Phytochemicals, antioxidant, anti-acetyl-cholinesterase, and antimicrobial activities of decoction and infusion of Pelargonium graveolens

Headspace aroma and secondary metabolites profiling in 3 Pelargonium taxa using a multiplex approach of SPME-GC/MS and high resolution-UPLC/MS/MS coupled to chemometrics

BACKGROUND

The present study focuses on the aroma and secondary metabolites profiling of three Pelargonium graveolens cultivars, baladi (GRB), sondos (GRS) and shish (GRSH), grown in Egypt. Utilizing a multiplex approach combining high resolution-ultraperformance liquid chromatography (HR-UPLC)/tandem mass spectrometry (MS/MS) and gas chromatography (GC)-MS coupled with chemometrics, the study aims to identify and profile various secondary metabolites and aroma compounds in these cultivars.

RESULTS

HR-UPLC/MS/MS analysis led to the annotation of 111 secondary metabolites, including phenolics, flavonoids, terpenes and fatty acids, with several compounds being reported for the first time in geranium. Multivariate data analysis identified vinylanisole, dimethoxy-flavonol, and eicosadienoic acid as discriminatory metabolites among the cultivars, particularly distinguishing the GRS cultivar in its phenolics profile. In total, 34 aroma compounds were detected using headspace solid-phase microextraction coupled with GC-MS, including alcohols, esters, ketones, ethers and monoterpene hydrocarbons. The major metabolites contributing to aroma discrimination among the cultivars were β-citronellol in GRB, α-farnesene in GRS and isomenthone in GRSH.

CONCLUSION

The study provides a comprehensive profiling of the secondary metabolites and aroma compounds in the three Pelargonium graveolens cultivars. The GRS cultivar was identified as particularly distinct in both its phenolics and aroma profiles, suggesting its potential as a premium variety for cultivation and use. Future studies should focus on isolating and investigating the newly detected metabolites and exploring the biological effects of these compounds in food applications and other uses. © 2024 Society of Chemical Industry.

Nano-Coating Loaded With Leaf and Flowers of Pelargonium graveolens Plant Extract Stabilized With Fenugreek Seed Gum and Soy Protein Isolate in Increasing the Shelf Life of Mutton Fillet

In this study, the extract of leaf and flower of Pelargonium graveolens was obtained using an ultrasonic-assisted extraction method. The extraction yield and the content of phenolic, flavonoid, and flavonol compounds in the flower extract were higher (13.93%, 74.97 mg GAE g DM-1, 31.93 mg QE g DM-1, and 9.08 mg QEE g DM-1) than leaf extract (10.69%, 67.46 mg GAE g DM-1, 23.04 mg QE g DM-1, and 11.34 mg QEE g DM-1). Both extracts demonstrated antioxidant properties in tests involving the scavenging of DPPH radicals and the ferric reduction assay. Extracts exhibited antimicrobial properties. MIC of flower extract against Staphylococcus aureus and Escherichia coli were 2500 and 5000, while MBC of leaf extract were 15,000, and 20,000 ppm, respectively. The concentration of 2000 ppm of extracts was encapsulated in fenugreek seed gum (FSG) and soy protein isolate (SPI) produced by the emulsification method. All nano-coatings exhibited a nanometric size range between 172.75 to 255.21 nm, and encapsulation efficiency higher than 80.0% (80.82% to 89.59%). The application of nano-coatings significantly reduced microbial counts and delayed lipid oxidation in mutton meat during 12 days of cold storage at 4°C, enhancing meat quality and extending shelf life. The inclusion of bioactive compounds like polyphenols in the coatings contributed to antimicrobial and antioxidant effects, decreasing pH levels and preventing spoilage. The findings indicated that the combination of edible FSG and SPI as wall materials with 2000 ppm of P. graveolens extract demonstrated efficacy in implementation bacterial growth and lipid oxidation in fresh mutton meat.

