Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy.

Nearly four years after its first appearance, and having gone from pandemic to endemic, the SARS-CoV-2 remains out of control globally. The purpose of this study was to evaluate the clinical efficacy of vitamin D (VD) in COVID-19 and long COVID-19, explain the discrepancy in clinical outcomes and highlight the potential impact of metformin on VD efficacy in recent articles. Articles from January 2022 to August 2023 were selected for this review. The objective of this study was achieved by reviewing, analyzing, and discussing articles demonstrating (1) the mechanism of action of VD (2) observational or randomized clinical trials (RCTs) that support or not the beneficial clinical effects of VD in COVID-19 or long COVID. (3) genetic and non-genetic reasons for the variation in the effects of VD. Articles were collected from electronic databases such as PubMed, Scopus, MEDLINE, Google Scholar, Egyptian Knowledge Bank, Science Direct, and Cochrane Database of Systematic Reviews. Twenty three studies conducted in vitro or in animal models indicated that VD may act in COVID-19 through protecting the respiratory system by antimicrobial peptide cathelicidins, reducing lung inflammation, regulating innate and adaptive immune functions and up regulation of autophagy gene activity. Our review identified 58 clinical studies that met the criteria. The number of publications supporting a beneficial clinical activity of VD in treating COVID-19 was 49 (86%), including 12 meta-analyses. Although the total patients included in all articles was 14,071,273, patients included in publications supporting a beneficial role of VD in COVID-19 were 14,029,411 (99.7%). Collectively, extensive observational studies indicated a decisive relationship between low VD levels and the severity of COVID-19 and mortality outcomes. Importantly, evidence from intervention studies has demonstrated the effectiveness of VD supplements in treating COVID-19. Furthermore, the results of 4 observational studies supported the beneficial role of VD in alleviating symptoms of long COVID-19 disease. However, eight RCTs and one meta-analysis of RCTs may contain low-grade evidence against a beneficial role of VD in COVID-19. Twenty-five articles have addressed the association between VDR and DBP genetic polymorphisms and treatment failure of VD in COVID-19. Impaired VDR signaling may underlie the variability of VD effects as non-genetic mechanisms. Interestingly, in recent studies, metformin has a beneficial therapeutic role in COVID-19 and long COVID-19, possibly by improving AMPK signaling of the VDR and enhancing the efficacy of the VD. In conclusion, evidence has been significantly strengthened over the past 18 months, with several meta-analyses and RCTs reporting conclusive beneficial effects of VD supplementation against COVID-19 and highlighting metformin to improve VDR sensitivity and efficacy in treating COVID-19 and long COVID-19.

Intermittent treatment with Apremilast, a phosphodiesterase-4 inhibitor, ameliorates Alzheimer's-like pathology and symptoms through multiple targeting actions in aged T2D rats.

BACKGROUND: Apremilast (Apre), a novel phosphodiesterase-4 (PDE4) inhibitor, has been shown to have anti-inflammatory, immunomodulator, neuroprotective and senolytic properties, therefore, Apre like other PDE4 inhibitors may be a promising candidate for treatment of Alzheimer's disease (AD). OBJECTIVE: To evaluate the effectiveness of Apre on Alzheimer's like pathology and symptoms in an animal model. METHODS: The effects of Apre and cilostazol, a reference drug, on the behavioral, biochemical, and pathological features of Alzheimer's disease induced by a high-fat/high-fructose diet combined with low-dose streptozotocin (HF/HFr/l-STZ) were investigated. RESULT: Apre 5 mg/kg IP/day for 3 consecutive days per week for 8 weeks attenuated memory and learning deficits tested by novel object recognition, Morris water maze and passive avoidance tests. Apre treatment significantly decreased the number of degenerating cells, and abnormal suppression of gene expression of AMPA and NMDA receptor subunits in the cortex and hippocampus of the AD rat model compared to rats that received vehicle. A significant decrease in elevated levels of hippocampal amyloid beta, tau-positive cell count, cholinesterase activity, and hippocampal caspase-3, a biomarker of neurodegeneration, was also observed after treatment with Apre in AD rats compared to rats that received placebo. Furthermore, a significant decrease in pro-inflammatory cytokines, oxidative stress, insulin resistance and GSK-3 was demonstrated in AD aged rats treated by Apre. CONCLUSION: Our findings demonstrate that intermittent treatment with Apre can enhance cognitive function in HF/HFr/l-STZ rats which may be related to decreased pro-inflammatory cytokines, oxidative stress, insulin resistance and GSK-3ß.

