Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

https://www.mdpi.com/2218-273X/9/10/551/pdf

Antidiabetic Potential of Medicinal Plants and Their Active Components.

Biodiesel is an alternative to petroleum-based fuels derived from a variety of feedstocks, including vegetable oils, animal fats, and waste cooking oil. At present, biodiesel is mainly produced from conventionally grown edible oils such as soybean, rapeseed, sunflower, and palm. The cost of biodiesel is the main obstacle to commercialization of the product. Biodiesel produced from edible oils is currently not economically feasible. On the other hand, extensive use of edible oils for biodiesel production may lead to food crisis. These problems can be solved by using low-cost feedstocks such as non-edible oils and waste cooking oils for biodiesel production. This paper reviews numerous options of non-edible oils as the substantial feedstocks, biodiesel processing, and effect of different parameters on production of biodiesel.

https://journals.sagepub.com/doi/pdf/10.1177/0144598716630166

Biodiesel production from non-edible plant oils:

GC-FID and GC-MS analysis of essential oil from oregano leaves (Origanum compactum) resulted in the identification of 46 compounds, representing more than 98% of the total composition. Carvacrol was the predominant compound (36.46%), followed by thymol (29.74%) and p-cymene (24.31%). Serial extractions with petroleum ether, ethyl acetate, ethanol, and water were performed on aerials parts of Origanum compactum. In these extracts, different chemical families were characterized: polyphenols (gallic acid equivalent 21.2 to 858.3 g/kg), tannins (catechin equivalent 12.4 to 510.3 g/kg), anthocyanins (cyanidin equivalent 0.38 to 5.63 mg/kg), and flavonoids (quercetin equivalent 14.5 to 54.7 g/kg). The samples (essential oil and extracts) were subjected to a screening for antioxidant (DPPH and ABTS assays) and antimalarial activities and against human breast cancer cells. The essential oil showed a higher antioxidant activity with an IC50= 2 ± 0.1 mg/L. Among the extracts, the aqueous extract had the highest antioxidant activity with an IC50= 4.8 ± 0.2 mg/L (DPPH assay). Concerning antimalarial activity, Origanum compactum essential oil and ethyl acetate extract showed the best results with an IC50 of 34 and 33 mg/mL, respectively. In addition, ethyl acetate extract (30 mg/L) and ethanol extract (56 mg/L) showed activity against human breast cancer cells (MCF7). The oregano essential oil was considered to be nontoxic.

Oregano: Chemical Analysis and Evaluation of Its Antimalarial, Antioxidant, and Cytotoxic Activities

An experimental evaluation of engine performance and emisssion characteristics of CI engine operated with Roselle and Karanja biodiesel

Screening of the antioxidative and antimicrobial properties of the essential oils of Pimpinella anisetum and Pimpinella flabellifolia from Turkey

Extracts from Polygonum senegalensis (Polygonaceae) and Pseudocedrela kotschyi (Meliaceae) are two important traditionally used medicinal plants in rural Benin to treat many diseases and notably type 2 diabetes. The aim of the study was to investigate the α-glucosidase inhibition, antioxidant and antibacterial activities of those plants extract: Polygonum senegalensis leaves, and Pseudocedrela kotschyi root. Hydro-alcoholic (50%) extracts were analyzed for their phytochemical content and tested for their inhibition potency on α-glucosidase from Saccharomyces cerevisiae. Antioxidant activities were assessed using the DPPH, ORAC, FRAP and DCFH-DA (cell based) assay. Finally, the antibacterial activity was evaluated using MIC determination on four Gram-positive cocci (Bacillus subtilis, Clostridium difficile, Enterococcus faecalis, Staphylococcus aureus), three Gram-negative bacilli (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae), and the yeast Candida albicans. Each extract presented significant α-glucosidase inhibition and antioxidant activities. Polygonum senegalensis leaf extracts were the most active in each in vitro assay with an IC50 = 1.5 μg/ml for α-glucosidase inhibition and an IC50 = 6.8 μg/ml for DPPH scavenging, - 4.5 μmol Fe II/g of dry matter - 9366 μmol Trolox / g DW - for FRAP and ORAC values, respectively. IC50 = 2.3 μg GA / ml for DCFH-DA assay. Concerning its antibacterial activity, a growth inhibitory effect was observed only against three Gram negative bacilli: B. subtilis, E. faecalis, S. aureus and the yeast C. albicans at high concentration. The results showed that the semi alcoholic extract of the two studied plants possess α-glucosidase inhibitory activity, antioxidant potency, and low antibacterial effect.

/pdf/in-vitro-biological-effects-of-two-anti-diabetic-medicinal-24tjgnrlrm.pdf

In vitro biological effects of two anti-diabetic medicinal plants used in Benin as folk medicine.

Composition of Azadirachta indica and Carapa procera (Meliaceae) seed oils and cakes obtained after oil extraction

The association of natural fibers and raw land soil has many advantages (thermal control, sound insulation, mechanical behavior, etc.). However, the major issue with the use of these materials is the lack of knowledge regarding their reliability and durability. In this work, we have evaluated the influence of kenaf fiber length on the mechanical and thermal properties of compressed earth blocks (CEB). Fibers with length 10, 20 or 30 mm were used at mixing rate of 1.2% dry weight of soil; with the aim to enhance the mechanical and thermal properties of CEB fabricated starting from a plastic clayey soil mined in Benin. Analysis of the mechanical behavior of different Soil/Fiber formulations in terms of flexural strength demonstrated the beneficial effect of the fibers. However, the mechanical strength of CEB obtained by immersing fibers till saturation prior to incorporation into the soil greatly diminished. The higher flexural strength was obtained with fibers 30 mm long. The thermal conductivity of CEB decreased when the fiber length was raised. The results showed the real possibility to improve CEB mechanical and thermal properties by using fibers for reinforcement.

Dominique K. C. Sohounhloue

Papers

In vitro biological effects of two anti-diabetic medicinal plants used in Benin as folk medicine.

Composition of Azadirachta indica and Carapa procera (Meliaceae) seed oils and cakes obtained after oil extraction

Influence of the kenaf fiber length on the mechanical and thermal properties of Compressed Earth Blocks (CEB)

Iconography : Propriétés antioxydantes de l'huile essentielle des feuilles de Clausena anisata (Wild) Hook