Effect of Antihypertensive Drugs on Cognition and Behavioral Symptoms of Patients with Alzheimer's Disease: A Meta-analysis

BACKGROUND

It has been found that there is a link between hypertension and elevated risk of Alzheimer's Disease (AD). Herein, a meta-analysis based on Randomized Clinical Trials (RCTs) was used to assess the effect of antihypertensive drugs on cognition and behavioral symptoms of AD patients.

METHODS

The three databases, PubMed/Medline, Scopus, and Cochrane Library, were searched up to March 2020. The quality of the studies included in the meta-analysis was evaluated by the Jadad score. Clinical Global Impression of Change (CGIC) included in two studies, Mini-Mental State Examination (MMSE) included in three studies, and Neuropsychiatric Inventory (NPI) in three studies were the main outcomes in this systematic review.

RESULTS

Out of 1506 studies retrieved in the databases, 5 RCTs were included and analyzed in the meta-analysis. The pooled mean differences of CGIC, MMSE, and NPI in patients with AD receiving antihypertensive drugs compared to placebo were -1.76 with (95% CI = -2.66 to -0.86; P=0.0001), 0.74 (95% CI = 0.20 to 1.28; P= 0.007), and -9.49 (95% CI = -19.76 to 0.79; P = 0.07), respectively.

CONCLUSION

The findings of the present meta-analysis show that antihypertensive drugs may improve cognition and behavioral symptoms of patients with AD. However, more well-designed RCTs with similar drugs are needed to achieve more conclusive results.

Ginger and Heart Health: From Mechanisms to Therapeutics

BACKGROUND

As a major cause of morbidity and mortality, cardiovascular diseases (CVDs) are globally increasing. In spite of recent development in the management of cardiovascular complications, CVDs have remained a medical challenge. Numerous conventional drugs are used to play cardioprotective roles; however, they are associated with several side effects. Considering the rich phytochemistry and fewer side effects of herbal medicines, they have gained particular attention to develop novel herbal drugs with cardioprotective potentials. Amongst natural entities, ginger is an extensively used and well-known functional food and condiment, possessing plentiful bioactivities, like anti-inflammatory, antioxidant, and antimicrobial properties in several disorders management.

OBJECTIVE

The current review deliberated phytochemical properties as well as the ginger/ginger constituents' biological activities and health benefits in several diseases, with particular attention to cardiovascular complications.

METHODS

A comprehensive search was conducted using multiple databases, including Scopus, PubMed, Medline, Web of Science, national database (Irandoc and SID), and related articles in terms of the health benefits and cardioprotective effects of ginger/ginger constituents. These data were collected from inception until August 2019.

RESULTS

In recent years, several herbal medicines were used to develop new drugs with more potency and also minor side effects. Amongst natural entities, ginger is used as a traditional medicine in several diseases. The crude extract, along with related pungent active constituents, is mostly attributed to heart health. The cardioprotective effects of ginger are contributed to its cardiotonic, anti- hypertensive, anti-hyperlipidemia, and anti-platelet effects. The signaling pathways and molecular mechanisms of ginger regarding its cardioprotective effects are also clarified.

CONCLUSION

This study revealed the biological activities, health benefits, and cardioprotective properties of ginger/ginger constituents along with related mechanisms of action, which gave new insights to show new avenues in the treatment of CVDs.

Targeting Mitogen-Activated Protein Kinases by Natural Products: A Novel Therapeutic Approach for Inflammatory Bowel Diseases

An increase in the prevalence of Inflammatory Bowel Diseases (IBD) as a multifactorial intestinal chronic inflammation as well as the absence of a certain cure, has created an innovative era in the management of IBD by molecule/pathway-based anti-inflammatory approaches. There are credible documentations that demonstrate Mitogen-Activated Protein Kinases (MAPK) acts as IBD regulator. Upon the activation of MAPK signalling pathway, the transcription and expression of various encoding inflammatory molecules implicated in IBD are altered, thereby exacerbating the inflammation development. The current pharmacological management of IBD, including drug and biological therapies are expensive, possess temporary relief and some adverse effects. In this context, a variety of dietary fruits or medicinal herbs have received worldwide attention versus the development of IBD. Infact, natural ingredients, such as Flavaglines, Fisetin, Myricitrin, Cardamonin, Curcumin, Octacosanol and Mangiferin possess protective and therapeutic effects against IBD via modulation of different segments of MAPK signaling pathway. This review paper calls attention to the role of MAPK signaling triggered by natural products in the prevention and treatment of IBD.

Naringenin and its Nano-formulations for Fatty Liver: Cellular Modes of Action and Clinical Perspective

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease mainly caused by high-fat diets and sudden feed changes, vitamin and energy deficiency, and inflammatory processes. Fatty liver leads to cirrhosis, hepatocellular carcinoma as well as liver failure. Lifestyle-modifying such as weight loss and a healthy diet have an inverse correlation with the risk of fatty liver. The promising effect of a diet rich in vegetables and fruits against fatty liver has been evidenced by several empirical studies focused on flavonoids. Among naturally occurring flavonoids, naringenin is one of the most important flavonoids which can be isolated from some edible fruits, especially citrus species.

