Metabolomic Profiles of Essential Oils from Selected Rosa Varieties and Their Antimicrobial Activities

Attraction of Nicotiana benthamiana to Bemisia tabaci is related to a chemical signal in plant volatile, undecane

BACKGROUND

The whitefly Bemisia tabaci is one of the world's foremost agricultural pests. Recently, we found that a wild relative of tobacco (Nicotiana benthamiana) demonstrates remarkable attractiveness and nearly 100% lethality towards whiteflies. Therefore, it can act as a dead-end trap crop for whitefly control in the field. However, the underlying mechanism of the significant attractiveness of N. benthamiana towards whiteflies is unclear.

RESULTS

Binary-choice assays and olfactory experiments showed that compared to common tobacco (N. tabacum), the volatile of N. benthamiana has a greater attraction to whiteflies. Then we analyzed and compared volatiles from these two Nicotiana species by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). We identified 16 chemical compounds that are more abundant in N. benthamiana than in N. tabacum. Seven compounds were further tested with olfactometer assays and we found that, among them, undecane strongly attracted whiteflies. Further experiments revealed that even 0.005 μg mL-1 undecane is attractive to whiteflies. We also silenced the genes that may influence the biosynthesis of undecane and found the production of undecane decreased after silencing NbCER3, and that N. benthamiana plants with less undecane lost their attraction to whiteflies. In addition, we found that applying 0.005 μg mL-1 undecane on yellow sticky traps can increase the number of stuck insects on the traps by ≈40%.

CONCLUSION

Undecane from the volatile of N. benthamiana is a critical chemical signal that attracts whiteflies and NbCER3 involved in the biosynthesis of undecane. Undecane may be used to improve the efficiency of yellow sticky traps for whitefly control. © 2024 Society of Chemical Industry.

Sanguisorba officinalis L. ethanolic extracts and essential oil - chemical composition, antioxidant potential, antibacterial activity, and ex vivo skin permeation study

Introduction

Sanguisorba officinalis L. is classified as a medicinal plant and used in traditional medicine. The root of this plant is mainly used as a medicinal raw material, but the above-ground parts are also a valuable source of health-promoting biologically active compounds.

Method

The study aimed to evaluate the antioxidant activity and total polyphenol content (TPC) of extracts prepared in 70% and 40% aqueous ethanol solution (dry extract content 50-500 g/L) from the aerial parts of S. officinalis. The essential oil was isolated from the tested raw material, and its composition was determined using GC-MS. Ethanolic extracts and essential oil have been tested for antibacterial activity. The extract in 70% v/v ethanol (dry extract content: 500 g/L) was subjected to HPLC analysis for the content of selected phenolic acids and an ex vivo skin permeation study. The ability of these metabolites to permeate and accumulate in the skin was analysed.

Results

Extracts prepared at both ethanol concentrations showed similar antioxidant activity and TPC. Depending on the method, concentration of solvent, and dry extract content (50-500 g/L), the activity ranged from 1.97 to 84.54 g Trolox/L. TPC range of 3.80-37.04 g GA/L. Gallic acid (424 mg/L) and vanillic acid (270 mg/L) had the highest concentrations among the phenolic acids analysed. Vanillic acid (10 μg) permeates the skin at the highest concentration. The highest accumulation in the skin was found for 2,5-dihydroxybenzoic acid (53 μg/g skin), 2,3-dihydroxybenzoic acid (45 μg/g skin), and gallic acid (45 μg/g skin). The tested ethanolic extracts exhibited antibacterial activity. Samples with a dry extract concentration of 500 g/L showed the largest growth inhibition zones. The most sensitive strains to these extracts were P. aeruginosa (24 mm), S. lutea (23 mm), and S. pneumoniae (22 mm). The smallest inhibition zones were observed for B. subtilis (17 mm). The essential oil showed weaker antimicrobial activity (growth inhibition zone 8-10 mm). The GC-MS method identified 22 major components of the essential oil, including aliphatic hydrocarbons, unsaturated terpene alcohols, aliphatic aldehydes, unsaturated and saturated fatty acids, sesquiterpene, phytyl ester of linoleic acid, nitrogen compound, phytosterol, terpene ketone, phenylpropanoids, aliphatic alcohol, diterpenoid, aromatic aldehyde, and aliphatic carboxylic acid.

