Pentacylic triterpenes from Lavandula coronopifolia: structure related inhibitory activity on α-glucosidase

Lavandula austroapennina: Assessment of the Antiviral Activity of Lipophilic Extracts from Its Organs

In a framework aimed at the recovery and enhancement of medicinal plants endemic to the territory of the Cilento and Vallo di Diano National Park, Lavandula austroapennina N.G. Passal., Tundis and Upson has aroused interest. An insight into the chemical composition of the corolla, calyx, leaf, stem, and root organs was carried out following ultrasound-assisted maceration in n-hexane. The obtained lipophilic extracts were explored using ultra-high-performance chromatography coupled to high-resolution mass spectrometry (UHPLC-ESI-QqTOF-MS/MS). The extracts from the different organs varied in their relative content of fatty acids, ursanes, and oleanane-type triterpenes. In particular, the oleanolic acid content appeared to increase in the order of corolla < leaf < stem. An MTT assay was performed to verify the possible cytotoxicity of the organ extracts of L. austroapennina at a concentration ranging from 12.5 to 400 µg/mL on the Vero CCL-81 cell line. Antiviral activity against herpes simplex virus type 1 (HSV-1), alpha human coronavirus 229E (HCoV-229E), and poliovirus type 1 (PV-1) was evaluated via a plaque reduction assay in the same cellular model. All the extracts did not show cytotoxic effects after 2 and 24 h exposure times, and the antiviral efficacy was particularly important for the stem extract, capable of completely inhibiting the tested viruses at low doses. The antiviral activity in a non-enveloped virus PV-1 allowed the assertion that the extracts from the organs of L. austroapennina, and especially the stem extract, interfered directly with the viral envelope. This study underlines how much knowledge of a territory's medicinal plant heritage is a harbinger of promising discoveries in the health field.

The effect of Lavandula Coronopifolia essential oil on the biophysical properties of desensitization and deactivation gating currents in ionotropic receptors

The rising incidence of cancer and the lack of effective therapeutic interventions for many neurological illnesses like Alzheimer's and epilepsy has prompted us to investigate the composition and effects of the Lavandula coronopifolia oil from Palestine on cancer cells and AMPA receptor subunits in the brain due to the vast range of beneficial properties of Lavandula coronopifolia essential oil (EO). GC/MS was used to analyze L. coronopifolia's EO chemistry. EO's cytotoxicity and biophysical effects on AMPA receptors were investigated using MTS and electrophysiological techniques. The GC-MS results revealed that L. coronopifolia EO has a high content of eucalyptol (77.23%), β-pinene (6.93%), and α-pinene (4.95%). The EO showed more significant antiproliferative selectivity activities against HepG2 cancer cell lines than HEK293T cell lines with IC₅₀ values of 58.51 and 133.22 µg/mL, respectively. The EO of L. coronopifolia affected AMPA receptor kinetics (desensitization and deactivation) and preferred homomeric GluA1 and heteromeric GluA1/A2 receptors. These findings indicate the potential therapeutic use of L. coronopifolia EO in the selective treatment of HepG2 cancer cell lines and neurodegenerative diseases.

Essential Oils Composition and Biological Activity of Chamaecyparis obtusa, Chrysopogon nigritanus and Lavandula coronopifolia Grown Wild in Sudan

Generally, there are scant data about the constituents and eventually the biological activity of essential oils (EOs) from aromatic plants that grow naturally in Sudan. The present study aimed to determine the chemical composition, and antioxidant and enzyme inhibitory activities of EO extracted from the fruit of Chamaecyparis obtusa (Siebold and Zucc.) Endl. (family Cupressaceae), root of Chrysopogon nigritanus (Benth.) Veldkampis (family Poaceae) and aerial part of Lavandula coronopifolia Poir (family Lamiaceae). The fruit of C. obtusa contained only monoterpenes, mainly hydrogenated ones, with α-pinene (69.07%) as the major component. Oxygenated sesquiterpenes comprised the highest content of the C. nigritanus root EO with cedr-8-en-15-ol (28.69%) as the major constituent while aerial parts of L. coronopifolia contained both monoterpenes and sesquiterpenes and the oxygenated monoterpene lavandulol (26.56%) as dominant compounds. The EO of the root of C. nigritanus significantly displayed (p < 0.05) the highest anti-DPPH radical, Fe³⁺- and Cu²⁺-reducing and metal-chelating activities, while that of C. obtusa fruit significantly exerted (p < 0.05) the best anti-ABTS radical and total antioxidant activity. The two EOs significantly exhibited (p < 0.05) the highest anti-acetylcholinesterase and -butyrylcholinesterase activities, respectively, while EO of L. coronopifolia was the only oil to show a considerable inhibitory effect against the tyrosinase and α-glucosidase enzymes. In conclusion, EOs from these three plants could be natural agents with promising functional properties for food, cosmetics, and pharmaceutical applications.

