Effects of curcumin on ethanol-induced hepatocyte necrosis and apoptosis: implication of lipid peroxidation and cytochrome c

Evaluating the combined toxicity of broflanilide and myclobutanil on honeybees (Apis mellifera L.): Molecular mechanisms and protective effects of curcumin

Pesticide toxicity to honeybees has become a pressing ecological issue, yet the effects of pesticide co-exposure are still not fully understood. This research investigates the toxicological implications of concurrent exposure to broflanilide (BFL), a novel diamide insecticide, and myclobutanil (MYC), a commonly used triazole fungicide, on honeybees (Apis mellifera L.), while exploring potential preventive strategies. Acute toxicity tests revealed a significantly lower 96-hour lethal concentration 50 (LC50) for BFL (0.34 mg a.i. L-1) compared to MYC (82.3 mg a.i. L-1), and their co-exposure resulted in pronounced synergistic toxicity. Worker bees were exposed to environmentally relevant doses of BFL and MYC for 7 days, and midgut toxicity was assessed. The co-exposure caused severe midgut damage, including G-layer deterioration, loss of columnar epithelium integrity, and downregulation of the tight junction protein ZO-2. Additionally, oxidative stress-related genes (Sod1, Catalase, SelK, GstD1) were upregulated, accompanied by higher MDA levels and increased CAT and SOD activities. Furthermore, a greater number of TUNEL-positive cells were detected, along with elevated expression of apoptosis-related genes (Caspase-3-like, Caspase-8-like, Caspase-9-like) and higher caspase enzyme activities. Curcumin (Cur) was tested for its protective effects, and it significantly alleviated midgut damage, oxidative stress, and apoptosis. This study reveals the synergistic ecotoxicological effects of pesticide combinations and suggests Cur as a potential prevention strategy for mitigating their harmful impact on honeybees.

Curcumin: A Potential Detoxifier Against Chemical and Natural Toxicants

The human body gets exposed to a variety of toxins intentionally or unintentionally on a regular basis from sources such as air, water, food, and soil. Certain toxins can be synthetic, while some are biological. The toxins affect the various parts of the body by activating numerous pro-inflammatory markers, like oxidative stresses, that tend to disturb the normal function of the organs ultimately. Nowadays, people use different types of herbal treatments, viz., herbal drinks that contain different spices for detoxification of their bodies. One such example is turmeric, the most commonly available spice in the kitchen and used across all kinds of households. Turmeric contains curcumin, which is a natural polyphenol. Curcumin is a medicinal compound with different biological activities, such as antioxidant, antineoplastic, anti-inflammatory, and antibacterial. Hence, this review gives a comprehensive insight into the promising potential of curcumin in the detoxification of heavy metals, carbon tetrachloride, drugs, alcohol, acrylamide, mycotoxins, nicotine, and plastics. The review encompasses diverse animal-based studies portraying curcumin's role in nullifying the different toxic effects in various organs of the body (especially the liver, kidney, testicles, and brain) by enhancing defensive signaling pathways, improving antioxidant enzyme levels, inhibiting pro-inflammatory markers activities and so on. Furthermore, this review also argues over curcumin's safety assessment for its utilization as a detoxifying agent.

Nrf2 depletion enhanced curcumin therapy effect in gastric cancer by inducing the excessive accumulation of ROS

Gastric cancer (GC) is the most common malignant tumor of the gastrointestinal tract and currently has a poor clinical outcome. Turmeric's rhizome contains a polyphenolic component called curcumin (Cur), which has been demonstrated to inhibit a variety of tumor cells, such as pancreatic, colon, lung and gastric cancers. However, it remains to be elucidated how Cur functions in GC and what molecular processes underlie it. Here, Cur showed a stronger inhibitory effect on GC cells AGS and HGC27. In addition, Cur's inhibition of GC cells growth was accompanied by increased ROS production, triggering of the Keap1-Nrf2 signaling pathway, and increased transcription of its downstream antioxidant genes HO-1, GCLM, and NQO1. However, when a ROS scavenger NAC was used, the inhibitory effect of Cur on GC cells was reversed. Nuclear factor erythroid 2-related factor 2 (Nrf2) is overexpressed or activated in cancers to shield cancer cells from oxidative damage by responding to oxidative stress (OS). Cur has been found to act as an activator of Nrf2. Notably, compared with Nrf2 knockdown and Cur alone, the combination of the two dramatically increased Cur-induced ROS overaccumulation and inhibition of GC cells proliferation, migration, and invasive abilities. Consistent with in vitro experiments, Cur combined with Nrf2 knockdown significantly inhibited tumor growth in nude mice transplanted with AGS cells. Therefore, we concluded that Nrf2 depletion enhanced Cur therapy effect in GC by inducing the excessive accumulation of ROS, indicating that this is a promising treatment strategy.

