Evaluation of polyherbal formulation (SJT-HT-03) for antihypertensive activity in albino rats

PhytoSelectDBT: A database for the molecular models of anti-diabetic targets docked with bioactive peptides from selected ethno-medicinal plants

It is of interest to assess the effectiveness of bioactive peptides derived from 41 ethno-medicinal plants, classify them according to their anti-diabetic protein targets (DPP-IV, alpha-amylase, alpha-glucosidase, GRK2, GSK3B, GLP-1R, and AdipoR1), and create a web tool named PhytoSelectDBT by using the top seven peptides per target. If one of the target-based medicinal plant suggestions made by PhytoSelectDBT is unsuccessful, alternative target-based possibilities are presented by PhytoSelectDBT for treating the condition and any other related complications. The results provide a useful resource for the management of type 2 diabetes and emphasize the significance of utilising ethnomedical knowledge for the identification of potent anti-diabetic plants and their peptides. We used molecular docking to investigate interactions between anti-diabetic targets (DPP-IV, alpha-amylase, alpha-glucosidase, GRK2, GSK3B, GLP-1R, and AdipoR1) and projected bioactive peptides from 41 ethnomedicinal plants. All bioactive peptides were cross-checked against several databases to determine their allergenicity, toxicity, and cross-reactivity. The presence of B and T cell epitopes was also examined in all simulated digested bioactive peptides for reference. This data is archived at the PhytoselectDBT database.

Chromatographic Techniques and Pharmacological Analysis as a Quality Control Strategy for Serjania triquetra a Traditional Medicinal Plant

Serjania triquetra is a medicinal plant widely used in traditional medicine for the treatment of urinary tract diseases, renal affections, and its complications. The population can buy this plant in folk markets as a raw material mixed with several herbal remedies or as a health supplement. On the market, two commercial presentations were found for the vegetal material; one had a bulk appearance and the other was marketed wrapped in cellophane bags (HESt-2, HESt-3). Nevertheless, the plant has not been exhaustively investigated and quality control techniques have not been developed. This research aimed to realize a phytochemical study using an authentic, freshly collected sample as a reference for S. triquetra (HESt-1), using the compounds identified. A method for the determination of preliminary chromatographic fingerprinting was developed. Additionally, the vasorelaxant effect from three samples was evaluated with ex vivo rat models. Thus, three hydroalcoholic extracts (HESt-1, HESt-2, and HESt-3) were prepared by maceration. A total of nine compounds were fully identified from HESt-1 after the extract was subjected to open-column chromatography. Seven metabolites were detected by gas chromatography, while ursolic acid (UA) and allantoin were isolated and identified using UPLC-MS and NMR, respectively. Three extracts were analyzed for their chromatographic fingerprint by UPLC-MS. Biological activity was explored by ex vivo rat aorta ring model to evaluate vasorelaxant activity. All extracts showed a vasorelaxant effect in a concentration-dependent and endothelium-dependent manner. S. triquetra vascular activity may be attributed to UA and allantoin compounds previously described in the literature for this activity.

Angiotensin-converting enzyme inhibitors from plants: A review of their diversity, modes of action, prospects, and concerns in the management of diabetes-centric complications

Angiotensin-converting enzyme (ACE) inhibitors are antihypertensive medications often used in the treatment of diabetes-related complications. Synthetic ACE inhibitors are known to cause serious side effects like hypotension, renal insufficiency, and hyperkalaemia. Therefore, there has been an intensifying search for natural ACE inhibitors. Many plants or plant-based extracts are known to possess ACE-inhibitory activity. In this review, articles focusing on the natural ACE inhibitors extracted from plants were retrieved from databases like Google Scholar, PubMed, Scopus, and Web of Science. We have found more than 50 plant species with ACE-inhibitory activity. Among them, Angelica keiskei, Momordica charantia, Muntingia calabura, Prunus domestica, and Peperomia pellucida were the most potent, showing comparatively lower half-maximal inhibitory concentration values. Among the bioactive metabolites, peptides (e.g., Tyr-Glu-Pro, Met-Arg-Trp, and Gln-Phe-Tyr-Ala-Val), phenolics (e.g., cyanidin-3-O-sambubioside and delphinidin-3-O-sambubioside), flavonoids ([-]-epicatechin, astilbin, and eupatorin), terpenoids (ursolic acid and oleanolic acid) and alkaloids (berberine and harmaline) isolated from several plant and fungus species were found to possess significant ACE-inhibitory activity. These were also known to possess promising antioxidant, antidiabetic, antihyperlipidemic and anti-inflammatory activities. Considering the minimal side effects and lower toxicity of herbal compounds, development of antihypertensive drugs from these plant extracts or phytocompounds for the treatment of diabetes-associated complications is an important endeavour. This review, therefore, focuses on the ACE inhibitors extracted from different plant sources, their possible mechanisms of action, present status, and any safety concerns.

