Radical-scavenging activities of citrus essential oils and their components: detection using 1,1-diphenyl-2-picrylhydrazyl

Formation and stability of Eucommia ulmoides Oliver seed oil-loaded inverse microemulsion formed by food-grade ingredients and its antioxidant activities

Eucommia ulmoides Oliver seed oil (E.u oil) as a functional oil is rich in many natural active components such as α-linolenic acid (56% to 63%), vitamin E, aucubin, and so on. In this study, water-in-oil (W/O) microemulsions composed of Eucommia ulmoides Oliver seed oil, distilled water, a blend of Sorbitan monooleate 80 (Span 80) and Polysorbate (20) sorbitan monooleate (Tween 80), and propylene glycol were prepared for improving the compatibility of Eucommia ulmoides Oliver seed oil. Pseudoternary phase diagrams were built to illustrate the phase behavior of the microemulsions, based on hydrophilic-lipophilic balance values, cosurfactant type, the proportion of cosurfactant, and the changing environmental stress. Dynamic light scattering, transmission electron microscopy, and electrical conductivity measurements were performed to characterize the microstructural aspects. The optimum process conditions at which the Eucommia ulmoides Oliver seed oil-loaded microemulsion had good tolerance to pH and salinity were: Propylene glycol served as cosurfactant, water-Propylene glycol, and Span 80-Tween 80 ratios separately kept constant at 1:1 and 6:4. These microemulsions with narrow size distribution, nanoscale particle size (below 60 nm), transparent appearance had a wide range of oil phase content and free-radical scavenging capacity toward DPPH and ABTS radicals with half-maximal inhibitory concentration (IC₅₀ ) values of 49.20 and 33.43 mg/mL, respectively. PRACTICAL APPLICATION: This nanostructure, environmental stability, and antioxidant activity of microemulsions containing Eucommia ulmoides Oliver seed oil is a potential delivery system as an alternative to α-linolenic acid and can be used for the delivery of peptides, proteins, antioxidants, and water-soluble nutrients.

Seasonal and Antioxidant Evaluation of Essential Oil from Eugenia uniflora L., Curzerene-Rich, Thermally Produced in Situ

The essential oil of Eugenia uniflora has been attributed anti-depressive, antinociceptive, antileishmanial, larvicidal, antioxidant, antibacterial, and antifungal activities. It is known that the cultivation of this plant can be affected by seasonality, promoting alteration in the oil composition and its biological activities. This study aims to perform the annual evaluation of the curzerene-type oil of E. uniflora and determine its antioxidant activity. The oil yield from the dry season (1.4 ± 0.6%) did not differ statistically from that of the rainy season (1.8 ± 0.8%). Curzerene, an oxygenated sesquiterpene, was the principal constituent, and its percentage showed no significant difference between the two periods: dry (42.7% ± 6.1) and rainy (40.8 ± 5.9%). Principal component and hierarchical cluster analyses presented a high level of similarity between the monthly samples of the oils. Also, in the annual study, the yield and composition of the oils did not present a significant correlation with the climatic variables. The antioxidant activity of the oils showed inhibition of DPPH radicals with an average value of 55.0 ± 6.6%. The high curzerene content in the monthly oils of E. uniflora suggests their potential for use as a future phytotherapeutic alternative.

Preventive Efficacy of Dried Lime (Citrus aurantifulia) in Common Cold Among Hajj Pilgrims: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Background

Dried lime (Citrus aurantifulia) is one of the herbal preparations used especially by Iranian pilgrims as a preventative agent and self-remedy for respiratory tracts symptoms in folklore medicine. Therefore, we evaluated the preventive efficacy of dried lime preparation in common cold among Iranian pilgrims.

Materials and Methods

In this randomized, double-blinded, clinical trial patients in the drug group received dried lime capsules, 500 mg in a single dose per day for four weeks. In the placebo group, the patients received placebo capsules using the same method. The primary outcome measure in this trial was the severity of cold symptoms assessed by a self-administered questionnaire.

Results

There were no significant differences between the two groups in terms of the trend of cold symptoms severity during the study period. However, in the second week, the severity of all the cold symptoms in the drug group was less, compared to the placebo, but at the end of the study, comparison of the two groups revealed no significant difference in any of the investigated options.

Conclusion

The findings revealed that although the severity of all the cold symptoms in the drug group was less as compared to the placebo group, the dried lime capsule showed no statistically significant effect on the control of these symptoms in Iranian pilgrims.

Medicinal Properties of Cannabinoids, Terpenes, and Flavonoids in Cannabis, and Benefits in Migraine, Headache, and Pain: An Update on Current Evidence and Cannabis Science

BACKGROUND

Comprehensive literature reviews of historical perspectives and evidence supporting cannabis/cannabinoids in the treatment of pain, including migraine and headache, with associated neurobiological mechanisms of pain modulation have been well described. Most of the existing literature reports on the cannabinoids Δ⁹ -tetrahydrocannabinol (THC) and cannabidiol (CBD), or cannabis in general. There are many cannabis strains that vary widely in the composition of cannabinoids, terpenes, flavonoids, and other compounds. These components work synergistically to produce wide variations in benefits, side effects, and strain characteristics. Knowledge of the individual medicinal properties of the cannabinoids, terpenes, and flavonoids is necessary to cross-breed strains to obtain optimal standardized synergistic compositions. This will enable targeting individual symptoms and/or diseases, including migraine, headache, and pain.

