Regioselective one-pot synthesis and anti-proliferative and apoptotic effects of some novel tetrazolo[1,5-a]pyrimidine derivatives

Potentials of Ulva spp.-derived sulfated polysaccharides as gelling agents with promising therapeutic effects

Ulvan, a sulfated polysaccharide extracted from Ulva spp., has garnered significant attention in the food and pharmaceutical industries due to its potential health benefits. These include immunomodulation, antiviral, anti-inflammatory, anti-hyperlipidemic, and anti-cancer effects. Nonetheless, practical applications in these fields remain limited due to an incomplete understanding of its gelation mechanisms. Additionally, the underlying mechanisms of its gelation have not been completely understood and thoroughly reviewed. The primary objective is to provide current insights into ulvan's gelling mechanisms and potential health impacts. This review also delves into the existing applications of ulvan polysaccharides. By unraveling these aspects, the information provided in this work is expected to deepen our understanding of ulvan's gelation mechanisms and its prospective role in enhancing health, holding promise for advancements in the fields of food science and disease prevention. This work's theoretical insights contribute significantly to a deeper understanding of these aspects, which holds paramount importance in unleashing the full potential of ulvan and elevating its scientific significance.

Shikimic acid recovers diarrhea and its complications in SD rats fed lactose diet to induce diarrhea

BACKGROUND

Diarrhea is the increase of excretion of human water content and an imbalance in the physiologic processes of the small and large intestine while shikimic acid is an important biochemical metabolite in plants. This study aims to study the anti-diarrheal activity of shikimic acid through restoring kidney function, antioxidant activity, inflammatory markers, sodium/potassium-ATPase activity, apoptosis genes, and histology of the kidney in SD rats fed lactose diet to induce diarrhea.

RESULTS

Thirty-six male SD rats (150 ± 10 g, 12 weeks old) were divided into 2 equal groups (18 rats/group) as follows: normal and diarrheal rats. Normal rats were divided into 3 equal groups of 6 rats each: the control, shikimic acid, and desmopressin drug groups. Diarrheal rats were also divided into 3 equal groups of 6 rats each: diarrheal, diarrheal rats + shikimic acid, and diarrheal rats + desmopressin drug groups. Shikimic acid restored serum urea and creatinine, urinary volume, kidney weight, sodium, potassium, and chloride balance in serum and urine. The acid returned the antioxidant (superoxide dismutase, glutathione peroxidase, catalase, malondialdehyde, NADPH oxidase activity, conjugated dienes, and oxidative index) activity and the inflammatory markers (tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-10) to values approaching the control values. Shikimic acid also restored the sodium/potassium-ATPase activity, the apoptosis genes p53 and bcl-2, and the histology of kidney tissue in diarrheal rats to be near the control group.

CONCLUSIONS

Shikimic acid rescues diarrhea and its complications through restoring kidney function, serum and urinary electrolytes, antioxidant activity, inflammatory markers, sodium/potassium-ATPase activity, the apoptosis genes, and the histology of the kidney in diarrheal rats to approach the control one.

Rutin and Hesperidin Revoke the Hepatotoxicity Induced by Paclitaxel in Male Wistar Rats via Their Antioxidant, Anti-Inflammatory, and Antiapoptotic Activities

Paclitaxel, one of the most effective chemotherapeutic drugs, is used to treat various cancers but it is exceedingly toxic when used long-term and can harm the liver. This study aimed to see if rutin, hesperidin, and their combination could protect male Wistar rats against paclitaxel (Taxol)-induced hepatotoxicity. Adult male Wistar rats were subdivided into 5 groups (each of six rats). The normal group was orally given the equivalent volume of vehicles for 6 weeks. The paclitaxel-administered control group received intraperitoneal injection of paclitaxel at a dose of 2 mg/Kg body weight twice a week for 6 weeks. Treated paclitaxel-administered groups were given paclitaxel similar to the paclitaxel-administered control group together with oral supplementation of rutin, hesperidin, and their combination at a dose of 10 mg/Kg body weight every other day for 6 weeks. The treatment of paclitaxel-administered rats with rutin and hesperidin significantly reduced paclitaxel-induced increases in serum alanine transaminase, aspartate transaminase, lactate dehydrogenase, alkaline phosphatase, and gamma-glutamyl transferase activities as well as total bilirubin level and liver lipid peroxidation. However, the levels of serum albumin, liver glutathione content, and the activities of liver superoxide dismutase and glutathione peroxidase increased. Furthermore, paclitaxel-induced harmful hepatic histological changes (central vein and portal area blood vessel congestion, fatty changes, and moderate necrotic changes with focal nuclear pyknosis, focal mononuclear infiltration, and Kupffer cell proliferation) were remarkably enhanced by rutin and hesperidin treatments. Moreover, the elevated hepatic proapoptotic mediator (caspase-3) and pro-inflammatory cytokine (tumor necrosis factor-α) expressions were decreased by the three treatments in paclitaxel-administered rats. The cotreatment with rutin and hesperidin was the most effective in restoring the majority of liver function and histological integrity. Therefore, rutin, hesperidin, and their combination may exert hepatic protective effects in paclitaxel-administered rats by improving antioxidant defenses and inhibiting inflammation and apoptosis.

