Culinary Spices in Food and Medicine: An Overview of Syzygium aromaticum (L.) Merr. and L. M. Perry [Myrtaceae]

Spices-dried aromatic parts of plants (leaves, seeds, bark, roots, rhizomes, buds, etc) used to enhance flavour, taste and colour (sensory quality) of foods, are increasingly finding other useful roles in healthcare beyond their primary use as culinary organoleptic enhancers. Several spices are currently being investigated for their potential health benefits, because of the failing efficacy, toxicity and high cost associated with conventional drugs. One such spice: Syzygium aromaticum (L.) Merr. and L.M.Perry [Myrtaceae] (Clove), has a multi-dimensional role in diet, medicine, functional foods and nutraceuticals, agriculture, among other industries. Peer-reviewed articles, mostly from PubMed and Google Scholar, were consulted for the purpose of this review. The nutritional and phytochemical contents, selected biological activities as well as some functional foods and beverages of clove and their uses for human health are presented. Although these observations are largely empirical, the efficacious attributes have led to their pharmacological applications in the indigenous system of medicine all over the world and bridge between food, diet and medicine. Considering the GRAS status of clove, more studies on bioavailability, accumulation, toxicity, dosage and efficacy of clove as a spice drug or functional foods in biological systems especially in humans are required. Meanwhile, clove and its products can be used as co-adjuvants in the prevention, treatment and management of chronic diseases. Further, many applications of clove in food, health, cosmetics, pharmaceutics, nanoparticles and agricultural industries are still open for investigations.

Cyclodextrins-in-Liposomes: A Promising Delivery System for Lippia sidoides and Syzygium aromaticum Essential Oils

Biological activity of essential oils (EOs) has been extensively reported; however, their low aqueous solubility, high photosensitivity, and volatility compromise a broad industrial use of these compounds. To overcome these limitations, we proposed a nanoencapsulation approach to protect EOs, that aims to increase their stability and modulate their release profile. In this study, drug-in-cyclodextrin-in-liposomes encapsulating two essential oils (Lippia sidoides and Syzygium aromaticum) and their respective major compounds (thymol and eugenol) were produced by ethanol injection and freeze-dried to form proliposomes and further physicochemically characterized. Liposomes showed high physical stability over one month of storage at 4 °C, with slight changes in the mean size, polydispersity index (PDI), and zeta potential. Reconstituted proliposomes showed a mean size between 350 and 3300 nm, PDI from 0.29 to 0.41, and zeta potential between −22 and −26 mV. Differential scanning calorimetry and X-ray diffraction of proliposomes revealed a less-ordered crystalline structure, leading to high retention of the major bioactive compounds (between 73% and 93% for eugenol, and 74% and 84% for thymol). This work highlights the advantages of using drug-in-cyclodextrin-in-liposomes as delivery systems to retain volatile compounds, increasing their physicochemical stability and their promising potential to be utilized as carriers in products in the pharmaceutical, food, and cosmetic industries.

COMPARATIVE STUDY ON DEGRADATION OF POLYLACTIC ACID/ SYZYGIUM AROMATICUM COMPOSITES AGEING IN OUTDOOR ENVIRONMENT AND SOIL BURIAL