OBJECTIVE

Review the medical literature for the use of cannabis/cannabinoids in the treatment of migraine, headache, facial pain, and other chronic pain syndromes, and for supporting evidence of a potential role in combatting the opioid epidemic. Review the medical literature involving major and minor cannabinoids, primary and secondary terpenes, and flavonoids that underlie the synergistic entourage effects of cannabis. Summarize the individual medicinal benefits of these substances, including analgesic and anti-inflammatory properties.

CONCLUSION

There is accumulating evidence for various therapeutic benefits of cannabis/cannabinoids, especially in the treatment of pain, which may also apply to the treatment of migraine and headache. There is also supporting evidence that cannabis may assist in opioid detoxification and weaning, thus making it a potential weapon in battling the opioid epidemic. Cannabis science is a rapidly evolving medical sector and industry with increasingly regulated production standards. Further research is anticipated to optimize breeding of strain-specific synergistic ratios of cannabinoids, terpenes, and other phytochemicals for predictable user effects, characteristics, and improved symptom and disease-targeted therapies.

Peel oils from three Citrus species: volatile constituents, antioxidant activities and related contributions of individual components

In the present study, peel oils were extracted through hydrodistillation and cold pressing from three Citrus species (Valencia orange, Ponkan and Eureka lemon) to investigate their volatile constituents and antioxidant activities. A total of 47 volatile components were identified by GC-MS, and then grouped by principal component analysis. The extraction methods were found to have an obvious effect on the proportion of terpenes and oxygenated compounds in the six Citrus oils, especially for Eureka lemon oils. The major fractions in the Citrus oils were found to be monoterpenes (78.65-96.57%), with limonene occupying a dominant percentage (51.22-86.65%). Furthermore, γ-terpinene and terpinolene displayed strong DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging abilities and efficient inhibition of lipid peroxidation, while oxygenated compounds of α-terpineol and terpinen-4-ol showed poor DPPH radical-scavenging abilities. Therefore, hydrodistillated Eureka lemon oil with high levels of α-terpineol (9.11%) and terpinen-4-ol (4.69%) presented low radical scavenging capability. Citral displayed a high pro-oxidant ability against thiobarbituric acid reactive species formation, which might lead to the decreased ability of the Eureka lemon oils in inhibition of lipid peroxidation, since citral was significantly high in Eureka lemon oils. This study facilitated the understanding of volatile constituents and antioxidant activities in different Citrus peel oils.

Decrease of chemical and volatile oxidation indicators using oregano essential oil combined with BHT in sunflower oil under accelerated storage conditions

This study compared the antioxidant properties of oregano essential oil (OEO) and butylated hydroxytoluene (BHT) alone and when combined. The principal components in OEO were gamma terpinene (25.1 g/100 g), terpinen-4-ol (16.7 g/100 g), and carvacrol (16.2 g/100 g). OEO showed 60% DPPH inhibition and 10 mg/g total phenolic compounds. The antioxidant capacity of OEO (0.02, 0.10, and 0.20 g/100 g) and BHT (0.01 and 0.02 g/100 g) and their combinations were tested in sunflower oil oven-heated at 60 °C, by measuring the chemical (peroxide value, p-anisidine value, and conjugated dienes) and volatile (hexanal, 2-heptanal, and 2,4-decadienal) indicators over 14 days. The combined samples (oregano essential oil and BHT) showed the greatest protection against lipid oxidation. On day 14, the peroxide value of the control (without added antioxidants), OEO (0.02 g/100 g), BHT (0.01 g/100 g), and OEO + BHT (0.02 + 0.01 g/100 g) treatments decreased in the order of 136.36, 102.68, 83.24, and 41.37 meqO2/kg, respectively, for example. In the consumer sensory test, samples containing OEO at 0.02 and 0.10 g/100 g attained greater acceptance scores (7.3 and 6.7, respectively, on a 9-point hedonic scale) as compared with the control (6.1). Discriminative duo-trio testing presented significant differences between all OEO-containing samples relative to the control. The synergistic antioxidant activity between OEO (termination-enhancing antioxidant) and BHT (chain-breaking antioxidant) demonstrates an alternative approach to impede lipid oxidation in foods, by decreasing the use of synthetic compounds in the food industry.

Composition, antioxidant capacity and cytotoxic activity of Eugenia uniflora L. chemotype-oils from the Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Oils and extracts of Eugenia uniflora have been reported as antimicrobial, antifungal, antinociceptive, antiprotozoal, antioxidant and cytotoxic.

AIM OF THE STUDY

The oils of five specimens (E1 to E5) that occur in the Brazilian Amazon were extracted, analyzed for their chemical composition, and submitted to antioxidant and cytotoxic assays.