The ameliorative effect of turmeric (Curcuma longa Linn) extract and its major constituent, curcumin, and its analogs on ethanol toxicity

Ethanol toxicity is a major public health problem that can cause damage to various organs in the body by several mechanisms inducing oxidative stress, inflammation, and apoptosis. Recently, there has been a growing interest in the potential of herbal medicines as therapeutic agents for the prevention and treatment of various disorders. Turmeric (Curcuma longa) extracts and its main components including curcumin have antioxidant, anti-inflammatory, and anti-apoptotic properties. This review aims to evaluate the literature on the ameliorative effects of turmeric extracts and their main components on ethanol toxicity. The relevant studies were identified through searches of Google Scholar, PubMed, and Scopus without any time limitation. The underlying mechanisms of turmeric and curcumin were also discussed. The findings suggest that turmeric and curcumin ameliorate ethanol-induced organ damage by suppressing oxidative stress, inflammation, apoptosis, MAPK activation, TGF-β/Smad signaling pathway, hyperlipidemia, regulating hepatic enzymes, expression of SREBP-1c and PPAR-α. However, the limited clinical evidence suggests that further research is needed to determine the efficacy and safety of turmeric and curcumin in human subjects. In conclusion, the available evidence supports the potential use of turmeric and curcumin as alternative treatments for ethanol toxicity, but further high-quality studies are needed to firmly establish the clinical efficacy of the plant.

Toxicity of curcumin nanoparticles towards alveolar macrophage: Effects of surface charges

Curcumin has been used for chronic lung diseases management due to its diversified molecular actions. However, the potential cytotoxicity which occurs in cells following the exposure to high concentrations of curcumin has been overlooked. This study evaluated the toxic events of curcumin nanoparticles (Cur-NPs) with alterable surface polarity in alveolar macrophages (NR8383). We aimed to establish the correlation between the toxicity of Cur-NPs with different surface charges and the internalization mechanisms of the NPs. Toxicity data showed that positively charged Cur-NPs (IC₅₀: 9.77 ± 0.5 μg/mL) was the most potent against NR8383, followed by negatively charged Cur-NPs (IC₅₀:13.33 ± 0.9 μg/mL) and neutral Cur-NPs (IC₅₀:18.68 ± 1.2 μg/mL). Results from mitochondrial membrane potential, ATP content and intracellular ROS in NR8383 showed similar ranking to the toxicity assay. The predominant uptake pathway for positively and negatively charged Cur-NPs was via clathrin-mediated endocytosis, while neutral Cur-NPs was internalized via phagocytosis, micropinocytosis and clathrin-mediated endocytosis. Positively charged Cur-NPs mediates the cytotoxicity of NR8383 via lysosomal and mitochondrial-associated destabilization upon entry. In conclusion, the cytotoxicity of Cur-NPs on NR8383 is surface-charge dependent, which in turn is associated to the uptake pathway and localization of Cur-NPs in cells.

Protective effects of melatonin and L-carnitine against methotrexate-induced toxicity in isolated rat hepatocytes

The present study was designed to evaluate the possible protective effects of melatonin (MEL) and/or L-carnitine (L-CAR) against methotrexate (MTX)-induced toxicity in isolated rat hepatocytes. Hepatocytes were prepared using collagenase techniques of perfusion and digestion of rat liver. Trypan blue uptake, as well as, glutathione (GSH), lipid peroxidation (LPO), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-α) levels were measured. Caspase-3 activity was also assessed. Pre-incubation of hepatocytes with MEL (1 mM) and/or L-CAR (10 mM) 30 min prior to intoxication with MTX, significantly protected hepatocytes against toxicity. In addition, LPO, NO, TNF-α levels, and caspase-3 activity were decreased in comparison to the MTX-intoxicated group. Furthermore, the two drugs increased the MTX-depleted GSH level. MEL and L-CAR prevented MTX-induced hepatocytotoxicity, at least partly, by their antioxidative, antiinflammatory, and antiapoptotic effects. Further studies are recommended on the clinical pharmacologic and toxicologic effects of MEL and L-CAR in patients receiving MTX.

Catalpol synergistically potentiates the anti-tumour effects of regorafenib against hepatocellular carcinoma via dual inhibition of PI3K/Akt/mTOR/NF-κB and VEGF/VEGFR2 signaling pathways

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common primary liver cancer characterized by dysregulation of several crucial cellular signaling pathways such as PI3K/p-Akt/mTOR/NF-κB and VEGF/VEGFR2 pathways. Novel therapies targeting these pathways have been discovered such as regorafenib which is small molecular multi-kinase inhibitor mainly targets VEGF/VEGFR2. Catalpol is an iridoid glycoside richly found in rehmannia glutinosa which is a fundamental herb used extensively in traditional Chinese medicine. It is evidenced that catalpol has many pharmacological effects on nervous and cardiovascular systems, in addition to exhibiting hypoglycemic, anti-inflammatory, anti-proliferative and anti-tumour activities. However, its effect on HCC isn't clear enough. So, this study aimed to investigate the anti-tumour effects of catalpol either alone or in combination with regorafenib on HCC.

