Effect Of epigallocatechin-3-gallate on the pharmacokinetics of amlodipine in rats

Cardiovascular Effects of Herbal Products and Their Interaction with Antihypertensive Drugs-Comprehensive Review

Hypertension is a highly prevalent population-level disease that represents an important risk factor for several cardiovascular complications and occupies a leading position in mortality statistics. Antihypertensive therapy includes a wide variety of drugs. Additionally, the potential antihypertensive and cardioprotective effects of several phytotherapy products have been evaluated, as these could also be a valuable therapeutic option for the prevention, improvement or treatment of hypertension and its complications. The present review includes an evaluation of the cardioprotective and antihypertensive effects of garlic, Aloe vera, green tea, Ginkgo biloba, berberine, ginseng, Nigella sativa, Apium graveolens, thyme, cinnamon and ginger, and their possible interactions with antihypertensive drugs. A literature search was undertaken via the PubMed, Google Scholar, Embase and Cochrane databases. Research articles, systematic reviews and meta-analyses published between 2010 and 2023, in the English, Hungarian, and Romanian languages were selected.

Cinnamon modulates the pharmacodynamic & pharmacokinetic of amlodipine in hypertensive rats

The objective of this study was to investigate the effects of cinnamon on the pharmacodynamic (PD) & pharmacokinetic (PK) of amlodipine in hypertensive rats. The hypertensive control group of Wistar rats received L-NAME (40 mg/kg, daily, orally) only. The cinnamon group of rats was treated with cinnamon (200 mg/kg, daily, orally) along with L-NAME. Following 14 days treatment period, blood pressures of rats were monitored at designated intervals over 24 h utilizing a tail-cuff system for measuring blood pressure. To assess the oral PK; amlodipine was administered as a single oral dose of 1 mg/kg to rats and blood samples were collected at specified intervals over 24 h and analysed by UPLC-LC MS/MS. Synergistic decreased in rat's blood pressure was observed in presence of cinnamon + amlodipine. Simultaneous administration of cinnamon ameliorates the Cmax and AUC0-t of amlodipine, the Cmax and AUC0-t was 11.04 ± 1.01 ng/ml and 113.76 ± 5.62 ng h/ml for the cinnamon + amlodipine group as compared to 4.12 ± 0.49 ng/ml and 48.59 ± 4.28 ng h/ml for the amlodipine alone group. The study demonstrates that the use of cinnamon considerably decreases the blood pressure levels and enhances the PK parameters of amlodipine in hypertensive rats.

Alzheimer's Disease and Green Tea: Epigallocatechin-3-Gallate as a Modulator of Inflammation and Oxidative Stress

Alzheimer's disease (AD) is the most common cause of dementia, characterised by a marked decline of both memory and cognition, along with pathophysiological hallmarks including amyloid beta peptide (Aβ) accumulation, tau protein hyperphosphorylation, neuronal loss and inflammation in the brain. Additionally, oxidative stress caused by an imbalance between free radicals and antioxidants is considered one of the main risk factors for AD, since it can result in protein, lipid and nucleic acid damage and exacerbate Aβ and tau pathology. To date, there is a lack of successful pharmacological approaches to cure or even ameliorate the terrible impact of this disease. Due to this, dietary compounds with antioxidative and anti-inflammatory properties acquire special relevance as potential therapeutic agents. In this context, green tea, and its main bioactive compound, epigallocatechin-3-gallate (EGCG), have been targeted as a plausible option for the modulation of AD. Specifically, EGCG acts as an antioxidant by regulating inflammatory processes involved in neurodegeneration such as ferroptosis and microglia-induced cytotoxicity and by inducing signalling pathways related to neuronal survival. Furthermore, it reduces tau hyperphosphorylation and aggregation and promotes the non-amyloidogenic route of APP processing, thus preventing the formation of Aβ and its subsequent accumulation. Taken together, these results suggest that EGCG may be a suitable candidate in the search for potential therapeutic compounds for neurodegenerative disorders involving inflammation and oxidative stress, including Alzheimer's disease.

