Enhancement of the Antioxidant and Skin Permeation Properties of Betulin and Its Derivatives

Abstract

This study investigated the antioxidant activity DPPH, ABTS, and Folin–Ciocalteu methods of betulin (compound 1) and its derivatives (compounds 2–11). Skin permeability and accumulation associated with compounds 1 and 8 were also examined. Identification of the obtained products (compound 2–11) and betulin isolated from plant material was based on the analysis of 1H- NMR and 13C-NMR spectra. The partition coefficient was calculated to determine the lipophilicity of all compounds. In the next stage, the penetration through pig skin and its accumulation in the skin were evaluated of ethanol vehicles containing compound 8 (at a concentration of 0.226 mmol/dm3), which was characterized by the highest antioxidant activity. For comparison, penetration studies of betulin itself were also carried out. Poor solubility and the bioavailability of pure compounds are major constraints in combination therapy. However, we observed that the ethanol vehicle was an enhancer of skin permeation for both the initial betulin and compound 8. The betulin 8 derivative showed increased permeability through biological membranes compared to the parent betulin. The paper presents the transformation of polycyclic compounds to produce novel derivatives with marked antioxidant activities and as valuable intermediates for the pharmaceutical industry. Moreover, the compounds contained in the vehicles, due to their mechanism of action, can have a beneficial effect on the balance between oxidants and antioxidants in the body, minimizing the effects of oxidative stress. The results of this work may contribute to knowledge regarding vehicles with antioxidant potential. The use of vehicles for this type of research is therefore justified.

Oleogel Formulations for the Topical Delivery of Betulin and Lupeol in Skin Injuries—Preparation, Physicochemical Characterization, and Pharmaco-Toxicological Evaluation

“…To evaluate the amount of betulin and lupeol accumulated into the skin, drug ex-traction was performed according to the method described by Günther et al with minor modification [ 68 ]. Briefly, after completing the permeation test, the two compartments of each vertical diffusion cell were disassembled, and the remnant oleogel was removed from the skin surface, which was washed three times with a 0.5% w / w sodium lauryl sulfate aqueous solution to rinse off the skin.…”

Biologically Active Preparations from the Leaves of Wild Plant Species of the Genus Rubus

“…Similarly, in our previous study [ 6 , 7 , 61 ] linoleic acid, methyl ester, and hexadecanoic acid (palmitic acid) were identified as major components of leaf extract. The presence of methyl esters of fatty acids (methyl palmitate and methyl oleate) has been confirmed by others in the extracts of dried and fresh leaves of plants [ 46 ] and essential oils from E. angustifolium [ 33 ] and E. hirsutum [ 61 , 62 , 63 ]. Among the major components identified by Canli et al [ 49 ] using GC-MS with ethanol extracts of plants, fatty acids were a large group [ 49 ].…”

“…Studies on the antioxidant activity of the plant preparations from the leaves of R. idaeus L. (P1) and R. fruticosus L. (P2) were carried out by free radical reduction (DPPH) [ 62 ] and (ABTS) [ 55 ] methods. Antioxidant activity was determined using the FRAP [ 56 ] method to determine the ferric reducing power assay.…”

Anticancer and Antioxidant Activities of the Root Extract of the Carnivorous Pitcher Plant Sarracenia purpurea

“…Furthermore, 7,8-dihydro-α-ionone is a phenolic compound and known to contribute to the plant's antioxidant effects [48,49]. Other abundant compounds (>2.4%) in S. purpurea-root-acetone (Table 5), i.e., 24-norursa-3,12-diene [50], α-amyrin [51], stigmast-5-en-3-ol [52], botulin [53], and 24-noroleana-3,12-diene also possess antioxidant activities. Therefore, the antioxidation capacity of S. purpurea-root-acetone might be from the co-effects of these compounds.…”