Isolation of some luteolin derivatives from Mentha longifolia (L.) Hudson subsp. longifolia and determination of their genotoxic potencies

Efficacy of various extracting solvents on phytochemical composition, and biological properties of Mentha longifolia L. leaf extracts

The current work attempts to explore the influence of three extraction solvents on phytochemical composition, content of polyphenols, antioxidant potential, and antibacterial capacity of hydroethanolic, acetonic, and aqueous extracts from Moroccan Mentha longifolia leaves. To achieve this goal, the chemical composition was identified using an HPLC-DAD examination. The contents of polyphenols were assessed, while the total antioxidant capacity (TAC), the DPPH test, and the reducing power test (RP) were utilized to determine antioxidant capacity. To assess the antibacterial activity, the microdilution technique was carried out to calculate the minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) of extracts against four nosocomial bacteria (Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus). Additionally, the antibacterial and antioxidant activities of all tested extracts were examined in silico against the proteins NADPH oxidase and Bacillus cereus phospholipase C. Study reveals that M. longifolia extracts contain high phenolic and flavonoids. Additionally, the hydroethanolic extract contained the highest amounts of phenolic and flavonoid content, with values of 23.52 ± 0.14 mg Gallic acid equivalent/g dry weight and 17.62 ± 0.36 mg Quercetin Equivalent/g dry weight, respectively compared to the other two extracts. The same extract showed the best antioxidant capacity (IC50 = 39 µg/mL ± 0.00), and the higher RP (EC50 of 0.261 ± 0.00 mg/mL), compared to the acetonic and aqueous extract regarding these tests. Furthermore, the hydroethanolic and acetonic extracts expressed the highest TAC (74.40 ± 1.34, and 52.40 ± 0.20 mg EAA/g DW respectively), compared with the aqueous extract. Regarding antibacterial activity, the MIC value ranges between 1.17 and 12.50 mg/mL. The in-silico results showed that the antibacterial activity of all extracts is principally attributed to kaempferol and ferulic acid, while antioxidant capacity is attributed to ferulic acid.

A flavonoid-rich fraction of Monolluma quadrangula inhibits xanthine oxidase and ameliorates potassium oxonate-induced hyperuricemia in rats

Hyperuricemia represents a risk factor for the progression of chronic kidney disease. Oxidative stress and inflammation are implicated in the mechanisms underlying hyperuricemia-mediated kidney injury. Monolluma quadrangula possesses several beneficial effects; however, its effect on hyperuricemia has not been investigated. This study evaluated the renoprotective and xanthine oxidase (XO) inhibitory activity of M. quadrangula in hyperuricemic rats. Phytochemical investigation revealed the presence of six known flavonoid isolated for the first time from this species. The rats received M. quadrangula extract (MQE) and potassium oxonate (PO) for 7 days. In vitro assays showed the radical scavenging and XO inhibitory activities of MQE, and in silico molecular docking revealed the inhibitory activity of the isolated flavonoids towards XO. Hyperuricemic rats showed elevated serum uric acid, creatinine, urea, and XO activity, and renal pro-inflammatory cytokines, MDA and NO, and decreased GSH, SOD, and catalase. MQE ameliorated serum uric acid, urea, creatinine, and XO activity, and renal pro-inflammatory cytokines. In addition, MQE attenuated renal oxidative stress, enhanced antioxidants, downregulated URAT-1, and GLUT-9 and upregulated OAT-1 in PO-induced rats. In conclusion, M. quadrangula attenuated hyperuricemia and kidney impairment by suppressing XO activity, oxidative stress and inflammation, and modulating urate transporters.

