Nematicidal Activity of Plant Essential Oils against Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae)

The nematicidal activity and poisoning symptoms of 88 plant essential oils against Bursaphelenchus xylophilus were examined by an immersion bioassay. Results were compared with those of three trunk-injection nematicides: fenitrithion, levamisol hydrochloride, and morantel tartrate. As judged by 24 h LC₅₀ values, cinnamon bark oil (0.12 mg/ml) was the most effective nematicide, followed by coriander herb oil (0.14 mg/ml). Potent nematicidal activity was also observed with lemongrass, oregano, thyme red, and clove bud oils (LC₅₀, 0.57-0.88 mg/ml). Fenitrothion was ineffective (LC₅₀, > 10 mg/ml). In typical poisoning symptoms in B. xylophilus, these essential oils exerted rapid nematicidal action and the nematodes killed usually showed an extended shape, whereas levamisole hydrochloride and morantel tartrate usually exhibited semicircular and coiling shapes, respectively. The essential oils described merit further study as botanical nematicides for the control of pine wilt disease caused by B. xylophilus.     

Nematicidal activity of essential oils: a review

Plant parasitic nematodes are the most destructive group of plant pathogens worldwide and their control is extremely challenging. Plant Essential oils (EOs) and their constituents have a great potential in nematode control since they can be developed for use as nematicides themselves or can serve as model compounds for the development of derivatives with enhanced activity. This study reviews the plant EOs evaluated as potential nematicides and their toxic effects against pinewood nematode (Bursaphelenchus xylophilus) and root-knot nematodes (Meloidogyne spp.). Additionally, the nematicidal activity to M. javanica of several EOs from Spanish aromatic plants and their components is described.     

The Essential Oil Compositions of Ocimum basilicum from Three Different Regions: Nepal,Tajikistan, and Yemen

The aerial parts of Ocimum basilicum L. were collected from four different geographical locations, Sindhuli and Biratnagar (Nepal), Chormaghzak village (Tajikistan), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 179 essential oil compositions revealed six major chemotypes: Linalool, eugenol, estragole, methyl eugenol, 1,8‐cineole, and geraniol. All four of the basil oils in this study were of the linalool‐rich variety. Some of the basil oils were screened for bioactivity including antimicrobial, cytotoxicity in human cancer cells, brine shrimp lethality, nematicidal, larvicidal, insecticidal, and antioxidant. The basil oils in this study were not notably antibacterial, cytotoxic, antioxidant, nor nematicidal, but were active in the brine shrimp lethality test, and did show larvicidal and insecticidal activities.     

Nematicidal and Molecular Docking Investigation of Essential Oils from Pogostemon cablin Ecotypes against Meloidogyne incognita

Root-knot nematode, Meloidogyne incognita is one of the most destructive nematodes worldwide. Essential oils (EOs) are being extensively utilized as eco-benign bionematicides, although the precise mechanism of action remains unclear. Pogostemon cablin Benth. is well-known as “Patchouli”. It is native to South East Asia and known for ethno-pharmacological properties. In this study, chemical composition and potential nematicidal effect of EOs hydrodistilled from the leaves of P. cablin grown at three different locations in India were comprehensively investigated to correlate their mechanism of action for target specific binding affinities toward nematode proteins. Aromatic volatile Pogostemon essential oils (PEO) from Northern India (PEO-NI), Southern India (PEO-SI) and North Eastern India (PEO-NEI) were analyzed by Gas Chromatography-Mass Spectrometry (GC/MS) to characterize forty volatile compounds. Maximum thirty-three components were identified in PEO-NEI. Sesquiterpenes were predominant with higher content of α-guaiene (2.3–24.4 %), patchoulol (6.1–32.7 %) and α-bulnesene (5.9–27.1 %). Patchoulol was the major component in PEO-SI (32.7±1.2 %) and PEO-NEI (29.2±1.1 %), while α-guaiene in PEO-NI (24.4±1.2 %). In vitro nematicidal assay revealed significant nematicidal action (LC₅₀ 44.6–87.0 μg mL⁻¹) against juveniles of M. incognita within 24 h exposure. Mortality increases with increasing time to 48 h (LC₅₀ 33.6–71.6 μg mL⁻¹) and 72 h (LC₅₀ 27.7–61.2 μg mL⁻¹). Molecular modelling and in silico studies revealed multi-modal inhibitive action of α-bulnesene (−22 to −13 kJ mol⁻¹) and α-guaiene (−22 to −12 kJ mol⁻¹) against three target proteins namely, acetyl cholinesterase (AChE), odorant response gene-1 (ODR1), odorant response gene-3 (ODR3). Most preferable binding mechanism was observed against AChE due to pi-alkyl, pi-sigma, and hydrophobic interactions. Structure nematicidal activity relationship suggested the presence of hydroxy group for nematicidal activity is nonessential, rather highly depends on synergistic composition of sesquiterpene hydrocarbons.     