Pelargonium graveolens: Towards In-Depth Metabolite Profiling, Antioxidant and Enzyme-Inhibitory Potential

Pelargonium graveolens L'Hèr. (Geraniaceae) is renowned for its traditional use as a flavor, ornamental and medicinal plant. This work aimed at an in-depth study of the phytochemical profiling and in vitro antioxidant and enzyme inhibition assessment of a methanol-aqueous extract from P. graveolens leaves. A UHPLC-HRMS analysis revealed more than 110 secondary metabolites, including 8 acyltartaric and 11 acylcitric/acylisocitric acids; 8 gallotannins; 36 flavonols, flavanones and methoxylated flavonoids together with 17 phenolic and aliphatic acids; and 21 phenolic acid glycosides. For the first time, acylcitric acids along with feruloyl- and coumaroyltartaric acids are reported in the species. The leaf extract actively scavenged 2,2-diphenyl-1-picrylhydrazyl DPPH (273.45 mg trolox equivalent (TE/g)) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radicals (531.97 mgTE/g) and showed a high reducing power: 431.32 mg TE/g Cupric reducing antioxidant capacity (CUPRAC) and 292.21 mg TE/g Ferric reducing antioxidant power (FRAP). It possessed a metal chelating capacity (13.44 ethylenediaminetetraacetic acid equivalent (EDTAE)/g) and contained 2.71 mmol TE/g in the phosphomolybdenum assay. The rose geranium extract exhibited high inhibition towards acetyl- and butyrylcholinesterase (2.80 and 2.20 mg galantamine equivalent (GALAE)/g, respectively) and tyrosinase (75.49 mg kojic acid equivalent (KAE)/g). It inhibited α-glucosidase and α-amylase (3.75 mmol and 0.79 acarbose equivalent (ACAE)/g, respectively) and lipase (28.91 mg orlistat equivalent (OE)/g). This study sheds light into the future potential application of the rose geranium in pharmaceutical and nutraceutical products.

Antimicrobial and synergistic effects of lemongrass and geranium essential oils against Streptococcus mutans, Staphylococcus aureus, and Candida spp

BACKGROUND

The oral cavity harbors more than 700 species of bacteria, which play crucial roles in the development of various oral diseases including caries, endodontic infection, periodontal infection, and diverse oral diseases.

AIM

To investigate the antimicrobial action of Cymbopogon Schoenanthus and Pelargonium graveolens essential oils against Streptococcus mutans, Staphylococcus aureus, Candida albicans, Ca. dubliniensis, and Ca. krusei.

METHODS

Minimum microbicidal concentration was determined following Clinical and Laboratory Standards Institute documents. The synergistic antimicrobial activity was evaluated using the Broth microdilution checkerboard method, and the antibiofilm activity was evaluated with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay. Data were analyzed by one-way analysis of variance followed by the Tukey post-hoc test (P ≤ 0.05).

RESULTS

C. schoenanthus and P. graveolens essential oils were as effective as 0.12% chlorhexidine against S. mutans and St. aureus monotypic biofilms after 24 h. After 24 h P. graveolens essential oil at 0.25% was more effective than the nystatin group, and C. schoenanthus essential oil at 0.25% was as effective as the nystatin group.

CONCLUSION

C. schoenanthus and P. graveolens essential oils are effective against S. mutans, St. aureus, Ca. albicans, Ca. dubliniensis, and Ca. krusei at different concentrations after 5 min and 24 h.

Phytochemical Investigations, Antioxidant and Insecticidal Properties of Essential Oil and Extracts from the Aerial Parts of Pelargonium graveolens from Morocco

The essential oil and the aqueous and ethanolic extracts obtained from the aerial parts of Pelargonium graveolens cultivated in Morocco were studied for their antioxidant and insecticidal activity against rice weevils (Sitophylus oryzae). The total phenolic content of the extracts was determined by a spectrophotometric method and the phenolic compounds were extensively characterized by HPLC-PDA/ESI-MS. To evaluate antioxidant potential, three in vitro assays were used. In the DPPH test, the ethanolic extract was the most active, followed by the aqueous extract and the essential oil. In the reducing power assay, excellent activity was highlighted for both extracts, while in the Fe2+ chelating activity assay, weak activity was observed for both the essential oil and the ethanolic extract and no activity for the aqueous extract. Concerning insecticide activity, the toxicity of the essential oil and the extracts was tested against rice weevils; the lethal concentrations LC50 and LC99 were determined, as well as the lethal time required for the death of 50% (LT50) and 99% (LT99) of the weevils. The essential oil had the highest activity; 100% mortality of S. oryzae was observed around 5, 9, and 8 days for the essential oil and the aqueous and ethanolic extracts, respectively.