Immunomodulatory, Antioxidant, Anticancer, and Pharmacokinetic Activity of Ulvan, a Seaweed-Derived Sulfated Polysaccharide: An Updated Comprehensive Review

Cancer is one of the most worldwide spread diseases and causes maximum death. Treatment of cancer depends on the host immune system and the type of drugs. The inefficiency of conventional cancer treatments as a result of drug resistance, nontargeted delivery, and chemotherapy-related negative side effects has caused bioactive phytochemicals to come into focus. As a result, recent years have seen an increase in research into screening and identifying natural compounds with anticancer properties. Recent studies on the isolation and use of polysaccharides derived from various marine algal species have revealed a variety of biological activities, including antioxidant and anticancer properties. Ulvan is a polysaccharide derived from various green seaweeds of the Ulva species in the family Ulvaceae. It has been demonstrated to have potent anticancer and anti-inflammatory properties through the modulation of antioxidants. It is vital to understand the mechanisms underlying the biotherapeutic activities of Ulvan in cancer and its role in immunomodulation. In this context, we reviewed the anticancer effects of ulvan based on its apoptotic effects and immunomodulatory activity. Additionally, we also focused on its pharmacokinetic studies in this review. Ulvan is the most conceivable candidate for use as a cancer therapeutic agent and could be used to boost immunity. Moreover, it may be established as an anticancer drug once its mechanisms of action are understood. Due to its high food and nutritive values, it can be used as a possible dietary supplement for cancer patients in the near future. This review may provide fresh perspectives on the potential novel role of ulvan, reveal a brand-new cancer-prevention strategy, and improve human health.

Rutin and Quercetin Counter Doxorubicin-Induced Liver Toxicity in Wistar Rats via Their Modulatory Effects on Inflammation, Oxidative Stress, Apoptosis, and Nrf2

The presented study was performed to verify whether rutin and/or quercetin can inhibit liver injury induced by doxorubicin (DXR) in male Wistar rats. In this study, male Wistar rats were treated via the oral route with rutin and quercetin (50 mg/kg) either alone or in combination every other day for five weeks concomitant with receiving intraperitoneal DXR (2 mg/kg) two times a week for five successive weeks. Quercetin, rutin, and their combination significantly improved the deteriorated serum AST, ALT, and ALP activities and total bilirubin level, as well as albumin, AFP, and CA 19.9 levels in DXR-injected rats. Treatments of the DXR-injected group with quercetin and rutin prevented the elevation in liver lipid peroxidation and the reduction in superoxide dismutase, glutathione-S-transferase and glutathione peroxidase activities, and glutathione content. Treatments with quercetin and rutin significantly repressed the elevated expression of liver p53 and TNF-α and enhanced Nrf2 expression. Furthermore, the treatments significantly reduced DXR-induced liver histological changes. In conclusion, rutin and quercetin either alone or in combination may have potential preventive effects against DXR-induced hepatotoxicity through inhibiting oxidative stress, inflammation, and apoptosis as well as modulating the Nrf2 expression.

Thyme Oil and Thymol Counter Doxorubicin-Induced Hepatotoxicity via Modulation of Inflammation, Apoptosis, and Oxidative Stress

Doxorubicin (DOX) is an effective anticancer agent with a wide spectrum of activities. However, it has many adverse effects on various organs especially on the liver. Thymol, one of the major components of thyme oil, has biological properties that include anti-inflammatory and antioxidant activities. Thus, this study was designed to examine thyme oil and thymol for their ability to prevent doxorubicin-induced hepatotoxicity in Wistar rats. Hepatotoxicity was induced by an intraperitoneal injection of doxorubicin, at a dose of 2 mg/kg bw/week, for seven weeks. Doxorubicin-injected rats were supplemented with thyme oil and thymol at doses 250 and 100 mg/kg bw, respectively, four times/week by oral gavage for the same period. Treatment of rats with thyme oil and thymol reversed the high serum activities of AST, ALT, and ALP and total bilirubin, AFP, and CA19.9 levels, caused by doxorubicin. Thyme oil and thymol also reduced the high levels of TNF-α and the decreased levels of both albumin and IL-4. These agents ameliorated doxorubicin-induced elevation in hepatic lipid peroxidation and associated reduction in GSH content and GST and GPx activities. Further, the supplementation with thyme oil and thymol significantly augmented mRNA expression of the level of antiapoptotic protein Bcl-2 and significantly downregulated nuclear and cytoplasmic levels of the hepatic apoptotic mediator p53. Thus, thyme oil and thymol successfully counteracted doxorubicin-induced experimental hepatotoxicity via their anti-inflammatory, antioxidant, and antiapoptotic properties.

