Physical, Chemical and Pharmacological Characterization of a New Oleogel-Forming Triterpene Extract from the Outer Bark of Birch (Betulae Cortex)

Abstract

Triterpenes are biologically active secondary plant substances that display antimicrobial, hepatoprotective and anti-inflammatory effects. However, the poor solubility of triterpenes in both polar and non-polar solvents as well as expensive purification procedures have prevented the large-scale isolation of these compounds for medicinal purposes. Here, we describe a novel quantitative extraction method of triterpenes from the outer bark of birch (Betula species) in which betulin, a lupan triterpene, predominates. The resulting highly purified triterpene extract (TE) in the form of a dry powder contains betulin as the major compound, but also betulinic acid, lupeol, erythrodiol and oleanolic acid. We have found that this TE is able to form an oleogel, thus providing an opportunity for the topical application of pharmacologically relevant amounts of triterpenes. Furthermore, we have investigated the TE in comparison to its major isolated compounds in cell culture experiments with human immortalized keratinocytes and skin cancer cells. We could demonstrate dose-dependent cytotoxic and apoptosis-inducing effects of TE and betulin. These experimental data support the notion from a previous clinical study that TE from the outer bark of birch might represent a new tool for the topical treatment of skin cancer and skin cancer precursors like actinic keratoses.

Hepatoprotective effects of Justicia adhatoda L. against carbon tetrachloride (CCl4) induced liver injury in Swiss albino mice

“…Due to the radical scavenging potential of these phytochemicals, toxicity level reduces and body tends back towards normalcy (Laszczyk et al, 2006). Several studies have shown the hepatoprotective effects of Justicia leaves (Pandit et al, 2004;Bhattacharya et al, 2005;Krishna et al, 2010), but no work has reported on flowers of J. adhatoda.…”

Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems

“…antibacterial, antiviral, anti-parasite BE: [5,6]; BA: [7][8][9]; BE/BA: [10,11]; BE/BA/OA: [12]; LU/BA: [13]; OA/BA: [14] hepatoprotective BE: [15]; BE/BA: [16]; OA: [17][18][19][20]; LU: [21]; BA: [22] antitumor BE: [23,24]; BA: [25,26] BE/BA: [27,28]; LU: [29]; OA: [18,19,30] wound healing extract: [31][32][33]; BA: [34]; OA: [35,36] anti-inflammatory BE: [5,37]; LU: [38,39]; OA: [18,40] Apart from these pharmacological effects, birch bark extract is able to act as a gelling agent and Pickering emulsifier [41][42][43]. Together with its anti-inflammatory and wound healing effects, this makes birch bark dry extract interesting for the stabilisation of semisolid systems, such as gels and creams, acting as an active ingredient and an excipient in parallel.…”

A preliminary pharmacokinetic study of betulin, the main pentacyclic triterpene from extract of outer bark of birch (Betulae alba cortex)

“…They can be extracted as a triterpene rich dry extract (TE) which is able to form a topically applicable oleogel [1,2]. The birch triterpenes have known antiviral, antimicrobial and hepatoprotective pharmacological activities [3][4][5].…”

“…The birch triterpenes have known antiviral, antimicrobial and hepatoprotective pharmacological activities [3][4][5]. BA, OA or BE also have antitumor effects [2,6,7]. These triterpenes show antiinflammatory activities, as do others such as ER or LU [7][8][9][10].…”