Antibacterial Activity of Chrysanthemum indicum, Centella asiatica and Andrographis paniculata against Bacillus cereus and Listeria monocytogenes under Osmotic Stress

Bacillus cereus and Listeria monocytogenes have an ability to survive in high osmotic stress. Three Thai herbs; Chrysanthemum indicum, Centella asiatica and Andrographis paniculata, are chosen to study their antibacterial activity on B. cereus and L. monocytogenes 10403S under normal and osmotic stress (5% NaCl) condition by agar disc diffusion method. The in vitro antibacterial screening results of crude 95% ethanolic extracted under normal stress showed A. paniculata, the highest antibacterial activity, C. asiatica and C. indicum crude 3.33 ± 0.47, 1.67 ± 0.94, and 1.17 ± 0.85 mm, respectively, against B. cereus. Only C. asiatica and A. paniculata crude showed antibacterial activity against L. monocytogenes; 1.67 ± 0.24, and 1.83 ± 0.24 mm, respectively. Under osmotic stress, the antibacterial activity of all crude 95% ethanolic extracted was increased two-fold. The MICs of A. paniculata, C. asiatica and C. indicum showed 4, 16, and 16 µl /ml against B. cereus while A. paniculata and C. asiatica showed 16 and 8 µl /ml, respectively, against L. monocytogenes, respectively. The MCBs of A. paniculata, C. asiatica and C. indicum showed 4, 16, and 32 µl /ml against B. cereus while A. paniculata and C. asiatica showed 16 and 32 µl /ml, respectively, against L. monocytogenes

Natural Antimicrobial Activity of Thai Red Curry’s Herbs on Salmonella Typhimurium DT104b

The outbreaks of Salmonella spp. have been reported as the major cause of food- borne illnesses worldwide. Thai red curry paste is an important ingredient of cultural foods and consists of herbs that have potential natural antibacterial activity. The objective of this experimental study was to measure the individual antibacterial activity of Thai red curry herbs on Salmonella under three different extraction methods (Kaeng Kathi - oil using fresh coconut milk, Kaeng Kathi - oil using UHT coconut milk, and Kaeng Pa - water). During the conducted experiments, the individual activities of the extracted herbs on Salmonella enterica serovar Typhimurium U302 (DT104b) were investigated by agar diffusion method using SS agar followed by MIC and MBC assay using broth dilution method. Among the three extraction methods, the extraction using fresh coconut milk gave the highest antibacterial activity in all herbs, followed by UHT coconut milk and water. Fresh coconut milk extracted cumin (Cuminum cyminum) and lemongrass (Citronella citrate) gave the highest antibacterial activity, 1.6 ± 0.22 cm and 1.4 ± 0.24 cm, respectively. The MIC assay showed 125 μl/ml and 100 μl/ml, while the MBC showed 125 μl/ml and 150 μl/ml, respectively. Thai red curry paste ingredients possess a significantly promising antibacterial activity against the food-borne pathogen S. enterica Typhimurium U302 (DT104b)

Process Optimization of Deep Eutectic Solvent Pretreatment of Coffee Husk Biomass

The increased processing of coffee beans has generated huge amount of coffee husk, which are improperly disposed. Inappropriate disposal of coffee husk has led to release of toxic compounds to the environment causing serious environmental concerns. To mitigate the impact of improperly disposed coffee husk, it is suggested for valorisation of the coffee husk. Hence, this study has focussed on identifying the potential of coffee husk in maximizing the sugar yield from it which can be converted to value added product. Deep eutectic solvent (DES) involving choline chloride and lactic acid (ChCl:LA) mixed at 1:4 molar ratio was studied to investigate the effect of DES pretreatment on coffee husk to produce reducing sugar in the hydrolysis process. Pretreatment conditions of the biomass were optimized for biomass loading (5-20%, w/w), temperature (70-120 °C), and duration (60-240 min) using Response Surface Methodology (RSM) for obtaining maximum yield of reducing sugar. The RSM model predicted an optimal pretreatment condition of biomass loading with 20% (w/w), pretreated at 120 °C for 231.80 min to achieve maximum sugar yield (30.522%). The pretreatment effect on biomass composition was analyzed using the Van Soest method, which showed an increase in the cellulose content along with the hemicellulose removal when compared with the native biomass. Moreover, evaluation of chemical structural changes also confirmed the effectiveness of DES pretreatment. Thus, the current study would illustrate the potential of coffee husk to produce value-added compounds from it

Bioactivity of Moringa oleifera and its Applications: A Review

In this paper, antimicrobial and antioxidant properties of Moringa oleifera plant are reviewed along with their potential application in food and medical industry. This tree is a source of healthy compounds contributing to human’s health and acts as a good source of natural antioxidants. It also inhibits bacterial growth assisting longer shelf life of food in preservation. The parts of the plant that had been reviewed are M. oleifera roots, leaves, barks and seeds. Each specific part was studied using different types of extraction methods for their microbial inhibition of Gram positive and Gram negative bacteria. Aqueous extract, alcohol extract and crude extracts (petroleum ether extract, chloroform extract, ethyl acetate extract and carbon tetrachloride extract) has been used for M. oleifera roots, barks and seeds. While M. oleifera had been extracted as powder, fresh leaf juice and water extract. M. oleifera is one of the best examples of plants which represent an emerging and interesting direction in food safety and production in the food industry. As consumers nowadays prefer essential products, use of these plant sources is now a new trend

