Chemical composition andin vitroantifungal and antioxidant activity of the essential oil and methanolic extract ofTeucrium sauvageiLe Houerou

Alpha-cadinol as a potential ACE-inhibitory volatile compound identified from Phaseolus vulgaris L. through in vitro and in silico analysis

Hypertension is a major risk factor of cardiovascular diseases, which is mainly caused due to over activation of renin-angiotensin system. The angiotensin converting enzyme (ACE), which is involved in formation of angiotensin II from angiotensin I, causes the blood vessels to constrict, in turn leading to hypertension. The current study was initiated to understand the role of bioactive volatile compounds from Phaseolus vulgaris L. (common bean), in ACE enzyme inhibition. Beans aqueous extract (BAE) showed maximum ACE inhibition of 88.4 ± 0.8% in comparison to other commonly consumed vegetables like spinach and garlic. The head space gas chromatography-mass spectrometry analysis showed the presence of a number of terpenes and terpenoids, which were present prominently in BAE. In silico molecular docking studies indicated that among the other volatile compounds, alpha-cadinol (-7.27 kcal/mol) and ar-tumerone (-6.44 kcal/mol) have the maximum binding affinity with the active site of ACE, as compared to that of captopril (-6.41 kcal/mol). The molecular dynamic simulation in biological environment, showed that alpha-cadinol forms a stable complex with ACE, with average binding energy of -42 kJ/mol. The ACE:alpha-cadinol complex was found to be stable mainly due to the hydrophobic interactions of alpha-cadinol with active site residues (Tyr523 and Phe457) of ACE. The in silico drug-likeness analysis showed that alpha-cadinol is appropriate for human system with no predicted hepatotoxicity or mutagenicity (AMES toxicity).Communicated by Ramaswamy H. Sarma.

Medicinal-Cosmetic Potential of the Local Endemic Plants of Crete (Greece), Northern Morocco and Tunisia: Priorities for Conservation and Sustainable Exploitation of Neglected and Underutilized Phytogenetic Resources

Medicinal-aromatic plants (MAPs) are important sources for the development of new valuable products of interest to human and animal health, and are also used as ornamentals for the horticulture industry. However, the increased global demand and the uncontrolled exploitation of these plants constitute a threat to their sustainability. To date, few scientific investigations have focused on MAPs valorization and their domestication. The purpose of this study was to evaluate for the first time the medicinal-cosmetic potential of 399 local endemic Mediterranean plants confined to Crete (223 taxa), the Mediterranean coast-Rif of Morocco (94), and Tunisia (82). The new methodological scheme was developed by experts through three multidisciplinary co-creative workshops and was adjusted by end-users to point-scoring of nine attributes evaluating the potential of the targeted neglected and underutilized plants (NUPs) in the medicinal-cosmetic sector. The results were demonstrated as percentage of the maximum possible score. These assessments were further linked and discussed with respect to feasibility and readiness timescale evaluations for sustainable exploitation of the focal NUPs. A great diversity of local endemic NUPs (30 taxa, 11 families) were associated with interesting medicinal-cosmetic properties (>35% up to 94.44%). Among them, 8 taxa showed the highest medicinal-cosmetic potential (>55% of maximum possible score), half of which are threatened with extinction. Although ex-situ conservation efforts and applied research work are needed to safeguard and unlock the full potential of the local endemic NUPs evaluated herein, the proposed multifaceted evaluation scheme revealed that some local endemic NUPs of the studied regions can be sustainably exploited in short- or medium-term, following successful examples of Cretan NUPs e.g., Origanum dictramnus. The sustainable exploitation of high scored taxa of the studied regions can be fastened through targeted species-specific research bridging extant research gaps and facilitating conservation and stakeholder attraction.

A Review of the Phytochemistry, Traditional Uses and Biological Activities of the Essential Oils of Genus Teucrium

The genus Teucrium is a large and polymorphic genus of the Lamiaceae family distributed in mild climate zones, particularly in the Mediterranean basin and Central Asia. Studies of nonvolatile constituents of Teucrium species showed that they are a rich source of neo-clerodane diterpenoids, considered as chemotaxonomic markers of the genus. In addition to the nonvolatile metabolites, there has been a large interest in the essential oils of this genus. In this review, a complete survey of the chemical composition and biological properties of the essential oils isolated from Teucrium taxa is provided. In traditional medicine, since ancient times, species of this genus have been widely implemented for their biological properties, including antimicrobial, anti-inflammatory, antispasmodic, insecticidal, anti-malaria, etc. Therefore, a complete review of all of the traditional uses of Teucrium taxa are also reported.