Polyphenols from Conyza dioscoridis (L.) ameliorate Alzheimer's disease- like alterations through multi-targeting activities in two animal models.

BACKGROUND: Recent investigations suggested that anticancer agents may inhibit the progression of Alzheimer's disease (AD) pathology. Conyza dioscoridis (L.) was demonstrated to have anticancer, antioxidant, anti-inflammatory and antidiabetic effects. This study was carried out to investigate the efficacy of polyphenols from Conyza dioscoridis (L.) extract (PCDE) on AD. METHODS: Impacts of 3 doses of PCDE and donepezil, a reference drug, on the features of Alzheimer's disease in two animal models were investigated. RESULTS: PCDE ameliorated the memory and learning impairment shown in rats following a single dose of scopolamine (scopolamine model) or 17 weeks of high-fat/high-fructose(HF/Hfr) diet coupled with a single dose of streptozotocin, (25 mg/kg) (T2D model). They reduced significantly the high hippocampal cholinesterase activity in the two models of rats. Administration of PCDE for 8 weeks in the T2D model showed a significant reduction in hippocampal GSK-3ß, caspase-3 activity and increase in the inhibited glutamate receptor expression (AMPA GluR1 subunit and NMDA receptor subunits NR1, NR2A, NR2B). A significant reduction of HOMA-insulin resistance and serum hypercholesterolemia was observed. The Tau hyperphosphorylation and Aß 1-42 generation in the hippocampal of T2D rats were significantly decreased by PCDE. Modulation of the oxidative stress markers, (rise in GH and SOD; decrease in MDA levels) and a significant reduction of TNF-α and IL-1ß in the hippocampus of T2D rats treated by PCDE extract were important findings in this study. The highest dose tested was 4% of the highest safe dose. CONCLUSION: Our study suggests that PCDE is multi-targeting agent with multiple beneficial activities in combating features of AD. This study may provide a novel therapeutic strategy for AD treatment that warrants clinical studies.

Glycyrrhizin and boswellic acids, the golden nutraceuticals: multitargeting for treatment of mild-moderate COVID-19 and prevention of post-COVID cognitive impairment.

Breakthrough infections have been reported in fully vaccinated persons. Furthermore, rebound symptoms have been reported following the new FDA granted emergency use to combat SARS-CoV-2. Glycyrrhizin (GR) and boswellic acids (BAs) combination has been shown to have highly successful actions against COVID-19 in our recent clinical trial. However, the study is limited by the small sample size, and therefore, the aim of this article is to comprehensively evaluate recent evidence on the efficacy of GR and BAs in preventing the development of COVID-19 in patients with mild and moderate infections and in preventing post-COVID-19 cognitive impairment, which is the most important symptom after recovery from Covid-19 disease. We have reviewed and discussed information published since the outbreak of the COVID-19 pandemic until July 2022 on preclinical (in vivo, in vivo and bioinformatics) and clinical studies related to the antiviral, anti-inflammatory and immunomodulatory activity of Gr and BAs. Sixteen studies were performed to determine the efficacy of GR against SARS-CoV-2. Ten studies were used primarily for in vitro and in vivo assays and six used molecular docking studies. However, the antiviral activity of BAs against SARS-CoV-2 was determined in only five studies using molecular modeling and bioinformatics. All these studies confirmed that GR n and BAs have strong antiviral activity and can be used as a therapeutic agent for COVID-19 and as a protective agent against SARS-CoV-2. They may act by inhibiting the main protease SARS-CoV-2 (Mpro) responsible for replication and blocking spike protein-mediated cell entry. Only seven rigorously designed clinical trials regarding the usefulness of GR, BAs or their combinations in the treatment of COVID-19 have been published as of July 2022. Although there is no clinical study regarding the treatment of cognitive impairment after COVID-19 that has been published so far, several preclinical and clinical studies have demonstrated the potential effect of GR and BAs in the prevention and treatment of cognitive impairment by inhibiting the activity of several molecules that activate inflammatory signaling pathway. In conclusion, the findings of our study documented the beneficial use of GR and BAs to treat SARS-CoV-2 and its variants and prevent post-COVID cognitive impairment. However, it warrants further studies with a larger randomized sample size to ensure that the studies have sufficient evidence of benefits against COVID-19 and post-COVID-19 symptoms.