Discussion

The conducted research has shown that ethanolic extracts from Sanguisorbae herba are a valuable source of compounds with antibacterial and antioxidant potential, including phenolic acids. The fact that selected phenolic acids contained in the tested extract have the ability to permeate and accumulate in the skin provides the basis for conducting extended research on the use of extracts from this plant raw material in cosmetic and pharmaceutical preparations applied to the skin.

Phytoconstituents with cardioprotective properties: A pharmacological overview on their efficacy against myocardial infarction

Myocardial infarction (MI) is considered one of the most common cardiac diseases and major cause of death worldwide. The prevalence of MI and MI-associated mortality have been increasing in recent years due to poor lifestyle habits viz. residency, obesity, stress, and pollution. Synthetic drugs for the treatment of MI provide good chance of survival; however, the demand to search more safe, effective, and natural drugs is increasing. Plants provide fruitful sources for powerful antioxidant and anti-inflammatory agents for prevention and/or treatment of MI. However, many plant extracts lack exact information about their possible dosage, toxicity and drug interactions which may hinder their usefulness as potential treatment options. Phytoconstituents play cardioprotective role by either acting as a prophylactic or adjuvant therapy to the concurrently used synthetic drugs to decrease the dosage or relief the side effects of such drugs. This review highlights the role of different herbal formulations, examples of plant extracts and types of several isolated phytoconstituents (phenolic acids, flavonoids, stilbenes, alkaloids, phenyl propanoids) in the prevention of MI with reported activities. Moreover, their possible mechanisms of action are also discussed to guide future research for the development of safer substitutes to manage MI.

The scent of roses, a bouquet of fragrance diversity

Roses have been domesticated since antiquity for their therapeutic, cosmetic, and ornamental properties. Their floral fragrance has great economic value, which has influenced the production of rose varieties. The production of rose water and essential oil is one of the most lucrative activities, supplying bioactive molecules to the cosmetic, pharmaceutical, and therapeutic industries. In recent years, major advances in molecular genetics, genomic, and biochemical tools have paved the way for the identification of molecules that make up the specific fragrance of various rose cultivars. The aim of this review is to highlight current knowledge on metabolite profiles, and more specifically on fragrance compounds, as well as the specificities and differences between rose species and cultivars belonging to different rose sections and how they contribute to modern roses fragrance.

Anti-Helicobacter pylori, anti-biofilm activity, and molecular docking study of citropten, bergapten, and its positional isomer isolated from Citrus sinensis L. leaves

Introduction

Citrus sinensis L. is a candidate plant with promising antimicrobial potential. In the current study, the phytochemical investigation of C. sinensis leaf extract led to the isolation of three coumarins, namely bergapten, xanthotoxin, and citropten.

Methods

The chemical structures of the isolated coumarins were elucidated using NMR and ESI-MS techniques. The total aqueous ethanol leaf extract and the isolated coumarins were evaluated for their antimicrobial effects against Helicobacter pylori using the MTT-micro-well dilution method and its anti-biofilm activity using MBEC assay, as compared to clarithromycin.

Results

The results showed that citropten scored the lowest MIC value at 3.9 μg/mL and completely inhibited the planktonic growth of H. pylori. In addition, it completely suppressed H. pylori biofilm at 31.25 μg/mL. These findings have been supported by molecular docking studies on the active sites of the H. pylori inosine 5'-monophosphate dehydrogenase (HpIMPDH) model and the urease enzyme, showing a strong binding affinity of citropten to HpIMPDH with seven hydrogen bonds and a binding energy of -6.9 kcal/mol. Xanthotoxin and bergapten showed good docking scores, both at -6.5 kcal/mol for HpIMPDH, with each having four hydrogen bondings. Furthermore, xanthotoxin showed many hydrophobic interactions, while bergapten formed one Pi-anion interaction. Concerning docking in the urease enzyme, the compounds showed mild to moderate binding affinities as compared to the ligand. Thus, based on docking results and good binding scores observed with the HpIMPDH active site, an in-vitro HpIMPDH inhibition assay was done for the compounds. Citropten showed the most promising inhibitory activity with an IC50 value of 2.4 μM. Conclusion: The present study demonstrates that C. sinensis L. leaves are a good source for supplying coumarins that can act as naturally effective anti-H. pylori agents.

