Essential oils of four Rwandese hepatoprotective herbs: Gas chromatography-mass spectrometry analysis and antioxidant activities

Antibacterial and Antioxidant Activities, Toxicity, and Physicochemical Properties of Crassocephalum montuosum (S Moore) Milne-Redh and Crassocephalum picridifolium (DC) S Moore

In traditional Congolese medicine, the plants Crassocephalum montuosum (CrasMon) and Crassocephalum picridifolium (CrasPic) are used to treat bacterial gastroenteritis. In the present study, the antibacterial and antioxidant activities as well as the acute and subacute toxicity of organic extracts from the whole plant of the two investigated taxa were evaluated. Physicochemical parameters were also determined, and total phenolics, flavonoids, and tannins were investigated and assayed. The antibacterial and antioxidant activities of the plant extracts were evaluated using disc diffusion, tube macrodilution, and DPPH tests. Conversely, traditional solution reactions, gravimetric tests, and spectrophotometric tests were used to generate physicochemical profiles, identify secondary metabolite groups, and perform microdilution and DPPH tests to evaluate the antibacterial and antioxidant activities, respectively. OECD tests were adapted to assess the acute and subacute toxicity. All the extracts showed antibacterial activity against E. coli and S. typhi strains with the diameter zone of inhibition (DZI) ranging from 12 to 23 mm and the minimum inhibitory concentration (MIC): 15.625-125 μg·mL-1. The methanolic extract of CrasPic showed the most pronounced activity with a DZI of 21-23 mm and MIC of 15.625-62.5 μg·mL-1. All extracts showed high antioxidant activity with IC50 (half maximal inhibitory concentration) ranging from 11.6 to 21.8 μg·mL-1, with the methanolic extract of CrasMon showing the most pronounced activity. Both plants contain a variety of phytochemicals including coumarins, quinones, flavonoids, phenols, saponins, tannins, and terpenoids. The methanolic extract of CrasPic exhibits the highest content of total phenolics (300 mg·GAE·g-1), flavonoids (56 mg·QE·g-1), and tannins (155 mg·GAE·g-1). These extracts have a median lethal dose (LD50) > 5000 mg·kg-1 and no signs of toxicity at 200 mg·kg-1 after 30 days of oral administration to Cavia porcellus. The total ash content was determined to be 14.2% and 15.8% (on a dry weight basis), with the ash insoluble in hydrochloric acid exhibiting a range of 4.04%-5.03%. CrasMon and CrasPic have been demonstrated to exhibit a good antibacterial and antioxidant activities, at least in part, due to the presence of phenolic compounds. These activities may provide a rationale for their use in traditional Congolese medicine against gastroenteritis.

Phytochemical Profiling and Bioactivity Assessment of Teucrium capitatum L. Essential Oil and Extracts: Experimental and In Silico Insights

Background:Teucrium capitatum L., a member of the Lamiaceae family, is widely used in traditional medicine for its therapeutic properties. This study aims to analyze the chemical composition of its essential oil and extracts, evaluate their antimicrobial and antioxidant activities, and investigate the interactions of their bioactive compounds with biological targets using in silico methods to better understand their mechanisms of action. Methods: Essential oil was extracted via hydrodistillation from leaves collected in Morocco, while phenolic compounds were obtained through Soxhlet and decoction extraction methods. Gas chromatography-mass spectrometry (GC-MS) was used for chemical profiling. Antimicrobial and antioxidant activities were assessed using standard methods, including DPPH, FRAP, and TAC assays. Molecular docking was conducted to explore interactions between major constituents and biological targets. Results: GC-MS analysis revealed significant bioactive components in the essential oil, such as β-pinene (24.5%), α-cadinol (17.02%), and shyobunol (12.13%). Extracts (hydro-ethanolic, hydro-methanolic, and aqueous via decoction) were rich in poliumoside (27.74%) and cirsimaritin (28.22%). The essential oil and extracts showed significant antimicrobial activity, particularly against Staphylococcus aureus, Escherichia coli, Candida albicans, and Aspergillus niger. Antioxidant assays confirmed strong activity. Molecular docking results supported strong interactions of major compounds with key biological targets. Conclusions: The high presence of phenolic and flavonoid compounds in Teucrium capitatum extracts contributes to their strong antimicrobial and antioxidant properties, supporting their potential for development as natural therapeutic agents.

Bornyl acetate: A promising agent in phytomedicine for inflammation and immune modulation

BACKGROUND

Bornyl acetate (BA), as a bicyclic monoterpene, is an active volatile component widely found in plants across the globe. BA can be used as essence and food flavor agent and is widely used in perfumes and food additives. It remains a key component in several proprietary Chinese medicines.