Vitamin D: an essential adjuvant therapeutic agent in breast cancer.

Low serum levels of vitamin D have been reported as a risk factor for breast cancer. This narrative review provides an update on the impact of vitamin D on hormone receptors, notably estrogen receptor subunits, and gives insights on possible therapeutic interventions to overcome breast cancer. In addition, evidence that supports the beneficial use of vitamin D as adjuvant treatment of breast cancer is summarized. Vitamin D deficiency is significantly widespread in patients with triple-negative tumors. Several studies have observed a possible modulatory effect of vitamin D or its analogues on the expression of different hormone receptors in breast cancer and increased sensitivity to tamoxifen. Vitamin D possesses anti-inflammatory and immunomodulatory effects in patients with breast cancer, and the mechanism of action of vitamin D in patients with breast cancer is discussed. In conclusion, vitamin D appears to have a beneficial role in the prevention and management of breast cancer, however, large-scale, randomized controlled trials are needed to confirm the effects of vitamin D in breast cancer prevention or treatment.

Advancing combination treatment with cilostazol and caffeine for Alzheimer's disease in high fat-high fructose-STZ induced model of amnesia.

Several studies have suggested that phosphodiesterase (PDE) inhibitors may be a disease-modifying for Alzheimer's disease (AD). Cilostazol (CSZ) has been shown to be a new treatment for cognitive impairment with limited efficacy. Our aim was to investigate the effect of caffeine on the efficacy of CSZ against STZ-induced type 2 diabetes (T2D)-related cognitive impairment in high fat/high fructose fed rats. The efficacy of low doses of caffeine, CSZ, and CSZ plus caffeine against abnormal behavioral, biochemical, histological, or genetic changes of animal models of AD was examined. Eight weeks treatment with CSZ plus caffeine was more effective than CSZ or caffeine in improving impaired behavioral tests for cognition and memory. Histological examination exhibited a significant augmentation in the efficacy of CSZ by caffeine in protecting neurons from damage in T2D rats. Importantly, CSZ and caffeine normalized the accumulation of Amyloid beta (Aß-42) and phosphorylated tau protein (p-tau) positive cells in the brain of T2D rats. CSZ or CSZ plus caffeine reversed low glutamate gene expression, elevated cholinesterase level, and elevated caspase-3 activity in T2D rats. Furthermore, CSZ plus caffeine was significantly more effective than CSZ or caffeine in inhibiting the increase in malondialdehyde (MDA) level, total oxidative stress, pro-inflammatory cytokines and glucogen synthase kinase-3 beta (GSK-3ß) in the hippocampus of T2D rats. Also, CSZ plus caffeine was more effective than CSZ or caffeine in alleviating insulin resistance and hypercholesterolemia in T2D rats. Our findings suggest the possibility of effective treatment of AD by enhancing the therapeutic potential of CSZ through combined treatment with lower doses of caffeine. The enhancement of CSZ effect by caffeine is attributed to the increased inhibitory effect of CSZ on insulin resistance, GSK-3ß activity, hypercholesterolemia, oxidative stress and pro-inflammatory cytokines.

Advancing combination treatment with glycyrrhizin and boswellic acids for hospitalized patients with moderate COVID-19 infection: a randomized clinical trial.

