Quantification of Polyphenols and Pharmacological Analysis of Water and Ethanol-Based Extracts of Cultivated Agarwood Leaves

Abstract

Summary Mangiferin ( 3 ) and genkwanin 5-O -␤ -primeveroside ( 5 ) are the two major bioactive polyphenols with laxative property present in the extracts of agarwood ( Aquilaria sinensis ) leaves (AL). Here we developed an HPLC method to determine these bioactive components and four other major polyphenols in AL extracts and evaluated the pharmacological equivalence of organic and water extracts. Using mobile phase gradient conditions combined with UV detection at 330 nm, all six compounds were separated and we determined the relative extraction ratios of the six compounds present in A. sinensis extracts that were prepared under different conditions and compared the contents of the two laxative polyphenols present in the 60% ethanol extracts of A. sinensis and A. crassna . The polyphenols present in water extracts of 13 commercially cultivated A. crassna plants have also been analyzed. The laxative properties of 60% ethanol and four water extracts of A. crassna were evaluated by the frequency and weight of stools in loperamide-induced constipation model mice. The pharmacological equivalence of 60% ethanol extract and hot water (95˚C) extract was identified in mice. Key Words agarwood leaves, laxative polyphenols, HPLC, mangiferin, genkwanin 5-O -␤ -primeverosideHerbal supplements play an important role in public health. The polyphenols present in herbal supplements prevent metabolic syndrome and possess remarkable therapeutic properties. To ensure the stability and efficiency of these polyphenols in clinical use, the quality control system of herbal supplements should measure and regulate the phytoequivalence and pharmacological effects of these compounds. Generally, two strategies are employed for the quality control of herbal supplements: ( 1 ) to assess the batch-to-batch consistency of the chemical constituents of the herbal supplement based on chromatographic fingerprints and ( 2 ) to measure a few key pharmacological compounds to assess the quality of the supplement. The first strategy is a blind analysis because the quantitative chemical information about the major pharmacological constituents is lacking; therefore, the pharmacological effects of the herbal supplement cannot be easily assessed. The other strategy focuses only on a few index compounds and does not provide a comprehensive insight into the quality of the constituents present in the herbal supplement; therefore, this strategy cannot ensure phytoequivalence. Thus, a quality evaluation method for herbal supplement should be developed for simultaneous comprehensive elucidation of constituents based on chemical fingerprinting and quantitative analysis of important pharmacological compounds.Aquilaria (Thymelaeaceae) is a woody plant that is native to Southeast Asia. A. sinensis and A. crassna , also known as incense trees, are two representative species of the Aquilaria ( 1 ). In Thailand, A. crassna is systematically cultivated for its resin, which is processed to manufacture perfume. The leaves, which are a source of bioactive polyphenols, are u...

Development of an Antioxidant Phytoextract ofLantana grisebachiiwith Lymphoprotective Activity againstIn VitroArsenic Toxicity

“…This was enhanced by the use of heated water, thus improving extraction [21]. Although hydrophilic organic solvents (e.g., ethanol) are usually utilized to obtain these kinds of compounds [22], a pharmacological equivalency has been demonstrated between alcoholic extracts and those derived from infusions [23]. Therefore, flavonoids become bioavailable in humans due to the presence of functional chemical groups (e.g., hydrophilic hydroxyl and carbonyl) in their polycyclic structures [24].…”

Evaluation of anti-lipase activity of leaf and bark extracts from Aquilaria subintegra and A. malaccensis

“…This hypothesis has been warranted with previous study indicated that Aquilaria species have pharmacological effect including in Alzheimer disease, diabetes mellitus and antioxidant [14]. This is followed by discovering laxative properties in Aquilaria leaves which believe contain active polyphenolic compound such as mangiferin and genkwanin 5-O-β-primeveroside [10,20]. Aligned with this, the antilipase activity of Aquilaria crude extracts is possibly related with existence of polyphenolic compounds.…”

“…The leaves of Aquilaria sp. are believed to have major polyphenolic compounds which can be used as herbal tea and showed a laxative [10][11][12], anti-bacterial [13], and anti-diabetic properties [7]. In addition, stem of A. subintegra has been reported as promising in Alzheimer therapy [14].…”

Pharmacological Effects of Aquilaria spp. Leaves and Their Chemical Constituents

“…have been reported in many studies (Nie et al 2009 ;Qi et al 2009 ;Feng and Yang 2012 ;Ito et al 2012 ;Cheng et al 2013 ;Xia et al 2013 ;Yu et al 2013 ;Tay et al 2014 ). Of the constituents studied, mangiferin and epigallocatechin gallate (EGCG) have been discussed the most.…”