Possible Side Effects of Polyphenols and Their Interactions with Medicines

Polyphenols are an important component of plant-derived food with a wide spectrum of beneficial effects on human health. For many years, they have aroused great interest, especially due to their antioxidant properties, which are used in the prevention and treatment of many diseases. Unfortunately, as with any chemical substance, depending on the conditions, dose, and interactions with the environment, it is possible for polyphenols to also exert harmful effects. This review presents a comprehensive current state of the knowledge on the negative impact of polyphenols on human health, describing the possible side effects of polyphenol intake, especially in the form of supplements. The review begins with a brief overview of the physiological role of polyphenols and their potential use in disease prevention, followed by the harmful effects of polyphenols which are exerted in particular situations. The individual chapters discuss the consequences of polyphenols’ ability to block iron uptake, which in some subpopulations can be harmful, as well as the possible inhibition of digestive enzymes, inhibition of intestinal microbiota, interactions of polyphenolic compounds with drugs, and impact on hormonal balance. Finally, the prooxidative activity of polyphenols as well as their mutagenic, carcinogenic, and genotoxic effects are presented. According to the authors, there is a need to raise public awareness about the possible side effects of polyphenols supplementation, especially in the case of vulnerable subpopulations.

Herb-drug interaction: Pharmacokinetics and pharmacodynamics of anti-hypertensive drug amlodipine besylate in presence of lepidium sativum and curcuma longa

1. Effects of Lepidium sativum and Curcuma longa were investigated on pharmacokinetics and pharmacodynamics of antihypertensive drug (amlodipine).2. Hypertensive rats were treated with amlodipine, Lepidium sativum, Lepidium sativum + amlodipine, Curcuma longa, and Curcuma longa + amlodipine; and their blood pressures were measured. Amlodipine in plasma samples was analysed using UPLC-TQD. Product ions of amlodipine were monitored at m/z 409.18 > 238 and 409.18 > 294; and of nitrendipine at m/z 361.16 > 315.1 and 361.16 > 329.10.3. Lepidium sativum + amlodipine treatment showed highest reduction in systolic blood pressure (SBP). Mean anti-hypertensive effect of Lepidium sativum and Curcuma longa was similar to amlodipine. Mean SBPs (1-24 h) of amlodipine, Lepidium sativum, Lepidium sativum + amlodipine, Curcuma longa, and Curcuma longa + amlodipine treated animals were found as 149.5 ± 2.4 mmHg, 151.6 ± 1.09 mmHg, and 141.8 ± 2.5 mmHg, 154.9 ± 2.2 mmHg and 144.4 ± 2.6 mmHg (p-values ≪0.05); respectively. Lepidium sativum and Curcuma longa significantly increased amlodipine C_max by 83% (p-value 0.018) and 53% (p-value 0.035); and AUC_0-t by 48% (p-value >0.05) and 56% (p-value 0.033); respectively.4. Results of pharmacokinetic and pharmacodynamic studies are in agreement. Lepidium sativum and Curcuma longa augment antihypertensive effect of amlodipine, which is also supported by pharmacokinetic observations.

Effect of Hibiscus sabdariffa and Zingiber officinale on pharmacokinetics and pharmacodynamics of amlodipine

OBJECTIVES

To study the effect of Zingiber officinale and Hibiscus sabdariffa on pharmacokinetics and pharmacodynamics of amlodipine.

METHODS

Hypertension was induced in rats (SBP 173.2 ± 1.7 mmHg, mean, 1-24 h). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and heart rate (HR) of group-I (amlodipine treated), group-II (Z. officinale, and Z. officinale + amlodipine) and group-III (H. sabdariffa, and H. sabdariffa + amlodipine) animals were measured by "tail-cuff system". Pharmacokinetics of amlodipine with and without herbs (Z. officinale or H. sabdariffa) was also investigated.