Recent evidence points to a potential therapeutic role for glycyrrhizin(GR) and boswellic acids (BA) in the treatment of COVID-19 but conclusive evidence is lacking. Our aim is to investigate the efficacy of GR + BA versus placebo for the treatment of hospitalized patients with moderate SARS-CoV-2 or COVID-19 variants infection. The current study is a randomized, double-blind, placebo-controlled, single-center trial. Patients with SARS-CoV-2 or COVID-19 variants diagnosed by PCR test who were admitted to Sohag University hospital were eligible if they were at least 18 years of age and had moderate symptoms. Patients were randomly assigned to receive oral GR capsule (60 mg) and BA (200 mg) twice daily for 14 days or a matching placebo. All patients also received treatment with the institutional protocol for COVID-19. The primary outcome was mortality and time to recovery. Secondary outcome was clinical status score, 14 days after receiving study drugs. Adverse events from use of study drugs have been evaluated for up to 14 days. The trial is registered at ClinicalTrials.gov (Identifier NCT04487964). During the 6-month enrollment period (June-November, 2021) only 50 patients (54% women; median age 60 years, IQR 54-65) met eligibility and were randomly assigned. Evaluation of the primary outcome at 14 days showed that there were five deaths in the placebo group and no deaths in the GR + BA group. With regard to recovery time, it was significantly shorter (p = 0.0001) in the group receiving GR + BA capsule compared to the placebo group (median 7.0; IQR 6.0-8.0 days vs. median 12.5; IQR 12-20 days). Clinical status on the ordinal score scale as a secondary outcome showed a significant difference between the GR + BA group (median (IQR) score, 2 [2-3]) and placebo groups (mean (IQR) score, 3 [3-5.5]). There was a significant decrease in CRB (p = 0.000041) in GR + BA compared with the placebo group. In conclusion, this safe, inexpensive, antiviral, immunomodulating and anti-inflammatory combination may be considered for use in mild to moderate infections of SARS-CoV-2 or COVID-19 variants. The study is limited by the small sample size; therefore, larger randomized trials are required.

Potential therapeutic effects of boswellic acids/Boswellia serrata extract in the prevention and therapy of type 2 diabetes and Alzheimer's disease.

The link between diabetes and cognitive dysfunction has been reported in many recent articles. There is currently no disease-modifying treatment available for cognitive impairment. Boswellia serrata (B. serrata) is used traditionally to treat chronic inflammatory diseases such as type 2 diabetes (T2D), insulin resistance (IR), and Alzheimer's disease (AD). This review aims to highlight current research on the potential use of boswellic acids (BAs)/B. serrata extract in T2D and AD. We reviewed the published information through June 2021. Studies have been collected through a search on online electronic databases (Academic libraries as PubMed, Scopus, Web of Science, and Egyptian Knowledge Bank). Accumulating evidence in preclinical and small human clinical studies has indicated that BAs/B. serrata extract has potential therapeutic effect in T2D and AD. According to most of the authors, the potential therapeutic effects of BAs/B. serrata extract in T2D and AD can be attributed to immunomodulatory, anti-inflammatory, antioxidant activity, and elimination of the senescent cells. BAs/B. serrata extract may act by inhibiting the IκB kinase/nuclear transcription factor-κB (IKK/NF-κB) signaling pathway and increasing the formation of selective anti-inflammatory LOX-isoform modulators. In conclusion, BAs/B. serrata extract may have positive therapeutic effects in prevention and therapy of T2D and AD. However, more randomized controlled trials with effective, large populations are needed to show a definitive conclusion about therapeutic efficacy of BAs/B. serrata extract in T2D and AD.

Boswellic acids/Boswellia serrata extract as a potential COVID-19 therapeutic agent in the elderly.

