Proanthocyanidins

Aging is a complex and inevitable biological process that is associated with numerous chronically debilitating health effects. Development of effective interventions for promoting healthy aging is an active but challenging area of research. Mechanistic studies in various model organisms, noticeably two invertebrates,Caenorhabditis elegansandDrosophila melanogaster, have identified many genes and pathways as well as dietary interventions that modulate lifespan and healthspan. These studies have shed light on some of the mechanisms involved in aging processes and provide valuable guidance for developing efficacious aging interventions. Nutraceuticals made from various plants contain a significant amount of phytochemicals with diverse biological activities. Phytochemicals can modulate many signaling pathways that exert numerous health benefits, such as reducing cancer incidence and inflammation, and promoting healthy aging. In this paper, we outline the current progress in aging interv...

Proanthocyanidins, also named condensed tannins, are the result of flavanols condensation. Oligomers and polymers of proanthocyanidins can widely be found in the plant kingdom, as in fruits and berries, seeds, flowers, and leaves. They have a putative role as antioxidants, and they affect the inflammatory process via calcium-dependent release of nitric oxide and protect against H(2)O(2)-induced lipid peroxidation. They also demonstrated a role in cardiovascular diseases via vessel relaxation and LDL oxidation inhibition. These condensed tannins have also shown activities that improve diabetic complications, such as neuropathy, retinopathy, or nephropathy, including a decrease in serum glucose and advanced glycation end products. Furthermore, proanthocyanidins have evidenced anticancer properties by mitigating tumor development through induction of apoptosis or inhibition of cell proliferation. Finally, they are able to produce antiadhesive actions against bacteria in urinary and den...

This study was designed to find the best method to separate
proanthocyanidins from other phenolic compounds extracted from
pomegranate’s peel and to investigate their radical scavenging
capacity. Water is used as an effective solvent for extracting
antioxidant compounds from pomegranate’s peel (Punica
granatum). The final extract contained closely related compounds
not readily separable. Proanthocyanidins are the most potent
antioxidant found in this extract and the purification and separation
from other phenolic compounds is an important challenge. A
comparison of two SPE cartridges, including silica-based C18 and
aminopropyl for the isolation and purification of proanthocyanidins
extracted from pomegranate’s peel, showed that the proposed SPE
method with aminopropyl cartridge using alkalized aqueous
acetone as eluent was more effective for the purification and the
separation of extractable proanthocyanidins.

Each grape variety has its own phenolic profile. However, the concentration of the phenolic compounds present in wine, are mainly dependent of the winemaking process. Phenolic compounds influence wine sensorial characteristics namely taste or mouthfeel, bitterness, astringency and color. Humans can perceive six basic tastes: sweet, salty; sour; umami; fat-taste and bitter taste. This last basic taste is considered as a defense mechanism against the ingestion of potential poisons. Some of the genes, encoding G-protein-coupled receptors - TAS2Rs, which translate for these distinct bitter compounds detectors have been identified. Different phenolic compounds activate distinguished combination of TAS2Rs. Astringency in wine is primarily driven by proanthocyanidins, soluble protein-proanthocyanidins complexes diminish the protective salivary film and bind to the salivary pellicle; insoluble protein-proanthocyanidins complex and proanthocyanidins are rejected against salivary film and trigger astringency sensation via increasing friction.
Thus, the aim of this review is to expand the knowledge about the role of wine phenolic compounds in wine sensorial properties, namely in bitterness and astringency phenomenon’s.

A lactation experiment was conducted to determine the influence of quebracho condensed tannin extract (CTE) on ruminal fermentation and lactational performance of dairy cows. The cows were fed a high forage (HF) or a low forage (LF) diet with a forage-to-concentrate ratio of 59:41 or 41:59 on a dry matter (DM) basis, respectively. Eight multiparous lactating Holstein cows (62 ± 8.8 d in milk) were used. The design of the experiment was a double 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments, and each period lasted 21 d (14 d of treatment adaptation and 7 d of data collection and sampling). Four dietary treatments were tested: HF without CTE, HF with CTE (HF+CTE), LF without CTE, and LF with CTE (LF+CTE). Commercial quebracho CTE was added to the HF+CTE and the LF+CTE at a rate of 3% of dietary DM. Intake of DM averaged 26.7 kg/d across treatments, and supplementing CTE decreased intakes of DM and nutrients regardless of forage level. Digestibilities of DM and nu...