Variation of the essential oil components of Citrus aurantium leaves upon using different distillation techniques and evaluation of their antioxidant, antidiabetic, and neuroprotective effect against Alzheimer's disease

Citrus fruit essential oil is considered one of the widely studied essential oils while its leaves attract less attention although being rich in nearly the same composition as the peel and flowers. The leaves of bitter orange or sour orange (Citrus aurantium L.) were extracted using three different techniques namely; hydrodistillation (HD), steam distillation (SD), and microwave-assisted distillation (MV) to compare their chemical composition. The three essential oil samples were analyzed through GC/FID and GC/MS analyses. The samples were tested in vitro using different antioxidant techniques (DPPH, ABTS, CUPRAC, FRAP, PBD, and MCA), neuroprotective enzyme inhibitory activities (acetylcholine and butyl choline enzymes), and antidiabetic activities (α-amylase and α-glucosidase). The results showed that thirty-five volatile ingredients were detected and quantified. Monoterpenes represented the most abundant class in the three essential oils followed by sesquiterpenes. C. aurantium essential oil carried potential antioxidant activity where SD exhibited the highest antioxidant activity, with values arranged in the following order: FRAP (200.43 mg TE/g), CUPRAC (138.69 mg TE/g), ABTS (129.49 mg TE/g), and DPPH (51.67 mg TE/g). SD essential oil also presented the most potent α-amylase (0.32) inhibition while the MV essential oil showed the highest α-glucosidase inhibition (2.73 mmol ACAE/g), followed by HD (2.53 mmol ACAE/g), and SD (2.46 mmol ACAE/g). The SD essential oil exhibited the highest BChE and AChE inhibitory activities (3.73 and 2.06 mg GALAE/g), respectively). Thus, bitter orange essential oil can act as a potential source of potent antioxidant, antidiabetic, and neuroprotective activities for future drug leads.

Role of Nutraceuticals in Obesity Management: A Mechanism and Prospective Supported by Molecular Docking Studies

Obesity and its comorbidities represent a major health problem worldwide. Treatment by reducing food intake and physical activity interventions has limited success especially with elderly people with chronic diseases. Nutraceuticals are naturally originated and successfully used for their physiological and nutritional benefit in health care. They might be alternative means to help lose weight and reduce obesity-associated metabolic disorders with the improvement of health, delay the aging process, prevention of chronic diseases, increase of life expectancy, or support to the structure or function of the body. The current study enumerates the inherent role of nutraceuticals in the management of obesity and its related comorbidities. The study is supported with the molecular docking studies discussing the mechanism of action. An attempt to optimize the role of nutraceuticals is made in this article in addition to widen the scope of its use in this chronic worldwide disease.

Chemical composition, seasonal variation and antiaging activities of essential oil from Callistemon subulatus leaves growing in Egypt

Callistemon is an aromatic genus of flowering plants belonging to family Myrtaceae. The essential oils of C. subulatus leaves were collected in four seasons and analyzed using GC/MS. The oils demonstrated monoterpenes as the predominant class. Eucalyptol was the main component in all seasons; summer (66.87%), autumn (58.33%), winter (46.74%) and spring (44.63%), followed by α-pinene; spring (31.41%), winter (28.69%), summer (26.34%) and autumn (24.68%). Winter oil, the highest yield (0.53 mL/100g), was further investigated for its inhibitory activity against enzymes associated with ageing; elastase and acetylcholinesterase. It remarkably inhibited elastase and acetylcholinesterase with IC₅₀ values of 1.05 and 0.20 µg/ml, respectively. A molecular docking study was conducted for the major oil components on the active sites of target enzymes. Eucalyptol revealed the best binding affinity for both enzymes. C. subualtus oil could be used as supplement for management of ageing disorders like skin wrinkles and dementia.