Anti-leishmanial activity of Avicennia marina (Avicenniaceae family) leaves hydroalcoholic extract and its possible cellular mechanisms

Natural products are the main source of potent antioxidants and anti-leishmanial agents. This study was aimed to evaluate Avicennia marina (Avicenniaceae family) extract inhibitory effect against Leishmania tropica by accessing apoptotic markers and arginase activity. The A. marina were extracted and phytochemical analysis conducted. The inhibitory effect of A. marina was evaluated on L. tropica promastigote and amastigote forms, compared to meglumine antimoniate (Glucantime, MA) as standard drug. The level of apoptosis, Reactive Oxygen Species (ROS) production and arginase activity was assessed in A. marina-treated cells compared to control group. Phytochemical screening of A. marina extract showed strong presence of tannins and saponins. We demonstrated the inhibitory effect of A. marina on promastigote stages in a dose dependent manner. Also, lower 50% inhibitory concentration (IC₅₀) value of amastigotes was indicated in A. marina group compared with the standard group of Glucantime (60.57 ± 1.46 vs. 73.19 ± 10.12 μg/mL, respectively, P < 0.05). Besides, A. marina represented no cytotoxicity as the selectivity index (SI) was 10.7. Also, it showed the potential to induce early apoptosis of 46.5% in promastigotes at 125 μg/mL concentration. Significant reduction of arginase level was observed in both A. marina-treated cells and promastigotes. The promising results indicated higher effectiveness of A. marina in decreasing parasite growth, inducing apoptosis in promastigotes, increasing ROS production and decreasing arginase level. So, A. marina can be a native plant candidate for anti-leishmanial drug in tropical regions with cutaneous leishmaniasis due to L. tropica.

Discrimination of Mentha species grown in different geographical areas of Algeria using 1H-NMR-based metabolomics

¹H-NMR-based metabolomics have been applied to identify potential NMR-markers and biomarkers capable of distinguishing, qualifying and classifying three Mentha species:- Mentha pulegium L., Mentha × rotundifolia (L.) Huds., Mentha spicata L., and their ecotypes. Samples of the 3 species were collected in seven different locations in Algeria, with the aim to establish a quality control protocol based on the use of NMR fingerprint profiles of polar extracts. NMR data indicate that the identification of the Mentha genus can be confirmed by the presence of the doublet proton signals with identical coupling constants at δ 7.49 (d, 15.9 Hz) and δ 6.29 (d, 15.9 Hz); these correspond to the protons of the double-bond conjugated to the ester group of rosmarinic acid, a bioactive compound found in all three species. Differences in NMR proton chemical shifts and/or signal intensities were clearly demonstrated on the orthogonal projections to latent structures discriminating analysis (OPLS-DA). Several potential biomarkers discriminating the three Mentha species were originated using S-plots, loading score plots, NMR data analysis and literature search. These discriminating signals point to glycosylated flavonols, oxygenated terpenoids and hydrocarbon terpenoids to distinguish M. pulegium, M. × rotundifolia and M. spicata, respectively. Within the same species, Principal Component Analysis (PCA) scores clearly discriminated the metabolite content according to regions in which the plants were grown. The 6 zones in which Mentha pulegium samples were harvested were clearly separated along either or both PC1 and PC2; by contrast, the harvesting locations were divided into two groups along PC1 for both M. × rotundifolia and M. spicata. The total antioxidant activity of the Mentha species was impacted by the abiotic factors of the different regions.

Potential Role of Phenolic Extracts of Mentha in Managing Oxidative Stress and Alzheimer's Disease

With an increase in the longevity and thus the proportion of the elderly, especially in developed nations, there is a rise in pathological conditions that accompany ageing, such as neurodegenerative disorders. Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive cognitive and memory decline. The pathophysiology of the disease is poorly understood, with several factors contributing to its development, such as oxidative stress, neuroinflammation, cholinergic neuronal apoptotic death, and the accumulation of abnormal proteins in the brain. Current medications are only palliative and cannot stop or reverse the progression of the disease. Recent clinical trials of synthetic compounds for the treatment of AD have failed because of their adverse effects or lack of efficacy. Thus, there is impetus behind the search for drugs from natural origins, in addition to the discovery of novel, conventional therapeutics. Mints have been used traditionally for conditions relevant to the central nervous system. Recent studies showed that mint extracts and/or their phenolic constituents have a neuroprotective potential and can target multiple events of AD. In this review, we provide evidence of the potential role of mint extracts and their derivatives as possible sources of treatments in managing AD. Some of the molecular pathways implicated in the development of AD are reviewed, with focus on apoptosis and some redox pathways, pointing to mechanisms that may be modulated for the treatment of AD, and the need for future research invoking knowledge of these pathways is highlighted.