Review: The Bioavailability Activity of Centella asiatica

Centella asiatica (Bao-bog, Tiger Herbal, Pennywort, Gotu kola) has been announced as one of five “Thailand Champion Herbal Products (TCHP)” by the Department for Development of Thai Transitional and Alternative Medicine, Ministry of Public Health. C. asiatica has been investigated for its bioavailability activity, antimicrobial activity, antioxidant activity, anti-inflammatory activity, wound healing activity and anticancer activity. C. asiatica contains many types of active compounds: terpenoids, terpenoids and phenols. Thus, C. asiatica has high potential to be applied in pharmaceutical, cosmetic and food industries

Antioxidant Activities of

Bioavailability of active compounds extracted from herbs is generally limited to be adsorbed or expressed to target organisms due to several physical and chemical factors. Nanoparticle encapsulation techniques was developed to carry bioactive macromolecules of Centella asiatica (Buabok) in the form of C. asiatica Extract-loaded Bovine Serum Albumin Nanoparticles (CBNPs) to improve bioavailability. In this study, the antioxidant activities of CBNPs and C. asiatica crude extract were evaluated by using DPPH radical scavenging assay in the simulated gastrointestinal system, including mastication, stomach, duodenum, and ileum conditions to provide the environment which similar to in vivo system in terms of chemical and physical parameters. CBNPs were prepared by mixing of C. asiatica crude extract and BSA at different ratio of 1:2, 1:3, and 1:4. The results showed that the highest antioxidant activity of CBNP was observed when the ratio of crude extract and BSA at 1:2 was used at pH 2.0 or in the simulated stomach condition. The denaturation or unfolding of BSA in the simulated stomach occurred when pH was low could lead to the release of active compounds at certain area in gastrointestinal system

The Antibacterial and Antioxidant Activity of Centella Asiatica Chloroform Extract-loaded Gelatin Nanoparticles

Nanoencapsulation of Centella asaitica (CA) crude chloroform extract seems to be an attractive approach that may improve drug bioavailability and drug delivery system. In the study, CA extract-loaded gelatin nanoparticles (CGNP) were developed by gelatin one-step and two-step desolvation methods, using three different ratios between CA crude chloroform extract and gelatin (1:2, 1:3, and 1:4 w/w). The antibacterial and antioxidants activities of CGNP and CA were compared. The antioxidant activity of CGNP and CA was evaluated by using DPPH radical scavenging assay and ferric reducing antioxidant power (FRAP) assay. Results showed an enhancement of CGNP antibacterial activity against food borne pathogen. The highest inhibition diameters and FRAP determined from CGNP prepared by one-step at 1:4 ratios (1.03±0.39 cm and 1.23±019 mmol Fe2+/mg dried weight, respectively). However, CGNP was no significant difference in DPPH radical scavenging activity compared to CA. These results provide useful information for developing effective nanoencapsulation of CA as effective natural ingredient

The Antibacterial and Antioxidant Activity of Centella Asiatica Chloroform Extract-loaded Gelatin Nanoparticles

Nanoencapsulation of Centella asaitica (CA) crude chloroform extract seems to be an attractive approach that may improve drug bioavailability and drug delivery system. In the study, CA extract-loaded gelatin nanoparticles (CGNP) were developed by gelatin one-step and two-step desolvation methods, using three different ratios between CA crude chloroform extract and gelatin (1:2, 1:3, and 1:4 w/w). The antibacterial and antioxidants activities of CGNP and CA were compared. The antioxidant activity of CGNP and CA was evaluated by using DPPH radical scavenging assay and ferric reducing antioxidant power (FRAP) assay. Results showed an enhancement of CGNP antibacterial activity against food borne pathogen. The highest inhibition diameters and FRAP determined from CGNP prepared by one-step at 1:4 ratios (1.03±0.39 cm and 1.23±019 mmol Fe2+/mg dried weight, respectively). However, CGNP was no significant difference in DPPH radical scavenging activity compared to CA. These results provide useful information for developing effective nanoencapsulation of CA as effective natural ingredient

Effect of Extraction Methods on Antibacterial Activity and Chemical Composition of Chinese Chives (Allium tuberosum Rottl. ex Spreng) Extract

The Bang-Phae organic vegetable grower community enterprise group, Ratchaburi province is one of the largest Chinese chives (Allium tuberosum Rottl. ex Spreng) growers in Thailand. However, not all of its Chinese chives meet the standard of retail markets and were sorted out. Producing Chinese chives extract is an alternative way to add value to the rejected produces. The Chinese chives essential oil contains many new and known bioactive compounds. Therefore, this experiment was aimed to study the antibacterial activity of Chinese chives extracts using 17 difference extraction conditions (Steam distillation for 1.0, 2.0, 2.5, 3.0 h; Ohmic pretreatment followed by steam distillation for 1.0, 2.0, 2.5, 3.0 h; 95% ethanol, hexane, soy bean oil extraction using dried, fresh and frozen Chinese chives) against 6 different pathogenic bacterium (Escherichia coli ATCC25822, Salmonella enterica Typhimurium U302, S. enterica Enteritidis, S. enterica 4,5,12:i (human) US clone, Bacillus cereus and Listeria monocytogenes 10403S). The disc agar diffusion method with 3 different concentrations of extracts (25, 50, 75 mg/mL) was used to evaluate the antibacterial activity. The results showed that different extraction conditions significantly affected the antibacterial activity. The higher extract concentration resulted in the better antibacterial activity. This finding indicated that both extraction condition and extract concentration significantly influence antibacterial activity. The extracts obtained from thermal extraction seem to have higher antibacterial activity than the ones obtained from cold extraction. The extract obtained from steam distillation for 2.5 h resulted in the highest antibacterial activity; 75 mg/mL of the extract caused 0.688 ±0.023 cm clear zone against B. cereus and L. monocytogenes 10403S. The chemical composition profile using GC-MS showed high percentage of organosulfide volatile compounds in thermally extracted Chinese chives. Therefore, the organosulfide volatile compounds might be responsible for effective bacteria inhibition