Essential Oils as Potent Source of Nematicidal Compounds

Bioassay tests were conducted to find out the nematicidal activity of eight essential oils against Meloidogyne incognita (Kofoid and White) Chitwood at four concentrations. Maximum activity was recorded in oils of Eucalyptus citriodora , Eucalyptus hybrida and Ocimum basilicum followed by Pelargonium graveolens , Cymbopogon martinii, Mentha arvensis, Mentha piperita and Mentha spicata oils, respectively. The eucalyptus ( E. citriodora and E. hybrida ) and Indian basil ( O. basilicum ) oils were highly toxic to M. incognita even at the lower concentrations, namely 500 and 250 ppm. The remaining oils were also toxic to the nematode but at different amounts.     

Bioactivity of semisynthetic eugenol derivatives against Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae infesting maize in Colombia

The anti-acetylcholinesterase, larvicidal, antifeedant activities and general toxicity of 15 semisynthetic eugenol derivatives based on clove oil (including the own oil), were evaluated against the maize armyworm, Spodoptera frugiperda (J.E. Smith). Therefore, promising eugenol molecules were classified with larvicidal, anti-acetylcholinesterase and antifeedant activities for controlling this pest. During structure–activity relationship studies and physicochemical profile analysis, it was found that among tested molecules 1–15, eugenol 1, prenyl eugenol 4, isoeugenol 8 and isoeugenol acetate 11 exhibited lethal effects LD₅₀ at concentrations <1 mg/g of insect. On the other hand, eugenol 1, metallyl eugenol 3, isoeugenol 8 and isoeugenol acetate 11 showed a good antifeedant activity (CE₅₀ = 158–209 µg/mL) with a high antifeedant index (70–78%) at concentration 1000 µg/mL, possessing a weak anti-acetylcholinesterase activity (IC₅₀ = 21–31 μg/mL). According to their ecotoxicological profiles (LC₅₀ = 2033.1–6303.8 µg/mL on Artemia salina larvae), isoeugenol 8 and its acetate derivative 11 could be potential used in control of the growth, feeding, or reproduction of S. frugiperda larvae, acting as moderate insecticidal acetylcholinesterase inhibitors and/or antifeedant molecules. Such structure–activity relationship studies could stimulate the identification of lead structures from natural sources for the development of larvicidal and deterrent products against S. frugiperda and related insect pests.     

Fumigant Toxicity of Plant Essential Oils to Plutella xylostella (Lepidoptera: Yponomeutidae) and Cotesia glomerata (Hymenoptera: Braconidae)

The fumigant toxicity of 66 plant essential oils to Plutella xylostella (L.) larvae and Cotesia glomerata (L.) adults was examined using a vapor-phase toxicity bioassay and compared with that of dichlorvos. Responses varied according to oil and insect species used. Based on 24 h LD₅₀ values, pennyroyal oil [10.77 mg/filter paper (4.25 cm diameter)] was the most toxic fumigant, followed by rosemary and sage (Dalmatin) oils (15.15 mg/paper). Potent fumigant toxicity was also produced from armoise, buchu leaf, cedarleaf, coriander, eucalyptus, howood, lavender, myrtle, niaouli, peppermint, and rosewood oils (LD₅₀, 21.29–27.31 mg/paper). All essential oils were less effective than dichlorvos (LD₅₀, 0.52 mg/paper). Against adult C. glomerata, dichlorvos (LD₅₀, 0.03 mg/paper) was the most toxic fumigant, whereas the LD₅₀ values of the 14 essential oils ranged from 1.59 to 8.51 mg/paper. Based on selective toxicity ratio (STR, P. xylostella LD₅₀/C. glomerata LD₅₀), the 14 essential oils (STR, 2.5–14.5) are more selective than dichlorvos (STR, 17.3). The essential oils tested merit further study as potential fumigants for the control of P. xylostella in greenhouses because of their selective toxicity to adult C. glomerata and their much greater activity as a fumigant.     