Nutraceutical potentials of algal ulvan for healthy aging

Several theories for aging are constantly put forth to explain the underlying mechanisms. Oxidative stress, DNA dysfunction, inflammation, and mitochondrial dysfunction, along with the release of cytochrome c are some of these theories. Diseases such as type 2 diabetes mellitus, intestinal dysfunction, cardiovascular diseases, hepatic injury, and even cancer develop with age and eventually cause death. Ulva polysaccharides, owing to their special structures and various functions, have emerged as desirable materials for keeping healthy. These polysaccharide structures are found to be closely related to the extraction methods, seaweed strains, and culture conditions. Ulvan is a promising bioactive substance, a potential functional food, which can regulate immune cells to augment inflammation, control the activity of aging-related genes, promote tumor senescence, enhance mitochondrial function, maintain liver balance, and protect the gut microbiome from inflammatory attacks. Given the desirable physiochemical and gelling properties of ulvan, it would serve to improve the quality and shelf-life of food.

Advances in the chemical and biological diversity of heterocyclic systems incorporating pyrimido[1,6-a]pyrimidine and pyrimido[1,6-c]pyrimidine scaffolds

Heterocycles incorporating a pyrimidopyrimidine scaffold have aroused great interest from researchers in the field of medical chemistry because of their privileged biological activities; they are used as anti-bacterial, antiviral, anti-tumor, anti-allergic, antihypertensive, anticancer, and hepatoprotective agents. Therefore, the present study aims to investigate the chemistry of heterocycles incorporating pyrimido[1,6-a]pyrimidine and pyrimido[1,6-c]pyrimidine skeletons and their biological characteristics. The main sections discuss (1) the synthetic routes to obtain substituted pyrimidopyrimidines, pyrimido[1,6-a]pyrimidin-diones, pyrimidoquinazolines, tricyclic, tetracyclic, and binary systems; (2) the reactivity of the substituents attached to the pyrimidopyrimidine skeleton, including thione and amide groups, nucleophilic substitutions, condensations, ring transformations, and coordination chemistry; (3) compounds of this class of heterocycles containing a significant characteristic scaffold and possessing a wide range of biological characteristics.

Rupatadine, a dual antagonist of histamine and platelet-activating factor (PAF), attenuates experimentally induced diabetic nephropathy in rats

The role of histamine and platelet activating factor (PAF) as involved mediators in the pathophysiology of diabetic complications, in particular diabetic nephropathy (DN), has become a new focus of concern. Accordingly, the present study designed to explore the effect of rupatadine (RUP), a dual antagonist of histamine (H1) and PAF, on the progression of experimentally induced DN in rats. Rats were divided into five groups: control, RUP alone, streptozotocin (STZ)-diabetic model, STZ/RUP (3 mg/kg/day), and STZ/RUP (6 mg/kg/day). Treatment has continued for 4 weeks after diabetes confirmation. At the end of the study, serum was collected for measurement of glucose, insulin, urea, creatinine, histamine, and PAF. Renal tissue homogenates were prepared for measuring oxidative stress indices, tumor necrosis factor (TNF-α), cystatin C, and p21. Moreover, immunohistochemical expression of transforming growth factor-β1 (TGF-β1) and p53 along with histological pictures was also conducted. Antagonizing H1 and PAF receptors by RUP ameliorated the experimentally induced DN as evident by decreasing all serum parameters augmented by STZ together with improvement of the histopathological picture. RUP administration also improved oxidative-antioxidative agents with reduction in the anti-inflammatory marker, TNF-α. Additionally, the immunohistochemical expression of the fibrosis marker; TGF-β1, was also decreased. STZ-induced DN showed a p21/p53-dependent induction of premature senescence and RUP administration decreased the expression of p21 and p53 levels in injured renal tissue. RUP represents a novel promising drug to prevent DN complicated diabetes probably via its inhibitory effect on H1 and PAF receptors. The renal protection was also related to the anti-inflammatory and antioxidant roles and PAF-facilitated senescence effect via p21/p53 signaling.