Essential Oils of Lamiaceae Family Plants as Antifungals

The incidence of fungal infections has been steadily increasing in recent years. Systemic mycoses are characterized by the highest mortality. At the same time, the frequency of infections caused by drug-resistant strains and new pathogens e.g., Candida auris increases. An alternative to medicines may be essential oils, which can have a broad antimicrobial spectrum. Rich in the essential oils are plants from the Lamiaceae family. In this review are presented antifungal activities of essential oils from 72 Lamiaceae plants. More than half of these have good activity (minimum inhibitory concentrations (MICs) < 1000 µg/mL) against fungi. The best activity (MICs < 100) have essential oils from some species of the genera Clinopodium, Lavandula, Mentha, Thymbra, and Thymus. In some cases were observed significant discrepancies between different studies. In the review are also shown the most important compounds of described essential oils. To the chemical components most commonly found as the main ingredients include β-caryophyllene (41 plants), linalool (27 plants), limonene (26), β-pinene (25), 1,8-cineole (22), carvacrol (21), α-pinene (21), p-cymene (20), γ-terpinene (20), and thymol (20).

Chemical Constituents, Antioxidant, Cyclooxygenase Inhibitor, and Cytotoxic Activities of Teucrium pruinosum Boiss. Essential Oil

Introduction

In traditional medicine, many pharmacological activities have already been ascribed to the genus of Teucrium plant. These include antirheumatic antispasmodic, anthelmintic, diuretic, hypoglycemic, and anticancer effects. The recent investigation aimed to characterize and estimate the chemical composition, anti-inflammatory, antioxidant, and anticancer potentials of the essential oil isolated by the microwave-ultrasonic apparatus from Teucrium pruinosum leaves collected from Palestine.

Methods

The essential oil (EO) was analyzed by Gas Chromatography equipped with mass spectrometry (GC-MS), while its anticancer activity was evaluated against HeLa cervical adenocarcinoma cells. The ability of T. pruinosum EO to inhibit the conversion of Arachidonic Acid (AA) to PGH₂ by ovine COX-1 and human recombinant COX-2 was determined using a COX inhibitor screening assay. In addition, the antioxidant activity of the EO was evaluated on the basis of the scavenging activity with a stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, while Trolox was used as a positive control.

Results

Forty-four molecules were identified in T. pruinosum EO, representing 100% of the total EO. Agarospirol was found to be the most abundant component (45.53%) followed by caryophyllene (19.35%). However, the cyclooxygenase inhibitor assay revealed that T. pruinosum has potential COX-1 and Cox-2 inhibitory activity with IC₅₀ values of 0.25 µg/ml and 0.5 µg/ml, respectively. Moreover, the T. pruinosum EO showed moderate antioxidant capacity with an IC₅₀ value of 16.98±0.84 µg/ml in comparison with the positive control Trolox, which has an antioxidant potential with an IC₅₀ value of 2.09±0.17 µg/ml. In addition, 250, 125, 62.5, 31.25, 15.625, 7.67, and 3.84 mg/ml of T. pruinosum EO treatments inhibited mitochondrial activity (cell viability) significantly and extremely by 90-95%.

Conclusion

The current study provided data that revealed that the T. pruinosum EO could be a suitable candidate for use as a novel anticancer, anti-inflammatory, and antioxidant medication. Further clinical trials would be required to ensure these effects and to allow the design of suitable pharmaceutical dosage forms from this natural oil.