PURPOSE

This review summarized the pharmacological activity and research prospects of BA, making it the first of its kind to do so. Our aim is to provide a valuable resource for those pursuing research on BA.

METHODS

Databases including PubMed, Web of Science, and CNKI were used based on search formula "(bornyl acetate) NOT (review)" from 1967 to 2022. For the relevant knowledge of TCM, we quoted Chinese literature. Articles related to agriculture, industry, and economics were excluded.

RESULTS

BA showed rich pharmacological activities: It inhibits the NF-κB signal pathway via affecting the phosphorylation of IKB and the production of IKKs, inhibits the MAPK signal pathway via inhibiting the phosphorylation of ERK, JNK, and p38, down-regulates pro-inflammatory cytokines such as TNF-α, IL-1β, IL-6, up-regulates IL-11, reduces NO production, regulates immune response via up-regulating CD86⁺, decreases catecholamine secretion, and reduces tau protein phosphorylation. In addition to the pharmacological activities of BA, its toxicity and pharmacokinetics were also discussed in this paper.

CONCLUSION

BA has promising pharmacological properties, especially anti-inflammatory and immunomodulatory effects. It also has sedative properties and potential for use in aromatherapy. Compared to traditional NSAIDs, it has a more favorable safety profile while maintaining efficacy. BA has potential for developing novel drugs for treating various conditions.

Ecological Preferences and Diversity of Essential Oil Composition in Endangered Wild-Growing Populations of Sideritis sipylea Boiss. (Lamiaceae) of the East Aegean Islands (Greece): Evidencing Antioxidant Potential, Antimicrobial and Cytotoxic Activities

Plants from the genus Sideritis (Lamiaceae) have been widely used in folk medicine for a long time and consequently are a focus of the scientific community. Despite this interest, explicit data about the essential oils (EOs) of the Endangered Sideritis sipylea have not been readily available to date. In this study, we investigated the ecological preferences of Greek S. sipylea and the chemical composition of the essential oils of wild-growing S. sipylea populations from two Greek islands (S1: Samos, S2: Lesvos); we explored concomitant associations with environmental factors; and we assessed their (i) antioxidant potential (two tests), (ii) antimicrobial activity against six microbial and two fungal strains, and (iii) cytotoxic effect in two human and one murine cell lines. We compiled an ecological profile in R based on all known Greek localities of S. sipylea, outlining for the first time its preferences regarding temperature (3.48 ± 1.53 °C to 30.70 ± 1.11 °C) and the precipitation regimes (5.92 ± 2.33 mm to 136 ± 11.43 mm) shaping its natural occurrence in the wild. The chemical analysis (42 compounds in total) confirmed the domination of monoterpene hydrocarbons in both samples (with quantitative and qualitative differences) and identified 12 new constituents reported in S. sipylea for the first time (e.g., Bicyclogermacrene and Cumacrene). Dominant compounds in S1 (39 constituents) were β-Myrcene (20.4%) followed by β-caryophyllene (11.8%), bicyclogermacrene (7.1%), β-pinene (6.3%), carvacrol (6.2%) and α-terpinene (6.1%), whereas in S2 (26 constituents) the main ones were α-pinene (37.3%), β-pinene (15.1%) and sabinene (12.1%), followed by β-caryophyllene (5.6%) and bicyclogermacrene (5.5%). The strong antioxidant capacity and cytotoxic activity of S. sipylea EOs are reported herein for the first time, while new insight is provided regarding their effect on bacterial and fungal strains (four ones originally tested herein). The biological activity analysis demonstrated variation among samples, with S2 being more potent than S1. Altogether, the results of the present study demonstrate the high biological potential of S. sipylea EOs with an interesting antioxidant capacity and antimicrobial and cytotoxic effects and reveal associations of natural chemodiversity with climatic factors.