Effects of enalapril and paricalcitol treatment on diabetic nephropathy and renal expressions of TNF-α, p53, caspase-3 and Bcl-2 in STZ-induced diabetic rats

This study aimed to assess the renopreventive effect of enalapril and/or paricalcitol on streptozotocin (STZ) diabetes-induced nephropathy and to elucidate their mechanisms of action through investigation of the effects on renal oxidative stress, antioxidant defense system and expressions of TNF-α, p53, caspase-3, and Bcl-2. Diabetes mellitus was induced in fasting male Wistar rats by single intraperitoneal injection of STZ (45 mg /kg b.w.) dissolved in citrate buffer (pH 4.5). Ten days after STZ injection, the diabetic rats were treated with enalapril (25 mg/l of drinking water) and/or paricalcitol (8 μg/kg b.w. per os) dissolved in 5% DMSO daily for 4 weeks. The obtained data revealed that the treatment of diabetic Wistar rats with enalapril and/or paricalcitol led to significant decreases in the elevated serum urea, uric acid, creatinine, sodium and potassium levels; thereby reflecting the improvement of the impaired kidney function. The deteriorated kidney lipid peroxidation, GSH content and GST and catalase activities in diabetic rats were significantly ameliorated as a result of treatment with enalapril and/or paricalcitol. The elevated fasting and post-prandial serum glucose levels and the lowered serum insulin and C-peptide levels were also improved. The treatment with enalapril and paricalcitol in combination was the most potent in decreasing the elevated serum glucose levels. Moreover, the treatment of diabetic rats successfully prevented the diabetes-induced histopathological deleterious changes of kidney and islets of Langerhans of pancreas. In association, the immunohistochemically detected pro-inflammatory cytokine, TNF-α, and apoptotic mediators, p53 and caspase-3, were remarkably decreased in kidney of diabetic rats as a result of treatment while the expression of anti-apoptotic protein Bcl-2 was increased. Based on these findings, it can be concluded that enalapril and paricalcitol alone or in combination can prevent STZ diabetes-induced nephropathy through amelioration of the glycemic state and antioxidant defense system together with the suppression of oxidative stress, inflammation and apoptosis. However, the treatment of diabetic rats with enalapril and paricalcitol in combination has no further significant improvement effects on renal function and damage when compared with enalapril or paclitaxel treated diabetic groups.

Effect of gabapentin on fetal rat brain and its amelioration by ginger

Intrauterine exposure to antiepileptic drugs (AEDs) is associated with neurodevelopmental alterations causing postnatal behavioral and cognitive alterations. These disorders are associated with the interference of these AEDs with the developing cerebral cortex and hippocampal neurons. Therefore, it is crucial to identify the drugs that should be avoided during pregnancy in order to prevent AED mediated developmental alterations. The present study was conducted to investigate the effects of prenatal exposure to the antiepileptic drug gabapentin (GBP) on the rat fetal brain during the organogenesis phase and to examine the potential ameliorative effect of ginger (Zingiber officinale). Consequently, the current study addressed the developmental neural changes on the histological, immuno-histochemical and ultrastructural levels. The brain of fetuses from the GBP group showed a highly significant decrease in their weight. Histologically, the cerebral cortex and hippocampus regions of fetuses maternally injected with GBP showed layer disorganization, vacuolated neuropil and massive cell degeneration. The expression of Caspase 3 was significantly increased in the brain of GBP fetuses, unlike the expression of Bcl-2 which was significantly decreased. On the ultrastructure level, the neurons showed pyknotic and chromatolytic nuclei. The cytoplasm was rarefied with swollen organelles. Co-administration of ginger evidently ameliorated most of these effects. In conclusion, GBP administration during pregnancy could possibly affect the developing fetal brain and ginger may have ameliorating effect against the induced GBP neurotoxicity and should be taken in parallel.

The Preventive Effects and the Mechanisms of Action of Navel Orange Peel Hydroethanolic Extract, Naringin, and Naringenin in N-Acetyl-p-aminophenol-Induced Liver Injury in Wistar Rats