MATERIAL AND METHODS

Oils were hydrodistilled, analyzed by GC and GC-MS, and submitted to PCA and HCA analyses. The antioxidant activity of the oils was evaluated by the DPPH radical scavenging and the β-carotene/linoleic acid assays. Antiproliferative effects of the oils and curzerene were tested against colon (HCT-116), gastric (AGP-01), and melanoma (SKMEL-19) human cancer cell lines and a normal human fibroblast cell line (MRC-5), using MTT assay.

RESULTS

Oxygenated sesquiterpenes and sesquiterpene hydrocarbons such as curzerene, selina-1,3,7(11)-trien-2-one, selina-1,3,7(11)-trien-2-one epoxide, germacrene B, caryophyllene oxide, and (E)-caryophyllene were predominant in the oils. PCA and HCA analyses classified the oils samples into four chemotypes. TEAC values of chemotype II (E3 oil, 228.3 ± 19.2 mg TE/mL) and chemotype III (E4 oil, 217.0 ± 23.3 mg TE/mL) displayed significant antioxidant activities. The oils E2 and E4 showed cytotoxic activity against all cell lines tested HCT-116 (IC₅₀ E2:16.26 μg/mL; IC₅₀ E4:9.28 μg/mL), AGP-01, (IC₅₀ E2:12.60 μg/mL; IC₅₀ E4:8.73 μg/mL), SKMEL-19 (IC₅₀ E2:12.20 μg/mL; IC₅₀ E4:15.42 μg/mL), and MRC-5 (IC₅₀ E2:10.27 μg/mL; IC₅₀ E4:14.95 μg/mL). Curzerene showed the more significant activity against melanoma cells (SKMEL-19, IC₅₀:5.17 μM), induced apoptosis at 5.0 μM and 10.0 μM compared to DMSO, exhibiting a decrease in the cell migration at 5.0 μM and 10.0 μM, after 30 h of treatment.

CONCLUSION

The curzerene chemotype oil and E. uniflora oils can be indicated as drug candidates for anticancer activity of the lung, colon, stomach, and melanoma, with a real prospect to their subsequent phytotherapeutic development.

Essential Oil Composition and Biological Activity of "Pompia", a Sardinian Citrus Ecotype

Pompia is a Sardinian citrus ecotype whose botanical classification is still being debated. In the present study, the composition of Pompia peel essential oil (EO) is reported for the first time, along with that of the leaf EO, as a phytochemical contribution to the classification of this ecotype. The peel EO was tested for its antioxidant ability (with both the 2,2-diphenyl-1-picarylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). Moreover, its antimicrobial activities were tested for the first time on dermatophytes (Microsporum canis, Microsporum gypseum, and Trichophyton mentagrophytes), on potentially toxigenic fungi (Fusarium solani, Aspergillus flavus, and Aspergillus niger) as well on bacteria (Escherichia coli, Staphylococcus aureus, and Staphylococcus pseudointermedius). The dominant abundance of limonene in the peel EO seems to distinguish Pompia from the Citrus spp. to which it had previously been associated. It lacks γ-terpinene, relevant in Citrus medica EO. Its relative content of α- and β-pinene is lower than 0.5%, in contrast to Citrus limon peel EO. Pompia peel and leaf EOs did not show significant amounts of linalool and linalyl acetate, which are typically found in Citrus aurantium. Pompia peel EO antioxidant activity was weak, possibly because of its lack of γ-terpinene. Moreover, it did not exert any antimicrobial effects either towards the tested bacteria strains, or to dermatophytes and environmental fungi.

Chemical composition, antioxidant activity and antimicrobial activity of essential oil from Citrus aurantium L zest against some pathogenic microorganisms

This study aims to investigate the chemical composition, antioxidant, and antimicrobial activity of Citrus aurantium L zest essential oil. The identification of the chemical compounds was done using chromatography analysis. The antioxidant activity was studied by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Results showed that the main components of the essential oil were limonene (85.22%), β-myrcene (4.3%), and α-pinene (1.29%). Regarding the DPPH radical scavenging ability, the zest essential oil showed higher activity than limonene. The antimicrobial activity of the essential oil against pathogenic [Staphylococcus aureus NBIMCC 3703, Salmonella sp. (clinical isolate), Pseudomonas aeruginosa NBIMCC 1390, Bacillus subtilis NBIMCC 1208, Escherichia coli NBIMCC 3702] microorganisms by disc-diffusion method was examined. Gram-positive bacteria were more sensitive to the oil (inhibition zones being between 9 and 12.5 mm) and the minimum inhibitory concentration was more than 600 ppm; Gram-negative bacteria were less sensitive. The obtained essential oil displayed promising results for its application as a biopreservative agent.

Anti-Oxidant and Anti-Melanogenic Properties of Essential Oil from Peel of Pomelo cv. Guan Xi

Here, we investigated the anti-oxidant and anti-melanogenic effects of pomelo peel essential oil (PPEO) from pomelo cv. Guan Xi. The volatile chemical composition of PPEO was analyzed with gas chromatography–mass spectrometry (GC/MS). The most abundant component of PPEO was limonene (55.92%), followed by β-myrcene (31.17%), and β-pinene (3.16%). PPEO showed strong anti-oxidant activities against 2,2-diphenyl-2-picryhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) and superoxide anion free radicals. Based on the B16 melanoma cell system, the effects of PPEO on the viability and morphology of B16 cells and the production of melanin were evaluated. The results revealed that PPEO at concentrations below 50 μg/mL could decrease the melanin content without affecting cell viability and morphology. Intracellular tyrosinase (TYR) activity and Western blot analysis showed that PPEO could down-regulate the expression level of TYR in B16 cells and dose-dependently inhibit TYR activity (by a maximum of 64.54%). In conclusion, PPEO has good anti-oxidant and anti-melanogenic activity, and thus can be widely used as a natural antioxidant in the food, pharmaceutical, and cosmetic industries.