Antibacterial Potent of Acetylated and Non-Acetylated Clove Bud Essential Oils and Their Main Compounds

Clove bud is a medicinal plant used traditionally in Asia for the treatment of various disease. Previously, Clove oil is a potential source of an antimicrobial compounds especially vis-a-vis bacterial pathogens. However, the compound responsible for this activity remains to be investigated. Essential oil (EO) clove, acetylated essential oil clove, eugenol, and acetyleugenol were evaluate as an antibacterial potential agent against Staphyloccocus aureus (SE), Escherichia coli (EC) and Pseudomonas aeruginosa (PA). Essential oil containing eugenol was extracted from buds of Eugenia caryophyllata commonly named clove (Syzygium aromaticum (L.) (Family Myrtaceae) by a simple hydrodistillation. The analysis of the essential oils (EOs) using gas chromatography-mass spectrometry (GC-MS) shows eugenol as the major constituent with 70.14 % of the total. The Eugenol was isolated from the EO using chemical treatment. Afterwards, the EO and eugenol were converted to acetylated EO and acetyleugenol, respectively using acetic anhydride. The antibacterial result revealed that all compounds showed a strong activity against the three strains. The Staphyloccocus aureus and Pseudomonas aeruginosa were extremely sensitive against eugenol with an inhibition diameters of 25 mm. The MIC values of eugenol versus S. aureus and P. aeruginosa were 0.58 and 2.32 mg/mL, respectively, while the MIB values were 2.32 mg/mL and 9.28 mg/mL.     

Nematicidal activity of (Z)-ligustilide isolated from Angelica tenuissima Nakai root extract against the pine wood nematode Bursaphelenchus xylophilus

In this study, we investigated the nematicidal activities of the ethanol extracts of 49 medicinal plants against the pine wood nematode, Bursaphelenchus xylophilus, and isolated a main nematicidal constituent, (Z)-ligustilide, from Angelica tenuissima Nakai root extract. Among the 49 plant extracts, only the A. tenuissima root extract showed the strong nematicidal activity against the pine wood nematode, with a 92.3% mortality rate at a concentration of 2 mg/mL. Based on bioassay-guided isolation and gas chromatography-mass spectrometry (GC-MS) analysis, (Z)-ligustilide was identified as the active component of A. tenuissima root extract at 73.6% of the total content ratio. The LC₅₀ value of (Z)-ligustilide against the pine wood nematode was 0.24 mg/mL. Our results indicated that (Z)-ligustilide as well as A. tenuissima root extract can be potential candidates for novel trunk injection agents against the pine wood nematode.     

Chemical Composition and Antibacterial Activity of Essential Oils from Different Parts of Litsea cubeba

The composition of the essential oils obtained by hydrodistillation of different parts of Litsea cubeba, including roots, stems, leaves, alabastra (flower buds), flowers, and fruits, were investigated by GC (RI) and GC/MS. The antimicrobial activity of the oils was assessed with disc diffusion and microbroth dilution assays. The results showed large variations in the composition among the different oils. The major components in the oils from roots and fruits, from stems, leaves, and alabastra, and from flowers were citral B (neral), β‐phellandrene, and β‐terpinene, respectively. The inhibition zone (DD) and MIC values for the bacterial strains tested, which were all sensitive to the essential oil of L. cubeba, were in the range of 10.1–35.0 mm and 100–1000 μg/ml, respectively. Hence, the oils of the various parts showed moderate activity against the tested bacteria. This investigation showed that the antibacterial activity of L. cubeba was attributed to the essential oils, thus they can be a potential medicinal resource.     

Essential Oils and Herbal Extracts as Antimicrobial Agents in Cosmetic Emulsion

The cosmetic industry adapts to the needs of consumers seeking to limit the use of preservatives and develop of preservative-free or self-preserving cosmetics, where preservatives are replaced by raw materials of plant origin. The aim of study was a comparison of the antimicrobial activity of extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinallis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben. Extracts (2.5 %), essential oils (2.5 %) and methylparaben (0.4 %) were tested against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Candida albicans ATCC 14053. Essentials oils showed higher inhibitory activity against tested microorganism strain than extracts and methylparaben. Depending on tested microorganism strain, all tested extracts and essential oils show antimicrobial activity 0.8–1.7 and 1–3.5 times stronger than methylparaben, respectively. This shows that tested extracts and essential oils could replace use of methylparaben, at the same time giving a guarantee of microbiological purity of the cosmetic under its use and storage.     