METHODS

In the present review, we discuss the effects of naringenin and its nano-formulations against fatty liver disease and the proposed molecular mechanism of action. A large number of studies attributed to naringenin anti-inflammatory, antioxidant and insulin-like actions, as well as different types of effects on sex hormone metabolism and lipid metabolism. Naringenin-loaded nanoparticles have been used to solve the limited stability, solubility, bioavailability and pharmacological activity of naringenin and, consequently, to improve its therapeutic effects.

RESULTS AND DISCUSSION

Naringenin exerts diverse biological actions including the decrease of biomarkers of lipid peroxidation and protein carbonylation, increase of antioxidant defenses, scavenging of reactive oxygen species and modulation of signaling pathways related to fatty acid metabolism which can favor the oxidation of fatty acid, lower lipid accumulation in the liver and thereby prevent fatty liver.

The Protective Effect of Melissa officinalis L. in Visceral Hypersensitivity in Rat Using 2 Models of Acid-induced Colitis and Stress-induced Irritable Bowel Syndrome: A Possible Role of Nitric Oxide Pathway

Background/Aims

The aim of present study is to estimate the effects of Melissa officinalis L. (MO) on visceral hypersensitivity (VH), defecation pattern and biochemical factors in 2 experimental models of irritable bowel syndrome (IBS) and the possible role of nitric oxide.

Methods

Two individual models of IBS were induced in male Wistar-albino rats. In the acetic acid model, the animals were exposed to rectal distension and abdominal withdrawal reflex, and the defecation patterns were determined. In the restraint stress model, the levels of TNF-α, myeloperoxidase, lipid peroxidation, and antioxidant powers were determined in the (removed) colon. Rats had been treated with MO, L-NG-nitroarginine methyl ester (L-NAME), aminoguanidine (AG), MO + AG, or MO + L-NAME in the mentioned experimental models.

Results

Hypersensitive response to rectal distension and more stool defecation in control rats have been observed in comparison to shams. MO-300 significantly reduced VH and defecation frequency in comparison to controls. VH and defecation pattern did not show significant change in AG + MO and L-NAME + MO groups compared to controls. Also, significant reduction in TNF-α, myeloperoxidase, thiobarbituric acid reactive substances (TBARS), and an increase in antioxidant power in MO-300 group was recorded compared to controls. AG + MO and L-NAME + MO groups showed a reverse pattern compared to MO-300 group.

Conclusions

MO can ameliorate IBS by modulating VH and defecation patterns. Antioxidant and anti-inflammatory properties along with its effect on the nitrergic pathway seem to play important roles in its pharmacological activity.

The Role of Visceral Hypersensitivity in Irritable Bowel Syndrome: Pharmacological Targets and Novel Treatments

Irritable bowel syndrome (IBS) is the most common disorder referred to gastroenterologists and is characterized by altered bowel habits, abdominal pain, and bloating. Visceral hypersensitivity (VH) is a multifactorial process that may occur within the peripheral or central nervous systems and plays a principal role in the etiology of IBS symptoms. The pharmacological studies on selective drugs based on targeting specific ligands can provide novel therapies for modulation of persistent visceral hyperalgesia. The current paper reviews the cellular and molecular mechanisms underlying therapeutic targeting for providing future drugs to protect or treat visceroperception and pain sensitization in IBS patients. There are a wide range of mediators and receptors participating in visceral pain perception amongst which substances targeting afferent receptors are attractive sources of novel drugs. Novel therapeutic targets for the management of VH include compounds which alter gut-brain pathways and local neuroimmune pathways. Molecular mediators and receptors participating in pain perception and visceroperception include histamine-1 receptors, serotonin (5-hydrodytryptamine) receptors, transient receptor potential vanilloid type I, tachykinins ligands, opioid receptors, voltage-gated channels, tyrosine receptor kinase receptors, protease-activated receptors, adrenergic system ligands, cannabinoid receptors, sex hormones, and glutamate receptors which are discussed in the current review. Moreover, several plant-derived natural compounds with potential to alleviate VH in IBS have been highlighted. VH has an important role in the pathology and severity of complications in IBS. Therefore, managing VH can remarkably modulate the symptoms of IBS. More preclinical and clinical investigations are needed to provide efficacious and targeted medicines for the management of VH.

The role of dietary polyphenols in the management of inflammatory bowel disease

Inflammatory bowel disease (IBD) is an idiopathic chronic, relapsing inflammation of the bowel which is caused by dysregulation of the mucosal immune system. Polyphenols as the secondary plant metabolites universally present in vegetables and fruits and are the most abundant antioxidants in the human diet. There is evidence demonstrating the beneficial health effects of dietary polyphenols. This review criticizes the potential of commonly used polyphenols including apple polyphenol, bilberry anthocyanin, curcumin, epigallocatechin-3-gallate (EGCG) and green tea polyphenols, naringenin, olive oil polyphenols, pomegranate polyphenols and ellagic acid, quercetin, as well as resveratrol specifically in IBD with an emphasis on cellular mechanisms and pharmaceutical aspects. Scientific research confirmed that dietary polyphenols possess both protective and therapeutic effects in the management of IBD mediated via down-regulation of inflammatory cytokines and enzymes, enhancing antioxidant defense, and suppressing inflammatory pathways and their cellular signaling mechanisms. Further preclinical and clinical studies are needed in order to understand safety, bioavailability and bioefficacy of dietary polyphenols in IBD patients.