A new sulfonylated flavonoid and other bioactive compounds isolated from the aerial parts of Cotula anthemoides L

A new sulfonyl flavonol glucoside, 5,7,4',5'-tetrahydoxyflavonol 2'-[propanoic acid-(2″'-acetoxy-1″'-sulfonyl)]-5'-O-β-d-glucopyranoside (1) was isolated from the aerial parts of Cotula anthemoides L. in addition to 15 known compounds (2-16). The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D-, 2D-NMR and HR-ESI-MS techniques and by comparing their NMR data with those reported in the literature. These compounds were evaluated for their DPPH radical scavenging and tyrosinase inhibitory activity. Compound 6 showed a high DPPH radical scavenging with EC₅₀ value of 9.1 ± 0.4 μM. Compound 11, 9 and 1 exhibited a mild tyrosinase inhibitory activity with IC₅₀ values of 85 ± 0.8, 95 ± 1.5 and 100 ± 0.5 μM, respectively.

Amphipaniculosides A-D, triterpenoid glycosides, and amphipaniculoside E, an aliphatic alcohol glycoside from the leaves of Amphilophium paniculatum

Four new triterpenoids; One oleanane-, one ursane- and two cycloartane-type triterpenoids, named amphipaniculosides A-D, in addition to one new aliphatic alcohol glycoside, named amphipaniculoside E, were isolated from the 1-BuOH fraction of the leaves of Amphilophium paniculatum (L.) Kunth., together with five known compounds, (+)-lyoniresinol 3α-O-β-D-glucopyranoside, (-)-lyoniresinol 3α-O-β-D-glucopyranoside, acteoside (verbascoside), isoacteoside (isoverbascoside), and luteolin 7-O-β-D-glucopyranoside. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments ((1)H, (13)C, DEPT, COSY, ROESY, HSQC, HMBC) in combination with HR-ESI-MS and by comparisons of their physical and spectroscopic data with literature values.

Pharmacological and therapeutic effects of Mentha Longifolia L. and its main constituent, menthol

Mentha longifolia (wild mint) is a popular folk remedy. Some parts of this plant have been used in traditional medicine of Iran and other countries. Many studies have shown various pharmacological and therapeutic effects of the plant. Our aim in preparing this study was to review the traditional uses of M. longifolia together with the pharmacological and therapeutic effects of its entire extract and major compounds. Mentha longifolia is an herb with a wide range of pharmacological properties such as antimicrobial, gastrointestinal, and nervous system effects. Pulegone is the main compound of the plant responsible for most of its pharmacological effects followed by menthone, isomenthone, menthol, 1, 8-cineole, borneol, and piperitenone. Moreover, the plant may dose-dependently exert toxic effects in different systems of the body. Based on the review of various studies, it can be concluded that M. longifolia is a potential natural source for the development of new drugs. However, further studies are required to determine the precise quality and safety of the plant to be used by clinicians.

