Bioactive compounds sourced from Terminalia spp. in bacterial malodour prevention: an effective alternative to chemical additives

Analysis of latrine fecal odor release pattern and the deodorization with composited microbial agent

As an important source of malodor, the odor gases emitted from public toilet significantly interfered the air quality of living surroundings, resulting in environmental problem which received little attention before. Thus, this paper explored the odor release pattern of latrine feces and deodorization effect with composited microbial agent in Chengdu, China. The odor release rules were investigated in sealed installations with a working volume of 9 L for 20 days. The odor units (OU), ammonia (NH3), hydrogen sulfide (H2S) and total volatile organic compounds (TVOC) were selected to assess the release of malodorous gases under different temperature and humidity, while the highest malodor release was observed under 45℃, with OU and TVOC concentration was 643.91 ± 2.49 and 7767.33 ± 33.50 mg/m3, respectively. Microbes with deodorization ability were screened and mixed into an agent, which composited of Bacillus amyloliquefaciens, Lactobacillus plantarum, Enterococcus faecalis and Pichia fermentans. The addition of microbial deodorant could significantly suppress the release of malodor gas during a 20-day trial, and the removal efficiency of NH3, H2S, TVOC and OU was 81.50 %, 38.31 %, 64.38 %, and 76.86 %, respectively. The analysis of microbial community structure showed that temperature was the main environmental factor driving the microbial variations in latrine feces, while Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes were the main bacteria phyla involved in the formation and emission of malodorous gases. However, after adding the deodorant, the abundance of Bacteroidetes, Proteobacteria and Actinobacteria were decreased, while the abundance of Firmicutes was increased. Furthermore, P. fermentans successfully colonized in fecal substrates and became the dominant fungus after deodorization. These results expanded the understanding of the odor release from latrine feces, and the composited microbial deodorant provided a valuable basis to the management of odor pollution.

Deodorants and antiperspirants: New trends in their active agents and testing methods

Sweating is the human body's thermoregulation system but also results in unpleasant body odour which can diminish the self-confidence of people. There has been continued research in finding solutions to reduce both sweating and body odour. Sweating is a result of increased sweat flow and malodour results from certain bacteria and ecological factors such as eating habits. Research on deodorant development focuses on inhibiting the growth of malodour-forming bacteria using antimicrobial agents, whereas research on antiperspirant synthesis focuses on technologies reducing the sweat flow, which not only reduces body odour but also improves people's appearance. Antiperspirant's technology is based on the use of aluminium salts which can form a gel plug at sweat pores, obstructing the sweat fluid from arising onto the skin surface. In this paper, we perform a systematic review on the recent progress in the development of novel antiperspirant and deodorant active ingredients that are alcohol-free, paraben-free, and naturally derived. Several studies have been reported on the alternative class of actives that can potentially be used for antiperspirant and body odour treatment including deodorizing fabric, bacterial, and plant extracts. However, a significant challenge is to understand how the gel-plugs of antiperspirant actives are formed in sweat pores and how to deliver long-lasting antiperspirant and deodorant benefits.

Comparison of the antibacterial activity of Australian Terminalia spp. extracts against Klebsiella pneumoniae: a potential treatment for ankylosing spondylitis

Traditional medicines prepared using Terminalia species have been used globally to treat inflammation and pathogenic infections. Recent studies have demonstrated that multiple Asian and African Terminalia spp. inhibit bacterial triggers of some autoimmune inflammatory diseases, including ankylosing spondylitis. Despite this, the effects of Australian Terminalia spp. on a bacterial trigger of ankylosing spondylitis (K. pneumoniae) remain unexplored. Fifty-five extracts from five Australian Terminalia spp. were investigated for K. pneumoniae growth inhibitory activity. Methanolic, aqueous and ethyl acetate extracts of most species and plant parts inhibited K. pneumoniae growth, with varying potencies. Methanolic leaf extracts were generally the most potent bacterial growth inhibitors, with minimum inhibitory concentration (MIC) values of 66 μg/mL (T. ferdinandiana), 128 μg/mL (T. carpenteriae) and 83 μg/mL (T. petiolares). However, the aqueous leaf extract was the most potent T. grandiflora extract (MIC = 87 μg/mL). All T. catappa extracts displayed low growth inhibitory activity. The Terminalia spp. methanolic leaf extracts were examined by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). All contained a relative abundance of simple gallotannins (particularly gallic and chebulic acids), the flavonoid luteolin, as well as the monoterpenoids cineole and terpineol. Notably, all Terminalia spp. were non-toxic or of low toxicity in ALA and HDF toxicity assays, highlighting their potential for preventing the onset of ankylosing spondylitis and treating its symptoms once the disease is established, although this needs to be verified in in vivo systems.

Use of specific combinations of the triphala plant component extracts to potentiate the inhibition of gastrointestinal bacterial growth

ETHNOPHARMACOLOGICAL RELEVANCE

Triphala is used in Ayurveda to treat a wide variety of diseases, including numerous bacterial infections. Interestingly, the plant components of triphala (Terminalia bellirica, Terminalia chebula and Emblica officinalis) are also good inhibitors of bacterial growth when used individually, yet plant preparations are generally used in combination in traditional medicine. Surprisingly, no previous studies have addressed the reason why the combination is preferred over the individual components to treat bacterial infections.

AIM OF THE STUDY

To test and compare the antibacterial efficacy of triphala and its component parts to quantify their relative efficacies. The individual plant components will also be tested as combinations, thereby determining whether combining the individual components potentiates the antibacterial activity of the components used alone.

MATERIALS AND METHODS

Triphala and the three individual plant components were extracted using solvents of varying polarity (methanol, water, ethyl acetate) and the antibacterial activity of the aqueous resuspensions was quantified by disc diffusion and broth microdilution MIC assays. Combinations of extracts produced from the individual components were also tested against each bacterial species and the ΣFICs was calculated to determine the class of interaction. Where synergy was detected, isobologram analysis was used to determine the optimal component ratios. The Artemia nauplii bioassay was used to test for toxicity and GC-MS headspace profiling analysis was used to highlight terpenoid components that may contribute to the antibacterial activity of triphala.

RESULTS

The aqueous and methanolic triphala, T. bellirica, T. chebula and E. officinalis extracts displayed good inhibitory activity against all bacterial strains, with MICs often in the 250-750 μg/mL range. The methanolic extracts were generally more potent than the aqueous extracts and T. chebula was the most potent of the individual plant components. Combining the extracts of the different plant species resulted in potentiation of the growth inhibitory activity of most combinations compared to that of the individual components. Indeed, with the exception of S. flexneri, all bacterial species were potentiated by at least one combination of methanolic plant extracts, with a substantial proportion of these displaying synergistic interactions. All extracts were found to be either non-toxic, or of low to moderate toxicity in Artemia nauplii assays.

CONCLUSION

Whilst the individual plant components of triphala all inhibit the growth of multiple pathogenic bacteria, the activity is potentiated for multiple combinations. Therefore, the traditional usage of the combination of the three plant materials in triphala not only extends the activity profile of the mixture over that of the individual components, but it also substantially potentiates the inhibitory activity towards multiple bacteria, partially explaining the preference of triphala compared to the individual components.