Polyphenol Characterization and Skin-Preserving Properties of Hydroalcoholic Flower Extract from Himantoglossum robertianum (Orchidaceae)

Abstract

Himantoglossum robertianum (Loisel.) P. Delforge is a Mediterranean orchid whose propagation in vitro has been achieved, making it eligible as a source of bioactive substances. Flowers were analyzed by light and SEM microscopy and used to obtain a polyphenol-rich, hydroalcoholic flower extract (HFE). HFE was characterized for total phenols, flavonoids and proanthocyanidins, and for polyphenol profile by RP-LC-DAD. Antioxidant assays, in vitro collagenase and elastase inhibition, and MTT and cell motility assays on HaCaT keratinocytes were done. Microscopy showed epidermal cells containing anthocyanins in the flower labellum. Flavonoids (flavones and flavan-3-ols) represented the most abundant compounds (42.91%), followed by scopoletin (33.79%), and phenolic acids (23.3%). Antioxidant assays showed strong activities, rating ORAC > FRAP > TEAC > β-carotene bleaching > DPPH > iron-chelation. Biological assays showed elastase and collagenase inhibition (up to 42% and 78%, respectively), improvement of HaCaT cell viability after treatment with 500 μM H2O2 (from 30% to 84% of control), and stimulation of cell migration rate up to 210% of control. In summary, HFE counteracted different free radicals, while protective properties were shown by cell-free and cell-based bioassays, suggesting the possible use of H. robertianum flowers for skin-preserving, repair, and anti-aging applications.

Malus baccata var. gracilis and Malus toringoides Bark Polyphenol Studies and Antioxidant, Antimicrobial and Anticancer Activities

“…Tree barks are promising sources of these polyphenols; they contain phenolic acids, flavonoids, and catechins, as well as sugars [2,12,19,21,22]. Phenolic acids are an important group of phenols as they act as antioxidant agents and have, for example, anticancer and antimicrobial properties [3,[23][24][25][26][27].Microbial infections with Staphylococcus aureus cause serious human diseases such as soft tissue infection, pneumonia, sepsis, and peritonitis [28,29]. Other serious diseases, such as listeriosis (which leads to preterm birth and miscarriage) and mild gastroenteritis of immunocompetent individuals, are caused by the bacterial foodborne pathogen Listeria monocytogenes [30].…”

“…Tree barks are promising sources of these polyphenols; they contain phenolic acids, flavonoids, and catechins, as well as sugars [2,12,19,21,22]. Phenolic acids are an important group of phenols as they act as antioxidant agents and have, for example, anticancer and antimicrobial properties [3,[23][24][25][26][27].…”

Antioxidant, Anti-Inflammatory and Anti-Angiogenic Properties of Citrus lumia Juice

“…However, in light of our study, what is even more interesting is that quercetin suppress the cyclooxygenase-2 (COX-2) expression in human breast cancer cells by specifically targeting the p300 signaling pathway. COX-2 is an inducible enzyme, which plays a critical role in several patho-physiological events including inflammation, atherosclerosis, tissue injury, angiogenesis and tumorigenesis, up-regulating different pathways such as estimated glomerular filtration rate (eGFR), phosphoinositide 3-kinase (PI3k) and extracellular signal-regulated protein kinase (Erk1/2) signaling ( Xiao et al, 2011 ).…”

“…Total flavonoids were determined according to Bazzicalupo et al (2019) with some modifications. Briefly, 450 µl of deionized water were added with 50 µl of sample (6.33–50.6 µl/6.25–50 mg/ml of CLJ diluted in deionized water) or rutin as reference compound (125–1000 µg/ml), mixed with 30 µl of 5% NaNO 2 and incubated for 5 min.…”

Six phenanthrenes from the roots of Cymbidium faberi Rolfe. and their biological activities

“…Until now, various compounds, such as phenols, phenanthrenes, stilbenoid derivatives and steroids, have been isolated in the Orchidaceae. For example, phenolic compounds were isolated from Himantoglossum robertianum and Rhynchostele rossii (Yang et al 2006;Bazzicalupo et al 2019). Phenanthrene compounds were also found in orchidaceae, but most of them were isolated from Dendrobium Sw. and Bletilla Rchb.…”