Nematicidal Principles from Two Species of Lamiaceae

Aqueous extracts of Ocimum sanctum and O. basilicum leaves contained compounds that killed Meloidogyne incognita larvae in 160 min. Thin layer and gas-liquid chromatography, and infrared spectrophotometry indicated that the essential oils eugenol and linalool were the active nematicidal compounds.     

Essential oils as spatial repellents for the brown marmorated stink bug,Halyomorpha halys (Stål) (Hemiptera: Pentatomidae)

The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), native to Northeastern Asia, is a serious invasive pest in the United States, Canada, Switzerland, Germany and France. Several common essential oils and their compositions were tested against BMSBs as potential repellents. All the tested individual essential oils and a ternary oil blend showed significant repellency to both BMSB nymphs and adults. Clove oil, lemongrass oil, spearmint oil, ylang‐ylang oil, and the ternary oil mixture (clove, lemongrass and spearmint) almost completely blocked attraction of BMSBs to the stink bug attractant‐baited traps; whereas wintergreen oil, geranium oil, pennyroyal oil and rosemary oil resulted in 60–85% trap catch reductions. Over 20 BMSB antennally active compounds were identified from SPME headspace samples of the eight repellent essential oils using GC‐EAD and GC‐MS techniques. Among the synthetic EAD‐active compounds tested in the field, eugenol, l‐carvone, p/l‐menthone, pulegone, methyl salicylate, trans/cis‐citral, methyl benzoate and β‐caryophyllene significantly reduced trap catches of BMSBs by 72–99%; these compounds are likely responsible for the repellency of their corresponding essential oils. Surprisingly, a synthetic mixture of the predacious spined soldier bug (SSB) [Podisus maculiventris (Say)] aggregation pheromone (trans‐2‐hexenal, α‐terpineol and benzyl alcohol) also showed a significant inhibition of BMSB response to its attractants. These repellent essential oils and their active compounds, as well as the synthetic SSB pheromone, are potentially useful as part of an efficient, environmentally sound semiochemical‐based IPM programme to combat this serious invasive stink bug.     

几种典型植物精油的化学成分与其抗菌活性

【目的】植物精油萃取自天然植物, 因具有抗菌活性, 近年来受到广泛关注。论文的目的是分析植物精油的化学成分, 测试其抗菌活性, 并研究其化学成分与抗菌活性之间的联系。【方法】实验选取了肉桂、山苍子、丁香、香茅、迷迭香和大蒜精油等6种典型植物精油, 通过气质联用分析方法研究了其化学组分, 并通过污染食物技术研究了其对黑曲霉和绳状青霉的抗真菌活性, 以及对大肠杆菌和金黄色葡萄球菌的抗细菌活性。【结果】气质联用分析结果表明, 肉桂、山苍子、香茅和迷迭香等4种植物精油的化学成分主要是醛类和醇类, 丁香精油的主要化学成分是丁香油酚, 大蒜精油化学成分基本上都是含硫的醚类, 其中二烯丙基三硫醚(大蒜素)含量最高。抗菌活性结果显示, 不同植物精油的抗菌活性不同, 6种植物精油的抗真菌活性由强到弱依次为: 肉桂>大蒜>丁香>山苍子=香茅>迷迭香, 抗细菌活性由强到弱依次为: 肉桂>山苍子>丁香>香茅=迷迭香>大蒜。【结论】植物精油的抗真菌、细菌活性与其化学组分密切相关, 肉桂、山苍子、香茅和迷迭香等4种精油的抗菌活性可能主要与其化学成分中的醛类和醇类有关, 丁香精油较高的抗菌活性可能主要源于丁香油酚; 大蒜精油具有高效的抗真菌活性主要源于其化学成分中的含硫醚。不同植物精油化学成分不同, 抗真菌、细菌活性也不同, 表明其可能有不同的抗真菌与抗细菌机制。     