Antimicrobial activities of metabolites isolated from endophytic Aspergillus flavus of Sarcophyton ehrenbergi supported by in-silico study and NMR spectroscopy

BACKGROUND

Endophytic Aspergillus species produce countless valuable bioactive secondary metabolites. In the current study, Aspergillus flavus an endophyte from the soft coral Sarcophyton ehrenbergi was chemically explored and the extracted phytoconstituents were subsequently evaluated for antimicrobial activity. This is accomplished by employing nuclear magnetic resonance (NMR) spectroscopy and computational techniques. Additionally, An in vitro anticancer analysis of A. flavus total extract against breast cancer cells (MCF-7) was investigated.

RESULT

Six compounds were separated from the crude alcohol extract of the endophytic Aspergillus flavus out of which anhydro-mevalonolactone was reported for the first time. The anti-fungal and anti-Helicobacter pylori properties of two distinct compounds (Scopularides A and B) were assessed. Additionally, computational research was done to identify the binding mechanisms for all compounds. Both the compounds were found to be active against H. pylori with minimum inhibitory concentration (MIC) values ranging from 7.81 to 15.63 µg/ mL as compared with clarithromycin 1.95 µg/ mL. Scopularides A was potent against both Candida albicans and Aspergillus niger with MIC values ranging from 3.9 to 31.25 µg/ mL, while scopularides B only inhibits Candida albicans with MIC value of 15.63 µg/ mL and weak inhibitory activity against A. niger (MIC = 125 µg/ mL). Furthermore, cytotoxic activity showed a significant effect (IC50: 30.46 mg/mL) against MCF-7 cells.

CONCLUSION

Our findings report that cytotoxic activity and molecular docking support the antimicrobial activity of Aspergillus flavus, which could be a promising alternative source as a potential antimicrobial agent.

Dynamic Changes in Plant Secondary Metabolites Induced by Botrytis cinerea Infection

In response to pathogen infection, some plants increase production of secondary metabolites, which not only enhance plant defense but also induce fungicide resistance, especially multidrug resistance (MDR) in the pathogen through preadaptation. To investigate the cause of MDR in Botrytis cinerea, grapes 'Victoria' (susceptible to B. cinerea) and 'Shine Muscat' (resistant to B. cinerea) were inoculated into seedling leaves with B. cinerea, followed by extraction of metabolites from the leaves on days 3, 6, and 9 after inoculation. The extract was analyzed using gas chromatography/quadrupole time-of-flight mass (GC/QTOF) combined with solid-phase microextraction (SPME) for volatile and nonvolatile metabolomic components. Nonvolatile metabolites γ-aminobutyric acid (GABA), resveratrol, piceid, and some carbohydrates or amino acids, coupled with volatile metabolites β-ocimene, α-farnesene, caryophyllene, germacrene D, β-copaene, and alkanes, accumulated at a higher level in grape leaves infected with B. cinerea compared to in noninoculated leaves. Among the established metabolic pathways, seven had greater impacts, including aminoacyl-tRNA biosynthesis, galactose metabolism, valine, leucine, and isoleucine biosynthesis. Furthermore, isoquinoline alkaloid biosynthesis; phenylpropanoid biosynthesis; monobactam biosynthesis; tropane, piperidine, and pyridine alkaloid biosynthesis; phenylalanine metabolism; and glucosinolate biosynthesis were related to antifungal activities. Based on liquid chromatography/quadrupole time-of-flight mass (LC/QTOF) detection and bioassay, B. cinerea infection induced production of plant secondary metabolites (PSMs) including eugenol, flavanone, reserpine, resveratrol, and salicylic acid, which all have inhibitory activity against B. cinerea. These compounds also promoted overexpression of ATP-binding cassette (ABC) transporter genes, which are involved in induction of MDR in B. cinerea.

Chemical Composition and Antimicrobial Activity of Essential Oils

This Special Issue entitled "Chemical Composition and Antimicrobial Activity of Essential Oils" focuses on the chemical characterization of essential oils (EOs) through analytical techniques that are necessary for the identification and quantification of individual compounds [...].