Assessing the effect of Mentha longifolia essential oils on COX-2 expression in animal model of sepsis induced by caecal ligation and puncture

CONTEXT

Mentha longifolia L. (Lamiaceae), a traditional Iranian plant, possesses antimicrobial and antioxidant activities.

OBJECTIVE

We investigated the potential protective effects of M. longifolia essential oils (E.Os) on caecal ligation and puncture (CLP) induced liver injury.

MATERIALS AND METHODS

Wistar Albino rats (n = 50) were grouped as follows: (1) a laparotomy group (LAP); (2) a CLP group (CLP); (3) the treatment groups received orally the E.Os (50 and 100 mg/kg b.w) and indomethacin (2 mg/kg b.w) for 2 weeks. The oxidative stress parameters, liver enzymes and prostaglandin E2 (PGE2) level were measured in liver and plasma tissues. The liver was also harvested for the real time PCR of cyclooxygenase (COX-2) expression following histopathological examinations.

RESULTS

The results indicated that the CLP operation significantly increased lipid peroxidation (LP) [1.79-fold], myeloperoxidase (MPO) [2.76-fold], PGE2 [1.56-fold] besides plasma aspartate aminotransferase (AST) [2.4-fold] and alanine aminotransferase (ALT) activities [2.22-fold], while, markedly reduced glutathione (GSH) [0.63-fold] and ferric reducing ability of plasma (FRAP) levels [0.63-fold]. Even COX2 expression significantly increased in the CLP group as compared to the LAP group. Treatments of rats with the E.Os could return all the hepatic and plasma biomarkers to the normal levels. These results were further confirmed by pathological examination on liver indicating that E.Os could successfully improve the CLP-induced liver injuries.

DISCUSSION AND CONCLUSIONS

Our findings suggest that E.Os is able to protect liver injuries against sepsis via modulating the oxidative stress parameters concomitant with the suppression of inflammatory reactions such as PGE2 and COX-2.

Oxidative stability, affective and discriminative sensory test of high oleic and regular peanut oil with addition of oregano essential oil

Peanut oil is widely used in food but is susceptible to oxidation. This study investigated the antioxidant stability of high oleic (HO: 78.85 g/100 g oleic acid) and regular (C: 43.85 g/100 g oleic acid) peanut oils with oregano essential oil (OEO) added as a natural antioxidant. OEO contained γ-terpinene (25.71%), carvacrol (16.73%) and terpinen-4-ol (16.17%) as the principal compounds. Thermal processing (60 °C for 28 days) of OEO increased the carvacrol and o-cymene contents and decreased the terpinen-4-ol, linalool and γ-terpinene levels. Thus, carvacrol was the major compound with high oxidative stability. Thermal processing of the peanut oils showed that HO peanut oil developed less oxidation than C peanut oil. OEO provided antioxidant activity, which increased as its concentration increased (at 0.02 and 0.10% p/p of OEO, the peroxide value decreased by 18 and 46%, respectively). OEO displayed 54.7% free radical scavenging activity and 9.2 mg/g total phenolic content, explaining its antioxidant activity. Sensory analysis showed that OEO was detected in all samples, but consumer acceptance was greater when OEO was present (hedonic values of 7.4 and 6.8 for OEO at 0.02 and 0.10 g/100 g, respectively) compared to the peanut oil only control (hedonic value of 6.0).

Effect of geraniol against arecoline induced toxicity in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

In the present study geraniol at the final concentration of 10, 20, 30, and 40 µM was mixed in the diet along with 80 µM of arecoline and the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg⁹ were allowed to feed on it for 24 hrs. After the exposure of 24 hrs the larvae were subjected to ONPG, X-gal, trypan blue exclusion test, oxidative stress markers and apoptotic and comet assays. The exposure of larvae to geraniol showed a dose dependent decrease in the activity of β-galactosidase, tissue damage and oxidative stress markers. A dose dependent decrease in apoptosis and DNA damage was also observed. Molecular docking studies also support the protective role of geraniol against the arecoline induced toxicity. The results suggest that geraniol is potent in reducing the toxicity induced by arecoline in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg⁹.

Chitosan nanoparticles-loaded Citrus aurantium essential oil: a novel delivery system for preserving the postharvest quality of Agaricus bisporus

BACKGROUND

One of the main problems in the button mushroom industry is the rapid deterioration of fruit bodies after harvest. Today, nanotechnology has become a more reliable technique to improve the quality of products in food packaging. In the present study, the effectiveness of chitosan nanoparticles containing Citrus aurantium essential oil on postharvest quality of white button mushroom was examined and compared to essential oil fumigation and control treatments.

