Characterization and Chemical Composition Analysis of Tea Tree (Meleuca alternifolia) Leaf Hydrosols Growing on Lombok Island

Tea tree is an essential oil-producing plant from Australia which is also found growing in several parts of Indonesia, including the island of Lombok. So far, tea tree essential oil producers on the island of Lombok do not utilize by-products in the form of hydrosol (distilled water) produced in the process of making essential oils. In this study, the characterization and analysis of the chemical composition of the hydrosol of tea tree leaves growing on the island of Lombok was carried out. The characteristic aroma of hydrosol is similar to that of tea tree essential oil. The results of the GC-MS analysis also showed that the hydrosol of tea tree leaves also had similarities with the essential oil, composed of major compounds in the form of trans-caryophyllene (28.58%), limonene (13.98%) and terpinen-4-ol (16.27%). Other compounds detected were -pinene (4.14%), -pinene (6.50%), -myrcene (8.09%), -terpineol (10.10%) and -terpinene (5.77%).

Antimicrobial activity of essential oils against Pasteurella spp. isolated from the oral cavity of domestic cats

ABSTRACT: Pasteurella spp. have been identified predominantly in the oral microbiota of domestic cats. However, Pasteurella spp. was significantly more prevalent in cats with inflammatory oral disease; and consequently, it was considered as part of the etiology in this disease. In addition, in animals, Pasteurella spp. have become increasingly resistant to a large number of antimicrobials. Natural products, especially essential oils, could contribute to minimizing this issue. This study determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of six essential oils against Pasteurella spp. isolates from the oral cavity of domestic cats. Our results showed that essential oils with better antimicrobial effectiveness against most of the Pasteurella isolates were lemongrass, tea tree and clove, with inhibition values between 50 to 800 µg mL-1. All essential oils showed bacteriostatic activity against the species of Pasteurella isolated from the domestic cats. These results suggested that lemongrass, tea tree and clove oils have potential to be used in products for oral hygiene and treatment of oral infections in domestic cats.

Botanical Pesticides: Use of Plants in pest management

Plants play a vital role in human life since the beginning of life on earth. Plants are not only directly used as a feed and fodder for humans and animals but are also used as drugs, food additives, pesticides, in flavor and fragrances and dye and pigments. The plants produce compounds for their growth and development and also produce secondary metabolites which provide additional properties to plants. These secondary metabolites produced by plant are responsible for these activities. Plants as a whole or in extracts/fractions form have been used as pesticides for protection of plants since thousands of years. Pyrethrum, neem, rotenone are such plants which has been used in many cultures and traditions for crop protection since ages and hold relevance in today’s world as well. The plant extracts contain secondary metabolites which provide protection to plants against pests by either causing mortality of pests or act as repellent to them. They can also impact pests by causing anti-feedancy, toxicity, alters insects behavior during oviposition and mating and inhibition of progeny emergence in pests. Essential oils isolated from the plants have also pesticidal properties. Lemongrass essential oil, Citronella essential oils, Tea tree essential oils and Oregano essential oils are the commonly used essential oils against the pests. In this review, botanical pesticides are discussed and their role in pest management and their advantageous over synthetic pesticides in terms of biodegradability, posing no or low risk to humans, environment and non-target organisms. Also, the future of botanical pesticides is discussed where they can be an alternative to synthetic pesticides if more research is done on their stability, efficacy, safety, modes of action, cost reduction is done.

Screening the antifungal properties of essential oils against Phytophthora colocasiae

Recently Microbicidal and micro-static activities of naturally obtained botanicals have been extensively explored, generally in response to the devastating apprehension of consumers towards the safety of edible products. However, scientists are paying more interest in using bio pesticides and phytochemicals that constitute environmentally favorable, non-toxic, long-lasting, and productive substitutes for preventing many hazardous plant pathogens. This research aimed to investigate the antifungal capabilities of sage and tea tree essential oils towards taro leaf blight, the most important cause of worldwide production losses. Using synthetic fungicides is a rapid and effective approach for controlling plant diseases, but it also creates human health risks, environmental threats, and chances of pathogen resistance. The essential oils of sage and tea tree were obtained by microwave-assisted hydro-distillation, and their chemical components were analyzed using FTIR spectroscopy. The main components of the oil were Thujone and Terpinen-4-ol, in sage and tea, respectively. A casual disease agent isolated from symptomatic taro leaves is used as a test fungus and identified as Phytophthora colocasiae. The antifungal properties of both essential oils were evaluated against mycelium, sporangium, zoospores, leaf necrosis, and corm lesions. Repeated experiments showed that the minimum concentrations for obtaining 100% inhibition of mycelium, zoospore germination, sporangia formation, and leaf necrosis were estimated at 2.5 and 5.0 mg/mL of sage and tea tree oils, respectively. Outcomes of this study provide an allusion for the prevention and curation of plant diseases promptly, economically, and environmentally by using phytochemicals and plant essential oil derivatives.