Mosquito Larvicidal Activity, Antimicrobial Activity, and Chemical Compositions of Essential Oils from Four Species of Myrtaceae from Central Vietnam

Abstract

Mosquitoes are important vectors of several diseases, and control of these insects is imperative for human health. Insecticides have proven useful in controlling mosquito populations, but insecticide resistance and environmental concerns are increasing. Additionally, emerging and re-emerging microbial infections are problematic. Essential oils have been shown to be promising mosquito larvicidal agents as well as antimicrobial agents. In this work, the essential oils from four species of Myrtaceae (Baeckea frutescens, Callistemon citrinus, Melaleuca leucadendra, and Syzygium nervosum) growing wild in central Vietnam have been obtained by hydrodistillation and analyzed by gas chromatographic techniques. The essential oils have been screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus, and for antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. Callistemon citrinus fruit essential oil, rich in α-pinene (35.1%), 1,8-cineole (32.4%), limonene (8.2%), and α-terpineol (5.8%) showed good larvicidal activity with 24-h LC 50 = 17.3 µg/mL against both Ae. aegypti and Cx. quinquefasciatus, and good antibacterial activity against E. faecalis (minimum inhibitory concentration (MIC) = 16 µg/mL) The 48-h larvicidal activities of M. leucadendra leaf essential oil, rich in α-eudesmol (17.6%), guaiol (10.9%), linalool (5.1%), (E)-caryophyllene (7.0%), and bulnesol (3.6%) were particularly notable, with LC 50 of 1.4 and 1.8 µg/mL on Ae. aegypti and Cx. quinquefasciatus. Similarly, M. leucadendra bark essential oil, with α-eudesmol (24.1%) and guaiol (11.3%), showed good antibacterial activity against. E. faecalis. Both B. frutescens and C. citrinus leaf essential oils demonstrated anti-Candida activities with MIC values of 16 µg/mL. The results of this investigation suggest that essential oils derived from the Myrtaceae may serve as "green" alternatives for the control of mosquitoes and/or complementary antimicrobial agents.

Chemical Composition of a Supercritical Fluid (Sfe-CO2) Extract from Baeckea frutescens L. Leaves and Its Bioactivity Against Two Pathogenic Fungi Isolated from the Tea Plant (Camellia sinensis (L.) O. Kuntze)

“…In most cases, 1,8-cineole or α-pinene are the most abundant and most common terpenes compounds in the majority of Myrtaceae foliar terpene profile, so in the vast majority of species (80%) there is an α-pinene or 1,8-cineole foliar terpene chemotype [34]. In this study, β-caryophyllene and α-caryophyllene were the The hydrodistillation volatile oil of B. frutescens leaves grown in Vietnam was found to contain β-pinene (19.0%), γ-terpinene (11.7%), α-pinene (11.1%) and (E)-caryophyllene (7.1%) [1]. Similarly, the hydrodistillation volatile oil of B. frutescens leaves collected in Vietnam was shown to contain α-humulene (19.2%), β-caryophyllene (17.3%), baeckeol (13.8%), α-thujene (8.8%), linalool (5.6%) and eucalyptol (5.6%) [33].…”

“…As an alternative to using chemical fungicides, plant extracts have attracted the attention of chemical companies as they may be used as botanical fungicides. Baeckea frutescens L. is an important medicinal plant belonging to the Myrtaceae family [ 1 ] and is found in Peninsular Malaysia and Sumatra and distributed along coastal areas of southeastern China and Australia [ 2 ]. B. frutescens has various bioactive properties, such as antibacterial [ 1 , 3 ], antioxidant [ 2 ], anticancer [ 4 ], anti-inflammatory [ 5 ] and insecticidal activities [ 1 ].…”

“…Baeckea frutescens L. is an important medicinal plant belonging to the Myrtaceae family [ 1 ] and is found in Peninsular Malaysia and Sumatra and distributed along coastal areas of southeastern China and Australia [ 2 ]. B. frutescens has various bioactive properties, such as antibacterial [ 1 , 3 ], antioxidant [ 2 ], anticancer [ 4 ], anti-inflammatory [ 5 ] and insecticidal activities [ 1 ]. The leaves of B. frutescens are rich in various volatile constituents such as terpenoids, sesquiterpenes and phenylpropanoids, which are secondary metabolites associated with numerous bioactivities [ 1 , 5 , 6 ].…”

“…B. frutescens has various bioactive properties, such as antibacterial [ 1 , 3 ], antioxidant [ 2 ], anticancer [ 4 ], anti-inflammatory [ 5 ] and insecticidal activities [ 1 ]. The leaves of B. frutescens are rich in various volatile constituents such as terpenoids, sesquiterpenes and phenylpropanoids, which are secondary metabolites associated with numerous bioactivities [ 1 , 5 , 6 ].…”

Essential Oils of Zingiber Species from Vietnam: Chemical Compositions and Biological Activities

“…The rhizome essential oil of Z. nudicarpum was rich in α-pinene (18.7%) and β-pinene (58.3%). The antimicrobial activities of α-pinene and β-pinene have ranged from excellent to inactive against E. faecalis , S. aureus , B. cereus , or C. albicans [ 69 , 70 , 71 ]. However, the presence of these two compounds as major components is not enough to impart good antimicrobial activity.…”