RESULTS

Based on high-resolution transmission electron microscopy and dynamic light scattering, nanoparticles exhibited a spherical shape of 20-60 nm diameter. The results revealed that the application of chitosan nanoparticles loaded with C. aurantium oil significantly decelerated the rate of color change, weight loss and firmness compared to fumigation with essential oil and control treatments. Treatment of fruit bodies with chitosan nanoparticles loaded with C. aurantium oil promoted the accumulation of phenolic compounds and ascorbic acid, and resulted in increases in catalase and superoxide dismutase and a decrease in polyphenol oxidase activities, as the highest antioxidant capacity was observed after 15 days of cold storage.

CONCLUSION

This present research demonstrates that gradual release of C. aurantium essential oil from chitosan nanoparticles could be an effective and practical method for extending the shelf life of white button mushroom up to 15 days without significant decrease in antioxidant capacity. © 2018 Society of Chemical Industry.

R-Limonene Enhances Differentiation and 2-Deoxy-D-Glucose Uptake in 3T3-L1 Preadipocytes by Activating the Akt Signaling Pathway

Adipocyte is an important place for lipid storage. Defects in lipid storage in adipocytes can lead to lipodystrophy and lipid accumulation in muscle, liver, and other organs. It is the condition of mixed dyslipidemia which may favor the development of insulin resistance via lipotoxic mechanisms. Our objective of the study was to investigate the potential role of R-limonene (LM) on differentiation, lipid storage, and 2-deoxy-D-glucose (2DG) uptake in 3T3-L1 preadipocytes. Genes and proteins associated with differentiation, lipid accumulation, 2DG uptake and its signaling pathways in the adipocytes were analyzed using qPCR and western blot methods. LM treatment increased differentiation, lipid accumulation, and the expression of adipogenic and lipogenic markers such as C/EBP-α, C/EBP-β, PPARγ, SREBP-1, RXR, FAS, and adiponectin. However, the LM concentration at 10μM decreased (p < 0.05) adipogenesis and lipogenesis via regulating key transcriptional factors. LM treatment increased activation of Akt by increasing its phosphorylation, but p44/42 activation was not altered. MK-2206, an Akt specific inhibitor, reduced the activation of Akt phosphorylation whereas LM treatment aborted the MK-2206 mediated inhibition of Akt activation. LM enhanced glucose uptake in differentiated adipocytes. Overall data suggested that LM treatment favored lipid storage and glucose uptake in adipocytes via activation of key transcriptional factors through activation of Akt phosphorylation in 3T3-L1 adipocytes.

Biological Activities and Safety of Citrus spp. Essential Oils

Citrus fruits have been a commercially important crop for thousands of years. In addition, Citrus essential oils are valuable in the perfume, food, and beverage industries, and have also enjoyed use as aromatherapy and medicinal agents. This review summarizes the important biological activities and safety considerations of the essential oils of sweet orange (Citrus sinensis), bitter orange (Citrus aurantium), neroli (Citrus aurantium), orange petitgrain (Citrus aurantium), mandarin (Citrus reticulata), lemon (Citrus limon), lime (Citrus aurantifolia), grapefruit (Citrus × paradisi), bergamot (Citrus bergamia), Yuzu (Citrus junos), and kumquat (Citrus japonica).

Chemical composition and in-vitro antioxidant and antimicrobial activity of the essential oil of Citrus aurantifolia L. leaves grown in Eastern Oman

Objectives

This study investigated the chemical composition and the antioxidant and antimicrobial activities of the essential oil isolated from the aerial parts of Citrus aurantifolia L.

Methods

Fresh Citrus aurantifolia L. leaves were collected from farms in Sur city, located in the Al-Sharqia (Eastern) region of the Sultanate of Oman, during June-July of 2015. The essential oil was isolated using hydrodistillation. Gas chromatography-mass spectrometry (GC-MS) was used to identify and quantify the chemical constituents of the oil. An in-vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method was used to determine the antioxidant activity of the isolated oil from the lime leaves while a disc diffusion method was used to evaluate the antibacterial activity against Gram-negative and Gram-positive bacteria.

Results

Thirty-three chemical compounds were identified, with d-limonene (63.35%) forming the major constituent. Other prominent constituents include 3,7-dimethyl-2,6-octadien-1-ol (7.07%), geraniol (6.23%), E-citral (4.35%), Z-citral (3.29%), and β-ocimene (2.25%). The essential oil of Citrus aurantifolia L. leaves showed excellent antibacterial activity against Staphylococcus aureus and moderate activity against pathogenic Escherichia coli strains. The oil exhibited promising in-vitro antioxidant activity (IC₅₀ value = 21.57 μg/mL) but showed moderate antibacterial activities.

Conclusions

The essential oil from Omani lime leaves is characterized by a high d-limonene content, making it useful for food, pharmaceutical, and perfumery industries.

