Antimicrobial and antioxidant activities of traditional Thai herbal remedies for aphthous ulcers

Abstract

Four medicinal plants (Quercus infectoria, Kaempferia galanga, Coptis chinensis and Glycyrrhiza uralensis) as well as one traditional Thai treatment for aphthous ulcers based on these four plants were tested for antimicrobial activity. MIC values for a range of bacteria and Candida albicans were determined, with both type strains and clinical isolates being used. Antioxidant activity was determined using the ABTS radical scavenging assay. Among the four plants, Q. infectoria showed antimicrobial activity against Staphylococcus aureus with an MIC of 0.41 mg/mL, while C. chinensis showed antifungal activity against C. albicans with an MIC of 6.25 mg/mL. Activity was also shown against a range of other organisms including Salmonella typhi, Serratia marcescens, Vibrio cholerae, Vibrio parahaemolyticus, Pseudomonas aeruginosa and Enterococcus faecalis. The antimicrobial activity of the traditional aphthous ulcer preparation (a powder) was comparable to that for the individual plant extracts, however, incorporation of the powder into a gel formulation resulted in the loss of almost all activity. All extracts, with the exception of K. galanga, also showed good antioxidant activity. This study supports the traditional use of these plants and suggests that they may also be useful in the treatment of other infections.

Phytochemical screening of methanolic dried galls extract of Quercus infectoria using gas chromatography-mass spectrometry (GC-MS) and Fourier transform-infrared (FT-IR)

“…The galls of Q. infectoria were documented to possess antibacterial (Basri et al, 2005;Darogha, 2009), anti-MRSA (Chusri and Voravuthikunchai, 2009), antiviral (Hussein et al, 2000), antifungus (Yamunarani et al, 2005;Yoshikawa et al, 2007;Hameed et al, 2015b), and anti-inflammatory activities. Previous investigation revealed that the ethanol extract of the nutgalls consists of tannins, flavonoids, and steroidal compounds (Rukayadi et al, 2006;Chusri and Voravuthikunchai, 2009;Mekseepralard et al, 2010). The constituents of the galls of Q. infectoria comprise a large amount of tannins, gallic acid, syringic acid, ellagic acid, beta sitosterol, amentoflavone hexamethyl ether, isocryptomerin, methyl betulate, methyl olenate, and hexagalloyl glucose (Lodhi et al, 2012;Hameed et al, 2015c).…”

Phytochemistry and medicinal properties of Kaempferia galanga L. (Zingiberaceae) extracts

“…KG extracts have weak anti-oxidant activity (Chan et al, 2008;Mekseepralard et al, 2010). Total phenolic content (TPC) of ethanolic extracts of leaves and rhizomes is found to be 146 mg galic acid equivalent (GAE)/100 g and 57 mg GAE/100 g, respectively whereas the antioxidant activity of leaves and rhizome extracts is 77 mg ascorbic acid (AA)/100 g and 17 mg AA/100 g (Chan et al, 2008).…”

“…More recently, this ethyl-p-methoxycinnamate by resazurin microtitre assay has shown to inhibit drug susceptible and multidrug resistant clinical isolates of M. tuberculosis with minimum inhibitory concentration (MIC) of 0.242 to 0.485 mM (Lakshmanan et al, 2011). KG extracts have also been found to exhibit antimicrobial activity against a number of organisms including Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Escheriachia coli, Klebsiella pneumonia, Salmonella typhi, Seratia marcescens, Vibrios cholera, Vibrios parahaemolyticus, Enterococcus faecalis, and Pseudomonas aeruginosa with MIC of 0.81, 3.25, 25, >6.5, > 6.5, >6.5, >6.5, >6.5, >6.5,1.625 and >6.5 µg/ml, respectively (Mekseepralard et al, 2010).…”

The effect of Matricaria chamomilla (chamomile) extract in Orabase on minor aphthous stomatitis, a randomized clinical trial

“…Considering the side effects of chemical drugs and patients' interest in using herbal medicines, medicinal plants have received increasing attention (Bakhtiari, 2010). Some herbs like Alchemilla vulgaris, Matricaria chamomilla and Aloe barbadensi have been reported to be used in the management of RAS (Mekseepralard et al, 2010). There have also been some trials on the effect of these substances on RAS, for example, in one, a paste containing Myrtus communis was compared to placebo in 45 patients with RAS and as a result the researchers declared that the herbal substance was effective in reduction of pain severity, ulcer size, erythema and exudates.…”