METHODS AND RESULTS

In vitro experiments were performed using HepG2 and HUH-7 hepatocellular carcinoma cell lines. MTT assays evaluated anti-proliferative effects of catalpol and/or regorafenib. Combination index was calculated via compusyn software to detect synergism. Tumour biomarkers were measured using ELISA technique. Results showed that catalpol has anti-tumour effects against HCC via targeting PI3K/p-Akt/mTOR/NF-κB and VEGF/VEGFR2 pathways. In addition, results revealed that our novel combination of catalpol and regorafenib showed potent synergistic anti-tumour effect via suppressing both of PI3K/p-Akt/mTOR/NF-κB and VEGF/VEGFR2 signaling pathways and their downstreams.

CONCLUSION

Catalpol and/or regorafenib markedly suppressed PI3K/p-Akt/mTOR/NF-κB and VEGF/VEGFR2 signaling pathways and consequently showed potent anti-tumour effects against HCC. Results encourage further pre-clinical and clinical studies of this novel combination as a promising targeted therapy for HCC management.

Combinatorial antitumor effects of amino acids and epigenetic modulations in hepatocellular carcinoma cell lines

Hepatocellular carcinoma (HCC) is a highly fatal form of liver cancer. Recently, the interest in using amino acids as therapeutic agents has noticeably grown. The present work aimed to evaluate the possible antiproliferative effects of selected amino acids supplementation or deprivation in human HCC cell lines and to investigate their effects on critical signaling molecules in HCC pathogenesis and the outcomes of their combination with the histone deacetylase inhibitor vorinostat. HepG2 and Huh7 cells were treated with different concentrations of L-leucine, L-glutamine, or L-methionine and cell viability was determined using MTT assay. Insulin-like growth factor 1 (IGF1), phosphorylated ribosomal protein S6 kinase (p70 S6K), p53, and cyclin D1 (CD1) protein levels were assayed using ELISA. Caspase-3 activity was assessed colorimetrically. L-leucine supplementation (0.8-102.4 mM) and L-glutamine supplementation (4-128 mM) showed dose-dependent antiproliferative effects in both cell lines but L-methionine supplementation (0.2-25.6 mM) only affected the viability of HepG2 cells. Glutamine or methionine deprivation suppressed the proliferation of HepG2 cells whereas leucine deprivation had no effect on cell viability in both cell lines. The combination between the effective antiproliferative changes in L-leucine, L-glutamine, and L-methionine concentrations greatly suppressed cell viability and increased the sensitivity to vorinostat in both cell lines. The growth inhibitory effects were paralleled with significant decreases in IGF-1, phospho p70 S6k, and CD1 levels and significant elevations in p53 and caspase-3 activity. Changes in amino acids concentrations could profoundly affect growth in HCC cell lines and their response to epigenetic therapy.

Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psychiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mechanisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well conducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

Curcumin Can be Acts as Effective agent for Prevent or Treatment of Alcohol-induced Toxicity in Hepatocytes: An Illustrated Mechanistic Review

Previous studies have shown that alcohol abuse can cause serious liver damage and cirrhosis. The main pathway for these types of hepatocellular cell neurodegeneration is mitochondrial dysfunction, which causes lipid peroxidation and dysfunction of the glutathione ring and the defect of antioxidant enzymes in alcoholic hepatic cells. Alcohol can also initiate malicious inflammatory pathways and trigger the initiation and activation of intestinal and extrinsic apoptosis pathways in hepatocellular tissues that lead to cirrhosis. Previous studies have shown that curcumin may inhibit lipid peroxidation, glutathione dysfunction and restore antioxidant enzymes. Curcumin also modulates inflammation and the production of alcohol-induced biomarkers. Curcumin has been shown to play a critical role in the survival of alcoholic hepatocellular tissue. It has been shown that curcumin can induce and trigger mitochondrial biogenesis and, by this mechanism, prevent the occurrence of both intrinsic and extrinsic apoptosis pathways in liver cells that have been impaired by alcohol. According to this mechanism, curcumin may protect hepatocellular tissue from alcohol-induced cell degeneration and may therefore survive alcoholic hepatocellular tissue. . Based on these mechanisms, the protective functions of curcumin against alcohol-induced cell degeneration due to oxidative stress, inflammation, and apoptosis events in hepatocellular tissue have been recorded. Hence, in this research, we have attempted to evaluate and analyze the main contribution mechanism of curcumin cell defense properties against alcohol-induced hepatocellular damage, according to previous experimental and clinical studies, and in this way we report findings from major studies.

Curcumin and colorectal cancer: An update and current perspective on this natural medicine

Colorectal cancer (CRC) is one of most common malignancies worldwide and its incidence is still growing. In spite of recent advances in targeted therapies, their clinical efficacy has been limited, non-curative and unaffordable. A growing body of literature indicates that CRC is a multi-modal disease, where a variety of factors within the tumor microenvironment play a significant role in its pathogenesis. For instance, imbalance in gut microbial profiles and impaired intestinal barrier function contribute to the overall intestinal inflammation and initiation of CRC. Moreover, persistent chronic inflammation favors a tumor microenvironment for the growth of cancer. In addition, autophagy or 'self-eating' is a surveillance mechanism involved in the degradation of cellular constituents that are generated under stressful conditions. Cancer stem cells (CSCs), on the other hand, engage in the onset of CRC and are able to endow cancer cells with chemo-resistance. Furthermore, the aberrant epigenetic alterations promote CRC. These evidences highlight the need for multi-targeted approaches that are not only safe and inexpensive but offer a more effective alternative to current generation of targeted drugs. Curcumin, derived from the plant Curcuma longa, represents one such option that has a long history of its use for a variety of chronic disease including cancer, in Indian ayurvedic and traditional Chinese medicine. Scientific evidence over the past few decades have overwhelmingly shown that curcumin exhibits a multitude of anti-cancer activities orchestrated through key signaling pathways associated with cancer. In this article, we will present a current update and perspective on this natural medicine - incorporating the basic cellular mechanisms it effects and the current state of clinical evidence, challenges and promise for its use as a cancer preventative and potential adjunct together with modern therapies for CRC patients.

