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Cinchona officinalis (Cinchona Tree) and Corylus avellana (Common Hazel)
Published in Azamal Husen, Herbs, Shrubs, and Trees of Potential Medicinal Benefits, 2022
Sawsan A. Oran, Arwa Rasem Althaher, Mohammad S. Mubarak
Tannins (also known as tannic acid) are water-soluble polyphenols found in many plant diets, whereas proanthocyanidins (also known as condensed tannins) are plant-derived flavonoid polymers with a variety of health benefits (Xie et al., 2006). Hazelnut contains five hydrolyzable tannins and related compounds: Ellagic acid hexoside isomer, ellagic acid pentoside isomer, flavogallonic acid dilactone isomer, bis(hexahydroxydiphenoyl)-glucose (HHDP-glucose) isomer, and valoneic acid dilactone/sanguisorbic acid dilactone (Prosperini et al., 2009). The condensed tannins oproanthocyanidins are oligomers or polymers found in hazelnut and its by-products that are classified as procyanidins, propelargonidins, or prodelphinidins based on the flavan-3-ol unit (epi)catechin, (epi)afzelechin, or (epi)gallocatechin, respectively (Jakopic et al., 2011). Procyanidins A2, B1, and B2 (ZEPPA and GERBI, 2010; Fanali et al., 2018) and other procyanidin dimers and trimers, were found in hazelnut kernels (Jakopic et al., 2011). Furthermore, four isomers of B-type procyanidin have been identified in hazelnut shells (Yuan et al., 2018). A-type PAs were found as minor compounds, while (epi)-gallocatechin and gallate derivatives were identified as monomer units (Piccinelli et al., 2016).
Recent Discoveries of Natural Products as Antimicrobial Alternatives for Bovine Mastitis Treatment
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Pâmella B. A. Domingues, João Paulo L. Morgado, Maria Aparecida S. Moreira, Valdir F. Veiga-Júnior, Fábio A. Pieri
The chemical evaluation of aqueous and ethanolic extracts obtained from mango leaves (Mangifera indica) showed different compositions. The aqueous extract had more polar substances, such as tannins, condensed tannins, flavones and flavonoids. The ethanolic extract also had condensed tannins, but together with gallic acid and fatty acids. Comparing the antimicrobial action of the two extracts, the ethanolic extract demonstrated better results, with the MIC ranging from 1.8 mg/mL to 7.5 mg/mL for S. aureus ATCC 25923 and clinical isolates. The ethanolic extract, but not the aqueous extract, also showed the ability to remove mature biofilms from steel or rubber at a concentration of 45.3 mg/mL within 5 minutes of incubation (Manzur et al. 2020).
Free Radicals and Antioxidants
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Proanthocyanidins are traditionally considered to be condensed tannins (147, 163). The building blocks of proanthocyanidins include catechin and epicatechin (163). Proanthocyanidins are oligomers or polymers of a basic flavan-3-ol unit, with an average degree of polymerization between 4 and 11 to form tannins (163–164). Oligomeric proanthocyanidins (OPCs) are also called condensed tannins, procyanidolic oligomers (PCOs), leucoanthocyanins, and pycnogenols. Pycnogenol is a trade name for an OPC extract from the pine bark isolated by French scientist Jacques Masquelier in 1953 (164). Oligomeric and polymeric proanthocyanidins are present in flowers, nuts, fruits, bark, and seeds of various plants, as a defense against biotic and abiotic stressors. Their astringency protects the plants from pathogens and predators. They are mainly found in apples, grapes, grape seeds, wine, cranberries, and the leaves of bilberry, birch, ginkgo, hawthorn, and the barks of pine (163–164). Due to potent antioxidant activity, proanthocyanidins and OPCs have different pharmacological properties such as antimicrobial, disinfection, anti-parasite, anti-obesity, anti-inflammation, anti-carcinogenicity, vasodilation, neuroprotection, for the prevention and eventual treatment of several diseases (163–164). They can inhibit lipid peroxidation and platelet aggregation. Plant tannins are also used to tan animal skins for leather production since antiquity.
