In vitro: |
Biol Pharm Bull. 2002 Aug;25(8):1045-8. | Mulberroside F isolated from the leaves of Morus alba inhibits melanin biosynthesis.[Pubmed: 12186407] | METHODS AND RESULTS: The current study was carried out to investigate the in vitro effects of an 85% methanol extract of dried Morus alba leaves on melanin biosynthesis, which is closely related to hyperpigmentation. These extracts inhibited the tyrosinase activity that converts dopa to dopachrome in the biosynthetic process of melanin. Mulberroside F (moracin M-6, 3'-di-O-beta-D-glucopyranoside), which was obtained after the bioactivity-guided fractionation of the extracts, showed inhibitory effects on tyrosinase activity and on the melanin formation of melan-a cells. This compound also exhibited superoxide scavenging activity that is involved in the protection against auto-oxidation. But its activity was low and was weaker than of kojic acid. CONCLUSIONS: These results suggest that mulberroside F isolated from mulberry leaves might be used as a skin whitening agent. | J Agric Food Chem . 2012 Mar 7;60(9):2299-308. | In vitro pharmacokinetic characterization of mulberroside A, the main polyhydroxylated stilbene in mulberry (Morus alba L.), and its bacterial metabolite oxyresveratrol in traditional oral use[Pubmed: 22225542] | Abstract
Mulberroside A (MulA) is one of the main bioactive constituents in mulberry (Morus alba L.). This study examined the determining factors for previously reported oral pharmacokinetic profiles of MulA and its bacterial metabolite oxyresveratrol (OXY) on in vitro models. When incubated anaerobically with intestinal bacteria, MulA underwent rapid deglycosylation and generated two monoglucosides and its aglycone OXY sequentially. MulA exhibited a poor permeability and predominantly traversed Caco-2 cells via passive diffusion; yet, the permeation of OXY across Caco-2 cells was much more rapid and involved efflux (both p-glycoprotein and MRPs)-mediated mechanisms. Moreover, OXY underwent extensive hepatic glucuronidation; yet, the parent MulA was kept intact in liver subcellular preparations. There was insignificant species difference in intestinal bacterial conversion of MulA and the extent of OXY hepatic glucuronidation between humans and rats, while OXY exhibited a distinct positional preference of glucuronidation in the two species. Overall, these findings revealed a key role of intestinal bacterial conversion in absorption and systemic exposure of MulA and its resultant bacterial metabolite OXY in oral route in humans and rats and warranted further investigational emphasis on OXY and its hepatic metabolites for understanding the benefits of mulberry. |
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