A review of the use of pteridophytes for treating human ailments

The aim of this review was to explore the pharmacological activity of early tracheophytes (pteridophytes) as an alternative medicine for treating human ailments. As the first vascular plants, pteridophytes (aka, ferns and fern allies) are an ancient lineage, and human beings have been exploring and using taxa from this lineage for over 2000 years because of their beneficial properties. We have documented the medicinal uses of pteridophytes belonging to thirty different families. The lycophyte Selaginella sp. was shown in earlier studies to have multiple pharmacological activity, such as antioxidant, anti-inflammatory, anti-cancer, antidiabetic, antiviral, antimicrobial, and anti-Alzheimer properties. Among all the pteridophytes examined, taxa from the Pteridaceae, Polypodiaceae, and Adiantaceae exhibited significant medicinal activity. Based on our review, many pteridophytes have properties that could be used in alternative medicine for treatment of various human illnesses. Biotechnological tools can be used to preserve and even improve their bioactive molecules for the preparation of medicines against illness. Even though several studies have reported medicinal uses of ferns, the possible bioactive compounds of several pteridophytes have not been identified. Furthermore, their optimal dosage level and treatment strategies still need to be determined. Finally, the future direction of pteridophyte research is discussed.

Extended aroma extract dilution analysis profile of Shiikuwasha ( Citrus depressa Hayata) pulp essential oil

Shiikuwasha pulp is an important raw material for producing citrus essential oils. The volatile aroma composition of pulp essential oil was evaluated using gas chromatography (GC) methods, and its aroma profile was assessed using GC-olfactometry with an extended aroma extract dilution analysis (AEDA) technique in regard to alterations of odor strength and sensorial perception throughout serial dilution steps. The essential oil comprised a mixture of 55 aroma compounds, including monoterpene hydrocarbon, sesquiterpene hydrocarbon, alcohol, aldehyde, ester, and oxide compounds. The predominant compounds were limonene [57.36% (4462.80 mg/100 g of pulp)] and γ-terpinene [25.14% (1956.21 mg/100 g of pulp)]. However, linalool was identified as one of the key aroma components providing the highest flavor dilution factor in AEDA, whilst three sesquiterpene hydrocarbons (δ-elemene, germacrene B, and bicyclosesquiphellandrene) and two esters (heptyl acetate and decyl acetate) had superior relative flavor activities. The extended AEDA profile identified variations in assessed odor perceptions, intensity, and duration of aroma components over dilution, whereas the 12 most odor-active compounds showed comparable odor strengths.

Composition and Bioactivity of Essential Oil from Citrus grandis (L.) Osbeck 'Mato Peiyu' Leaf

'Mato Peiyu' pomelo (Citrus grandis (L.) Osbeck 'Mato Peiyu') leaves from pruning are currently an agricultural waste. The aim of this study was to isolate essential oils from these leaves through steam distillation (SD) and solvent-free microwave extraction (SFME) and to evaluate their applicability to skin care by analyzing their antimicrobial, antioxidant (diphenyl-1-picrylhydrazyl scavenging assay, β-carotene/linoleic acid assay, and nitric oxide scavenging assay), anti-inflammatory (5-lipoxygenase inhibition assay), and antityrosinase activities. The gas chromatography-mass spectrometry results indicated that the main components of 'Mato Peiyu' leaf essential oils were citronellal and citronellol, with a total percentage of 50.71% and 59.82% for SD and SFME, respectively. The highest bioactivity among all assays was obtained for 5-lipoxygenase inhibition, with an IC₅₀ value of 0.034% (v/v). The MIC₉₀ of the antimicrobial activity of essential oils against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans ranged from 0.086% to 0.121% (v/v). Citronellal and citronellol were the main contributors, accounting for at least 54.58% of the essential oil's bioactivity. This paper is the first to report the compositions and bioactivities of 'Mato Peiyu' leaf essential oil, and the results imply that the pomelo leaf essential oil may be applied in skin care.

Geraniol, a natural monoterpene, ameliorates hyperglycemia by attenuating the key enzymes of carbohydrate metabolism in streptozotocin-induced diabetic rats

CONTEXT

Geraniol, an acyclic monoterpene alcohol is found in medicinal plants, is used traditionally for several medical purposes including diabetes.

OBJECTIVES

The present study evaluates the antihyperglycemic potential of geraniol on key enzymes of carbohydrate metabolism in streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Diabetes was induced in experimental rats, by a single intraperitoneal (i.p) injection of STZ [40 mg/kg body weight (b.w.)]. Different doses of geraniol (100, 200 and 400 mg/kg b.w.) and glyclazide (5 mg/kg b.w.) were administrated orally to diabetic rats for 45 days. Body weight, food intake, plasma glucose, insulin, blood haemoglobin (Hb), glycosylated haemoglobin (HbA_1c), hepatic glucose metabolic enzymes and glycogen were examined.

RESULTS

The LD₅₀ value of geraniol is 3600 mg/kg b.w. at oral administration in rats. Administration of geraniol in a dose-dependent manner (100, 200, 400 mg/kg b.w.) and glyclazide (5 mg/kg b.w.) for 45 days significantly improved the levels of insulin, Hb and decreased plasma glucose, HbA_1C in diabetic-treated rats. Geraniol at its effective dose (200 mg/kg b.w.) ameliorated the altered activities of carbohydrate metabolic enzymes near normal effects compared with two other doses (100 and 400 mg/kg b.w.). Geraniol treatment to diabetic rats improved hepatic glycogen content suggesting its anti-hyperglycemic potential. Geraniol supplement was found to preserve the normal histological appearance of hepatic cells and pancreatic β-cells in diabetic rats.