A chemical analysis of the Pelargonium species: P. odoratissimum, P. graveolens, and P. zonale identifies secondary metabolites with activity against gram-positive bacteria with multidrug-resistance

The Pelargonium genus encompasses around 280 species, most of which are used for medicinal purposes. While P. graveolens, P. odoratissimum, and P. zonale are known to exhibit antimicrobial activity, there is an evident absence of studies evaluating all three species to understand their chemical differences and biological effects. Through the analysis of the hydroalcoholic extracts of P. graveolens, P. odoratissimum, and P. zonale, using HPLC-DAD-MS/MS, quercetin and kaempferol derivatives were identified in these three species. Conversely, gallotannins and anthocyanins were uniquely detected in P. zonale. P. graveolens stood out due to the various types of myricetin derivatives that were not detected in P. odoratissimum and P. zonale extracts. Evaluation of their biological activities revealed that P. zonale displayed superior antibacterial and antibiofilm activities in comparison to the other two species. The antibacterial efficacy of P. zonale was observed towards the clinically relevant strains of Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) 333, Enterococcus faecalis ATCC 29212, and the Vancomycin-resistant E. faecalis INSPI 032. Fractionation analysis of P. zonale suggested that the antibacterial activity attributed to this plant is due to the presence of quercetin derivatives and kaempferol and its derivatives, alongside their synergistic interaction with gallotannins and anthocyanins. Lastly, the three Pelargonium species exhibited notable antioxidant activity, which may be attributed to their high content of total phenolic compounds.

Adding New Scientific Evidences on the Pharmaceutical Properties of Pelargonium quercetorum Agnew Extracts by Using In Vitro and In Silico Approaches

Pelargonium quercetorum is a medicinal plant traditionally used for treating intestinal worms. In the present study, the chemical composition and bio-pharmacological properties of P. quercetorum extracts were investigated. Enzyme inhibition and scavenging/reducing properties of water, methanol, and ethyl acetate extracts were assayed. The extracts were also studied in an ex vivo experimental model of colon inflammation, and in this context the gene expression of cyclooxygenase-2 (COX-2) and tumor necrosis factor α (TNFα) were assayed. Additionally, in colon cancer HCT116 cells, the gene expression of transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8), possibly involved in colon carcinogenesis, was conducted as well. The extracts showed a different qualitative and quantitative content of phytochemicals, with water and methanol extracts being richer in total phenols and flavonoids, among which are flavonol glycosides and hydroxycinnamic acids. This could explain, at least in part, the higher antioxidant effects shown by methanol and water extracts, compared with ethyl acetate extract. By contrast, the ethyl acetate was more effective as cytotoxic agent against colon cancer cells, and this could be related, albeit partially, to the content of thymol and to its putative ability to downregulate TRPM8 gene expression. Additionally, the ethyl acetate extract was effective in inhibiting the gene expression of COX-2 and TNFα in isolated colon tissue exposed to LPS. Overall, the present results support future studies for investigating protective effects against gut inflammatory diseases.

Preparation of geranium oil formulations effective for control of phenotypic resistant cattle tick Rhipicephalus annulatus

The aim of the present study was to evaluate in vitro and in vivo the acaricidal activity of two forms of geranium (Pelargonium graveolens) (PG). These two forms were the P. graveolens essential oil nanoemulsion (PGN), and the PG in combination with the sesame oil (SO), PGSO). These forms were first evaluated in vitro for their adulticidal, ovicidal, and larvicidal activities against the different stages of acaricide-resistant Rhipicephalus annulatus (Say). Geranium nanoemulsion was prepared and then characterized by UV-Vis spectrophotometer, and zeta droplet size measurement. The results revealed that LC₅₀ of the PG against the adult ticks was attained at concentration of 7.53% while it was decreased to 1.91% and 5.60% for PGSO and PGN, respectively. Also, the LC₅₀ of PGN and PGSO were reached at concentrations of 1.688 and 0.944%, respectively against the larvae while the LC₅₀ of the PG was reached at concentration of 3.435% for. The combination of PGN with PG exhibited non-significant ovicidal effect meanwhile PGSO showed significant ovicidal effect even at the low concentration (2.5%). The PGSO and PGN formulations were applied in a field trial to control the ticks of the naturally infested cattle. PGSO and PGN significantly reduced the tick burden to 74.83% and 87.97%, respectively at 3 weeks post-application with performance better than the deltamethrin (29.88%). In conclusion, the two PG forms can be used as suitable alternatives to control R. annulatus tick and they need further modifications for effective field application.

