ABSTRACT
Many anticancer active compounds are known to have the capacity to destroy pathologically proliferating cancer cells in the body, as well as to destroy rapidly proliferating normal cells. Despite remarkable advances in cancer research over the past few decades, the inclusion of natural compounds in researches as potential drug candidates is becoming increasingly important. However, the perception that the natural is reliable is an issue that needs to be clarified. Among the various chemical classes of natural products, anthraquinones have many biological activities and have also been proven to exhibit a unique anticancer activity. Emodin, an anthraquinone derivative, is a natural compound found in the roots and rhizomes of many plants. The anticancer property of emodin, a broad-spectrum inhibitory agent of cancer cells, has been detailed in many biological pathways. In cancer cells, these molecular mechanisms consist of suppressing cell growth and proliferation through the attenuation of oncogenic growth signaling, such as protein kinase B (AKT), mitogen-activated protein kinase (MAPK), HER-2 tyrosine kinase, Wnt/-catenin, and phosphatidylinositol 3-kinase (PI3K). However, it is known that emodin, which shows toxicity to cancer cells, may cause kidney toxicity, hepatotoxicity, and reproductive toxicity especially at high doses and long-term use. At the same time, studies of emodin, which has poor oral bioavailability, to transform this disadvantage into an advantage with nano-carrier systems reveal that natural compounds are not always directly usable compounds. Consequently, this review aimed to shed light on the anti-proliferative and anti-carcinogenic properties of emodin, as well as its potential toxicities and the advantages of drug delivery systems on bioavailability.
ABSTRACT
OBJECTIVES: To determine the secondary metabolites from Verbascum mucronatum Lam. and evaluate their antimicrobial activity. MATERIALS AND METHODS: Antimicrobial activities of the isolated metabolites were determined using broth microdilutions against the bacteria (Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213) and fungi (Candida albicans ATCC 90028, Candida krusei ATCC 6258, Candida parapsilosis ATCC 90018). RESULTS: Four iridoid glycosides; ajugol (1), aucubin (2), lasianthoside I (3), catalpol (4), two triterpenic saponins; ilwensisaponin C (5), ilwensisaponin A (=mimengoside A) (6), and one phenylethanoid glycoside; verbascoside (=acteoside) (7) were isolated from the water soluble parts of the methanolic extract gained flowery parts of V. mucronatum Lam. CONCLUSION: Within the obtained compounds, ajugol and ilwensisaponin A showed moderate antimicrobial activity, especially against fungi.
ABSTRACT
CONTEXT: Xeranthemum annuum L. (Asteraceae) (XA) is an ornamental and medicinal species with limited bioactivity and phytochemical data. OBJECTIVE: Identification of anticholinesterase, antioxidant, anti-inflammatory and analgesic effects of the flower and root-stem (R-S) extracts of XA. MATERIALS AND METHODS: Anticholinesterase (at 100 µg mL-1) and antioxidant (at 1000 µg mL-1) effects of various extracts were evaluated via microtiter assays, while anti-inflammatory and analgesic effects of the R-S extracts were tested using carrageenan-induced hind paw oedema (100 and 200 mg kg-1) and p-benzoquinone (PBQ) writhing models (200 mg kg-1) in male Swiss albino mice. The R-S ethanol extract of XA was subjected to isolation studies using conventional chromatographic methods. RESULTS: Most of the extracts showed inhibition over 85% against butyrylcholinesterase and no inhibition towards acetylcholinesterase. The flower chloroform and the R-S ethyl acetate extracts were most effective (97.85 ± 0.94% and 96.89 ± 1.09%, respectively). The R-S ethanol extract displayed a remarkable scavenging activity against DPPH (77.33 ± 1.99%) and in FRAP assay, while the hexane extract of the R-S parts possessed the highest metal-chelating capacity (72.79 ± 0.33%). The chloroform extract of the R-S caused a significant analgesic effect (24.4%) in PBQ writhing model. No anti-inflammatory effect was observed. Isolation of zierin and zierin xyloside, which were inactive in anticholinesterase assays, was achieved from the R-S ethanol extract. DISCUSSION AND CONCLUSION: This is the first report of anticholinesterase, antioxidant, analgesic and anti-inflammatory activities and isolation of zierin and zierin xyloside from XA. Therefore, XA seems to contain antioxidant and BChE-inhibiting compounds.