Antidiabetic Properties of Curcumin I: Evidence from In Vitro Studies

Type 2 diabetes mellitus (T2DM) is a growing metabolic disease characterized by insulin resistance and hyperglycemia. Current preventative and treatment strategies for T2DM and insulin resistance lack in efficacy resulting in the need for new approaches to prevent and manage/treat the disease better. In recent years, epidemiological studies have suggested that diets rich in fruits and vegetables have beneficial health effects including protection against insulin resistance and T2DM. Curcumin, a polyphenol found in turmeric, and curcuminoids have been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, neuroprotective, immunomodulatory and antidiabetic properties. The current review (I of II) summarizes the existing in vitro studies examining the antidiabetic effects of curcumin, while a second (II of II) review summarizes evidence from existing in vivo animal studies and clinical trials focusing on curcumin’s antidiabetic properties.

MoS2-Modified Curcumin Nanostructures: The Novel Theranostic Hybrid Having Potent Antibacterial and Antibiofilm Activities against Multidrug-Resistant Hypervirulent Klebsiella pneumoniae

The recent emergence of hypervirulent clinical variants of Klebsiella pneumoniae (hvKP) causing community-acquired, invasive, metastatic, life-threatening infections of lungs, pleura, prostate, bones, joints, kidneys, spleen, muscles, soft-tissues, skin, eyes, central nervous system (CNS) including extrahepatic abscesses, and primary bacteremia even in healthy individuals has posed stern challenges before the existing treatment modalities. There is therefore an urgent need to look for specific and effective therapeutic alternatives against the said bacterial infection or recurrence. A new type of MoS₂-modified curcumin nanostructure has been developed and evaluated as a potential alternative for the treatment of multidrug-resistant isolates. The curcumin quantum particles have been fabricated with MoS₂ via a seed-mediated hydrothermal method, and the resulting MoS₂-modified curcumin nanostructures (MQCs) have been subsequently tested for their antibacterial and antibiofilm properties against hypervirulent multidrug-resistant Klebsiella pneumoniae isolates. In the present study, we found MQCs inhibiting the bacterial growth at a minimal concentration of 0.0156 μg/mL, while complete inhibition of bacterial growth was evinced at concentration 0.125 μg/mL. Besides, we also investigated their biocompatibility both in vitro and in vivo. MQCs were found to be nontoxic to the SiHa cells at a dose as high as 1024 μg/mL on the basis of the tested adhesion, spreading of the cells, and also on the various serological, biochemical, and histological investigations of the vital organs and blood of the Charles Foster Rat. These results suggest that MQCs have potent antimicrobial activities against hvKP and other drug resistant isolates and therefore may be used as broad spectrum antibacterial and antibiofilm agents.

Pathogenesis, Early Diagnosis, and Therapeutic Management of Alcoholic Liver Disease

Alcoholic liver disease (ALD) refers to the damages to the liver and its functions due to alcohol overconsumption. It consists of fatty liver/steatosis, alcoholic hepatitis, steatohepatitis, chronic hepatitis with liver fibrosis or cirrhosis, and hepatocellular carcinoma. However, the mechanisms behind the pathogenesis of alcoholic liver disease are extremely complicated due to the involvement of immune cells, adipose tissues, and genetic diversity. Clinically, the diagnosis of ALD is not yet well developed. Therefore, the number of patients in advanced stages has increased due to the failure of proper early detection and treatment. At present, abstinence and nutritional therapy remain the conventional therapeutic interventions for ALD. Moreover, the therapies which target the TNF receptor superfamily, hormones, antioxidant signals, and MicroRNAs are used as treatments for ALD. In particular, mesenchymal stem cells (MSCs) are gaining attention as a potential therapeutic target of ALD. Therefore, in this review, we have summarized the current understandings of the pathogenesis and diagnosis of ALD. Moreover, we also discuss the various existing treatment strategies while focusing on promising therapeutic approaches for ALD.

