Interaction effects on cytochrome P450 both in vitro and in vivo studies by two major bioactive xanthones from Halenia elliptica D. Don

In vitro safety evaluation of (6-methoxy-9-oxo-9H-xanthen-2-yl)methyl (E)-3-(2,4-dimethoxyphenyl)acrylate (K-116) - the novel potential UV filter designed by means of a double chromophore strategy

The use of topical photoprotection is necessary to reduce adverse effects caused by excessive exposure to ultraviolet radiation. Despite the high standards set for UV filters, many of them may contribute to the occurrence of adverse effects. The newly synthesised compound K-116, the (E)-cinnamoyl xanthone derivative, could be an alternative. We conducted extended in vitro safety evaluation of compound K-116. The research included assessment of irritation potential on skin tissue, evaluation of penetration through the epidermis, and assessment of phototoxicity, and mutagenicity. Additionally, the eco-safety of compound K-116 was evaluated, including an examination of its degradation pathway in the Cunninghamella echinulata model, as well as in silico simulation of the toxicity of both the parent compound and its degradation products. The research showed that compound K-116 tested in future application conditions is deprived of skin irritant potential additionally it does not penetrate through the epidermis. Results showed that K-116 concentrate is not phototoxic and not mutagenic. The eco-safety studies showed that it undergoes biodegradation in 27% in Cunninghamella echinulata model. The parent compound and formed metabolite are less toxic than reference UV filters (octinoxate and octocrylene).

Synthesis and preliminary anti-inflammatory evaluation of xanthone derivatives

Xanthone derivatives of acetic, propionic and 2-methylpropionic acids were synthesized and assayed for their anti-inflammatory, analgesic and ulcerogenic activities. Compound 8 causes a dose-dependent diminution of paw edema (up to 61%) in the carrageenan model and at the highest tested dose reduces mechanical hyperalgesia in the Randall-Selitto test more effectively than the reference compound (~75% and ~32%, respectively). It shows high in vitro metabolic stability (Clint=12.5 μL/mg/min, t1/2=138.6 min) in the rat liver microsomes. None of the studied xanthone derivatives are ulcerogenic. The results of the present study suggest that compound 8 can be of interest in the future for the search for antinociceptive and antiedematous agents devoid of ulcerogenic effect.