Brachychiton rupestris (T.Mitch. ex Lindl.) K. Schum. Extracts Inhibit the Growth of Streptococcus pyogenes

Abstract

Introduction: Streptococcus pyogenes is a gram positive pathogenic bacterium which causes a variety of diseases including streptococcal pharyngitis, impetigo and rheumatic heart disease. Many Brachychiton spp. have reported uses to treat pathogenic illness and are rich in flavonoids with reported antibacterial activity. Despite this, B. rupestris leaf extracts have not previously been examined for bacterial growth inhibitory properties. Methods: The ability of B. rupestris leaf extracts to inhibit the growth of S. pyogenes was investigated by disc diffusion and growth time course assays. The growth inhibitory activity was further quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: The methanolic and aqueous B. rupestris leaf extracts were potent inhibitors of S. pyogenes growth, with MIC values as low as 445µg/mL. The antibacterial activity of the methanolic and aqueous B. rupestris leaf extracts were further investigated by growth time course assays that showed significant growth inhibition within 1h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for use in preventing S. pyogenes associated diseases caused by these pathogens. Conclusion: The lack of toxicity of the B. rupestris leaf extracts and their growth inhibitory bioactivity against S. pyogenes indicate their potential in the development of new therapies for rheumatic fever, pharyngitis, impetigo and other illnesses caused by this bacterium.

The medicinal plant Tabebuia impetiginosa potently reduces pro-inflammatory cytokine responses in primary human lymphocytes

“…Non-targeted GC-MS headspace analysis. As previously described [17][18][19][20][21] , separation and quantification of phytochemical components were performed using a Shimadzu GC-2010 plus (USA) linked to a Shimadzu MSTQ8040 (USA) mass selective detector system as previously described 22 . Briefly, the system was equipped with a Shimadzu auto-sampler AOC-5000 plus (USA) fitted with a solid phase micro-extraction fibre (SPME) handling system utilising a Supelco (USA) divinyl benzene/carbowax/polydimethylsiloxane (DVB/ CAR/PDMS).…”

Herbal Tea for the Management of Pharyngitis: Inhibition of Streptococcus pyogenes Growth and Biofilm Formation by Herbal Infusions

“…Herbaceous plants are a source of complementary and alternative remedies to conventional medications in treating several bacterial infectious diseases, including streptococcal pharyngitis (strep throat). Previous studies have demonstrated that numerous herbal extracts could act as antibacterial agents against S. pyogenes [10,34,35,36,37,38]. In the present study, we focused on 13 HWIs, known to Canadian traditional and indigenous healers who used them against sore throat.…”

“…Spices and herbs (flavor foods) comprise a large number of phytochemicals [39], which have been revealed to possess antimicrobial properties. For example, anti- S. pyogenes ability of phenolic compounds [40,41], flavonoids [35], alkaloids [42], terpenoids [43], and tannins [35] have been reported. Qualitative UPLC analysis in the present study for HWI revealed the presence of polyphenols, flavonoids, alkaloids, terpenoids, steroids, and tannins.…”

Brachychiton acerifolius (A.Cunn. ex G.Don) Macarthur and C. moore Leaf and Flower Extracts Inhibit the Growth of a Panel of Pathogenic Bacteria

“…leaf extracts are potent inhibitors of Streptococcus pyogenes growth. 22 Several investigations have reported the chemical composition of B. acerifolius leaves and several interesting phytochemical components have been identified. The flavonoid content has been particularly well reported and apigenin-7-O-glucuronide ( Figure 1d), rutin (Figure 1e), luteolin-7-O-D-glucuronide ( Figure 1f), quercetin (Figure 1g), kaempferol (Figure 1h), luteolin ( Figure 1i) and apigenin ( Figure 1j) have been identified.…”