Synergistic antiproliferative effects of curcumin and celecoxib in hepatocellular carcinoma HepG2 cells

Hepatocellular carcinoma (HCC) is still a leading cancer killer in the community. Molecular targeted therapy with celecoxib (CXB) has shown promising antitumor effects; however, its use may be limited due to serious side effects. Curcumin (CUR) has also shown beneficial effects against HCC. Then, it was aimed to investigate the effects of adding CUR to CXB on HCC HepG2 cells. HepG2 cells were treated with CXB and/or CUR at increasing concentrations to investigate synergistic drug interactions, as calculated combination index (CI). Combination treatment effects on cell viability and caspase-3 activation were assessed. The levels of Akt, nuclear factor-kappa B (NF-κB), prostaglandin E₂ (PGE₂), malondialdehyde (MDA), cyclin D1 (CD1), and vascular endothelial growth factor (VEGF) were also evaluated. CXB (3.13-100 μM) and/or CUR (1.25-40 μM) reduced HepG2 cell viability dose-dependently. Nevertheless, lower combined concentrations showed higher synergism (CI < 1) and higher CXB dose reduction index (DRI > 1). Also, the addition of CUR to CXB resulted in increased cytotoxicity and caspase-3 activation, as compared to CXB alone. In addition, the selected combination significantly reduced the levels of Akt, NF-κB, PGE₂, MDA, CD1, and VEGF, as compared to either agent alone. In conclusion, CUR augmented the CXB-mediated antitumor effects in HepG2 cells through, at least in part, antiproliferative, antioxidant, and pro-apoptotic mechanisms. This may allow the further use of CXB at lower concentrations, combined with CUR, as a promising safer targeted strategy for HCC management.

Natural Antioxidants as Potential Therapy, and a Promising Role for Melatonin Against Pulmonary Hypertension

Plasma and serum samples, and lung/heart tissue of pulmonary hypertension (PH) patients and animal models of PH display elevated oxidative stress. Moreover, the severity of PH and levels of oxidative stress increase concurrently, which suggests that oxidative stress could be utilized as a biomarker for PH progression. Accumulating evidence has well established that oxidative stress is also key role player in the development of PH. Preclinical studies have demonstrated that natural antioxidants improved PH condition, and, therefore, antioxidant therapy has been proposed as a potential therapeutic strategy against PH. These natural antioxidants include medicinal plant extracts and compounds such as resveratrol and melatonin. Recent studies suggest that melatonin provides health benefit against PH, by enhancing antioxidant capacity, increasing vasodilation, counteracting lung and cardiac fibrosis, and stunting right ventricular (RV) hypertrophy/failure. This chapter comprehensively reviews and discusses a variety of natural antioxidants and their efficacy in modulating experimental PH. This chapter also demonstrates that antioxidant therapy remains a therapeutic strategy for PH, and particularly identifies melatonin as a safe, cost-effective, and promising antioxidant therapy.

Curcumin and Osteosarcoma: Can Invertible Polymeric Micelles Help?

Systematic review of experimental and clinical data on the use of curcumin in the treatment of osteosarcoma is presented. The current status of curcumin's therapeutic potential against bone cancer is analyzed in regard to using polymeric micelles (including recently developed invertible, responsive, micelles) as a platform for curcumin delivery to treat osteosarcoma. The potential of micellar assemblies from responsive macromolecules in a controlled delivery of curcumin to osteosarcoma cells, and the release using a new inversion mechanism is revealed.

Beneficial effects of Androctonus australis hector venom and its non-toxic fraction in the restoration of early hepatocyte-carcinogenesis induced by FB1 mycotoxin: Involvement of oxidative biomarkers

Some venom components are known to present potential biological activities that are useful as tools in therapeutics. In this study anti-tumoral activity of Androctonus australis hector (Aah) venom and its purified fraction on early step of hepato-carcinogenesis initiated by Fumonisin (FB1), was tested. Initiated hepatic tumor was assessed in mice by decreased doses of Fumonisin B1 associated to phenobarbital. Scorpion venom was used to investigate its activity on initiated tumor by FB1. Evaluation of oxidative unbalance, enzymatic activities and DNA quantification in the liver were correlated with tissue analysis. Obtained results showed that the initiated pathogenesis by FB1 at seven months was characterized by tissue alterations and biomarker variations. These alterations were characterized by atypical lesions such as muffled nucleus, karyo- and cyto-megaly; up normal and large number of nuclei into hepatocytes. These alterations were confirmed by DNA alteration. An unbalance of oxidative status was also observed, characterized by an increased levels of respectively oxidant (NO and MDA) and antioxidant (GSH and catalase activity) mediators. Aah venom and its non-toxic fraction used at low doses seemed to be able to restore partially the hepatic altered tissue induced by FB1. Decreased levels of oxidative and anti-oxidative mediators were also observed. DNA in hepatocytes returned also to the physiological values. Structure of hepatic tissue showed restoration of some alterations such as karyo- and cyto-megaly; decrease of polyploidy hepatocytes induced by FB1. Aah venom and its non-toxic fraction seem to contain some bioactive components with anti-tumoral activity. Purification of this activity from non-toxic fraction F1 could be of interest to identify the components with anti-tumoral activities.