Antioxidant and Antimicrobial Activities of Chemically-Characterized Essential Oil from Artemisia aragonensis Lam. against Drug-Resistant Microbes

This study investigated the chemical composition, antioxidant and antimicrobial activity of essential oil extracted from Artemisia aragonensis Lam. (EOA). Hydrodistillation was employed to extract EOA. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to determine the phytochemical composition of EOA. Antioxidant potential was examined in vitro by use of three tests: 2.2-diphenyl-1-picrilhidrazil (DPPH), ferric reducing activity power (FRAP) and total antioxidant capacity assay (TAC). Agar diffusion and microdilution bioassays were used to assess antimicrobial activity. GC/MS and GC-FID detected 34 constituents in the studied EOA. The major component was Camphor (24.97%) followed by Borneol (13.20%), 1,8 Cineol (10.88%), and Artemisia alcohol (10.20%). EOA exhibited significant antioxidant activity as measured by DPPH and FRAP assays, with IC50 and EC50 values of 0.034 ± 0.004 and 0.118 ± 0.008 mg/mL, respectively. EOA exhibited total antioxidant capacity of 7.299 ± 1.774 mg EAA/g. EOA exhibited potent antibacterial activity as judged by the low minimum inhibitory concentration (MIC) values against selected clinically-important pathogenic bacteria. MIC values of 6.568 ± 1.033, 5.971 ± 1.033, 7.164 ± 0.0 and 5.375 ± 0.0 μg/mL were observed against S. aureus, B. subtills, E. coli 97 and E. coli 57, respectively. EOA displayed significant antifungal activity against four strains of fungi: F. oxysporum, C. albicans, A. flavus and A. niger with values of 21.50 ± 0.43, 5.31 ± 0.10, 21.50 ± 0.46 and 5.30 ± 0.036 μg/mL, respectively. The results of the current study highlight the importance of EOA as an alternative source of natural antioxidant and antibacterial drugs to combat antibiotic-resistant microbes and free radicals implicated in the inflammatory responses accompanying microbial infection.

Chemical Characterization and Antioxidant, Antimicrobial, and Insecticidal Properties of Essential Oil from Mentha pulegium L

The chemical composition and antibacterial, insecticidal, and antioxidant properties of the essential oil from Mentha pulegium L. (M. pulegium) growing in Morocco were investigated in this work. To achieve this goal, the oils were obtained by using hydrodistillation before being characterized by GC-MS. The antibacterial and antifungal activities were conducted against pathogenic strains using the disc diffusion and MICS bioassays. The insecticidal activity was carried out versus C. maculatus using contact and inhalation tests. The antioxidant activity was performed by using DPPH and total antioxidant capacity bioassays. The chemical analysis of the oil showed that 20 compounds were identified, which represented 98.91% of the total oil. In the oil, the main components detected were R-(+)-pulegone (76.35%), carvone (5.84%), dihydrocarvone (5.09%), and octanol-3 (2.25%). The essential oil has moderate-to-strong broad-spectrum antibacterial and antifungal properties; the results showed that B. subtilis was the most sensitive strain to M. pulegium oil, with the largest inhibition diameter (25 ± 0.33). For the antifungal activity, the results obtained indicated that Aspergillus niger was the most sensitive fungal strain to M. pulegium oil with an inhibition percentage up to 100%. Regarding the insecticidal activity, the inhalation test showed a high efficacy (100% mortality), and a lethal concentration of LC₅₀ = 1.41 + 0.48 μL/L air was obtained after 24 hours of exposure. Moreover, the contact test showed that a total reduction in fertility and emergence was obtained with a dose of 20 μL/mL of acetone. Regarding the antioxidant activity, the sample concentration necessary to inhibit 50% of HE radicals (IC₅₀) was 7.659 mg/mL (DPPH) and 583.066 57.05 mg EAA/g EO (TAC).

Capillary Liquid Chromatography for the Determination of Terpenes in Botanical Dietary Supplements

Dietary supplements of botanical origin are increasingly consumed due to their content of plant constituents with potential benefits on health and wellness. Among those constituents, terpenes are gaining attention because of their diverse biological activities (anti-inflammatory, antibacterial, geroprotective, and others). While most of the existing analytical methods have focused on establishing the terpenic fingerprint of some plants, typically by gas chromatography, methods capable of quantifying representative terpenes in herbal preparations and dietary supplements with combined high sensitivity and precision, simplicity, and high throughput are still necessary. In this study, we have explored the utility of capillary liquid chromatography (CapLC) with diode array detection (DAD) for the determination of different terpenes, namely limonene, linalool, farnesene, α-pinene, and myrcene. An innovative method is proposed that can be applied to quantify the targets at concentration levels as low as 0.006 mg per gram of sample with satisfactory precision, and a total analysis time <30 min per sample. The reliability of the proposed method has been tested by analyzing different dietary supplements of botanical origin, namely three green coffee extract-based products, two fat burnings containing Citrus aurantium (bitter orange), and an herbal preparation containing lime and leaves of orange trees.