Phytochemical Constituents, Folk Medicinal Uses, and Biological Activities of Genus Angelica: A Review

Genus Angelica is one of the widely distributed and well-known genera of family Umbelliferae. It is utilized mainly by Chinese and Korean populations especially in their folk medicine. Angelica comprises a lot of medicinally important phytoconstituents such as coumarins, furanocoumarins, flavonoids, essential oils, verbascosides, polysaccharides, etc. Members of this genus play important roles, namely antioxidant, anti-inflammatory, anti-microbial, anti-diabetic, skin-whitening, cytotoxic, hepatoprotective, and many others. This review draws attention to many species of genus Angelica with much focus on A. dahurica being one of the highly medicinally used species within this genus.

GC-MS metabolites profiling of anethole-rich oils by different extraction techniques: antioxidant, cytotoxicity and in-silico enzymes inhibitory insights

GC-MS profiling and metabolomics study of anise and star anise oils obtained by hydrodistillation, n-hexane, and microwave-assisted extraction methods were conducted herein. Trans-anethole was the major phenylpropanoid in both oils. Principal component and hierarchical cluster analyses revealed a clear separation of different extraction methods. Microwave-assisted star anise oil (MSA) revealed the highest anethole content (93.78%). MSA oil showed antioxidant activity using DPPH and ABTS assays, this was verified via an in-silico docking study of its major compounds on human tyrosinase and NAD(P)H oxidase. Trans-anethole displayed the best fitting scores (-8.9 and -10.1 Kcal/mole, respectively). MSA oil showed promising cytotoxic activity on different cell lines, mainly the cervical (HeLa) cell lines. Cell cycle inhibition at the G0-G1 phase was observed with an early apoptotic effect of the oil on HeLa cells. Trans-anethole achieved the best docking scores (-7.9, -9.3 and -9.9 Kcal/mole) for in-silico study on EGFR, CDK2 and CDK4 enzymes engaged in cancer, respectively.

Herbal Arsenal against Skin Ailments: A Review Supported by In Silico Molecular Docking Studies

Maintaining healthy skin is important for a healthy body. At present, skin diseases are numerous, representing a major health problem affecting all ages from neonates to the elderly worldwide. Many people may develop diseases that affect the skin, including cancer, herpes, and cellulitis. Long-term conventional treatment creates complicated disorders in vital organs of the body. It also imposes socioeconomic burdens on patients. Natural treatment is cheap and claimed to be safe. The use of plants is as old as mankind. Many medicinal plants and their parts are frequently used to treat these diseases, and they are also suitable raw materials for the production of new synthetic agents. A review of some plant families, viz., Fabaceae, Asteraceae, Lamiaceae, etc., used in the treatment of skin diseases is provided with their most common compounds and in silico studies that summarize the recent data that have been collected in this area.

In Silico Docking, Resistance Modulation and Biofilm Gene Expression in Multidrug-Resistant Acinetobacter baumannii via Cinnamic and Gallic Acids

Despite the mounting global burden of antimicrobial resistance (AMR), the generation of new classes of effective antimicrobials still lags far behind. The interplay between multidrug resistance and biofilm formation in Acinetobacter baumannii has drastically narrowed the available therapeutic choices. The use of natural compounds holds promise as an alternate option for restoring the activity of existing antibiotics and attenuating virulence traits through reduced biofilm formation. This study aimed to evaluate the modulatory effect of combining cinnamic and gallic acids at ½MIC with various antibiotics against multidrug-resistant (MDR) A. baumannii clinical isolates as well as study the effect on the expression of the biofilm-associated genes (bap, csuE, ompA) via quantitative, real-time PCR. Combining cinnamic or gallic acid with imipenem, amikacin or doxycycline resulted in significant reduction of resistance (p < 0.05). On the contrary, no effect was recorded when both acids were combined with levofloxacin, and only cinnamic acid had a synergistic effect with colistin. The transcriptomic changes of biofilm-related genes in the presence of gallic acid at ½MIC were compared with untreated control samples. The fold expression values proved that gallic acid substantially down-regulated the respective genes in all five strong biofilm formers. Molecular docking studies of gallic and cinnamic acids on target genes revealed good binding affinities and verified the proposed mechanism of action. To the best of our knowledge, this is the first report on the effect of gallic acid on the expression of bap, csuE and ompA genes in A. baumannii, which may permit its use as an adjunct anti-virulence therapeutic strategy.