Nematicidal activity of essential oils and volatiles derived from Portuguese aromatic flora against the pinewood nematode, Bursaphelenchus xylophilus

Twenty seven essential oils, isolated from plants representing 11 families of Portuguese flora, were screened for their nematicidal activity against the pinewood nematode (PWN), Bursaphelenchus xylophilus. The essential oils were isolated by hydrodistillation and the volatiles by distillation-extraction, and both were analysed by GC and GC-MS. High nematicidal activity was achieved with essential oils from Chamaespartium tridentatum, Origanum vulgare, Satureja montana, Thymbra capitata, and Thymus caespititius. All of these essential oils had an estimated minimum inhibitory concentration ranging between 0.097 and 0.374 mg/ml and a lethal concentration necessary to kill 100% of the population (LC(100)) between 0.858 and 1.984 mg/ml. Good nematicidal activity was also obtained with the essential oil from Cymbopogon citratus. The dominant components of the effective oils were 1-octen-3-ol (9%), n-nonanal, and linalool (both 7%) in C. tridentatum, geranial (43%), neral (29%), and β-myrcene (25%) in C. citratus, carvacrol (36% and 39%), γ-terpinene (24% and 40%), and p-cymene (14% and 7%) in O. vulgare and S. montana, respectively, and carvacrol (75% and 65%, respectively) in T. capitata and T. caespititius. The other essential oils obtained from Portuguese flora yielded weak or no activity. Five essential oils with nematicidal activity against PWN are reported for the first time.     

Plant Essential Oils Synergize and Antagonize Toxicity of Different Conventional Insecticides against Myzus persicae (Hemiptera: Aphididae)

Plant-derived products can play an important role in pest management programs. Essential oils from Lavandula angustifolia (lavender) and Thymus vulgaris (thyme) and their main constituents, linalool and thymol, respectively, were evaluated for insecticidal activity and synergistic action in combination with insecticides against green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). The essential oils and their main constituents exerted similar insecticidal activity when aphids were exposed by direct sprays, but were non-toxic by exposure to treated leaf discs. In synergism experiments, the toxicity of imidacloprid was synergized 16- to 20-fold by L. angustifolia and T. vulgaris essential oils, but far less synergism occurred with linalool and thymol, indicating that secondary constituents of the oils were probably responsible for the observed synergism. In contrast to results with imidacloprid, the insecticidal activity of spirotetramat was antagonized by L. angustifolia and T. vulgaris essential oils, and linalool and thymol. Our results demonstrate the potential of plant essential oils as synergists of insecticides, but show that antagonistic action against certain insecticides may occur.     

Lantana camara Essential Oils from Vietnam: Chemical Composition,Molluscicidal, and Mosquito Larvicidal Activity

Lantana camara is a troublesome invasive plant introduced to many tropical regions, including Southeast Asia. However, the plant does hold promise as a source of essential oils that may be explored for potential use. Fresh water snails such as Pomacea canaliculata, Gyraulus convexiusculus, and Tarebia granifera can be problematic agricultural pests as well as hosts for parasitic worms. Aedes and Culex mosquitoes are notorious vectors of numerous viral pathogens. Control of these vectors is of utmost importance. In this work, the essential oil compositions, molluscicidal, and mosquito larvicidal activities of four collections of L. camara from north-central Vietnam have been investigated. The sesquiterpene-rich L. camara essential oils showed wide variation in their compositions, not only compared to essential oils from other geographical locations (at least six possible chemotypes), but also between the four samples from Vietnam. L. camara essential oils showed molluscicidal activities comparable to the positive control, tea saponin, as well as other botanical agents. The median lethal concentrations (LC₅₀) against the snails were 23.6–40.2 μg/mL (P. canaliculata), 7.9–29.6 μg/mL (G. convexiusculus), and 15.0–29.6 μg/mL (T. granifera). The essential oils showed good mosquito larvicidal activities with 24-h LC₅₀ values of 15.1–29.0 μg/mL, 26.4–53.8 μg/mL, and 20.8–59.3 μg/mL against Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus, respectively. The essential oils were more toxic to snails and mosquito larvae than they were to the non-target water bug, Diplonychus rusticus (24-h LC₅₀=103.7–162.5 μg/mL). Sesquiterpene components of the essential oils may be acting as acetylcholinesterase (AChE) inhibitors. These results suggest that the invasive plant, L. camara, may be a renewable botanical pesticidal agent.     

