Nepeta angustifolia attenuates responses to vascular inflammation in high glucose-induced human umbilical vein endothelial cells through heme oxygenase-1 induction

Advances in the pharmacological study of Chinese herbal medicine to alleviate diabetic nephropathy by improving mitochondrial oxidative stress

Diabetic nephropathy (DN) is one of the serious complications of diabetes mellitus, primarily arising from type 2 diabetes (T2DM), and can progress to chronic kidney disease (CKD) and end stage renal disease (ESRD). The pathogenesis of DN involves various factors such as hemodynamic changes, oxidative stress, inflammatory response, and lipid metabolism disorders. Increasing attention is being given to DN caused by oxidative stress in the mitochondrial pathway, prompting researchers to explore drugs that can regulate these target pathways. Chinese herbal medicine, known for its accessibility, rich historical usage, and remarkable efficacy, has shown promise in ameliorating renal injury caused by DN by modulating oxidative stress in the mitochondrial pathway. This review aims to provide a reference for the prevention and treatment of DN. Firstly, we outline the mechanisms by which mitochondrial dysfunction impairs DN, focusing on outlining the damage to mitochondria by oxidative stress. Subsequently, we describe the process by which formulas, herbs and monomeric compounds protect the kidney by ameliorating oxidative stress in the mitochondrial pathway. Finally, the rich variety of Chinese herbal medicine, combined with modern extraction techniques, has great potential, and as we gradually understand the pathogenesis of DN and research techniques are constantly updated, there will be more and more promising therapeutic targets and herbal drug candidates. This paper aims to provide a reference for the prevention and treatment of DN.

Activation of Nrf2/HO-1 signaling: An important molecular mechanism of herbal medicine in the treatment of atherosclerosis via the protection of vascular endothelial cells from oxidative stress

Introduction

Recently, Nrf2/HO-1 has received extensive attention as the main regulatory pathway of intracellular defense against oxidative stress and is considered an ideal target for alleviating endothelial cell (EC) injury.

Objectives

This paper aimed to summarized the natural monomers/extracts that potentially exert protective effects against oxidative stress in ECs.

Methods

A literature search was carried out regarding our topic with the keywords of “atherosclerosis” or “Nrf2/HO-1” or “vascular endothelial cells” or “oxidative stress” or “Herbal medicine” or “natural products” or “natural extracts” or “natural compounds” or “traditional Chinese medicines” based on classic books of herbal medicine and scientific databases including Pubmed, SciFinder, Scopus, the Web of Science, GoogleScholar, BaiduScholar, and others. Then, we analyzed the possible molecular mechanisms for different types of natural compounds in the treatment of atherosclerosis via the protection of vascular endothelial cells from oxidative stress. In addition, perspectives for possible future studies are discussed.

Results

These agents with protective effects against oxidative stress in ECs mainly include phenylpropanoids, flavonoids, terpenoids, and alkaloids. Most of these agents alleviate cell apoptosis in ECs due to oxidative stress, and the mechanisms are related to Nrf2/HO-1 signaling activation. However, despite continued progress in research on various aspects of natural agents exerting protective effects against EC injury by activating Nrf2/HO-1 signaling, the development of new drugs for the treatment of atherosclerosis (AS) and other CVDs based on these agents will require more detailed preclinical and clinical studies.

Conclusion

Our present paper provides updated information of natural agents with protective activities on ECs against oxidative stress by activating Nrf2/HO-1. We hope this review will provide some directions for the further development of novel candidate drugs from natural agents for the treatment of AS and other CVDs.

Mitochondrial Targeting of Herbal Medicine in Chronic Kidney Disease

Chronic kidney disease (CKD) is a common progressive disease that is typically characterized by the permanent loss of nephrons and an eventual decline in glomerular filtration rate. CKD increases mortality and has a significant impact on the quality of life and the economy, which is becoming a major public health issue worldwide. Since current conventional-medicine treatment options for CKD are not satisfactory, many patients seek complementary and alternative medicine treatments including Traditional Chinese Medicine. Herbal medicine is often used to relieve symptoms of renal diseases in the clinic. The kidney is abundant in the number of mitochondria, which provide enough energy for renal function and metabolism. In recent years, a vital role for mitochondrial dysfunction has been suggested in CKD. Mitochondria have become a new target for the treatment of diseases. A growing number of studies have demonstrated herbal medicine could restore mitochondrial function and alleviate renal injury both in vivo and in vitro. In this review, we sum up the therapeutic effect of herbal medicine in CKD via targeting mitochondrial function. This implies future strategies in preventing CKD.