RESULTS

Z. officinale as well as H. sabdariffa decreased the SBP, DBP and MBP. Concurrent treatment with Z. officinale + amlodipine (SBP 129.4 ± 4.5) or H. sabdariffa + amlodipine (SBP 130.4 ± 3.9) showed higher decrease in BP (mean, 1-24h), than individually administered amlodipine (SBP 149.5 ± 2.4) or Z. officinale (SBP 150.2 ± 3.1) or H. sabdariffa (SBP 139.1 ± 1.2). These herbs also influenced the Cmax, AUC0-t, and Tmax of amlodipine. H. sabdariffa increased AUC0-t of amlodipine from 81.8 ± 14.7 to 125.0 ± 10.6 (ng h/mL).

CONCLUSION

Simultaneous administration of Z. officinale or H. sabdariffa with amlodipine, improves its pharmacodynamic response.

Effects of curcumin on the pharmacokinetics of amlodipine in rats and its potential mechanism

Context: Hyperlipidaemia and hypertension are often treated together with curcumin and amlodipine. It is necessary to investigate the drug-drug interaction between curcumin and amlodipine.Objective: The interaction between curcumin and amlodipine was investigated in rats and with rat liver microsomes.Methods: The pharmacokinetics of amlodipine (1 mg/kg) was investigated in rats with or without curcumin pre-treatment (2 mg/kg), six rats in each group. The metabolic stability of amlodipine was investigated with rat liver microsomes.Results: Curcumin significantly increased the C_max (26.19 ± 2.21 versus 17.80 ± 1.56 μg/L), AUC_(0-t) (507.27 ± 60.23 versus 238.68 ± 45.59 μg·h/L), and t_1/2 (14.69 ± 1.64 versus 11.43 ± 1.20 h) of amlodipine (p < 0.05). The metabolic stability of amlodipine was significantly increased with the half-life time in rat liver microsomes increased from 34.23 ± 3.33 to 44.15 ± 4.12 min, and the intrinsic rate decreased from 40.49 ± 3.26 to 31.39 ± 2.78 μL/min/mg protein.Discussion and conclusions: These results indicated that drug-drug interaction might appear during the co-administration of curcumin and amlodipine. The potential mechanism may be due to the inhibition of CYP3A4 by curcumin. Thus, this interaction should be given special attention in the clinic and needs further experiments to characterize the effect in humans.

Effect of Nigella sativa and Fenugreek on the Pharmacokinetics and Pharmacodynamics of Amlodipine in Hypertensive Rats

BACKGROUND

The present article is related to in-vitro and in-vivo herb-drug interaction studies.

OBJECTIVES

This study aimed to investigate the effect of Nigella sativa and fenugreek on the pharmacodynamics and pharmacokinetics of amlodipine.

METHOD

Hypertensive rats of group-I were treated with amlodipine and rats of group-II and III were treated with N. sativa, and N. sativa + amlodipine and fenugreek, and fenugreek + amlodipine, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP) of group-I, II and III rats were measured by the "tail-cuff system".

RESULTS

N. sativa, as well as fenugreek, reduced the SBP, DBP and MBP. Simultaneously, administration of fenugreek + amlodipine or N. sativa + amlodipine showed better control of BP. Individually, fenugreek, as well as N. sativa, showed a surprising reduction in the heart rate. There was no remarkable effect of any of these two herbs on Cmax, AUC0-t, Kel, and terminal elimination half-life of amlodipine, but fenugreek altered the Tmax of amlodipine significantly, from 2 ± 1.2h in control to 7.2 ± 1.7h in fenugreek treated group, probably by delaying the absorption.

CONCLUSION

Results of pharmacodynamics and pharmacokinetics studies suggested that simultaneous administration of fenugreek or N. sativa with amlodipine improved the pharmacological response of amlodipine in hypertensive rats, though there was no remarkable change in pharmacokinetic parameters (Cmax, Kel, elimination t1/2, and AUC0-t).