Variation in essential oil composition of Teucrium hircanicum L. from Iran-A rich source of (E)-α-bergamotene

In present work, the chemical composition of the essential oils obtained from dried flowering aerial parts of Teucrium hircanicum L. (Labiatae) originated from ten wild populations in Iran was analyzed by a GC-FID and GC/MS system. The oil yields varied from 0.04% to 0.1%. A total of thirty-two compounds representing 67.6-97.7% of the oil were identified. The essential oil was found to be rich in sesquiterpene hydrocarpons (E)-α-bergamotene (17.5-86.9%) and (E)-β-farnesene (0.5-21.4%). Of the total identified compounds, sesquiterpene hydrocarpons (36.1-89.7%) were included the greatest essential oil fraction in all the populations, followed by oxygenated monoterpenes (2.2-21.6%), oxygenated sesquiterpenes (0.0-14.4%) and monoterepene hydrocarbons (0.0-9.5%). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used to distinguish any geographical variations, indicating that the clustering of populations is related to their geographic origin. According to the GC/MS analysis, two chemotypes consisting of (E)-α-bergamotene and (E)-α-bergamotene-(E)-β-farnesene were identified in the populations.

Protective effect of Egyptian propolis against rabbit pasteurellosis

The present study was conducted to study the protective effect of ethanolic extract of propolis given subcutaneously (S/C) either alone or in combination with inactivated formalized Pasteurella multocida (P. multocida) vaccine in rabbits challenged with virulent P. multocida strain. Twenty-eight New-Zealand rabbits, 6-8 weeks old and not vaccinated against pasteurellosis, were randomly divided into four equal groups. Group (1) was kept as nonvaccinated control. Group (2) was injected S/C with propolis. Group (3) was vaccinated (S/C) with P. multocida vaccine only. Group (4) was injected with vaccine mixed with propolis as adjuvant. Groups (2, 3, and 4) received the same doses of propolis and vaccine after 4 weeks as a booster dose. The experiment continued for six weeks during which clinical signs, body weight, and mortality rate were recorded. Blood samples were collected every 2 weeks of treatment for evaluating the erythrogram and biochemical parameters. At the end of six weeks, all groups were subjected to challenge with a virulent strain of P. multocida. Two weeks later, tissue specimens were collected from different organs for histopathological investigation. Results showed that before challenge all rabbits of different groups were apparently healthy and had good appetite. After challenge, control group (1) showed acute form of the disease, 100% mortality rate, and severe histopathological changes. Rabbits of groups (2 and 3) showed less severe clinical signs, mortality rate, and histopathological changes than control. Rabbits of group (4) were apparently healthy with normal histological picture. In conclusion, an ethanolic extract of propolis injected alone or combined with formalized inactivated P. multocida vaccine improved general health conditions, liver and kidney functions in addition to reduction of the severity of adverse clinical signs, mortality rates, and histopathological changes associated with challenge of rabbits with P. multocida strain.

Comparative study of genotoxicity and antimutagenicity of methanolic extracts from Teucrium chamaedrys and Teucrium montanum in human lymphocytes using micronucleus assay

Since Teucrium chamaedrys and Teucrium montanum are the most popular plants used in the treatment of many diseases, we evaluated genotoxic potential of their methanolic extracts on cultured human peripheral blood lymphocytes (PBLs) using cytokinesis-block micronucleus (MN) assay. Cultures were treated with four concentrations of both plants (125, 250, 500 and 1,000 μg/ml), both separately and in combination with mitomycin C (MMC). The results revealed that extract of T. chamaedrys administered at the tested concentrations did not significantly affect the mean MN frequency in comparison to untreated cells. Methanolic extract of T. montanum increased the mean MN frequency in PBL at the tested concentrations, but significantly only at the concentration of 1,000 μg/ml. In all tested concentrations, the extract of T. chamaedrys significantly reduced the MMC-induced MN frequency, in a dose dependent manner (r = - 0.687, p < 0.01). The extract of T. montanum decreased the MMC-induced MN frequency at the tested concentrations, but statistically only at 125 μg/ml. Both extracts administered alone did not significantly affect the nuclear division index (NDI) at the tested concentrations. In the combined treatments with MMC, the extract obtained from T. chamaedrys in the concentrations of 500 and 1,000 μg/ml significantly decreased NDI values in comparison to MMC-treated cells alone, while the extract of T. montanum significantly decreased NDI at all tested concentrations. Both extracts nonsignificantly decreased NDI at all tested concentrations in comparison to untreated cells. Our results suggest the important function of T. chamaedrys extract in cancer therapy, this methanolic extract may prevent genotoxic effects of chemotherapy in PBLs.

Protective effect of propolis against oxidative stress and immunosuppression induced by oxytetracycline in rainbow trout (Oncorhynchus mykiss, W.)