The genus Nepeta: Traditional uses, phytochemicals and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Nepeta is a multiregional genus of the "Lamiaceae" (Labiatae or Mint) family. Species of Nepeta are a valuable part of traditional medicine and used extensively, particularly in the Himalayan region of India (Uttarakhand, Himachal Pradesh, Jammu and Kashmir, Leh-Ladakh), Pakistan (Khyber Pakhtunkhwaand Pakistani Kashmir), Nepal (Baglund district), also in China and hilly regions of Turkey and Iran. Nepeta species are extensively used as a remedy against a variety of ailments and conditions like chicken pox, tuberculosis, malaria, pneumonia, influenza, measles, stomach disorders, eye complaints, respiratory disorders, asthma, colds, coughs etc. AIM OF THE REVIEW: The main aim of this review is to present a comprehensive and detailed study on traditional uses, pharmacology, phytochemistry, toxicology of Nepeta species and suggest future direction on the design and conduct of various preparations, either alone or in blends with prevailing conventional remedies. The review also emphasizes encouraging researchers towards the wide range of pharmaceutical applications of the various species of Nepeta for their better use and exploration in the future.

MATERIAL AND METHODS

All the relevant data and information on different species of Nepeta were assembled using different databases, such as Science Direct, Springer, PubMed, Taylor and Francis imprints, Chemspider, Google scholar, review and research articles from peer-reviewed journals and unpublished data. Some select 'grey literature' sources viz. ethnobotanical books, chapters, Wikipedia and webpages were also studied.

RESULTS

A variety of bioactive secondary metabolites and nutraceuticals has been isolated from various species of Nepeta. These bioactive compounds belong to different classes of secondary metabolites, such as phenolic acids and their glycosides (rosmarinic acid, gallic acid, caffeic acid), flavonoids and their glycosides (cirsimaritin, salvigenin, luteolin, apigenin), iridoids (nepetalactones and their derivatives), terpenoids (1,8-cineole, linalool, β-caryophyllene, germacrene D, parnapimaro, β-amyrin, oleanolic acid, ursolic acid), steroids (β-sitosterol, stigmasterol), lignans, amino acids, carbohydrates, volatile oils, etc. The species of the genus Nepeta possess a variety of pharmacological activities namely anti-inflammatory, anti-nociceptive, anti-alzheimer, anticancer and cytotoxic, antioxidant, immunomodulatory, antimicrobial, antifungal, insecticidal and along with other biological activities.

CONCLUSION

The species of the genus Nepeta contains a rich source of various bioactive compounds, which are well tolerated as traditional medicines. In fact, different species of Nepeta are widely used in a variety of traditional medicinal systems all around the world. Owing to the variety of pharmacological properties of Nepeta species, more comprehensive and inclusive clinical trials are necessary for the utilization of different Nepeta species against the treatment of a wide range of ailments. There are also various other uses such as food, cosmetic and agriculture that can be investigated or explored in future. Some of the major domains that can be explored within this genus are the investigation of different species for their unexplored biological potential, isolation and characterization of new bioactive constituents and finally, investigation of new applications and possible commercialization of these bioactive leads. No doubt, there are various viable research domains outside those discussed above, but presently for the purposes of this review we will only emphasize the activities herein.

Mitochondrial Dysfunction and Diabetic Nephropathy: Nontraditional Therapeutic Opportunities

Diabetic nephropathy (DN) is a progressive microvascular diabetic complication. Growing evidence shows that persistent mitochondrial dysfunction contributes to the progression of renal diseases, including DN, as it alters mitochondrial homeostasis and, in turn, affects normal kidney function. Pharmacological regulation of mitochondrial networking is a promising therapeutic strategy for preventing and restoring renal function in DN. In this review, we have surveyed recent advances in elucidating the mitochondrial networking and signaling pathways in physiological and pathological contexts. Additionally, we have considered the contributions of nontraditional therapy that ameliorate mitochondrial dysfunction and discussed their molecular mechanism, highlighting the potential value of nontraditional therapies, such as herbal medicine and lifestyle interventions, in therapeutic interventions for DN. The generation of new insights using mitochondrial networking will facilitate further investigations on nontraditional therapies for DN.

Salviplenoid A from Salvia plebeia attenuates acute lung inflammation via modulating NF-κB and Nrf2 signaling pathways

Acute lung injury (ALI) involves series of inflammatory pathologies and cause high morbidity. Salviplenoid A (SA) was a new sesquiterpenoid from the traditional inflammatory herb Salvia plebeia. In our previous study, SA exhibited antiinflammatory activity in RAW264.7 cells. However, the extensive effects of SA in human cells and in vivo and the active mechanisms are unclear. Thus, in this study, we sought to access its effects in vitro and in vivo and to investigate its mechanisms. SA was proved to inhibit the induction of proinflammatory cytokines in human cell types, including pulmonary epithelial cells and endothetial cells. It also depressed monocyte adhesion. Moreover, SA potently attenuated the acute lung inflammation in the LPS-induced mouse model shown by down-regulation of proinflammatory mediators, inhibition of polymorphonuclear neutrophil infiltration, and alleviation of related symptoms like alveolar congestion and mucus secretion. Further evaluation confirmed that SA regulated NF-κB pathway by inhibiting the IκB-α phosphorylation. And it markedly mediated Nrf2/HO-1 pathway by activating the Nrf2/HO-1 expression and promoting Nrf2 nuclear translocation. Therefore, SA could attenuate acute lung inflammation via suppressing NF-κB and activating Nrf2, which provide a theoretical basis for the potential application of SA in clinic.