Inhibitory Effect of Essential Oils on Aspergillus ochraceus Growth and Ochratoxin A Production

Ochratoxin A (OTA) is a mycotoxin which is a common contaminant in grains during storage. Aspergillus ochraceus is the most common producer of OTA. Essential oils play a crucial role as a biocontrol in the reduction of fungal contamination. Essential oils namely natural cinnamaldehyde, cinnamon oil, synthetic cinnamaldehyde, Litsea citrate oil, citral, eugenol, peppermint, eucalyptus, anise and camphor oils, were tested for their efficacy against A. ochraceus growth and OTA production by fumigation and contact assays. Natural cinnamaldehyde proved to be the most effective against A. ochraceus when compared to other oils. Complete fungal growth inhibition was obtained at 150–250 µL/L with fumigation and 250–500 µL/L with contact assays for cinnamon oil, natural and synthetic cinnamaldehyde, L. citrate oil and citral. Essential oils had an impact on the ergosterol biosynthesis and OTA production. Complete inhibition of ergosterol biosynthesis was observed at ≥100 µg/mL of natural cinnamaldehyde and at 200 µg/mL of citral, but total inhibition was not observed at 200 µg/mL of eugenol. But, citral and eugenol could inhibit the OTA production at ≥75 µg/mL and ≥150 µg/mL respectively, while natural cinnamaldehyde couldn’t fully inhibit OTA production at ≤200 µg/mL. The inhibition of OTA by natural cinnamaldehyde is mainly due to the reduction in fungal biomass. However, citral and eugenol could significant inhibit the OTA biosynthetic pathway. Also, we observed that cinnamaldehyde was converted to cinnamic alcohol by A. ochraceus, suggesting that the antimicrobial activity of cinnamaldehyde was mainly attributed to its carbonyl aldehyde group. The study concludes that natural cinnamaldehyde, citral and eugenol could be potential biocontrol agents against OTA contamination in storage grains.     

Acaricidal Activity of Pla.nt Essential Oils against Tyrophagus putrescentiae (Acari: Acaridae)

The acaricidal activity of 54 commercially available plant essential oils against Tyrophagus putrescentiae adults was compared with those of benzyl benzoate and N, N-diethyl-m-toluamide (deet). Responses varied with test oils. In a test with an impregnated fabric disc bioassay at 12.7 μg/cm², over 80% mortality was observed with bay, citronella java, clove bud, clove leaf, lemongrass, nutmeg, oregano, pimento berry, thyme red, and thyme white oils. These oils were more toxic to T. putrescentiae adults than benzyl benzoate and deet. At 6.4 μg/cm², lemongrass and thyme white oils exhibited 76 and 84% mortality, respectively, whereas the acaricidal activity of the other essential oils was significantly decreased. In a fumigation test with adult mites, lemongrass and pimento berry oils were much more effective in closed containers than in open ones, indicating that the effects of these oils were largely due to action in the vapor phase. Plant essential oils described merit further study as potential T. putrescentiae control agents.     

Evaluation of in vitro antimicrobial activity of leaf and stem essential oils of <Emphasis Type="Italic">Chloroxylon swietenia</Emphasis> DC.

The essential oils obtained by hydrodistillation of leaves and stems of Chloroxylon swietenia DC. were analysed by GC and GC-MS. The main components in the leaf oil were limonene, pregeijerene, geijerene and germacrene D, while stem oil was rich in limonene, methyl eugenol, pregeijerene and geijerene. The essential oils were evaluated for antimicrobial activity against two gram-positive and two gram-negative bacteria and four pathogenic fungi using agar disc diffusion technique. Subsequently, the minimum inhibitory concentration (MIC) from oils was determined by broth microdilution. Both the oils exhibited moderate to strong activities against all the organisms tested. Bacillus subtilis was most susceptible at 100 μg/ml of leaf and stem oils with inhibition zones of 15.9 and 13.1 mm respectively. Among all the fungi tested, A. niger inhibited effectively with a zone of inhibition of 14.9 and 11.5 mm for leaf and stem oils respectively. The results obtained suggest that the essential oils of the plant possess antimicrobial properties and serve as a biofriendly source of antimicrobial ingredients for the food and pharmaceutical industries.