DISCUSSION AND CONCLUSIONS

The present findings suggest that geraniol can potentially ameliorate key enzymes of glucose metabolism in experimental diabetes even though clinical studies used to evaluate this possibility are warranted.

Chemical Composition of Four Essential Oils of Eugenia from the Brazilian Amazon and Their Cytotoxic and Antioxidant Activity

Background:Eugenia species are appreciated for their edible fruits and are known as having anticonvulsant, antimicrobial and insecticidal actions. Methods: The plant material was collected in the southeastern Pará state of Brazil and submitted to hydrodistillation. GC-MS analyzed the oils, and their antioxidant and cytotoxic activities were evaluated by the DPPH and MTT assays. Results: The main components identified in the Eugenia oils were 5-hydroxy-cis-calemene, (2E,6E)-farnesol, (2E,6Z)-farnesol, caryophylla-4(12),8(13)-dien-5α-ol-5β-ol, E-γ-bisabolene, β-bisabolene, germacrene D, and ishwarane. The oil of E. egensis showed the most significant antioxidant activity (216.5 ± 11.6 mg TE/mL), followed by the oils of E. flavescens (122.6 ± 6.8 mg TE/mL) and E. patrisii (111.2 ± 12.4 mg TE/mL). Eugenia oils were cytotoxic to HCT-116 (colon cancer) cells by the MTT assay, where the most active was the oil of E. polystachya (10.3 µg/mL), followed by the oils of E. flavescens (13.9 µg/mL) and E. patrisii (16.4 µg/mL). The oils of E. flavescens and E. patrisii showed the highest toxicity for MRC5 (human fibroblast) cells, with values of 14.0 µg/mL and 18.1 µg/mL, respectively. Conclusions: These results suggest that Eugenia oils could be tested in future studies for the treatment of colon cancer and oxidative stress management.

Cannabis Pharmacology: The Usual Suspects and a Few Promising Leads

The golden age of cannabis pharmacology began in the 1960s as Raphael Mechoulam and his colleagues in Israel isolated and synthesized cannabidiol, tetrahydrocannabinol, and other phytocannabinoids. Initially, THC garnered most research interest with sporadic attention to cannabidiol, which has only rekindled in the last 15 years through a demonstration of its remarkably versatile pharmacology and synergy with THC. Gradually a cognizance of the potential of other phytocannabinoids has developed. Contemporaneous assessment of cannabis pharmacology must be even far more inclusive. Medical and recreational consumers alike have long believed in unique attributes of certain cannabis chemovars despite their similarity in cannabinoid profiles. This has focused additional research on the pharmacological contributions of mono- and sesquiterpenoids to the effects of cannabis flower preparations. Investigation reveals these aromatic compounds to contribute modulatory and therapeutic roles in the cannabis entourage far beyond expectations considering their modest concentrations in the plant. Synergistic relationships of the terpenoids to cannabinoids will be highlighted and include many complementary roles to boost therapeutic efficacy in treatment of pain, psychiatric disorders, cancer, and numerous other areas. Additional parts of the cannabis plant provide a wide and distinct variety of other compounds of pharmacological interest, including the triterpenoid friedelin from the roots, canniprene from the fan leaves, cannabisin from seed coats, and cannflavin A from seed sprouts. This chapter will explore the unique attributes of these agents and demonstrate how cannabis may yet fulfil its potential as Mechoulam's professed "pharmacological treasure trove."

Traditional Small-Size Citrus from Taiwan: Essential Oils, Bioactive Compounds and Antioxidant Capacity

Background: The calamondin (Citrus microcarpa Bunge) and the kumquat (Fortunella crassifolia Swingle) are two small-size citrus fruits that have traditionally been consumed in Taiwan; however, there has been a lack of scientific research regarding the active compounds and functionalities of these fruits. Methods: Analysis of volatile composition of essential oil and phytosterol was carried out using Gas Chromatography–Mass Spectrometry (GC-MS). Flavonoid and limonoid were analyzed by High Performance Liquid Chromatography (HPLC). Moreover, antioxidant capacity from their essential oils and extracts were assessed in vitro. Results: The compositions of the essential oils of both fruits were identified, with the results showing that the calamondin and kumquat contain identified 43 and 44 volatile compounds, respectively. In addition, oxygenated compounds of volatiles accounted for 4.25% and 2.04%, respectively, consistent with the fact that oxygenated compounds are generally found in high content in citrus fruits. In terms of flavonoids, the calamondin exhibited higher content than the kumquat, with disomin-based flavonoids being predominant; on the other hand, phytosterol content of kumquat was higher than that of calamondin, with amyrin being the dominant phytosterol. Both of them contain high amounts of limonoids. The ethanol extracts and essential oils of small-sized citrus fruits have been shown to have antioxidant effects, with those effects being closely related to the flavonoid content of the fruit in question. Conclusions: The present study also reviewed antioxidant activity in terms of specific bioactive compounds in order to find the underlying biological activity of both fruits. The calamondin and kumquat have antioxidant effects, which are in turn very important for the prevention of chronic diseases.