In vitro antibacterial and anti-inflammatory effects of Anacardium occidentale L. extracts and their toxicity on PBMCs and zebrafish embryos
Published in Drug and Chemical Toxicology, 2022
Luana Souza Amorim, Pedro Everton Marques Goes, Rebeca Dantas Alves Figueiredo, Juliana Alves da Costa Ribeiro Souza, Josean Fechine Tavares, Lucio Roberto Cançado Castellano, Ricardo Dias de Castro, Davi Farias, Sabrina Garcia de Aquino
The medicinal plants with potential use for the prevention and treatment of oral infections include the cashew tree Anacardium occidentale L. (da Silveira Vasconcelos et al. 2015). In folk medicine, this species has been widely used for various therapeutic purposes, such as toothache, gingival inflammation, sore throat, bronchitis, arthritis, intestinal colic, jaundice, diabetes, and asthma (Silva et al. 2007). Phytochemical analyses show the high presence of condensed tannins in the cashew tree bark, leaves, fruit, and peel, and these are the main chemical components responsible for their pharmacological actions (Rocha et al. 2011). Efficient antimicrobial action has also been reported, including against several oral pathogens (Akinpelu and Ojewole 2001). Specifically regarding the modulation of inflammation, the available literature indicates the action of A. occidentale on the acute inflammatory process, possibly via modulation of prostanoid production (Onasanwo et al. 2012) and antioxidant effects (Baptista et al. 2018) Its biological activity may vary according to the part of the plant used, as well as the use in the fresh or dehydrated form (Yamassaki et al. 2015, Hollands et al. 2016).
Health effects, sources, utilization and safety of tannins: a critical review
Published in Toxin Reviews, 2021
Kartik Sharma, Vikas Kumar, Jaspreet Kaur, Beenu Tanwar, Ankit Goyal, Rakesh Sharma, Yogesh Gat, Ashwani Kumar
Tannins are plant based polyphenols which are astringent in nature and are found in different parts of the herbs, plants are consumed as food and feed. These are majorly categorized into two groups, namely, condensed tannins (non hydrolyzable) and hydrolyzable tannins. Hydrolyzable tannins are further sub categorized into gallotannins and ellagitannins, where former are the simplest type among the hydrolyzable tannins (Khanbabaee and van Ree, 2001). A brief explanation of the different types of tannins is given in Figure 1. Condensed tannins, also known as proanthocyanidins, are more complex and therefore not yet determined completely. These are present in amounts greater than condensed tannins which occur only in trace amounts in certain foods (Chung et al.1998). Condensed tannins are the most commonly existing ones that are generally found in stems, legumes, trees, forages, etc. (Hassanpour et al.2011), whereas hydrolyzable tannins are found in seedpod, bark, wood, leaves, fruits, etc.
Chemopreventive Potential of Cereal Polyphenols
Published in Nutrition and Cancer, 2018
Shiwangni Rao, Abishek B. Santhakumar, Kenneth A. Chinkwo, Thiru Vanniasinkam, Jixun Luo, Christopher L. Blanchard
Tannins are the second most abundant polyphenols present in cereals (17). There are two major types of tannins: hydrolysable and condensed tannins. Hydrolysable tannins are composed of a single building block of gallic acid (a simple phenolic acid) and its derivatives (18). Condensed tannins, on the other hand, are comprised of a flavan-3-ol nucleus and its derivatives e.g., catechin and epicatechin (17,18). The high antioxidant activity of tannins has been attributed to the number of hydroxyl groups comprising of ortho-dihydroxy or galloyl groups in its skeletal structure. The degree of antioxidant activity has been shown to increase with an expansion in tannin structure as this translates to a higher number of hydroxyl groups available for hydroxylation and radical stabilization (34). Proanthocyanidin is one form of condensed tannin found in cereals and has exhibited the highest antioxidant activity amongst all tannins (17). Proanthocyanidins are commonly found in red pigmented cereal bran layers such as in red rice and sorghum (11,35,36). The ability of proanthocyanidin extracts to stabilize free radicals has been associated with its potential anti-inflammatory and anti-metastatic activity (37,38).