Major environmental problems resulting from non-degradable components of plastic wastes have awakened great attention to bioplastic as an alternative material. Among various bioplastic materials, polylactic acid (PLA) is recognised as a promising material especially as a food packaging material. The development of PLA composites using various fillers has extensively been in focus in order to preserve the high quality, safety, and extended shelf-life of packed food. Among the interesting fillers is Syzygium aromaticum (SA). SA, also known as clove, has biological activities such as antibacterial, antifungal, insecticidal, and antioxidant properties. This work investigated the effects of SA filler on the degradations of virgin PLA (VPLA) and recycled PLA (RPLA). The VPLA/SA composites and RPLA/SA composites were prepared using the solvent casting method. The content of SA filler varied in the range of 0 to 20 wt%. The composites were aged in outdoor environment and soil burial. The results revealed that the degradation rate was increased with the increase of SA filler in both ageing environments. After 10 weeks of ageing in the outdoor environment, the weight loss of VPLA/SA composites and RPLA/SA composites containing 20 wt% of SA were 7.7% and 12.8% respectively. Whereas in soil burial, the weight loss of VPLA/SA composites and RPLA/SA composites with similar SA content were 25.6% and 38.3% respectively. The degradation rate was observed to be more rapid in the soil burial as compared to the outdoor environment. Comparably, RPLA and RPLA/SA composites experienced higher degradation rates than VPLA and VPLA/SA composites. The degradation rate was consistent with scanning electron microscope (SEM) images which observed the formation of holes, cavities, cleavages, and grooves on the surfaces of the samples. Thermogravimetric analysis (TGA) results on aged samples showed that VPLA/SA composites and RPLA/SA composites that had aged in soil burial decomposed at lower temperatures. The shortening of degradation time of the VPLA/SA composites and RPLA/SA composites could increase their potential to be used as food packaging materials. ABSTRAK: Masalah utama terhadap alam sekitar yang disebabkan oleh sisa plastik yang sukar terurai, telah menarik perhatian terhadap bioplastik sebagai bahan alternatif. Di antara pelbagai jenis bahan bioplastik sedia ada, asid polilaktik(PLA) dilihat sebagai bahan yang paling sesuai terutamanya sebagai bahan pembungkusan makanan. Perkembangan di dalam penghasilan komposit asid polilaktik yang ditambah dengan pelbagai bahan pengisi telah menjadi fokus terutamanya bagi tujuan meningkatkan kualiti, kesegaran dan jangka hayat makanan. Salah satu pengisi yang mendapat perhatian adalah Syzygium aromaticum (SA). SA yang juga dikenali sebagai bunga cengkeh mempunyai aktiviti biologi, seperti sifat antibakteria, antijamur, racun serangga dan antioksidan yang tinggi. Didalam kajian ini, siasatan terhadap kesan penambahan SA terhadap penguraian PLA asal (VPLA) dan PLA kitar semula (VPLA). Komposit VPLA/SA dan komposit RPLA/SA disediakan dengan menggunakan kaedah pelarutan pelarut. Kandungan pengisi SA adalah didalam julat 0 – 20% mengikut berat. Komposit tersebut dibiarkan menua didalam persekitaran luaran dan didalam tanah. Keputusan kajian mendapati bahawa kadar penguraian semakin meningkat dengan penambahan peratus berat bahan pengisi SA setelah melalui penuaan didalam kedua-dua persekitaran. Setelah penuaan selama10 minggu di dalam persekiran luaran, pengurang berat komposit VPLA/SA dan komposit RPLA/SA yang mengandungi 20 wt% SA adalah 7.7% dan 12.8%. Manakala bagi penuaan didalam tanah, pengurangan berat komposit VPLA/SA dan komposit RPLA/SA dengan kandungan SA yang sama masing-masing adalah 25.6% dan 38.3%. Kadar penguraian diperhatikan lebih cepat bagi penuan didalam tanah dibandingkan dengan penuaan didalam persekitaran luaran. Disamping itu, RPLA dan komposit RPLA/SA mengalami kadar penguraian yang lebih tinggi berbanding VPLA dan komposit VPLA/SA. Kadar penguraian adalah konsisten dengan imej yang dihasilkan oleh imbasan mikroskop elektron (SEM) dimana dapat dilihat pembentukan lubang, rongga, pembelahan dan alur di permukaan sampel. Hasil analisis termogravimetri (TGA) terhadap sampel yang telah dituakan menunjukkan bahawa komposit VPLA/SA dan komposit RPLA/SA yang melalui penuaan didalam tanah terurai pada suhu yang lebih rendah. Tempoh penguraian komposit VPLA/SA dan komposit RPLA/SA yang lebih pendek ini meningkatkan potensi penggunaannya komposit ini sebagai bahan pembungkusan makanan.

Determination of antimicrobial activity of traditional spices extracts against clinical isolates in Dhaka city

Spices are dried aromatic substances derived from plants and have demonstrated antimicrobial activity against pathogenic microorganisms. In the present study, a total of six spices turmeric (Curcuma longa), garlic (Allium sativum), black pepper (Piper nigrum), ginger (Zingiber officinale), clove (Syzygium aromaticum) and cinnamon (Cinnamomum verum) were evaluated for their antibacterial activity. Antibacterial activities of ethanol, propanol and water extracts were determined by agar well diffusion assay against previously isolated Klebsiella pneumoniae, Staphylococcus aureus from urine samples and Citrobacter spp. from throat swab samples. All spices examined in this study showed antibacterial activity in different types of extraction methods. Water, ethanol and propanol extracts exhibited anti-bacterial activity measured as zone of inhibition between 6 mm and 25 mm in diameter. Water extract of garlic (Allium sativum) showed the highest antibacterial activity (25mm) against clinical isolates of Staphylococcus aureus and Citrobacter spp. Water extract of other species showed the lowest antibacterial activity (6 mm) against throat swab isolates Staphylococcus aureus and Citrobacter spp. Spices which showed signifiant antimicrobial activities can be further studied for the isolation of active ingredients and development of novel drugs. Stamford Journal of Microbiology, Vol.11 (1) 2021: 17-19

