Bilge Sener

Bio: Bilge Sener is an academic researcher from Gazi University. The author has contributed to research in topics: DPPH & Butyrylcholinesterase. The author has an hindex of 40, co-authored 214 publications receiving 5501 citations. Previous affiliations of Bilge Sener include Ankara University.

Resveratrol: A Double-Edged Sword in Health Benefits

Abstract: Resveratrol (3,5,4′-trihydroxy-trans-stilbene) belongs to polyphenols’ stilbenoids group, possessing two phenol rings linked to each other by an ethylene bridge. This natural polyphenol has been detected in more than 70 plant species, especially in grapes’ skin and seeds, and was found in discrete amounts in red wines and various human foods. It is a phytoalexin that acts against pathogens, including bacteria and fungi. As a natural food ingredient, numerous studies have demonstrated that resveratrol possesses a very high antioxidant potential. Resveratrol also exhibit antitumor activity, and is considered a potential candidate for prevention and treatment of several types of cancer. Indeed, resveratrol anticancer properties have been confirmed by many in vitro and in vivo studies, which shows that resveratrol is able to inhibit all carcinogenesis stages (e.g., initiation, promotion and progression). Even more, other bioactive effects, namely as anti-inflammatory, anticarcinogenic, cardioprotective, vasorelaxant, phytoestrogenic and neuroprotective have also been reported. Nonetheless, resveratrol application is still being a major challenge for pharmaceutical industry, due to its poor solubility and bioavailability, as well as adverse effects. In this sense, this review summarized current data on resveratrol pharmacological effects.

Inhibitory Activity of Marine Sponge-Derived Natural Products against Parasitic Protozoa

Abstract: In this study, thirteen sponge-derived terpenoids, including five linear furanoterpenes: furospinulosin-1 (1), furospinulosin-2 (2), furospongin-1 (3), furospongin-4 (4), and demethylfurospongin-4 (5); four linear meroterpenes: 2-(hexaprenylmethyl)-2-methylchromenol (6), 4-hydroxy-3-octaprenylbenzoic acid (7), 4-hydroxy-3-tetraprenyl-phenylacetic acid (8), and heptaprenyl-p-quinol (9); a linear triterpene, squalene (10); two spongian-type diterpenes dorisenone D (11) and 11β-acetoxyspongi-12-en-16-one (12); a scalarane-type sesterterpene; 12-epi-deoxoscalarin (13), as well as an indole alkaloid, tryptophol (14) were screened for their in vitro activity against four parasitic protozoa; Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Plasmodium falciparum. Cytotoxic potential of the compounds on mammalian cells was also assessed. All compounds were active against T. brucei rhodesiense, with compound 8 being the most potent (IC50 0.60 μg/mL), whereas 9 and 12 were the most active compounds against T. cruzi, with IC50 values around 4 μg/mL. Compound 12 showed the strongest leishmanicidal activity (IC50 0.75 µg/mL), which was comparable to that of miltefosine (IC50 0.20 µg/mL). The best antiplasmodial effect was exerted by compound 11 (IC50 0.43 µg/mL), followed by compounds 7, 10, and 12 with IC50 values around 1 µg/mL. Compounds 9, 11 and 12 exhibited, besides their antiprotozoal activity, also some cytotoxicity, whereas all other compounds had low or no cytotoxicity towards the mammalian cell line. This is the first report of antiprotozoal activity of marine metabolites 1–14, and points out the potential of marine sponges in discovery of new antiprotozoal lead compounds.

Flavonoids: an overview

Abstract: Flavonoids, a group of natural substances with variable phenolic structures, are found in fruits, vegetables, grains, bark, roots, stems, flowers, tea and wine. These natural products are well known for their beneficial effects on health and efforts are being made to isolate the ingredients so called flavonoids. Flavonoids are now considered as an indispensable component in a variety of nutraceutical, pharmaceutical, medicinal and cosmetic applications. This is attributed to their anti-oxidative, anti-inflammatory, anti-mutagenic and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Research on flavonoids received an added impulse with the discovery of the low cardiovascular mortality rate and also prevention of CHD. Information on the working mechanisms of flavonoids is still not understood properly. However, it has widely been known for centuries that derivatives of plant origin possess a broad spectrum of biological activity. Current trends of research and development activities on flavonoids relate to isolation, identification, characterisation and functions of flavonoids and finally their applications on health benefits. Molecular docking and knowledge of bioinformatics are also being used to predict potential applications and manufacturing by industry. In the present review, attempts have been made to discuss the current trends of research and development on flavonoids, working mechanisms of flavonoids, flavonoid functions and applications, prediction of flavonoids as potential drugs in preventing chronic diseases and future research directions.

Natural antioxidants: sources, compounds, mechanisms of action, and potential applications

Abstract: While use of synthetic antioxidants (such as butylated hydroxytoluene and butylated hydroxyanisole) to maintain the quality of ready-to-eat food products has become commonplace, consumer concern regarding their safety has motivated the food industry to seek natural alternatives. Phenolic antioxidants can inhibit free radical formation and/or interrupt propagation of autoxidation. Fat-soluble vitamin E (α-tocopherol) and water-soluble vitamin C (L-ascorbic acid) are both effective in the appropriate matrix. Plant extracts, generally used for their flavoring characteristics, often have strong H-donating activity thus making them extremely effective antioxidants. This antioxidant activity is most often due to phenolic acids (gallic, protocatechuic, caffeic, and rosmarinic acids), phenolic diterpenes (carnosol, carnosic acid, rosmanol, and rosmadial), flavonoids (quercetin, catechin, naringenin, and kaempferol), and volatile oils (eugenol, carvacrol, thymol, and menthol). Some plant pigments (anthocyanin and anthocyanidin) can chelate metals and donate H to oxygen radicals thus slowing oxidation via 2 mechanisms. Tea and extracts of grape seeds and skins contain catechins, epicatechins, phenolic acids, proanthocyanidins, and resveratrol, all of which contribute to their antioxidative activity. The objective of this article is to provide an overview of natural antioxidants, their mechanisms of action, and potential applications.