The most severe cases of COVID-19, and the highest rates of death, are among the elderly. There is an urgent need to search for an agent to treat the disease and control its progression. Boswellia serrata is traditionally used to treat chronic inflammatory diseases of the lung. This review aims to highlight currently published research that has shown evidence of potential therapeutic effects of boswellic acids (BA) and B. serrata extract against COVID-19 and associated conditions. We reviewed the published information up to March 2021. Studies were collected through a search of online electronic databases (academic libraries such as PubMed, Scopus, Web of Science, and Egyptian Knowledge Bank). Several recent studies reported that BAs and B. serrata extract are safe agents and have multiple beneficial activities in treating similar symptoms experienced by patients with COVID-19. Because of the low oral bioavailability and improvement of buccal/oral cavity hygiene, traditional use by chewing B. serrata gum may be more beneficial than oral use. It is the cheapest option for a lot of poorer people. The promising effect of B. serrata and BA can be attributed to its antioxidant, anti-inflammatory, immunomodulatory, cardioprotective, anti-platelet aggregation, antibacterial, antifungal, and broad antiviral activity. B. serrata and BA act by multiple mechanisms. The most common mechanism may be through direct interaction with IκB kinases and inhibiting nuclear factor-κB-regulated gene expression. However, the most recent mechanism proposed that BA not only inhibited the formation of classical 5-lipoxygenase products but also produced anti-inflammatory LOX-isoform-selective modulators. In conclusion a small to moderate dose B. serrata extract may be useful in the enhancing adaptive immune response in mild to moderate symptoms of COVID-19. However, large doses of BA may be beneficial in suppressing uncontrolled activation of the innate immune response. More clinical results are required to determine with certainty whether there is sufficient evidence of the benefits against COVID-19.

The potential of glycyrrhizin and licorice extract in combating COVID-19 and associated conditions.

Background: Several recent studies have stated that glycyrrhizin and licorice extract are present in most traditional Chinese medicine formulas used against SARS-CoV-2 in China. Significant data are showing that glycyrrhizin and licorice extract have multiple beneficial activities in combating most features of SARS-CoV-2. Purpose: The aim of current review was to highlight recent progresses in research that showed the evidence of the potential use of glycyrrhizin and licorice extract against COVID-19. Methodology: We have reviewed the information published from 1979 to October 2020. These studies demonstrated the effects , use and safety of glycyrrhizin and icorice extract against viral infections,bacterial infections, inflammatory disorders of lung ( in vitro and in vivo).  These studies were collated through online electronic databases research (Academic libraries as PubMed, Scopus, Web of Science and Egyptian Knowledge Bank). Results: Pooled effect size of articles provides information about the rationale for using glycyrrhizin and licorice extract to treat COVID-19. Fifty studies demonstrate antiviral activity of glycyrrhizin and licorice extract. The most frequent mechanism of the antiviral activity is due to disrupting viral uptake into the host cells and disrupting the interaction between receptor- binding domain (RBD) of SARS-COV2 and ACE2 in recent articles. Fifty studies indicate that glycyrrhizin and licorice extract have significant antioxidant, anti-inflammatory and immunomodulatory effects. Twenty five studies provide evidence for the protective effect of glycyrrhizin and licorice extract against inflammation-induced acute lung injury and cardiovascular disorders. Conclusion: The current study showed several evidence regarding the beneficial effects of glycyrrhizin and licorice extract in combating COVID-19. More randomized clinical trials are needed to obtain a precise conclusion.

Evaluation of the neuroprotective effect of donepezil in type 2 diabetic rats.

