Influence of phenolic compounds of Kangra tea [Camellia sinensis (L) O Kuntze] on bacterial pathogens and indigenous bacterial probiotics of Western Himalayas

Abstract

Phenolic compounds of nutraceutical importance viz., catechins (C), (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epigallocatechin-3-gallate (EGCG) and (−)-epicatechin-3-gallate (ECG) were estimated in fresh green tea shoots of Camellia sinensis (L) O Kuntze cultivar. The total polyphenols and total catechins were in the range of 219.90 to 317.81 and 140.83 to 271.39 g/kg, respectively in monthly samples of tea. The values of C, EC, EGC, EGCG and ECG in tea powders as analyzed through high performance liquid chromatography (HPLC) were in the range of 1.560 to 3.661, 13.338 to 27.766, 26.515 to 39.597, 62.903 to 102.168 and 18.969 to 39.469 mg/g, respectively. Effect of tea extracts and standard flavanols against five pathogenic bacteria viz., Listeria monocytogenes (MTCC-839), Pseudomonas aeruginosa (MTCC-741), Bacillus cereus (MTCC-1272), Staphylococcus aureus (MTCC-96) and Escherichia coli (MTCC-443), and eleven indigenous potential bacterial probiotics belonging to genera Enterococcus, Bacillus and Lactobacillus spp. obtained from fermented foods of Western Himalayas, was investigated. EGCG, ECG and EGC exhibited antibacterial activity but, C and EC did not show this activity. Tea extracts having high concentrations of EGCG and ECG were more potent in antibacterial action against bacterial pathogens. Tea extracts and standard flavan-3-ols augmented viability of potential probiotics in an order of EGCG > EGC > ECG > EC > C. Tea extracts and standard flavanols had no antibacterial activity against Escherichia coli (MTCC-443) but, in combination with probiotic culture supernatants, this activity was seen. The Kangra tea thus, exerts antibacterial effect on bacterial pathogens through EGCG, ECG and EGC constituents while stimulatory effect on growth of indigenous potential probiotics.

Effect of Catechins, Green tea Extract and Methylxanthines in Combination with Gentamicin Against Staphylococcus aureus and Pseudomonas aeruginosa - Combination therapy against resistant bacteria -

“…The antibacterial activity of green tea extract was previously described, and the finding that it was related to the catechin content was noteworthy [14, 15]. Additionally, green tea extract was shown to be able to kill S. aureus and other harmful bacteria [26].…”

“…These compounds provide health benefits and show remarkable antimicrobial activity against resistant pathogens [13, 14]. Tea extracts having high concentrations of epigallocatechin gallate (EGCG) and epigallocatechin (EGC) are more potent in antibacterial activity against bacterial pathogens [15]. EGCG at concentrations between 78 and 625 μg/mL was able to inhibit Acinetobacter baumannii [16].…”

Some Contributions to the Study of Oenological Lactic Acid Bacteria through Their Interaction with Polyphenols

“…Therefore, our results confirmed that the chemical structure of polyphenols did indeed influence their effects on bacterial growth. In relation to this, other authors observed that flavanols with galloyl moiety ((−)-epigallocatechin, (−)-epicatechin-3-gallate and (−)-epigallocatechin-3-gallate) exhibited more activity on bacteria growth than those without galloyl moiety (catechins and (−)-epicatechin) [29]. Also, the microbial potency of polyphenols towards bacteria growth has also been reported to be dependent upon bacterial strain, species and genera [30], as we have also observed in our study.…”

Evaluation of the In Vitro Antimicrobial Activity of Ethanolic Extracts Derived from Leaves Of Camellia Japonica Cultivars (Theaceae) Against Enterobacter Cloacae Strain

“…Spot screening indicated that the presence of active biological compounds such as flavonoids, proteins, phenols, alkaloids, and glycosides also exhibited strong activity against tested bacterial strains (Bashir et al, 2014). Sourabh et al (2014). As is generally well known, the antimicrobial effect of plant extracts, including extract derived from Camellia spp.…”