Hypolipidaemic and Insulin Secretagogue Activities of (R)-(-)-Carvone

Molecular Mechanisms Underlying the Anti-Inflammatory Properties of (R)-(-)-Carvone: Potential Roles of JNK1, Nrf2 and NF-κB

To explore the molecular mechanisms underlying the anti-inflammatory activity of (R)-(-)-carvone, we evaluated its ability to inhibit the signaling pathways involving the mitogen-activated protein kinases (MAPKs) and the transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). (R)-(-)-carvone significantly decreased c-Jun N-terminal kinase (JNK) 1phosphorylation, but not that of the other MAPKs, induced by bacterial lipopolysaccharides (LPS) in the RAW 264.7 macrophage cell line. Although (R)-(-)-carvone significantly inhibited resynthesis of the inhibitor of NF-κB (IκB)-α induced by LPS, it did not interfere with the canonical NF-κB activation pathway, suggesting that it may interfere with its transcriptional activity. (R)-(-)-carvone also showed a tendency to decrease the levels of acetylated NF-κB/p65 in the nucleus, without affecting the activity and protein levels of Sirtuin-1, the major NF-κB/p65 deacetylating enzyme. Interestingly, the nuclear protein levels of the transcription factor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and the expression of its target,, heme oxygenase-1 (HO-1), an antioxidant enzyme, also showed a tendency to increase in the presence of (R)-(-)-carvone. Taken together, these results suggest that the ability of (R)-(-)-carvone to inhibit JNK1 and to activate Nrf2 can underlie its capacity to inhibit the transcriptional activity of NF-κB and the expression of its target genes. This study highlights the diversity of molecular mechanisms that can be involved in the anti-inflammatory activity of monoterpenes.

Antidiabetic effects of Eryngium billardieri hydrosol in the treatment of type 2 diabetic patients: A double-blind randomized clinical trial

Objective

Medicinal plants with fewer side effects and low cost than synthetic medicines are increasingly advised to treat diseases. The present study aimed to identify Eryngium billardieri compounds and evaluate the plant's effects on hyperglycemic and hyperlipidemia indices, and liver, and kidney function.

Materials and Methods

Following identification of Eryngium billardieri using GC/MS method, 72 participants were randomly divided into two groups (n=36 per group), receiving oral hypoglycemic medication (metformin) with or without 50 ml hydrosol twice a day for three months as intervention and placebo control, respectively. Body mass index (BMI), systolic and diastolic blood pressure, fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c), total cholesterol, triglyceride, HDL-C, and LDL-C levels were measured at the beginning and end of the experiment. Also, aspartate transaminase, alanine transaminase, blood urea nitrogen, and creatinine levels were measured to assess adverse effects on liver and kidney functions.

Results

The main components were terpenes with 46.69% of the total ingredients of E. billardieri essential oil. Other prominent compounds identified included octanoic acid (12.14 %) and isoxazole (6.72 %). Intergroup changes in blood parameters showed that E. billardieri hydrosol for three months could significantly reduce HbA1C and blood cholesterol levels but did not affect other measured parameters. Also, there were no adverse effects on kidney or liver function.

Conclusion

The present findings showed that the consumption of 50 ml of E. billardieri hydrosol as a complementary treatment in diabetic patients reduced HbA1C and cholesterol levels without adverse effects on the liver or kidneys functions.

Advocacy for the Medicinal Plant Artabotrys hexapetalus (Yingzhao) and Antimalarial Yingzhaosu Endoperoxides

The medicinal plant Artabotrys hexapetalus (synonyms: A.uncinatus and A. odoratissimus) is known as yingzhao in Chinese. Extracts of the plant have long been used in Asian folk medicine to treat various symptoms and diseases, including fevers, microbial infections, ulcers, hepatic disorders and other health problems. In particular, extracts from the roots and fruits of the plant are used for treating malaria. Numerous bioactive natural products have been isolated from the plant, mainly aporphine (artabonatines, artacinatine) and benzylisoquinoline (hexapetalines) alkaloids, terpenoids (artaboterpenoids), flavonoids (artabotrysides), butanolides (uncinine, artapetalins) and a small series of endoperoxides known as yingzhaosu A-to-D. These natural products confer antioxidant, anti-inflammatory and antiproliferative properties to the plant extracts. The lead compound yingzhaosu A displays marked activities against the malaria parasites Plasmodium falciparum and P. berghei. Total syntheses have been developed to access yingzhaosu compounds and analogues, such as the potent compound C14-epi-yingzhaosu A and simpler molecules with a dioxane unit. The mechanism of action of yingzhaosu A points to an iron(II)-induced degradation leading to the formation of two alkylating species, an unsaturated ketone and a cyclohexyl radical, which can then react with vital parasitic proteins. A bioreductive activation of yingzhaosu A endoperoxide can also occur with the heme iron complex. The mechanism of action of yingzhaosu endoperoxides is discussed, to promote further chemical and pharmacological studies of these neglected, but highly interesting bioactive compounds. Yingzhaosu A/C represent useful templates for designing novel antimalarial drugs.