Recent studies raise the possibility that donepezil can delay the progression of Alzheimer's disease (AD). This research evaluated the efficacy of donepezil in an animal model with brain insulin resistance and AD-like alterations. Rats were fed with high-fat/high-fructose (HF/Hfr) diet during the study period (17 weeks) and received one injection of streptozotocin (STZ) (25 mg/kg) after 8 weeks of starting the study. Diabetic (T2D) rats were treated with donepezil (4 mg/kg; p.o.) or vehicle for 8 weeks after STZ injection. The influence of donepezil on AD-related behavioral, biochemical, and neuropathological changes was investigated in T2D rats. Treatment of diabetic rats with donepezil led to a significant decrease in both amyloid-ß deposition and the raised hippocampal activity of cholinesterase (ChE). It significantly increased the suppressed glutamate receptor expression (AMPA GluR1 subunit and NMDA receptor subunits NR1, NR2A, NR2B). It also improved cognitive dysfunction in the passive avoidance and the Morris water maze tests. However, donepezil treatment did not significantly decrease the elevated levels of P-tau, caspase-3, GSK-3ß, MDA, TNF-α, and IL-1ß in the hippocampus of diabetic rats. Also, it did not restore the suppressed levels of glutathione and superoxide dismutase in the brain of these rats. Moreover, donepezil did not alter the elevated serum level of glucose, insulin, and total cholesterol. These findings suggest that donepezil treatment could ameliorate learning and memory impairment in T2D rats through reversal of some of the AD-related alterations, including reduction of amyloid-ß burden and ChE activity as well as restoration of glutamate receptor expression. However, lack of any significant effect on P-tau load, oxidative stress, neuroinflammation, and insulin resistance raises the question about the ability of donepezil to delay the development or arrest the progression of T2D-induced AD and it is still a matter of debate that requires further studies.

Inhibition of adiposity and related metabolic disturbances by polyphenol-rich extract of Boswellia serrata gum through alteration of adipo/cytokine profiles.

BACKGROUND: The role of proinflammatory cytokines in adiposity is well established. The anti-inflammatory and antihyperglycemia effects of Boswellia serrata (B. Serrata) gum have been demonstrated by many investigators. The present study aimed to investigate the anti-obesity potential of B. serrata extract. METHODS: The effects of B. serrata extract on lipase activity and acute food intake were investigated. The present study aimed to investigate the anti-obesity potential of B. serrata extract. The effects on lipase activity and acute food intake were investigated. Body weight changes, biochemical and histopathological markers were demonstrated in rats fed a high-fat diet. RESULTS: Boswellia serrata extract inhibited alterations in pancreatic lipase activity, but orlistat was more efficacious. B. serrata and ephidrene, but not orlistat, significantly suppressed cumulative food intake in mice. In obese rats, B. serrata or orlistat significantly decreased weight gain and weight of visceral white adipose tissue. B. serrata-treated animals exhibited a significant reduction in serum glucose, TC, TG, LDL-C, FFA, IL-1ß, TNF-α, insulin and leptin levels of obese rat groups while HDL-C and adiponectin levels were significantly increased by orlistat or B. serrata extract. Histopathological examination of the liver revealed that B. serrata was more effective than orlistat in alleviating steatosis and adipocyte hypertrophy shown in obese control rats. CONCLUSIONS: Boswellia serrata is as effective as orlistat in preventing obesity, hyperlipidemia, steatosis and insulin resistance. These actions may be mediated by suppression of food intake and decrease levels of TNF-α, IL-1ß and leptin resistance along with increasing adiponectin.

Polyphenol-rich Boswellia serrata gum prevents cognitive impairment and insulin resistance of diabetic rats through inhibition of GSK3ß activity, oxidative stress and pro-inflammatory cytokines.

Type 2 diabetes (T2D) is associated with accelerated cognitive decline. To date, there is no T2D-specific treatment to prevent or ameliorate cognitive dysfunction. Boswellia serrate (BS) gum has been shown to possess multiple pharmacological actions including anti-inflammatory, anticancer and ant- apoptotic actions. The present study was aimed to investigate the effect of BS on cognitive impairment associated with T2D induced in rats by high fat/high fructose (HF/HFr) diet with a single injection of streptozotocin (STZ) and to explore the mechanism of action. The effect of 3 doses of BS extract and the reference drug on the behavioral, biochemical, histopathological and glutamate gene expression abnormalities in T2D rates was evaluated. HF/HFr diet/ STZ induces learning and memory deficits, which were reversed by BS extract. It showed a significant decrease in Aß deposits and p-tau positive cells. BS extract also reduced significantly the hippocampal elevated levels of caspase-3, cholinesterase (ChE), GSK-3ß, TNF-α, IL-1ß, IL-6, and MDA. Moreover, BS extract enhanced significantly the suppressed hippocampal level of GSH, SOD and glutamate receptor expression (GluR, NR1, NR2 A, and NR2B). In addition, BS extract alleviated insulin resistance and hyperlipidemia of T2D rats. Our findings suggest that BS extract reversed learning and memory impairment in HF/ HFr diet / STZ induced diabetic rats. This effect may be attributed to the inhibition of insulin resistance, pro-inflammatory cytokines, oxidative stress and hyperlipidemia.