Pomegranate peels (Punica granatum) are usually discarded as waste even a significant portion of polyphenols are often present in high concentrations in the outer parts of fruits. The objective of this study was to establish an extraction procedure for polyphenols and proanthocyanidins from pomegranate’s peels (PMP), and to assess their potential radical scavenging activity. Water extraction efficiency at extraction temperature of 20 to 90 °C and extraction times of 5 to 60 min were studied. The recovery of polyphenols and proanthocyanidins was the highest at 50°C for 20 min. Water gave the highest extract yield of polyphenols and proanthocyanidins (17.78%, 1.22%) respectively, followed by 50% aqueous ethanol while ethyl acetate gave the lowest extract yield (0.75%, 0.049%) respectively. The DPPH (2,2-Diphenyl-1- picrylhydrazyl) radical scavenging activity of extracts had a linear relationship with the polyphenols yield in the extracts. The study of the effect of different pH medium revealed that polyphenols were more extractable by water and proanthocyanidins recovery was better in a buffer at pH 3.5. The extracts were stable in a freezer for about two weeks. This study revealed that two sequential water extractions has the economic and safety merits, and can be used as an environmentally friendly method for producing antioxidants from the PMP.

Several pharmaceutical products have been formulated over the past decades for the treatment of male and female alopecia, and pattern baldness, but relatively few metadata on their efficacy have been published. For these reasons, the pharmaceutical and medical attention has recently focused on the discovery of new and safer remedies. Particularly, great interest has been attracted by oligomeric procyanidin bioactivity, able to promote hair epithelial cell growth as well as to induce the anagen phase. Specifically, the procyanidin B2, a dimeric derivative extracted from apples, has demonstrated to be one of the most effective and safest natural compounds in promoting hair growth, both in vitro and in humans by topical applications. By evaluating the polyphenolic content of different apple varieties, we have recently found in the apple fruits of cv Annurca (AFA), native to Southern Italy, one of the highest contents of oligomeric procyanidins, and, specifically, of procyanidin B2. Thu...

A number of experiments have been conducted to investigate effects of tropical plants containing condensed tannins and/or saponins present in tropical plants and some plant oils on rumen fermentation and ecology in ruminants. Based on both in vitro and in vivo trials, the results revealed important effects on rumen microorganisms and fermentation including methane production. Incorporation and/or supplementation of these plants containing secondary metabolites have potential for improving rumen ecology and subsequently productivity in ruminants.

Introduction – White grape pomace is not subject to maceration, keeping nearly all polyphenols of grapes, so they represent important sources of bioactive compounds such as proanthocyanidins. Preparation of plant polyphenol extracts is usually performed using raw material powder. However, the fine particles make the further extraction procedure steps more difficult. Objective – To study the effect of mechanical treatments on extraction yields and anti-oxidant activity from different parts of white grape pomace. Methods – Skins, stems and seeds were isolated from the pomace of white winemaking process. Sequential solvent extraction of polyphenols, first using 80% methanol in water followed by 75% acetone in water, was carried out on both entire and milled (< 1 mm) grape solids; extraction on seed polyphenols was also performed in its squashed form. The phenolic content of each extract was verified by spectrometric and HPLC methods and its anti-oxidant activity was evaluated by the 1,1-diphenyl-2-picrylhydrazyl test. Results – More total polyphenols can be extracted from each milled tissue than from its entire form. Seeds present the highest total phenol, oligomeric and polymeric proanthocyanidin content, and similar extraction yield was found between milled and squashed tissues. The HPLC analysis showed no difference in extraction yield of low-molecular-weight proanthocyanidins between milled and entire stems. Anti-oxidant activity showed a positive correlation with total phenol content, galloyled oligomers and polymeric proanthocyanidins. Conclusion – The use of entire stems and squashed seeds for solvent extraction of polyphenols makes manipulation simpler and more cost-efficient, providing similar extraction yields to using their powdery forms.

Epidemiologic studies indicate that millions of people suffer from recurrent cystitis, a pathology requiring antibiotic prophylaxis and entailing high social costs. Cranberry is a traditional folk remedy for cystitis and, which, in the form of a variety of products and formulations has over several decades undergone extensive evaluation for the management of urinary tract infections (UTI). The aim of this retrospective study is to summarize and review the most relevant and recent preclinical and clinical studies on cranberries for the treatment of UTIs. The scientific literature selected for this review was identified by searches of Medline via PubMed. A variety of recent experimental evidence has shed light on the mechanism underlying the anti-adhesive properties of proanthrocyanidins, their structure-activity relationships, and pharmacokinetics. Analysis of clinical studies and evaluation of the cranberry efficacy/safety ratio in the prevention of UTIs strongly support the use of cranberry in the prophylaxis of recurrent UTIs in young and middle-aged women. However, evidence of its clinical use among other patients remains controversial.