.

Essential oils are intensively studied in recent years as promising bio-herbicides. A strong inhibitory activity on seed germination and phytotoxic effect on seedling growth have been reported for Origanum vulgare subsp hitum (Link) Ietswaart essential oil. It has also been found that the phytotoxic effect is weaker in the treatment of plants at a more advanced stage in their development. Thus, when treating potato plants with a height of 30-40 cm with aqueous solutions of essential oil, the effect comes down to the appearance of single spots on the leaves, which does not disturb the growth of the plants. In the present study, the metabolic profiles of healthy leaves of control potato plants and leaves with spots formed as a result of processing with aqueous solutions of Origanum vulgare subsp hirtum essential oil, were comparatively analyzed. The metabolite analysis was made by GC/MS. Potato plants were treated with concentrations of essential oil - 5 and 10 µl/mL. The leaves were collected 7 days after treatment. Metabolites representatives of basic groups of substances - amino acids, organic and phenolic acids, mono- and disaccharides were identified. In the damaged leaves, a higher content of monosaccharides - fructose and glucose, pyroglutamic acid and amino acids – proline, serine, aspartic acid, was found compared to control leaves. A less differences were found in terms of the accumulation of chlorogenic, ferulic, and quinic acids, sucrose. The results presented complement the knowledge of a plant reaction to abiotic stress.

Melissa officinalis L., from the Lamiaceae family, is one of the most important medicinal and aromatic plants with potential in the market. With the passing of time, the use of medicinal plants in the treatment of some illness has gone from the simplest forms of local treatment to the industrial manufacture of phytotherapics. In addition to their medicinal effect, they can also be used in the form of infusions and decoctions and in various food preparations. In this sense, the objective of this work was to compare three different extraction methods: infusion (100% water), maceration (80:20 ethanol: water v:v) and ultrasound assisted extraction (UAE) under previous optimized extraction conditions (33.0 ± 3.2 min, 371.7 ± 19.3 W and 39.9 ± 1.4% ethanol), in plants grown under sustainable cultivation under full irrigation in June. The parameters studied included bioactive evaluation through antimicrobial (microdilution method), antioxidant (thiobarbituric acid reactive substances - TBARS), cytotoxicity (sulforhodamine B) and anti-inflammatory (RAW cells) assays. The composition of phenolic compounds and organic acids was also studied by GC-MS and HPLC-DAD, respectively. According to the obtained results, eight phenolic compounds were identified and quantified, being rosmarinic acid the main one for the three extraction methods (infusion: 107.1±0.9 mg/g extract; maceration: 155.7±0.3 mg/g extract; UAE: 118.7±0.6 mg/g extract). For Lithospermic acid A isomer (25.25 ± 0.01 mg/g) and Hydroxylsalvianolic E (111.70 ± 2.20 mg/g), the UAE revealed the lowest content of individual polyphenols, whereas maceration recorded the highest extractability. On the other hand, the content of six of the eight polyphenols detected for the ultrasound-assisted extraction was similar to the infusion and maceration methods. In terms of antioxidant activity, the infusions showed the highest capacity (3.00 ± 0.14 μg/mL), followed by maceration (5.33 ± 0.30 μg/mL) and UAE (12 ± 0.15 μg/mL). The highest anti-inflammatory activity was verified for the infusion (244 ± 11 μg/mL), followed by UAE (305 ± 9 μg/mL), with no activity recorded for the maceration extract (>400 μg/mL). The antitumor properties were evaluated in 5 cell lines, with the best results being recorded for infusion, except AGS (24 ± 1 μg/mL) where the best results were for the UAE; being the maceration extract more active against NCI-H460 (190 ± 7 μg/mL). It is therefore concluded that the extraction method that contributes to the highest obtainment of phenolic compounds is maceration, followed by infusion and ultrasound-assisted extraction. As for the bioactive and antioxidant compounds, infusion is the most efficient method, followed by maceration and ultrasound. Overall, these natural extracts are interesting ingredients, capable of replacing counterparts of synthetic origin, and can find wide applications in the industrial sector (e.g. food, pharmaceutical and cosmetic companies). Also emphasizing the high contents in rosmarinic acid, and the obtained bioactivity, that turns this samples of great interest to increase their production to obtain extracts enriched with this bioactive molecule.

Micronutrients play a critical role in plant growth and development, and their deficiency can cause adverse effects on plant performance. Also, these elements can influence plant physiological processes as they incorporate in the molecular structure of enzymes as cofactors. In this study, the impacts of micronutrients solution containing manganese (125 ppm), iron (200 ppm), zinc (60 ppm), and copper (20 ppm) were investigated on growth parameters, yield, and antioxidant enzymes activity of tomato (Solanum lycopersicum) plants. Greenhouse tomatoes (cultivar Jet Star F1) were irrigated with the mentioned concentrations of elements in a completely randomized design with five independent biological replicates. The micronutrient treatment increased the specific activities of superoxide dismutase, ascorbate peroxidase, glutathione reductase, guaiacol peroxidase, catalase, phenylalanine ammonia-lyase, as well as phenols and salicylic acid contents in tomato leaves. However, malondialdehyde level and electrolyte leakage index were unaffected. Analysis of plant growth parameters revealed that micronutrients increased the stem diameter, root length, the number of leaves, stem height, and fruit’s fresh weight in the treated plants. Overall, our results indicated that micronutrients positively affected the growth and development of tomato plants without adverse effects on the health indices. Moreover, the application of micronutrients can magnify the antioxidant capacity of tomato plants through increasing enzymes activity as well as phenols and salicylic acid levels. These changes would benefit the plants under abiotic/biotic stress conditions where elevated levels of antioxidant activities are crucial.

Cowpea (Vigna unguiculata) is a heat and drought resistant legume which thrives in poor and marginal soils, also due to its symbiosis with nitrogen fixing bacteria. Its high protein content suggests this crop fits perfectly with the three dimensions of sustainable development; social, economic and environmental issues. Extensive use of commercial varieties causes genetic variability loss, compromising breeding efforts in a context of climate changes. To contribute to the evaluation of Portuguese cowpea germplasm, several landraces were compared with a commercial variety (CV) in terms of productivity and physiological responses to drought. Potted plants were grown in a semi-controlled environment and well irrigated during the vegetative growth. Water stress was induced during the reproductive phase in half of the plants. Physiological measurements were conducted during stress. At the end of the cycle pods and seeds were counted and weighted. Despite a clear effect of stress in photosynthesis, there were no differences between the CV and landraces. However, under drought higher relative chlorophyll content (SPAD), was kept for a longer time in CV. Both the CV and landraces showed a marked decrease in productivity (60 - 70%) under stress. The induced drought had no impact on grains weight. As expected, the CV produced bigger and heavier seeds, eventually more appealing to consumers. Results suggest that CV and the studied landraces present a similar behaviour, reflecting the species adaptation to Mediterranean climate. Molecular characterization of genetic diversity is on course using microsatellites.