Liver fibrosis and protection mechanisms action of medicinal plants targeting apoptosis of hepatocytes and hepatic stellate cells

Following chronic liver injury, hepatocytes undergo apoptosis leading to activation of hepatic stellate cells (HSC). Consequently, activated HSC proliferate and produce excessive extracellular matrix, responsible for the scar formation. The pandemic trend of obesity, combined with the high incidence of alcohol intake and viral hepatitis infections, highlights the urgent need to find accessible antifibrotic therapies. Treatment strategies should take into account the versatility of its pathogenesis and act on all the cell lines involved to reduce liver fibrosis. Medicinal plants are achieving popularity as antifibrotic agents, supported by their safety, cost-effectiveness, and versatility. This review will describe the role of hepatocytes and HSC in the pathogenesis of liver fibrosis and detail the mechanisms of modulation of apoptosis of both cell lines by twelve known hepatoprotective plants in order to reduce liver fibrosis.

Protective effect of Aframomum melegueta phenolics against CCl₄-induced rat hepatocytes damage; role of apoptosis and pro-inflammatory cytokines inhibition

Aframomum melegueta is a commonly used African spice. Through a hepatoprotective bioassay-guided isolation, the chloroform fraction of A.melegueta seeds yielded one new diarylheptanoid named 3-(S)-acetyl-1-(4′-hydroxy-3′, 5′-di methoxyphenyl)-7-(3″,4″, 5″-trihydroxyphenyl)heptane (1), and two new hydroxyphenylalkanones, [8]-dehydrogingerdione (2) and [6]-dehydroparadol (3), in addition to six known compounds (4–9). The hepatoprotective effect of A. melegueta methanol extract, sub-fractions and isolated compounds was investigated using carbon tetrachloride (CCl₄)-induced liver injury in a rat hepatocytes model. The methanol, chloroform extracts and compounds 1, 5, 8 and 9 of A. melegueta significantly inhibited the elevated serum alanine aminotransferase (ALT), thiobarbituric acid reactive substances (TBARS), tumor necrosis factor (TNFα), interleukin-1beta (Il-1β), caspase3 and 9 and enhanced the reduced liver glutathione (GSH) level caused by CCl₄ intoxication. These results indicate that A.melegueta extracts, and isolated compounds play a protective role in CCl₄ induced acute liver injury which might be due to elevated antioxidative defense potentials, suppressed inflammatory responses and apoptosis of liver tissue.

Novel microstructured sildenafil dosage forms as wound healing promoters

PURPOSE

Study the possible benefit of combining biodegradable polymers with sildenafil citrate (SC) in wound healing.

METHOD

Biodegradable micronized powdered formulations of SC were prepared by spray drying using chitosan (P₁) or chitosan/gum Arabic (P₂). Powders were characterized by differential scanning calorimetry, Scanning electron microscope, particle size analysis, flow and swelling behavior. The powders were also incorporated into microstructured gels and in vitro SC release from powders and gels was tested. In vivo wound healing acceleration was tested by measuring area contraction of excision wounds and histologically. Post-healing tensile strength (TS) for incision wounds in rats receiving powder formulations was tested.

RESULTS

The powders were in the micron-size range showing no SC-polymers interaction. Powders had poor flow with angle of repose (θ) of 41 - 48°, and high moisture uptake reaching 107% for placebo powder P₁. Good excision wound healing was seen with P1 and G1 formulations showing 98.4 and 98.5% reduction in wound area, respectively, compared with 83% for the control. Incision wounds were improved with P1 showing TS value of 6.9 compared with 3.7 kg/cm² for control. Histological examinations supported.

CONCLUSION

Spray-dried chitosan/SC powder (P₁) and its gel form (G₁) could be promising wound healing promoters as supported by the histological examinations.

Structure-Function Elucidation of Antioxidative and Prooxidative Activities of the Polyphenolic Compound Curcumin

Phenolic compounds have been very well known for their antioxidant properties, owing to their unique ability to act as free radical scavengers which, in turn, is an outstanding attribute of their unique biochemical structure. Recent accumulating lines of evidence inculcate sustainable interest and curiosity towards the chemoprotective nature of the natural polyphenolic compound curcumin (diferuloylmethane) against oxidative stress-mediated disorders. Curcumin is naturally found as a constituent of dietary spices called turmeric, extracted from the plant Curcuma longa. However, like every phenolic antioxidant, curcumin possesses a concentration and medium dependent anti- and pro-oxidant behaviour. A detailed study of the structure-function analysis and the understanding of the mode of action of curcumin as well as its chemical analogues is thus essential to understand the selective biochemical consequences of curcumin. Moreover, the presence of transition metal ions, route of administration, and localized tissue are also the vital decisive factors to determine curcumin behaviour. With this viewpoint, this paper sheds lights on the medium dependent prooxidative and antioxidative attributes of curcumin. Further, with respect to emergence of nanocarriers, a brief discussion focusing on the biochemical effect exertion of curcumin chiefly due to targeted and slow release has also been added towards the end.

Hepatoprotective effects of Astragalus kahiricus root extract against ethanol-induced liver apoptosis in rats

The hepatoprotective activity of the ethanol extract of Astragalus kahiricus (Fabaceae) roots against ethanol-induced liver apoptosis was evaluated and it showed very promising hepatoprotective actions through different mechanisms. The extract counteracted the ethanol-induced liver enzymes leakage and glutathione depletion. In addition, it demonstrated anti-apoptotic effects against caspase-3 activation and DNA fragmentation that were confirmed by liver histopathological examination. Moreover, the phytochemical study of this extract led to the isolation of four cycloartane-type triterpenes identified as astrasieversianin II (1), astramembrannin II (2), astrasieversianin XIV (3), and cycloastragenol (4). The structures of these isolates were established by HRESI-MS and 1D and 2D NMR experiments. The antimicrobial, antimalarial, and cytotoxic activities of the isolates were further evaluated, but none of them showed any activity.