The aim of this study was to investigate the effects of propolis on oxytetracycline (OTC)-induced oxidative stress and immunosuppression in fish. OTC (100 mg per kg⁻¹ body weight) was orally administered to fish for 14 days. A significant elevation in the level of malondialdehyde, as an index of lipid peroxidation, and reductions in antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase) and low molecular weight antioxidant (reduced glutathione) levels were observed in the blood, liver, kidney, spleen, and heart tissues of OTC-treated fish. OTC also had a suppressive effect on specific and non-specific immune system parameters, such as leucocyte counts, oxidative radical production (nitrobluetetrazolium activity), total plasma protein and immunoglobulin levels, and phagocytic activity. Pre-treatment, post-treatment, and simultaneous treatment with propolis (50 mg per kg⁻¹ body weight, orally) attenuated the OTC-induced oxidative stress by significantly decreasing the levels of malondialdehyde in tissues. In addition, propolis significantly increased the level of reduced glutathione and the catalase, glutathione peroxidase, and superoxide dismutase activities. Upon the administration of propolis, the suppressed immune system parameters were significantly increased in fish treated with OTC. The present results suggest that pre-treatment, post-treatment, and simultaneous administration of propolis might alleviate OTC-induced oxidative stress and immunosuppression.

Herbal bioactivation, molecular targets and the toxicity relevance

There have been increasing reports on the adverse reactions associated with herbal consumption. For many of these adverse reactions, the underlying biochemical mechanisms are unknown, but bioactivation of herbal compounds to generate reactive intermediates have been implicated. This minireview updates our knowledge on metabolic activation of herbal compounds, molecular targets and the toxicity relevance. A number of studies have documented that some herbal compounds can be converted to toxic or even carcinogenic metabolites by Phase I [e.g. cytochrome P450s (CYPs)] and less frequently by Phase II enzymes. For example, aristolochic acids (AAs) in Aristolochia spp, which undergo reduction of the nitro group by hepatic CYP1A1/2 or peroxidases in extrahepatic tissues to generate highly reactive cyclic nitrenium ions. The latter can react with macromolecules (DNA and protein), resulting in activation of H-ras and myc oncogenes and gene mutation in renal cells and finally carcinogenesis of the kidneys. Teucrin A and teuchamaedryn A, two diterpenoids found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming herbal supplements that caused severe hepatotoxicity, are converted by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase and inactivate them. Some naturally occurring alkenylbenzenes (e.g. safrole, methyleugenol and estragole) and flavonoids (e.g. quercetin) can undergo bioactivation by sequential 1-hydroxylation and sulfation, resulting in reactive intermediates capable of forming DNA adducts. Extensive pulegone metabolism generated p-cresol that is a glutathione depletory. The hepatotoxicity of kava is possibly due to intracellular glutathione depletion and/or quinone formation. Moreover, several herbal compounds including capsaicin from chili peppers, dially sulfone in garlic, methysticin and dihydromethysticin in kava, oleuropein in olive oil, and resveratrol found in grape seeds are mechanism-based (suicide) inhibitors of various CYPs. Together with advances of proteomics, metabolomics and toxicogenomics, an integrated systems toxicological approach may provide deep insights into mechanistic aspects of herb-induced toxicities, and contribute to bridging the relationships between herbal bioactivation, protein/DNA adduct formation and the toxicological consequences.

Natural products--antifungal agents derived from plants

A new spectrum of human fungal infections is increasing due to increased cancer, AIDS, and immunocompromised patients. The increased use of antifungal agents also resulted in the development of resistance to the present drugs. It makes necessary to discover new classes of antifungal compounds to cure fungal infections. Plants are rich source of bioactive secondary metabolites of wide variety such as tannins, terpenoids, saponins, alkaloids, flavonoids, and other compounds, reported to have in vitro antifungal properties. Since the plant kingdom provides a useful source of lead compounds of novel structure, a wide-scale investigation of species from the tropics has been considered. Therefore, the research on natural products and compounds derived from natural products has accelerated in recent years due to their importance in drug discovery. A series of molecules with antifungal activity against different strains of fungus have been found in plants, which are of great importance to humans. These molecules may be used directly or considered as a precursor for developing better molecules. This review attempts to summarize the current status of important antifungal compounds from plants.