Hepatoprotective effect of limonene against chronic immobilization induced liver damage in rats

Prolonged immobilization may impair the physiological functions of various organs of the body, including the liver, brain, and heart. In this study, we investigated the hepatoprotective effect of limonene (a monoterpene) in male rats exposed to chronic immobilization. Rats were exposed to immobilization stress (6 h/21 days) and received limonene (10 mg/kg, oral gavage) during this period. Chronic immobilization increased the levels of liver enzymes alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase in serum. Increased levels of malondialdehyde and decreased glutathione content were also observed in the liver tissue of immobilized rats. Expression of TNF-α, IL-1β, IL-6, and NF-κB mRNA was increased, and infiltrated cells were also observed in the liver parenchyma in rats exposed to chronic immobilization. Limonene prevented all these changes in immobilized rats. These results suggest that limonene, due to its antioxidant and anti-inflammatory effects, rescues the liver from damages caused by chronic immobilization.

Identification and comparison of the volatile constituents of fresh and dried leaves of Spondias mombin found in North-central Nigeria: in vitro evaluation of their cytotoxic and antioxidant activities

CONTEXT

Various studies have shown that the leaf extracts of Spondias mombin Linn (Anacardiaceae) possess pharmacological properties such as antioxidant and antiviral effects. However, no biological activity from its essential oil has been reported in literature.

OBJECTIVE

To analyse the chemical constituents, cytotoxic activity and antioxidant capability of the essential oils from fresh and dried leaves of S. mombin.

MATERIALS AND METHODS

Hydrodistillation using Clevenger-type apparatus was employed to obtain the essential oil. Oil analysis was performed using an HP 6890 Gas Chromatograph coupled with an HP 5973 Mass Selective Detector. The cytotoxicity bioassay was carried out using the brine shrimp lethality test (10,000-0.01 μg/mL). Additionally, the reactive oxygen species scavenging potential of the two S. mombin oils (1000-200 μg/mL) were investigated using a hydroxyl radical scavenging and ferric iron reducing system.

RESULTS

Chemical analysis of essential oils from S. mombin revealed the presence of 41 compounds, with predominance of monoterpenoids, sesquiterpenoids and non-terpenoids derivatives. In both fractions, the principal component was β-caryophellene (27.9-30.9%), followed by γ-cadinene (9.7-12.3%). There was an increase in the oxygenated monoterpenoid contents and a concomitant decrease in the amounts of sesquiterpenoids hydrocarbons observed on drying the leaves. The oil obtained from the fresh leaves was more active than that obtained from dried leaves, with LC₅₀ values (from the brine shrimp lethality assay) of 0.01 and 4.78 μg/mL, respectively. The two oils (from fresh and dried leaves) at 1.0 mg/mL scavenged hydroxyl radical by 83% and 99.8%, respectively. Moreover, they reduced ferric ion significantly and compared favourably with vitamin C.

CONCLUSIONS

Essential oil derived from the leaves of S. mombin could hold promise for future application in the treatment of cancer-related diseases.

Variability, toxicity, and antioxidant activity of Eupatorium cannabinum (hemp agrimony) essential oils

CONTENT

Eupatorium cannabinum L. (Asteraceae) is as a potential source of biologically active compounds. The plant is used in traditional medicine for the treatment of diarrhea and livers diseases.

OBJECTIVE

The present study provides investigation on pharmacological properties (antioxidant and toxic activities) of essential oils of E. cannabinum, collected from 11 wild populations in Lithuania.

MATERIALS AND METHODS

Twenty-two hemp agrimony essential oil samples were prepared by hydrodistillation according to the European Pharmacopoeia, and their chemical composition was determined by GC-FID and GC-MS. Compositional data were subjected to principal components analysis (PCA). Instead of conventional spectrophotometric methods, cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques were applied to determine antioxidant activity of hemp agrimony essential oils. Meanwhile, toxicity of the oils was determined using brine shrimp (Artemia sp.) assay.

RESULTS

Chemical profiles of E. cannabinum oils were described according to the first predominant components: germacrene D (≤22.0%), neryl acetate (≤20.0%), spathulenol (≤27.2%), and α-terpinene (11.5%). For the first time, α-zingiberene (≤7.8%) was found to be among three major constituents (as the second one) for hemp agrimony oils. SWV measurements revealed that oxidation potentials of compounds present in the oils are lower (below 0.1 V) compared with that of well-known antioxidant quercetin (0.15 V). Toxicity tests evaluated that hemp agrimony oils containing predominant amounts of germacrene D and neryl acetate were notably toxic (LC50 value 16.3-22.0 μg/mL).

CONCLUSION

The study provided some new data concerning chemical composition and pharmaceutical properties of E. cannabinum essential oils.