Composition and Insecticidal Activity of Essential Oil of Bacopa caroliniana and Interactive Effects of Individual Compounds on the Activity.

Bacopa caroliniana (BC) is a perennial creeping herb and popular aquarium plant. This plant is easily cultivated; consequently, it has the potential to be a raw material which is readily available for mass production if it contains useful bioactive substances. The information about the functionality of this plant has been very limited. Therefore, the aims of this research were to analyze the composition of the essential oil (EO) of BC and to study its insecticidal effect on rice weevils. Moreover, the interactive effects of active compounds of the EO on this activity were also investigated. A total of 18 volatile compounds was identified, accounting for ca. 94% of the BC-EO in terms of quantity. Of them, α-terpinolene was the largest compound. The impact of individual volatile compounds on the inhibition of acetylcholine esterase and insecticidal activity were determined. α-Terpinolene exhibited the highest activity on these assays. Both additive and synergistic effects existed in terms of the insecticidal activity. Many compounds found in the BC-EO are widely present in other EOs. Thus, the information obtained from this study is useful for EO-related research, applications in selecting EOs or in seeking the best combination of EOs or individual compounds to achieve efficient insecticidal effects.

Identification of ß-Sitosterol as in Vitro Anti-Inflammatory Constituent in Moringa oleifera.

ß-Sitosterol is a well known phytosterol in plants, but owing to its poor solubility in typical media, determining its cellular mechanisms has been proven to be difficult. In this study, we investigated the anti-inflammatory activity of ß-sitosterol (BSS) isolated from Moringa oleifera in two cell lines. Over a dose range of 7.5 to 30 µM, BSS dispersed well in the medium as nanoparticles with diameters of 50 ± 5 nm and suppressed the secretion of inflammatory factors from keratinocytes and macrophages induced by PGN, TNF-α, or LPS, such as TNF-α, IL-1ß, IL-6, IL-8, and ROS, separately. In addition, BSS significantly reduced the expression of NLRP3, a key component of NLRP3 inflammasomes, and inhibited the activation of caspase-1. There was partial inhibition of NF-κB in macrophages. This is the first study to report an increase in the solubility of nearly water-insoluble phytosterols via the formation of nanoparticles and to delineate the formulation's capacity to inhibit the signal transduction pathways of inflammation in macrophages.

Effects of processing methods on composition and functionality of volatile components isolated from immature fruits of atemoya.

Atemoya is one of the most important commercial fruits of the family Annonaceae. The immature fruits of atemoya amply produced from a fruit-thinning process is normally regarded as waste and discarded. This research aimed at studying antimicrobial, antioxidant, and anti-inflammatory activities of the essential oil (EO) isolated from the immature fruits to explore its potential application. The fruits were subjected to different drying methods: solar drying (SD), oven drying at 30°C (OD-30), and at 50°C (OD-50). The oven drying method gave a higher EO yield than the solar drying method. Spathulenol was the largest compound in the EO after the drying process. Antimicrobial effect was not affected by the different drying methods. Antioxidant activity of the EO was measured by DPPH, nitric oxide, and reducing power methods. The EOOD-50 exhibited a stronger antioxidant activity than EOSD and EOOD-30. The EO also showed an anti-inflammatory activity in a cell model.

Antimicrobial activity of the essential oil of Glossogyne tenuifolia against selected pathogens.

BACKGROUND: Glossogyne tenuifolia (GT) is a perennial herb widely distributed in the areas from south Asia to Australia. Many biological effects of G. tenuifolia have been reported; however, the information about antimicrobial activity of the essential oil (EO) of the herb remains unavailable. Therefore, the aims of this study were to investigate the antimicrobial activity of the GT-EO in vitro and food systems, the antimicrobial impact (AI) of its individual compounds, and interactive effects of major active compounds (linalool, 4-terpineol, α-terpineol, ρ-cymene) on selected Gram-positive (S. aureus, L. monocytogenes, S. mutans and S. sanguinis) and Gram-negative (E. coli O157:H7, V. parahaemolyticus and S. enterica) pathogens. RESULTS: The minimal microbicidal concentration (MMC) of the GT-EO ranged from 0.75 to 12 mg mL(-1) against the test bacteria in vitro. Except for L. monocytogenes, the GT-EO exhibited more inhibitory effect on the selected Gram positive than against the Gram negative bacteria at the GT-EO concentrations ≤ 12 mg mL(-1) . The interactive effects of major active compounds (linalool, 4-terpineol, α-terpineol, ρ-cymene) are additive instead of synergistic via the checkerboard analysis. The bacteria with a microbial load of ca. 10(2) CFU mL(-1) in the milk tea could be completely inactivated by the GT-EO with the MMC of 1.5 mg mL(-1) . CONCLUSION: ρ-Cymene is the largest component in the GT-EO; however, it is not the compound predominantly affecting the entire antimicrobial activity of the EO. Instead, 4-terpineol is the most influential among the test compounds that contribute to the antimicrobial activity of the GT-EO.