Essential oils are concentrated liquids of complex mixtures of volatile compounds and can be extracted from several plant organs. Essential oils are a good source of several bioactive compounds, which possess antioxidative and antimicrobial properties. In addition, some essential oils have been used as medicine. Furthermore, the uses of essential oils have received increasing attention as the natural additives for the shelf-life extension of food products, due to the risk in using synthetic preservatives. Essential oils can be incorporated into packaging, in which they can provide multifunctions termed "active or smart packaging." Those essential oils are able to modify the matrix of packaging materials, thereby rendering the improved properties. This review covers up-to-date literatures on essential oils including sources, chemical composition, extraction methods, bioactivities, and their applications, particularly with the emphasis on preservation and the shelf-life extension of food products.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1750-3841.12492

Essential oils: extraction, bioactivities, and their uses for food preservation.

In this present study, a comparative evaluation of the antioxidant capacities, phenol and polyphenol composition, membrane stabilization, and cytotoxicity to brine shrimps (Arthemia salina) of the leaf and stem extracts of Cissus multistriata were carried out. 2,2- Diphenyl-1-picryl hydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in the stem extract with IC50 of 29.25 ig/ml. The potency of radical scavenging effect of the stem extract was close to the synthetic antioxidant quercetin with IC50 of 21.05 ig/ml. The antioxidant activities of each extract increased with increasing concentration of extracts. The phenol and polyphenol content of the stem varied between 0.564 ± 0.000 to 6.200 ± 0.557% and that of the leaf content is lower (0.523 ± 0.000 to 3.400 ± 0.355%). The higher amount of phenolic compound in the stem could be contributory to the greater radical scavenging effects observed. The methanolic extracts exhibited minimum and maximum percentage membrane stability of 51.364 ± 11.241 and 56.098 ± 14.654% on human erythrocyte. The highest membrane stabilizing activity was observed in the stem extract with percentage stability of 56.098 ± 14.654%. The activity of the extracts was comparable to the standard anti-inflammatory drug (Indomethacin) used. The extracts are less toxic to the cell (Arthenia salina) with their LC/EC50 higher than that of standard potassium dichromate used. The results obtained in this present study indicate that C. multistriata can be a potential source of natural antioxidant and is relatively safe.

/pdf/comparative-antioxidant-capacity-membrane-stabilization-3iqn5exrgt.pdf

Comparative antioxidant capacity, membrane stabilization, polyphenol composition and cytotoxicity of the leaf and stem of Cissus multistriata

http://if-pan.krakow.pl/pjp/pdf/2010/1_185.pdf

Scavenging and antioxidant potential of physiological taurine concentrations against different reactive oxygen/nitrogen species

Plants of the genus Bauhinia (Fabaceae, Leguminosae), commonly known as cow's-paw or cow's hoof, are widely distributed in most tropical countries and have been used frequently in folk medicine to treat different kinds of pathologies, particularly diabetes, infections, as well as pain and inflammation. In recent years, interest in these plants has increased considerably throughout the world. The biological properties of different phytopreparations and pure metabolites have been investigated in numerous experimental in vivo and in vitro models. Although some contradicting evidence has been documented, in general, the results support the reported therapeutic properties, indicating that they are mainly due to the presence of flavonoids. This review summarizes the recent chemical and biological knowledge of plants of the genus Bauhinia.

Chemical composition and biological potential of plants from the genus Bauhinia

Bauhinia forficata Link authenticity using flavonoids profile: relation with their biological properties.

The present study was carried out to evaluate the antioxidant and antimicrobial activities of a methanol extract of Bauhinia racemosa (MEBR) (Caesalpiniaceae) stem bark in various systems. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, superoxide anion radical, nitric oxide radical, and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of the methanol extract increased in a concentration-dependent manner. About 50, 100, 250, and 500 µg MEBR inhibited the peroxidation of a linoleic acid emulsion by 62.43, 67.21, 71.04, and 76.83%, respectively. Similarly, the effect of MEBR on reducing power increased in a concentration-dependent manner. In DPPH radical scavenging assays the IC50 value of the extract was 152.29 µg/ml. MEBR inhibited the nitric oxide radicals generated from sodium nitroprusside with an IC50 of 78.34 µg/ml, as opposed to 20.4 µg/ml for curcumin. Moreover, MEBR scavenged the superoxide generated by the PMS/NADH-NBT system. MEBR also inhibited the hydroxyl radical generated by Fenton's reaction, with an IC50 value of more than 1000 µg/ml, as compared to 5 µg/ml for catechin. The amounts of total phenolic compounds were also determined and 64.7 µg pyrocatechol phenol equivalents were detected in MEBR (1 mg). The antimicrobial activities of MEBR were determined by disc diffusion with five Gram-positive, four Gram-negative and four fungal species. MEBR showed broad-spectrum antimicrobial activity against all tested microorganisms. The results obtained in the present study indicate that MEBR can be a potential source of natural antioxidant and antimicrobial agents.

/pdf/antioxidant-and-antimicrobial-activities-of-bauhinia-4cr0mjitlc.pdf

Antioxidant and antimicrobial activities of Bauhinia racemosa L. stem bark

We propose an unbiased methodology to rank compounds for advancement into comprehensive preclinical testing for Alzheimer's disease (AD). Translation of compounds to the clinic in AD has been hampered by poor predictive validity of models, compounds with limited pharmaceutical properties, and studies that lack rigor. To overcome this, MODEL-AD's Preclinical Testing Core developed a standardized pipeline for assessing efficacy in AD mouse models. We hypothesize that rank-ordering compounds based upon pharmacokinetic, efficacy, and toxicity properties in preclinical models will enhance successful translation to the clinic. Previously compound selection was based solely on physiochemical properties, with arbitrary cutoff limits, making ranking challenging. Since no gold standard exists for systematic prioritization, validating a selection criteria has remained elusive. The STOP-AD framework evaluates the drug-like properties to rank compounds for in vivo studies, and uses an unbiased approach that overcomes the validation limitation by performing Monte-Carlo simulations. HIGHLIGHTS: Promising preclinical studies for AD drugs have not translated to clinical success. Systematic assessment of AD drug candidates may increase clinical translatability. We describe a well-defined framework for compound selection with clear selection metrics.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/alz.13108

K. Murugesh

Papers

Antioxidant and antimicrobial activities of Bauhinia racemosa L. stem bark

STOP-AD portal: Selecting the optimal pharmaceutical for preclinical drug testing in Alzheimer's disease.