Antithrombotic and antidiabetic flavonoid glycosides from the grains of Sorghum bicolor (L.) Moench var. hwanggeumchal

A phytochemical study of the grains of S. bicolor, resulting in the isolation of twelve flavonoid glycosides 1-12. Their chemical structures were elucidated on the basis of spectroscopic (1D and 2D NMR) and MS data analyses. All compounds were tested on thrombin time (TT) assay and α-glucosidase assay in order to assess their inhibitory effects on blood coagulation and α-glucosidase enzyme. At the concentration of 500 μg/mL, compounds 3, 4, 7 and 10 possessed the potential effects on blood coagulation with inhibitory percentage of 197, 152, 120 and 158 %, respectively, whereas aspirin, which used as a positive control, indicated 181 and 138 % inhibition at 500 and 375 μg/mL, respectively. Furthermore, compounds 3, 4, 7, 9 and 10 also displayed strong inhibitory effects on α-glucosidase enzyme, with 85.2, 55.7, 43.9, 52.7 and 65.2 % inhibition at 100 μg/mL, respectively, whereas acarbose, as a positive control, possessed only 38.7 % at the same concentration. Taken together, our data suggest that S. bicolor and its flavonoid-enrich extracts could be considered as supplemental and or functional foods having beneficial effects against blood coagulation-induced ischemia, possibly thromboembolism disease, as well as diabetes.

Cytotoxic activity of methanolic extract of Mentha longifolia and Ocimum basilicum against human breast cancer

Labiatae family is represented in Saudi Arabia. The aim of the present study was to go insight to investigate the anticancer activity and antioxidative potentials of methanolic extracts of Mentha longifolia L. (ML) and Ocimum basilicum L. (OB) that grown in Madina province, western region, Saudi Arabia. OB exhibited the greater phenolic contents as mg gallic acid equivalent/g weight (mg GAE/g) for a value of 105 +/- 5.5 mg GAE/g. On the other hand, ML produced 29 +/- 3.12 mg GAE/g. The standard antioxidant vitamin E used in this experiment elicited a value of total phenolic contents equal 22 +/- 2.2 mg GAE/g. The percentage scavenging activity of against diphenylpicrylhydrazyl (DPPH) was 850 and 160% for OB and ML extracts, respectively. Vitamin E elicited% scavenging activity of against DPPH equal to 198%. Brine shrimp cytotoxic assay clearly indicated the cytotoxic effects of either ML or OB extract. The brine shrimp survival is inversely proportional to the concentration of either ML or OB extract used with LD50 191.23 and 235.50 ppm, respectively. Toxic effects on brine shrimps indicated the anticancer potential of ML or OB extract. The ML or OB extract was unable to produce pbluescript (pBS) plasmid DNA damage, while the plasmid DNA treated with EcoRI produced a single band as a result of DNA damage. Also, both ML and OB extract exhibited marked cytotoxic activity against MCF-7 cells at various concentrations (20, 40, 80, 160 and 320 microg mL(-1)). The 160 and 320 microg mL(-1) showed more cytotoxic effect against MCF-7 cells. Based on results achieved, we can concluded that, OB and ML extracts have the potency to act as powerful antioxidants and protect against DNA damage and have cytotoxic activity against MCF-7 cell line.

Determination of the antigenotoxic potencies of some luteolin derivatives by using a eukaryotic cell system, Saccharomyces cerevisiae

In this study, we aimed to examine the mutagenic and antimutagenic potencies of three luteolin derivatives (luteolin-7-O-glucoside, luteolin-7-O-rutinoside and luteolin-7-O-glucuronide) by using a eukaryotic cell system, Saccharomyces cerevisiae (RS112). In the antimutagenicity assays, these luteolin derivatives showed antimutagenic effects in deletion and intrachromosomal recombination events against ethyl methanesulfonate and acridine mutagen agents. In deletion events, the highest inhibition rates for luteolin-7-O-glucoside, luteolin-7-O-rutinoside and luteolin-7-O-glucuronide against ethyl methanesulfonate were 57.6%, 58.3% and 62.5%, respectively. Likewise, the highest inhibition rates for luteolin-7-O-glucoside, luteolin-7-O-rutinoside and luteolin-7-O-glucuronide against acridin were 21.8%, 22.4% and 23.6%, respectively. Our findings showed that these luteolin derivatives have stronger antimutagenic properties against ethyl methanesulfonate compared to the acridine mutagen agent.