Effects of firibastat in combination with enalapril and hydrochlorothiazide on blood pressure and vasopressin release in hypertensive DOCA-salt rats

In the brain, aminopeptidase A (APA) generates angiotensin III, one of the effector peptides of the brain renin-angiotensin system (RAS), exerting tonic stimulatory control over blood pressure (BP) in hypertensive rats. Oral administration of firibastat, an APA inhibitor prodrug, in hypertensive rats, inhibits brain APA activity, blocks brain angiotensin III formation and decreases BP. In this study, we evaluated the efficacy of firibastat in combination with enalapril, an angiotensin I-converting enzyme inhibitor, and hydrochlorothiazide (HCTZ), in conscious hypertensive deoxycorticosterone acetate (DOCA)-salt rats, which display high plasma arginine-vasopressin levels, low circulating renin levels and resistance to treatment by systemic RAS blockers. We determined mean arterial BP, heart rate, plasma arginine-vasopressin levels and renin activity in DOCA-salt rats orally treated with firibastat, enalapril or HCTZ administered alone or in combination. Acute oral firibastat administration (30 mg/kg) induced a significant decrease in BP, whereas enalapril (10 mg/kg) or HCTZ (10 mg/kg) administered alone induced no significant change in BP in conscious DOCA-salt rats. The BP decrease induced by acute and nine-day chronic tritherapy [Firibastat+Enalapril+HCTZ] was significantly greater than that observed after bitherapy [Enalapril+HCTZ]. Interestingly, the chronic administration of a combination of firibastat with [Enalapril+HCTZ] reduced plasma arginine-vasopressin levels by 62% relative to those measured in DOCA-salt rats receiving bitherapy. Our data show that tritherapy with firibastat, enalapril and HCTZ improves BP control and arginine-vasopressin release in an experimental salt-dependent model of hypertension, paving the way for the development of new treatments for patients with currently difficult-to-treat or resistant hypertension.

Medicinal plants used for hypertension treatment by folk healers in Songkhla province, Thailand

ETHNOPHARMACOLOGICAL RELEVANCE

Hypertension is the most dominant risk factor for the development of cardiovascular, kidney, and eye diseases. In Thailand, illness and hospitalisation in the modern public health system due to high blood pressure is increasing. However, some Thai people have turned their attention to the use of herbal medicines for healthcare. Therefore, this study aimed (1) to study the folk knowledge of hypertension treatment and (2) to study plant utilisation in the treatment of high blood pressure by Songkhla folk healers.

MATERIALS AND METHODS

Field surveys and semi-structured interviews about theories of disease, principles of healing, and herbal usage (plant species, parts used, preparation, and application methods) were gathered. The data were analysed by descriptive statistics. The literatures regarding medicinal plants used in any traditional medicine, antihypertension activity, and toxicity was reviewed.

RESULTS

Most healers believed that hypertension was caused by the disorder of fire and wind elements in the body. The medicinal plants containing hot and mild tastes, which had the potential for treating problems in the wind element, were applied. A total of 62 species were used for hypertension treatment. Most plants were in the Asteraceae, Piperaceae, Rutaceae, or Zingiberaceae family (4 species each). Herbal medicines were preferred to be prepared by boiling (78%) and consumed by drinking 1 teacup before 3 meals each day (26%). Piper retrofractum and Cleome viscosa had the greatest Frequency of Citation (FC = 6, n = 14). Thirty-seven species have been reported for use in traditional medicine. Twenty-four and 46 species have already been investigated for antihypertension activity and toxicity, respectively.

CONCLUSION

Identifying medicinal plants that have been tested by experienced folk doctors would provide an opportunity for people to choose and consume local herbs that are easy to access in their local area. However, the remaining plants that have not been studied for antihypertension activity and toxicity should be further analysed to confirm their efficacy.

Molecular understanding of the protective role of natural products on isoproterenol-induced myocardial infarction: A review

Modern medicine has been used to treat myocardial infarction, a subset of cardiovascular diseases, and have been relatively effective but not without adverse effects. Consequently, this issue has stimulated interest in the use of natural products, which may be equally effective and better tolerated. Many studies have investigated the cardioprotective effect of natural products, such as plant-derived phytochemicals, against isoproterenol (ISO)-induced myocardial damage; these have produced promising results on the basis of their antioxidant, anti-atherosclerotic, anti-apoptotic and anti-inflammatory activities. This review briefly introduces the pathophysiology of myocardial infarction (MI) and then addresses the progress of natural product research towards its treatment. We highlight the promising applications and mechanisms of action of plant extracts, phytochemicals and polyherbal formulations towards the treatment of ISO-induced myocardial damage. Most of the products displayed elevated antioxidant levels with decreased oxidative stress and lipid peroxidation, along with restoration of ionic balance and lowered expression of myocardial injury markers, pro-inflammatory cytokines, and apoptotic parameters. Likewise, lipid profiles were positively altered and histopathological improvements could be seen from, for example, the better membrane integrity, decreased necrosis, edema, infarct size, and leukocyte infiltration. This review highlights promising results towards the amelioration of ISO-induced myocardial damage, which suggest the direction for future research on natural products that could be used to treat MI.