Repellent and Toxicant Effects of Eight Essential Oils against the Red Flour Beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae)

This study was conducted to compare the repellent effect and contact toxicity of eight essential oils (EOs), including Syzygium aromaticum, Allium sativum, Eucalyptus camaldulensis, Lavandula officinalis, Simmondsia chinensis, Matricaria chamomilla, Citrus limon, and Prunus dulcis, against adults of Tribolium castaneum Herbst. Four concentrations (1, 5, 10, and 15% in acetone solvent) of each EO were tested. The 5, 10, and 15% concentrations of S. aromaticum EO had a high repellency effect against T. castaneum compared with A. sativum, E. camaldulensis, L. officinalis, S. chinensis, M. chamomilla, C. limon, and P. dulcis after 30 min of exposure. The repellency test of the S. aromaticum, E. camaldulensis, L. officinalis, M. chamomilla, C. limon, and P. dulcis EOs on T. castaneum has shown that the mortality percentages enhanced with the increase in the EOs concentration and also with the exposure time. The 15% concentration of P. dulcis and M. chamomilla EOs have a significant impact on the mortality rate of T. castaneum compared with S. aromaticum, A. sativum, E. camaldulensis, L. officinalis, and S. chinensis after the 24 h of contact test. Moreover, the 15% concentration of the C. limon EO caused a greater mortality percentage compared with S. aromaticum, A. sativum, E. camaldulensis, and L. officinalis. It could be concluded that using the S. aromaticum EO as a repellent oil and using P. dulcis, M. chamomilla, and C. limon for contact toxicity to treat the flour infested by T. castaneum can play an important role in protecting stored grains and their products.

Biological activities and chemical composition of Mentha piperita and Syzygium aromaticum essential oil fractions against cowpea weevil, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae)

Callosobruchus maculatus (Fabricius) is one of the major, common, pests of stored grains as it causes quantitative and qualitative losses in legume crops. This research sought to find the most active fraction in Mentha piperita and Syzygium aromaticum essential oils, to evaluate bioactivity of those crude essential oils and active fractions against C. maculatus, and to identify the compounds contained in the active fraction. The essential oils were fractionated using three solvents, namely n-hexane, ethyl acetate, and methanol. The n-hexane fraction was identified as the active fraction, causing mortality, oviposition deterrence, and ovicidal effects. In fumigation chambers, LD95 values of M. piperita (Mnf) and S. aromaticum n-hexane fractions (Snf) were 0.045 ml/l and 0.057 ml/l respectively. ED50 values for oviposition deterrence were 0.016 ml/l for Mnf and 0.022 ml/l for Snf. ED50 value of ovicidal effects for Mnf- and Snf-treated eggs were 0.014 ml/l for both fractions. GC-MS analysis showed 8 dominant compounds in Mnf and 5 dominant compounds in Snf. Overall it is concluded that Mnf and Snf oils have effective biological activities against stored pest C. maculatus and have potential to be considered as alternatives to synthetic insecticides.

Evaluation of the Total Mercury Weight Exposure Distribution Using Tree Bark Analysis in an Artisanal and Small-Scale Gold Mining Area, North Gorontalo Regency, Gorontalo Province, Indonesia

It is well known that atmospheric mercury (Hg) contaminates air, water, soil, and living organisms, including trees. Therefore, tree bark can be used for the environmental assessment of atmospheric contamination because it absorbs heavy metals. This study aimed to establish a new biomonitoring for the assessment of atmospheric Hg pollution. Reporting on atmospheric Hg contamination in an artisanal and small-scale gold mining (ASGM) area in North Gorontalo, Indonesia, we calculated the total weight of Hg (THg) and quantitatively measured the concentrations of Hg in the tree bark of Mangifera indica,Syzygium aromaticum, Terminalia catappa, and Lansium domesticum. The THg of Hg in the M. indica tree bark samples ranged from not detected (ND) to 74.6 μg dry weight (DW) per sample. The total Hg in the tree bark of S. aromaticum, T. catappa, and L. domesticum ranged from ND to 156.8, ND to 180, and ND to 63.4 μg DW, respectively. We concluded that topography significantly influences the accumulation of Hg together with local weather conditions. A mapped distribution of the THg suggested that the distribution of THg in the tree bark was not affected by the distance to the amalgamation site. Therefore, tree bark can be used as biomonitoring of atmospheric Hg contamination for the assessment of ASGM areas.