Cyclodepsipeptides: Isolation from Endophytic Fungi of Sarcophyton ehrenbergi and Verification of Their Larvicidal Activity via In-Vitro and In-Silico Studies

Culex pipiens mosquitoes are vectors to many viruses and can transmit diseases such as filariasis and avian malaria. The present study evaluated the larvicidal activity of marine-derived endophytic fungi Aspergillus nomius and Aspergillus flavus from the soft coral Sarcophyton ehrenbergi along with two known cyclodepsipeptide compounds, scopularide A (1) and B (2), isolated from A. flavus extract, against third-instar larvae of C. pipiens, using distilled water as a negative control and toosenedanin as a positive control. The structures of the isolated compounds were confirmed by various spectroscopic analyses. The lethal concentrations (LC₅₀ and LC₉₀) were calculated by probit analysis. Scopularide A was the most potent after 96 h treatment, with LC₅₀ and LC₉₀ values of 58.96 and 994.31 ppm, respectively, and with 82.66% mortality at a concentration of 300 ppm. To unravel the biochemical mechanism of the tested extracts and compounds, their effects against protease, chitinase, phenoloxidases and lipase enzymes from the whole-body tissue of C. pipiens were evaluated after 72 h treatment at LC₅₀ dose. Superior activity was observed for A. flavus extract against all tested enzymes. A molecular docking study was conducted for scopularide A and B on the four tested enzymes, to further verify the observed activity. Results revealed good binding affinities for both compounds as compared to the docked ligands, mainly via a number of hydrogen bonds. This was the first study to report the isolation of endophytic fungi A. flavus and A. nomius from the marine soft coral S. ehrenbergi. The endophytic fungal extract of A. flavus was found to be a promising source for a natural larvicidal agent against C. pipiens populations.

GC/MS Profiling, Anti-Collagenase, Anti-Elastase, Anti-Tyrosinase and Anti-Hyaluronidase Activities of a Stenocarpus sinuatus Leaves Extract

Today, skin care products and cosmetic preparations containing natural ingredients are widely preferred by consumers. Therefore, many cosmetic brands are encouraged to offer more natural products to the market, such as plant extracts that can be used for their antiaging, antiwrinkle, and depigmentation properties and other cosmetic purposes. In the current study, the volatile constituents of the hexane-soluble fraction of a Stenocarpus sinuatus (family Proteaceae) leaf methanol extract (SSHF) were analyzed using GC/MS analysis. Moreover, the antiaging activity of SSHF was evaluated through in vitro studies of anti-collagenase, anti-elastase, anti-tyrosinase, and anti-hyaluronidase activities. In addition, an in silico docking study was carried out to identify the interaction mechanisms of the major compounds in SSHF with the active sites of the target enzymes. Furthermore, an in silico toxicity study of the identified compounds in SSHF was performed. It was revealed that vitamin E (α-tocopherol) was the major constituent of SSHF, representing 52.59% of the extract, followed by γ-sitosterol (8.65%), neophytadiene (8.19%), β-tocopherol (6.07%), and others. The in vitro studies showed a significant inhibition by SSHF of collagenase, elastase, tyrosinase, and hyaluronidase, with IC₅₀ values of 60.03, 177.5, 67.5, and 38.8 µg/mL, respectively, comparable to those of the positive controls epigallocatechin gallate (ECGC, for collagenase, elastase, hyaluronidase) and kojic acid (for tyrosinase). Additionally, the molecular docking study revealed good acceptable binding scores of the four major compounds, comparable to those of ECGC and kojic acid. Besides, the SSHF identified phytoconstituents showed no predicted potential toxicity nor skin toxicity, as determined in silico. In conclusion, the antiaging potential of SSHF may be attributed to its high content of vitamin E in addition to the synergetic effect of other volatile constituents. Thus, SSHF could be incorporated in pharmaceutical skin care products and cosmetics after further studies.