Hippophae rhamnoides L. is an important source of natural antioxidant and antimicrobial agents. Phytochemical compounds, antioxidant and antibacterial properties of berries, and leaf extracts from four Romanian sea buckthorn cultivars were investigated. Large differences in the content of total polyphenols and flavonoids between the varieties were observed. HPLC analysis of the polyphenolic compounds showed greater differences in content in leaves than in berries. This study confirmed that sea buckthorn leaves and berries are a rich source of phenolic compounds, especially quercetin derivatives and hydrocinnamic acid derivatives. Five carotenoid compounds were identified in the berries: lutein, zeaxanthin, β-cryptoxanthin, cis-β-carotene, and β-carotene. From the results obtained in this study, it can be stated that the varieties whose berries yielded the highest quantities of polyphenols, flavonoids, and antioxidant activity, can be ranked as follows: SF6 > Golden Abundant > Carmen > Colosal, and for leaf extracts the ranked order is SF6 > Golden Abundant > Colosal > Carmen. A strong correlation between the total flavonoid yield and antioxidant activity (r = 0.96), was observed. All extracts showed antibacterial activity against S. aureus, B. cereus, and P. aeruginosa, however extracts from berries were less potent than extracts from leaves.

The biological properties and main phenolic compounds of the O. vulgare L. ssp. vulgare extract are described in the present paper. The polyphenolic compounds were analyzed by chromatographic and spectrophotometric techniques. The antioxidant potential was evaluated using several methods: CUPRAC (cupric ion reducing antioxidant capacity), FRAP (ferric reducing ability of plasma), inhibition of lipid peroxidation catalyzed by cytochrome c, and superoxide (SO) scavenging assays. The antimicrobial activity of the oregano extract was evaluated by means of agar-well diffusion assay. The hepatoprotective effect of the O. vulgare extract on CCl₄-induced hepatotoxicity was evaluated in rats. Liver injury was estimated by determination of alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), gamma-glutamyl transferase GGT, total protein and albumin concentrations, glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA). These values were improved by the administration of oregano extract. A specific phenolic profile was evidenced by these data, with large amounts of rosmarinic and chlorogenic acids. The oregano extract showed very strong antioxidant activity in good agreement with the phenolic content. Antimicrobial activity was good, especially against Salmonella enteritidis and Aspergillus niger strains. The high hepatoprotective, antioxidant and antimicrobial activity, along with polyphenol-rich content, can support the use of O. vulgare in therapy. We also expect our results to open new research directions for designing important new drug products, using indigenous plant material.

This study was performed to evaluate the phenolic profile, antioxidant and diuretic effects of black cumin and lady-in-a-mist seeds. In the phenolic profile, differences between the two species are significant. Qualitative and quantitative analyses of the phenolic compounds were performed using a HPLC-UV/MS method. Hyperoside was the only identified flavonoid glycoside (1.08 ± 0.01 μg∙g⁻¹ dw plant material), in the N. damascena extract. Regarding the flavonol profile, kaempferol was identified before the hydrolysis, only in the N. sativa extract (6.06 ± 0.02 μg∙g⁻¹ dw plant material) and quercetin only in N. damascena seeds (14.35 ± 0.02 μg∙g⁻¹ dw plant material). The antioxidant potential of the two species was tested through several electron transfer assays, which indicated, excepting for the FRAP assay, N. damascena as exhibiting a higher free radical scavenging activity. The diuretic activity of the two extracts was tested using a rat-experimental model on acute diuresis. Administration of the ethanolic extract of N. sativa (100 mg∙kg⁻¹) resulted in a significant increase in urine volume, although less than found with the reference drug; in addition N. damascena extract did not present a diuretic effect. In reference to the elimination of Na⁺, K⁺ and uric acid, the black cumin extract exhibited a higher natriuretic than kaluretic effect and a similar uricosuric effect with control and N. damascena. For N. damascena, the Na⁺/K⁺ ratio was sub unitary, but not due to an increasing of the kaluretic effect, but mostly to a decrease of Na⁺ excretion.

Colorectal cancer (CRC) represents the third type of cancer in incidence and second in mortality worldwide, with the newly diagnosed case number on the rise. Among the diagnosed patients, approximately 70% have no hereditary germ-line mutations or family history of pathology, thus being termed sporadic CRC. Diet and environmental factors are to date considered solely responsible for the development of sporadic CRC; therefore; attention should be directed towards the discovery of preventative actions to combat the CRC initiation, promotion, and progression. Quercetin is a polyphenolic flavonoid plant secondary metabolite with a well-characterized antioxidant activity. It has been extensively reported as an anti-carcinogenic agent in the scientific literature, and the modulated targets of quercetin have been also characterized in the context of CRC, mainly in original research publications. In this fairly comprehensive review, we summarize the molecular targets of quercetin reported to date in in vivo and in vitro CRC models, while also giving background information about the signal transduction pathways that it up- and downregulates. Among the most relevant modulated pathways, the Wnt/β-catenin, PI3K/AKT, MAPK/Erk, JNK, or p38, p53, and NF-κB have been described. With this work, we hope to encourage further quests in the elucidation of quercetin anti-carcinogenic activity as single agent, as dietary component, or as pharmaconutrient delivered in the form of plant extracts.

Thuja occidentalis L. (Cupressaceae) has its origins in Eastern North America and is cultivated in Europe and Brazil as an ornamental tree, being known as the “tree of life” or “white cedar”. In traditional medicine, it is commonly used to treat liver diseases, bullous bronchitis, psoriasis, enuresis, amenorrhea, cystitis, uterine carcinomas, diarrhea, and rheumatism. The chemical constituents of T. occidentalis have been of research interest for decades, due to their contents of essential oil, coumarins, flavonoids, tannins, and proanthocyanidines. Pharmacology includes antioxidant, anti-inflammatory, antibacterial, antifungal, anticancer, antiviral, protective activity of the gastrointestinal tract, radioprotection, antipyretic, and lipid metabolism regulatory activity. Therefore, the present review represents the synthesis of all the relevant information for T. occidentalis, its ethnobotany, phytochemistry, and a thorough analysis of their pharmacological activities, in order to promote all the biological activities shown so far, rather than the antitumor activity that has promoted it as a medicinal species.