Amelioration of experimental metabolic syndrome induced in rats by orlistat and Corchorus olitorius leaf extract; role of adipo/cytokines.

OBJECTIVES: To determine the efficacy of Corchorus olitorius (C. olitorius) leaf extract in the prevention of metabolic syndrome induced in rats by high-fat diet (HFD) and compare it with that of orlistat. METHODS: Phytochemical analysis was performed. Effect of orlistat and C. olitorius extract on lipase activity and acute food intake were investigated. Body weight, biochemical parameters and histopathological examination were demonstrated. KEY FINDINGS: Corchorus olitorius extract inhibited the pancreatic lipase activity, but orlistat was more potent. Cumulative food intake has not changed by the tested agents. In obese rats, C. olitorius or orlistat significantly decreased weight gain and visceral white adipose tissue. They exhibited a significant reduction in serum glucose, total cholesterol, triglycerides, low density lipoprotein cholesterol, free fatty acids, IL-1ß, tumour necrosis factor-α (TNF-α), insulin and leptin levels of obese rat groups while high density lipoprotein cholesterol and adiponectin levels were significantly increased by them. Histopathological examination of the liver revealed that C. olitorius was more effective than orlistat in the alleviating of steatosis and adipocyte hypertrophy shown in obese control rats. CONCLUSIONS: Corchorus olitorius is effective as orlistat in preventing obesity, hyperlipidaemia, steatosis and insulin resistance. These actions may be mediated by inhibiting of lipase activity, TNF-α, IL-1ß and leptin resistance along with increasing of adiponectin.

Terpenoid-rich Elettaria cardamomum extract prevents Alzheimer-like alterations induced in diabetic rats via inhibition of GSK3ß activity, oxidative stress and pro-inflammatory cytokines.

PURPOSE: Recent studies suggested that the non-familiar form of Alzheimer's disease (AD) could be consequence of metabolic syndrome and neuroinflammation. Elettaria cardamomum extract (EC) has exhibited antidiabetic, antioxidant and anti-inflammatory properties. This research was conducted to evaluate the effects of EC on AD-like alterations in rats induced by high fructose and high fat diet coupled with a single small dose of STZ (25 mg/kg) (T2DM rats). METHODS: Phytochemical analysis was carried out. Behavioral tests, immunohistochemical examination, biochemical analysis and gene expression determination were performed in treated and controls rats. RESULTS: The majority of EC compounds were terpenoids. EC extract administration for 8 weeks attenuated AD-like alterations. It reversed a T2DM-induced decline in cognitive functions in passive avoidance task and Morris water maze test. It significantly lowered the elevated hippocampal level of AChE activity and caspase-3 activity, an indicator of degeneration in T2DM rats Also, it reduced the accumulation of Aß and p-tau in the brain of T2DM rats. Furthermore, it elevated the suppressed glutamate receptor expression (AMPA GluR1 subunit and NMDA receptor subunits NR1, NR2A, NR2B). EC treatment reduced hippocampal lipid peroxidation marker malondialdehyde (MDA) and augmented antioxidant defensive system, including superoxide dismutase (SOD) and reduced glutathione (GSH). Meanwhile, it lowered hippocampal TNFα, IL ß1but not IL6 and reduced GSK-3ß in brainT2D rats. CONCLUSION: EC treatment could ameliorate AD-like alterations in T2DM rats through activation of blunted insulin signal transduction in the brain, attenuation of associated oxidative stress and neuroinflammation.

Dual effect of nitric oxide donor on adjuvant arthritis.