Tyrosinase inhibitory activity, molecular docking studies and antioxidant potential of chemotypes of Lippia origanoides (Verbenaceae) essential oils

The essential oils (EOs) of the aerial parts of Lippia origanoides (LiOr), collected in different localities of the Amazon region, were obtained by hydrodistillation and analyzed by GC and CG-MS. Principle component analysis (PCA) based on chemical composition grouped the oils in four chemotypes rich in mono- and sesquiterpenoids. Group I was characterized by 1,8-cineole and α-terpineol (LiOr-1 and LiOr-4) and group II by thymol (LiOr-2). The oil LiOr-3 showed β-caryophyllene, α-phellandrene and β-phellandrene as predominant and LiOr-5 was rich in (E)-nerolidol and β-caryophyllene. All samples were evaluated for antioxidant activity and inhibition of tyrosinase in vitro and in silico. The highest antioxidant activity by the DPPH free radical method was observed in LiOr-2 and LiOr-5 oils (132.1 and 82.7 mg TE∙mL^-1, respectively). The tyrosinase inhibition potential was performed using L-tyrosine and L-DOPA as substrates and all samples were more effective in the first step of oxidation. The inhibition by samples LiOr-2 and LiOr-4 were 84.7% and 62.6%, respectively. The samples LiOr-1, LiOr-4 and LiOr-5 displayed an interaction with copper (II) ion with bathochromic shift around 15 nm. In order to elucidate the mechanism of inhibition of the main compounds, a molecular docking study was carried out. All compounds displayed an interaction between an oxygen and Cu or histidine residues with distances less than 4 Å. The best docking energies were observed with thymol and (E)-nerolidol (-79.8 kcal.mol^-1), which suggested H-bonding interactions with Met281 and His263 (thymol) and His259, His263 ((E)-nerolidol).

Chemical characterization and antioxidant potential of volatile oil from an edible seaweed Porphyra tenera (Kjellman, 1897)

Background

Porphyra tenera (Kjellman, 1897) is the most common eatable red seaweed in Asia. In the present study, P. tenera volatile oil (PTVO) was extracted from dried P. tenera sheets that were used as food by the microwave hydrodistillation procedure, after which the characterization of its chemical constituents was done by gas chromatography and mass spectroscopy and its antioxidant potential was evaluated by a number of in vitro biochemical assays such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, nitric oxide (NO) scavenging, superoxide radical scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging, hydroxyl radical scavenging and reducing power assay and inhibition of lipid peroxidation.

Results

A total of 30 volatile compounds comprising about 99.4% of the total volume were identified, of which trans-beta-ionone (20.9%), hexadecanoic acid (9.2%) and 2,6-nonadienal (8.7%) were present in higher quantities. PTVO exhibited strong free radical scavenging activity by DPPH scavenging (44.62%), NO scavenging (28.45%) and superoxide scavenging (54.27%) at 500 µg/mL. Similarly, it displayed strong ABTS radical scavenging (IC₅₀ value of 177.83 µg/mL), hydroxyl radical scavenging (IC₅₀ value of 109.70 µg/mL), and moderate lipid peroxidation inhibition activity (IC₅₀ value of 231.80 µg/mL) and reducing power (IC_0.5 value of 126.58 µg/mL). PTVO exhibited strong antioxidant potential in a concentration dependent manner and the results were comparable with the BHT and α-tocopherol, taken as the reference standard compounds (positive controls).

Conclusions

Taken together, PTVO with potential bioactive chemical compounds and strong antioxidant activity could be utilized in the cosmetic industries for making antioxidant rich anti-aging and sun-screen lotion and in the food sector industries as food additives and preservatives.

Chemical Profile and Antioxidant Properties of Extracts and Essential Oils from Citrus × limon (L.) Burm. cv. Femminello Comune

Citrus × limon cv. Femminello Comune (Rutaceae) from Rocca Imperiale (Italy), one of the six Protected Geographical Indication (PGI) Italian lemon crops, has been recently received renewed interest. In this work, fresh and dried peels and leaves were extracted by hydrodistillation, supercritical fluid extraction (SFE), and Soxhlet apparatus. Chemical profile was assessed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Except for leaves extracts obtained by Soxhlet apparatus, the monoterpene hydrocarbons fraction dominated. Limonene, γ-terpinene, and β-pinene were the main identified compounds. The antioxidant activity was investigated using different in vitro assays namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS, ferric reducing ability power (FRAP), and β-carotene bleaching test. In DPPH test, the essential oil obtained by hydrodistillation of fresh peel exhibited the highest activity (IC50 of 1.17 mg/ml). Leaves extracted by SFE showed a good activity in both DPPH and β-carotene bleaching test with IC50 values of 2.20 and 6.66 mg/ml, respectively. Monoterpene hydrocarbons fraction exhibited a positive Pearson's correlation coefficient with all antioxidant assays. Leaves, often considered waste material, should be considered from a different point because they represent a matrix of indisputable interest.