Curcumin pretreatment prevents potassium dichromate-induced hepatotoxicity, oxidative stress, decreased respiratory complex I activity, and membrane permeability transition pore opening

Curcumin is a polyphenol derived from turmeric with recognized antioxidant properties. Hexavalent chromium is an environmental toxic and carcinogen compound that induces oxidative stress. The objective of this study was to evaluate the potential protective effect of curcumin on the hepatic damage generated by potassium dichromate (K₂Cr₂O₇) in rats. Animals were pretreated daily by 9-10 days with curcumin (400 mg/kg b.w.) before the injection of a single intraperitoneal of K₂Cr₂O₇ (15 mg/kg b.w.). Groups of animals were sacrificed 24 and 48 h later. K₂Cr₂O₇-induced damage to the liver was evident by histological alterations and increase in the liver weight and in the activity of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase in plasma. In addition, K₂Cr₂O₇ induced oxidative damage in liver and isolated mitochondria, which was evident by the increase in the content of malondialdehyde and protein carbonyl and decrease in the glutathione content and in the activity of several antioxidant enzymes. Moreover, K₂Cr₂O₇ induced decrease in mitochondrial oxygen consumption, in the activity of respiratory complex I, and permeability transition pore opening. All the above-mentioned alterations were prevented by curcumin pretreatment. The beneficial effects of curcumin against K₂Cr₂O₇-induced liver oxidative damage were associated with prevention of mitochondrial dysfunction.

Anti-apoptotic effects of tamarind leaves against ethanol-induced rat liver injury†

Objectives

The leaf decoctions of Tamarindus indica (TI) have long been traditionally used in liver ailments. The aim of this study was to investigate the anti-apoptotic activity of TI leaf extract against acute ethanol (EtOH)-induced liver injury. The major constituents of the extract were also examined for standardization purposes.

Methods

Rats (n = 5–7) were orally pretreated with TI leaf extract (25, 50 and 100 mg/kg) for seven days. Silymarin was used as a positive control. Liver tissue biochemical assays included key markers of apoptosis and its redox signalling. Serum enzyme levels were also determined.

Key findings

All graded doses of TI leaf extract mitigated the EtOH-induced liver caspase-3 activation (42, 57 and 64%) as well as DNA fragmentation (32, 47 and 50%), respectively. The highest dose of the extract demonstrated membrane-stabilizing (38%) in addition to glutathione-replenishing (88%) effects. Also, the leaves improved the liver histopathological alterations. Moreover, major plant bioactive polyphenolics, that might be responsible for the extract's observed effects, were isolated and identified.

Conclusions

TI leaf extract demonstrated promising anti-apoptotic hepatoprotective effects in rats. The use of TI leaves in different liver diseases, having apoptosis as the underlying pathology, hence warrants further clinical investigation.

Curcumin-loaded γ-cyclodextrin liposomal nanoparticles as delivery vehicles for osteosarcoma

The delivery of curcumin, a broad-spectrum anticancer drug, has been explored in the form of liposomal nanoparticles to treat osteosarcoma (OS). Curcumin is water insoluble and an effective delivery route is through encapsulation in cyclodextrins followed by a second encapsulation in liposomes. Liposomal curcumin's potential was evaluated against cancer models of mesenchymal (OS) and epithelial origin (breast cancer). The resulting 2-Hydroxypropyl-γ-cyclodextrin/curcumin - liposome complex shows promising anticancer potential both in vitro and in vivo against KHOS OS cell line and MCF-7 breast cancer cell line. An interesting aspect is that liposomal curcumin initiates the caspase cascade that leads to apoptotic cell death in vitro in comparison with DMSO-curcumin induced autophagic cell death. In addition, the efficiency of the liposomal curcumin formulation was confirmed in vivo using a xenograft OS model. Curcumin-loaded γ-cyclodextrin liposomes indicate significant potential as delivery vehicles for the treatment of cancers of different tissue origin.

FROM THE CLINICAL EDITOR

Curcumin-loaded γ-cyclodextrin liposomes were demonstrated in vitro to have significant potential as delivery vehicles for the treatment of cancers of mesenchymal and epithelial origin. Differences between mechanisms of cell death were also evaluated.

Liquiritigenin Derivatives and Their Hepatotoprotective Activity

Liquiritigenin (7,4’-dihydroxyflavanone), isolated from the roots of Glycyrrhiza Glabra, was derivatized to liquiritigenin 7, 4’-diacetate, liquiritigenin 4’-acetate, isoliquiritigenin, and liquiritigenin 7, 4’-dibenzoate. All these derivatives were evaluated for in vitro hepatoprotective activity against D-galactosamine–lipopolysaccharide(GalN/LPS) induced toxicity. In-vitro hepatotoxicity was manifested by a significant increase ( P < 0.05) in liver toxicity biomarkers (SGPT, SGOT, ALKP, triglyceride, LPO, NO and LDH). The level of biomarkers in the treatment groups was significantly decreased ( P< 0.05) when compared with the GalN/LPS group. The results revealed that isoliquiritigenin exhibited better hepatoprotective activity than liquiritigenin and its derivatives.