The effect of medical use of NO donors on the pathogenesis of arthritis is still yet unclear. We investigated the effects of the NO donor, sodium nitroprusside (SNP), on the pathogenesis of adjuvant-induced arthritis in rats. Rats were given SNP intraperitoneally either from day 5 to day 14 (as a prophylactic protocol) or from day 16 to day 25 (as a therapeutic protocol) after inoculation of adjuvant. SNP administration, whether prophylactic or therapeutic, in doses of 0.1 and 1 mg/kg/d significantly aggravated pathogenesis of adjuvant arthritis in rats. SNP-treated rats showed significant (P<0.05) increase in arthritis index, hind paw volume, ankle joint diameter and hyperalgesia compared with control adjuvant arthritic rats. However, in adjuvant rats given the smallest dose of SNP (0.01 mg/kg/d), arthritis index, volume of hind paws, ankle joint diameter, body weight loss, and hyperalgesia were significantly lower than that of control adjuvant rats. After 30 d of the induction of adjuvant arthritis, TNF alpha levels exhibited insignificant changes either in control adjuvant rats or in rats given SNP compared with control non adjuvant rats. IL-10 levels in adjuvant control rats and adjuvant rats given 1 mg or 0.1 mg/kg/d from day 15 to day 25 were significantly lower than that of control non adjuvant rats. Histopathology examination of ankle joint showed that large doses of SNP (1 mg or 0.1 mg/kg/d) increased the mononuclear cells infiltration and erosion of cartilage induced by adjuvant while the infiltration of the inflammatory cells in the synovium of adjuvant rats treated with 0.01 mg/kg/d was minimal and the pannus was inhibited with alleviation of erosion of articular cartilage. Prophylactic small dose of SNP improved the histological status more than the therapeutic small dose. The present work reveals that SNP administration, either prophylactic or therapeutic, was deleterious in higher doses. However, the smallest dose used 0.01 mg/kg/d attenuates joint inflammation, hyperalgesia and body weight loss in adjuvant arthritic rats. These results suggest that small dose of NO donor may exert partial protective effects while the safety of the clinical use of NO donors, in higher doses, in patients with rheumatoid arthritis is questioned.

The immunopotentiator effects of nefopam.

The effects of opiate analgesics and non-steroidal anti-inflammatory drugs on the immune functions have been reported. The effect of the non-opiate analgesic nefopam on the immune functions has not yet been investigated. Male Swiss albino mice were treated with either heat killed E. coli or saline. They were classified into 12 groups. The effects of subacute (15 mg/kg/12 h S.C. daily for one week) and chronic (10 mg/kg/12 h S.C. daily for one month) treatment with nefopam on the levels of interferon-gamma (IFN-gamma) and total immunoglobulins were examined in both normal and immunized mice. Also, the effect of the chronic administration of nefopam on the phagocytic activity of peritoneal macrophage was evaluated in both normal and immunized mice. Subacute and chronic administration of nefopam induced no significant raise in the level of interferon-gamma (IFN-gamma) or in the level of total immunoglobulins in non-immunized animals, while subacute and chronic treatment with nefopam augmented markedly the immunization induced increase of level of interferon-gamma (IFN-gamma). Furthermore, chronic treatment with nefopam potentiated significantly the production of total immunoglobulin induced by heat killed E. coli. Chronic treatment with nefopam also was associated with significant enhancement of innate immune response reflected in the pronounced increase in the phagocytic activity of macrophages in non-immunized and immunized animals. The enhancement of phagocytic activity of macrophages by nefopam in immunized animals was significantly higher than that of non-immunized animals. These findings revealed that nefopam has the ability to trigger the immune response for bacterial antigen. The mechanism behind the immunostimulatory effect of nefopam requires further investigation, but it may be due, at least in part, to the inhibitory effect of nefopam on the serotonin and norepinephrine reuptake at nerve endings. In conclusion, our findings postulated that nefopam stimulated the immune functions and improved the defence mechanism. This information may be of future therapeutic value in diseases that need immunologic enhancement.