Potentiation of anti-Helicobacter pylori activity of clarithromycin by Pelargonium graveolens oil

BACKGROUND AND STUDY AIM

Peptic ulcer is one of the most serious diseases in Egypt, affecting more than one-third of the population. Helicobacter pylori is the main organism responsible for peptic ulcer formation. These ulcers can lead to chronic active gastritis and lymphoma. As such, in this study, we evaluate the efficacy of Pelargonium graveolens oil for the treatment of H pylori, as well as its synergistic effects with the antibiotic clarithromycin (CLR).

PATIENTS AND METHODS

We evaluated the chemical composition of P. graveolens volatile oil as well as its anti-Helicobacter activities. We assessed the volatile oil components using gas chromatography coupled with mass spectrometry. We determined anti-H. pylori potential using a micro-well dilution method.

RESULTS

We identified 92 compounds from the oil. Citronellol, geraniol, citronellyl formate, and isolongifolan-7-α-ol were the predominant components (15.64%, 11.31%, 10.19%, and 7.84%, respectively). The oil exhibited a good activity against H. pylori at an minimal inhibitory concentration of 15.63 µg/ml. Once we combined the volatile oil with CLR, a significant synergistic effect appeared at an fractional inhibitory concentration index of 0.38 µg/ml.

CONCLUSION

The in-vitro interaction between the P. graveolens oil and CLR improved the antimicrobial activity of the latter, suggesting that further studies are needed to determine formulations for potential antimicrobial applications in food and pharmaceuticals.

Studies on essential oil from rose-scented geranium, Pelargonium graveolens L'Hérit. (Geraniaceae)

Rose-scented geranium, Pelargonium graveolens L'Hérit. (Geraniaceae), is an economically important plant. GC-MS analysis of the essential oil, prepared by hydro-distillation from this plant species, showed the presence of iso-menthone (15.71%), epi-α-cadinol (15.49%), iso-menthol (6.46%), geranyl formate (6.22%), geraniol (6.16%) and citronellol (5.53%). The composition of the absolute prepared by solvent extraction was compared to that of the essential oil. Change in citronellol to geraniol ratio in the absolute was monitored during leaf development. Estimation of the ratio of the two compounds was carried out using ¹H NMR spectroscopy. Geraniol content was highest in young leaves and citronellol content increased with increase in leaf age. Meta-analysis of the essential oil constituents reported from different countries was carried out. Menthone and isomenthone as well as citronellol and geraniol were negatively correlated. A significantly positive correlation was found between geraniol and linalool.

Polyphenolic profile, antibacterial activity and brine shrimp toxicity of leaf extracts from six Tunisian spontaneous species

The aim of this study was to investigate the polyphenolic profile and biological properties of leaves acetonic extracts from six Tunisian spontaneous plants of Marrubium vulgare L., Rhus tripartita (Ucria) D.C., Hernaria fontanesii J. Gay subsp. fontanesii, Ziziphus lotus L., Plantago ovata Forsk., Thymelaea hirsuta (L.) Endl. Bioassay-guided and HPLC-PDA-ESI-MS procedures demonstrated that R. tripartita contained the highest amount of phenolic compounds (1475.1 µg/g), followed by Z. lotus (1087.8 µg/g) and P. ovata (1027.6 µg/g). Interestingly, in R. tripartita myricetin-3-O-galactoside turned out to be the most abundant one. The plant extracts showed antimicrobial efficacy against Listeria monocytogenes, Staphylococcus aureus and S. epidermidis including methicillin resistant strains; no activity was detected against Gram-negative bacteria. R. tripartita revealed the best MIC and MBC values and caused significant decrease of S. aureus biofilm. Both R. tripartita and Z. lotus did not display any toxicity against Artemia salina Leach (LC₅₀ > 1000 μg/mL).