Antidiabetic Activity of Extract Combination of Orthosiphon aristatus and Oryza sativa L. var glutinosa

Traditionally and scientifically, research has shown that Orthosiphon aristatus and Oryza sativa L. var. glutinosa have antidiabetic activity. The combination of two medicinal plants can increase their biological activity. This study aimed to determine the antidiabetic activity of O. aristatus and O. sativa L. var. glutinosa on single and combined extracts. Phytochemical screening of the single extract was done qualitatively. The α-glucosidase inhibitory method was used as an antidiabetic activity. The results showed that every extract contained alkaloids, steroids/triterpenoids, flavonoids, tannins, quinones, and coumarins. A single extract of O. sativa L. var glutinosa, O. aristatus, and their combinations (1:1, 1:2, and 2:1) had an α-glucosidase enzyme inhibitory activity with an IC50 value of 67.82, 80.93, 73.81, 88.72, and 61.51 µg/ml, respectively. The combination shows that the ratio of 1:1 was nearly additive, 1:2 was slight to moderate antagonism, and 2:1 was moderate to slight synergism. The combination of 96% ethanol extract of O. sativa L. var. glutinosa and O. aristatus in a ratio of 2:1 was the most effective in increasing its inhibitory activity.

Phytochemical Profiling of Lavandula coronopifolia Poir. Aerial Parts Extract and Its Larvicidal, Antibacterial, and Antibiofilm Activity Against Pseudomonas aeruginosa

Infections associated with the emergence of multidrug resistance and mosquito-borne diseases have resulted in serious crises associated with high mortality and left behind a huge socioeconomic burden. The chemical investigation of Lavandulacoronopifolia aerial parts extract using HPLC-MS/MS led to the tentative identification of 46 compounds belonging to phenolic acids, flavonoids and their glycosides, and biflavonoids. The extract displayed larvicidal activity against Culex pipiens larvae (LC50 = 29.08 µg/mL at 72 h). It significantly inhibited cytochrome P-450 monooxygenase (CYP450), acetylcholinesterase (AChE), and carboxylesterase (CarE) enzymes with the comparable pattern to the control group, which could explain the mode of larvae toxification. The extract also inhibited the biofilm formation of Pseudomonas aeruginosa by 17-38% at different Minimum Inhibitory Concentrations (MICs) (0.5-0.125 mg/mL) while the activity was doubled when combined with ciprofloxacin (ratio = 1:1 v:v). In conclusion, the wild plant, L.coronopifolia, can be considered a promising natural source against resistant bacteria and infectious carriers.

Postprandial Hyperglycemia Lowering Effect of the Isolated Compounds from Olive Mill Wastes - An Inhibitory Activity and Kinetics Studies on α-Glucosidase and α-Amylase Enzymes

In the present study, we isolated seven compounds from olive mill wastes (OMW), one of them being novel, and investigated their antidiabetic potential through inhibition of α-glucosidase and α-amylase enzymes. To assist the possible characterization of the mechanisms involved, we analyzed the inhibitory kinetics of the active compounds. Oleanolic acid 1, maslinic acid 2, 1-acetoxypinoresinol 3, and luteolin-7-O-β-d-glucoside 6 exhibited stronger inhibitory activity against both enzymes, with IC₅₀ values less than or close to that of acarbose. Other compounds pinoresinol and hydroxytyrosol-containing compounds (hydroxytyrosol acetate 4, hydroxytyrosol 7, and the novel one, 3,4-dihydroxyphenyl-2-methoxyethanol 5) showed weak activity against both enzymes (IC₅₀ > 500 μM). Our findings show that, first, the esterification of C-1 of the furofuran ring is the key feature for the stronger activity of 1-acetoxypinoresinol 3 against both enzymes (IC₅₀ = 13.9 and 313 μM for α-amylase and α-glucosidase, respectively), as compared to pinoresinol; second, the oleanane skeletons of the triterpenes (1 and 2) are optimum for the α-glucosidase and α-amylase inhibitory activities, while the hydroxytyrosol moiety may be responsible for the weak activities of 4, 5, and 7. Additionally, kinetics analysis of 1, 6, and 3 revealed that they inhibit α-glucosidase in mixed-type, noncompetitive, and uncompetitive mechanisms, respectively. We confirmed their mechanisms by measuring their affinity for the enzyme (K _i), and they all (1, 6, and 3) had a higher affinity for the enzyme, K _i > 1. This work adds more value to OMW for further studies as a potential source of lead antidiabetic compounds for the prevention and/or treatment of type 2 diabetes.