Nepeta angustifolia C. Y. Wu improves renal injury in HFD/STZ-induced diabetic nephropathy and inhibits oxidative stress-induced apoptosis of mesangial cells

ETHNOPHARMACOLOGICAL RELEVANCE

As an important medicinal material constituting a variety of traditional Chinese medicine prescriptions, Nepeta angustifolia C. Y. Wu was used as a folk medicine to treat various vascular-related diseases including apoplexia, and cerebral haemorrhage in Tibet, China. Our previous studies have shown that this plant had a significant protective effect on vascular dysfunction of the intracerebral haemorrhage and diabetic rats. In present study, we aimed to investigate the protective effects and underlying mechanisms of Nepeta angustifolia on diabetic nephropathy (DN), a microvascular complication.

AIM OF THE STUDY

This study is aim to evaluate the protective effect of ethanol extracts of N. angustifolia (NA) on DN, and explore mechanism of action to provide basis for its pharmacological action against DN.

MATERIALS AND METHODS

High-fat diet and low-dose streptozotocin administration (HFD/STZ) induced diabetic rats were randomly divided into 5 groups (n = 8): the diabetic model group, metformin group, and three dose groups of NA (60 mg/kg, 120 mg/kg, 240 mg/kg). After administration of NA for 8 weeks, the blood, urine and renal tissue were collected for subsequent experiments. Biochemical markers (urine protein, Cr, BUN), oxidative stress makers (SOD, GSH-px and MDA) and pro-inflammatory mediators (TNF-α, IL-1β, IL-6 and MCP-1) were evaluated by commercial kit and ELISA, respectively. The effect of NA on DN was further confirmed by evaluation of renal histopathology by using the H&E, PAS and Masson staining. The H₂O₂-induced HBZY-1 cells (rat glomerular mesangial cells) were also been used to evaluate the renal protective effect of NA (50 μg/mL, 100 μg/mL, 200 μg/mL). The oxidative stress makers were detected by commercial kit. The levels of apoptosis and related proteins (caspase 3, 9) were detected by TUNEL assay and western blot analysis, respectively. The depolarization of mitochondrial membrane potential was detected by JC-1 staining assay.

RESULTS

The administration of NA is helpful to maintain near normal body weight, blood glucose, urine volume, urine protein, kidney index and serum levels of Cr and BUN. NA treatment significantly improve renal dysfunction by the down-regulation of renal oxidative stress and pro-inflammatory mediators in HFD/STZ induced diabetic rats. In vitro experiments, NA has a significant cellular protective effect in H₂O₂-induced HBZY-1 cells, as well as the regulation in increases of SOD level and the decreases of ROS and MDA levels. Furthermore, NA treatment can significantly inhibit H₂O₂ induced mesangial cells apoptosis by the increasing mitochondrial potential and suppressing caspases-madiated signaling pathway.

CONCLUSIONS

NA has obvious improvement on renal dysfunction in HFD/STZ induced diabetic rats. NA can protect mesangial cells by inhibiting oxidative stress induced apoptosis, which may be related to its regulation of mitochondrial-caspase apoptosis pathway.

Phytochemical and biological investigations on two Nepeta species: Nepeta heliotropifolia and N. congesta subsp. cryptantha

In the present study, the essential oil and aroma compositions of Nepeta heliotropifolia (NH) and N. congesta subsp. cryptantha (NC) were determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC/FID), and their phenolic compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, antioxidant, cytotoxic, anticholinesterase, urease, and tyrosinase activities of essential oils obtained from NH and NC aerial parts and ethanol extracts prepared from different parts of NH and NC were investigated. The major constituent of water-distilled essential oils was found to be germacrene D (36.7% and 38.5%, respectively), and their main aroma component was eucalyptol (48.0% and 24.7%, respectively). Among the studied parts of NH and NC, their flowers extracts were found to be the richest in phenolic compounds and in which the most abundant compound was rosmarinic acid (8,909.91 and 4,317.20 μg/g, respectively). NH and NC flower extracts exhibited also strong antioxidant activity in DPPH, ABTS, and CUPRAC assays. Among the tested samples, NH essential oil indicated the best cytotoxic effect against PDF, HT-29, and MCF-7 (IC₅₀ 52.34, 25.89, and 44.70 μg/ml, respectively), and the highest butyrylcholinesterase (77.21 ± 1.12% inhibition) and moderate acetylcholinesterase (41.36 ± 0.69% inhibition) inhibitory activities. PRACTICAL APPLICATIONS: This is the first report on the essential oil and aroma compositions, the phenolic compounds, the antioxidant with total phenolic and flavonoid contents, cytotoxic, anticholinesterase, urease, and tyrosinase activities of Nepeta heliotropifolia and N. congesta subsp. cryptantha, except for their essential oil compositions. The reported results suggested that Nepeta heliotropifolia and N. congesta subsp. cryptantha flowers being rich in rosmarinic acid and having strong antioxidant potential, and NH essential oil possessing significant cytotoxic and butyrylcholinesterase inhibitory effect could be source for nutraceutical, food, and drug industries.