Loading of curcumin in polyelectrolyte multilayers

Polyelectrolyte multilayer (PEM) thin films prepared using the layer-by-layer technique are proposed as a matrix for the immobilization of 1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-2,5-dione (curcumin), a lipophilic model drug. The PEM assembly was based on the layer-by-layer deposition of cationic poly(diallyldimethyl-ammonium chloride) (PDADMAC) and anionic poly(4-styrene sulfonate, sodium salt) (PSS) onto a quartz slide. Curcumin was loaded by dipping the PEM film into a dilute solution of curcumin dispersed in an 80/20% v/v water/ethanol solution. Within a few minutes, the film turned bright yellow as a result of the curcumin loading. The effect of the solvent composition, curcumin concentration and film thickness on the final concentration of curcumin in the PEM films was measured by UV-vis spectroscopy. The loading of curcumin was driven by its partitioning in the PEM film, and its partitioning coefficient between the 80/20 solvent and the PEM thin film was found to have a value of 2.07 x 10(5). The extinction coefficient of curcumin loaded into PEM was calculated to 64,000 M(-1) cm(-1). Results show that the loading of curcumin into the PEM films increased with the number of deposited layers, implying that curcumin partitioned into the bulk of the thin film. The maximum curcumin dose in the PEM film was measured by exposing films of various thicknesses to a high concentration (0.01% w/v) of curcumin and recording the maximum absorbance after saturation. The films thicknesses were controlled by the number of deposited PDADMAC/PSS layers (10, 20, 30, 40, 50, and 60). Results show that increasing amounts of curcumin could be loaded into the film with an increasing number of layers and up to 8 microg/cm(2) of curcumin could be loaded into a 20-layer film. These results demonstrate that the loading of lipophilic curcumin in PEM thin films is done through a partitioning mechanism and that the PDADMAC/PSS film can be used as a loading matrix for lipophilic drugs.

Rubus sanctus protects against carbon tetrachloride-induced toxicity in rat isolated hepatocytes: isolation and characterization of its galloylated flavonoids

Objectives

Rubus sanctus Schreb., known from the Bible as ‘holy thorn bush’, grows wild in Egypt. Rubus sanctus aqueous alcoholic extract (RE) contains a complicated phenolic mixture (ellagitanins, flavonoids and caffeic acid derivatives). In this study, the phytochemical investigation of the plant was re-evaluated. Herein, we report on the isolation and identification of three galloylated flavonoids, namely kaempferol-3-O-(6″-O-galloyl)-4C1-β-d-galactopyranoside, quercetin-3-O-(6″-O-galloyl)-4C1-β-d-galactopyranoside and myricetin-3-O-(6″-O-galloyl)- C1-β-d-galactopyranoside for the first time from the Rubus genus. We further aimed at evaluating the potential protective effects of RE against carbon tetrachloride (CCl4)-induced toxicity in isolated rat hepatocytes.

Methods

Based on an initial concentration-response experiment, a concentration of 100 μg/ml was selected to investigate the hepatoprotective activity of RE.

Key findings

Pretreatment with RE afforded protection as indicated by counteracting CCl4-induced cell death, and reduced glutathione depletion. In addition, RE ameliorated CCl4-induced enzyme leakage by 40% for lactate dehydrogenase, 30% for alanine aminotransferase and 20% for aspartate aminotransferase as compared with CCl4-treated cells. Moreover, RE counteracted CCl4-induced lipid peroxidation and inhibited spontaneous lipid peroxidation in the control group.

Conclusions

In conclusion, RE protects against CCl4-induced toxicity in isolated rat hepatocytes.

Curcumin and cancer cells: how many ways can curry kill tumor cells selectively?

Cancer is a hyperproliferative disorder that is usually treated by chemotherapeutic agents that are toxic not only to tumor cells but also to normal cells, so these agents produce major side effects. In addition, these agents are highly expensive and thus not affordable for most. Moreover, such agents cannot be used for cancer prevention. Traditional medicines are generally free of the deleterious side effects and usually inexpensive. Curcumin, a component of turmeric (Curcuma longa), is one such agent that is safe, affordable, and efficacious. How curcumin kills tumor cells is the focus of this review. We show that curcumin modulates growth of tumor cells through regulation of multiple cell signaling pathways including cell proliferation pathway (cyclin D1, c-myc), cell survival pathway (Bcl-2, Bcl-xL, cFLIP, XIAP, c-IAP1), caspase activation pathway (caspase-8, 3, 9), tumor suppressor pathway (p53, p21) death receptor pathway (DR4, DR5), mitochondrial pathways, and protein kinase pathway (JNK, Akt, and AMPK). How curcumin selectively kills tumor cells, and not normal cells, is also described in detail.