N-Acetyl-p-aminophenol (APAP) or acetaminophen is the most common drug ingredient worldwide. It is found in more than 600 different over-the-counter and prescription medicines. Its long-term and overdose use is highly toxic and may result in liver injury. Thus, this study was designed to assess the preventive effects and to suggest the mechanisms of action of the navel orange peel hydroethanolic extract, naringin, and naringenin in APAP-induced hepatotoxicity in male Wistar rats. APAP was administered to male Wistar rats at a dose level of 0.5 g/kg body weight (b.w.) by oral gavage every other day for 4 weeks. APAP-administered rats were treated with the navel orange peel hydroethanolic extract (50 mg/kg b.w.), naringin (20 mg/kg b.w.), and naringenin (20 mg/kg b.w.) by oral gavage every other day during the same period of APAP administration. The treatments of APAP-administered rats with the peel extract, naringin, and naringenin produced a significant decrease in the elevated serum AST, ALT, ALP, LDH, and GGT activities as well as total bilirubin and TNF-α levels while they induced a significant increase in the lowered serum albumin and IL-4 levels. The treatments also resulted in a significant decrease in the elevated liver lipid peroxidation and enhanced the liver GSH content and SOD, GST, and GPx activities as compared with APAP-administered control; the peel extract was the most potent in improving the liver LPO, GSH content, and GPx activity. In addition, the three treatments significantly downregulated the elevated hepatic proapoptotic mediators p53, Bax, and caspase-3 and significantly upregulated the suppressed antiapoptotic protein, Bcl-2, in APAP-administered rats. In association, the treatments markedly amended the APAP-induced liver histopathological deteriorations that include hepatocyte steatosis, cytoplasmic vacuolization, hydropic degeneration, and necrosis together with mononuclear leucocytic and fibroblastic inflammatory cells' infiltration. In conclusion, the navel orange peel hydroethanolic extract, naringin, and naringenin may exert their hepatopreventive effects in APAP-administered rats via enhancement of the antioxidant defense system and suppression of inflammation and apoptosis.

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

An efficient synthesis methodology for a series of tetrazolo[1,5-a]pyrimidines substituted at the 5- and 7-positions from the cyclocondensation reaction [CCC + NCN] was developed. The NCN corresponds to 5-aminotetrazole and CCC to β-enaminone. Two distinct products were observed in accordance with the β-enaminone substituent. When observed in solution, the compounds can be divided into two groups: (a) precursor compounds with R = CF₃ or CCl₃, which leads to tetrazolo[1,5-a]pyrimidines in high regioselectivity with R at the 7-position of the heterocyclic ring; and (b) precursor compounds with R = aryl or methyl, which leads to a mixture of compounds, tetrazolo[1,5-a] pyrimidines (R in the 5-position of the ring) and 2-azidopyrimidines (R in the 4-position of the ring), which was attributed to an equilibrium of azide–tetrazole. In the solid state, all compounds were found as 2-azidopyrimidines. The regiochemistry of the reaction and the stability of the products are discussed on the basis of the data obtained by density functional theory (DFT) for energetic and molecular orbital (MO) calculations.

Effective DABCO-catalyzed synthesis of new tetrazolo[1,5-a]pyrimidine analogs

In this study, an efficient multicomponent one-pot route is described for the DABCO-catalyzed synthesis of tetrazolo[1,5-a]pyrimidines. This synthesis strategy is based on the reaction of malononitrile and aldehydes with 5-aminotetrazole monohydrate using 1,4-diazabicyclo[2.2.2]octane (DABCO) in i-PrOH under reflux conditions. This protocol is a simple, green, and low-cost technique to prepare new compounds with potential medicinal properties.

Ulva lactuca polysaccharides prevent Wistar rat breast carcinogenesis through the augmentation of apoptosis, enhancement of antioxidant defense system, and suppression of inflammation

BACKGROUND

Recently, several research studies have been focused on the isolation and function of the polysaccharides derived from different algal species, which revealed multiple biological activities such as antioxidant and antitumor activities. This study assesses the possible breast cancer chemopreventive properties of common seaweeds, sea lettuce, Ulva lactuca (ulvan) polysaccharides using in vitro bioassays on human breast cancer cell line (MCF-7) and an in vivo animal model of breast carcinogenesis.

METHODS

Cytotoxic effect of ulvan polysaccharides on MCF-7 was tested in vitro. For an in vivo investigation, a single dose of 25 mg/kg body weight 7,12-dimethylbenz[a]anthracene (DMBA) and ulvan polysaccharides (50 mg/kg body weight every other day) for 10 weeks were administered orally to the Wistar rats.

RESULTS

Deleterious histopathological alterations in breast tissues including papillary cyst adenoma and hyperplasia of ductal epithelial lining with intraluminal necrotic materials and calcifications were observed in the DMBA-administered group. These lesions were prevented in the DMBA-administered group treated with ulvan polysaccharides. The immunohistochemical sections depicted that the treatment of DMBA-administered rats with ulvan polysaccharides markedly increased the lowered pro-apoptotic protein, p53, and decreased the elevated anti-apoptotic marker, bcl2, expression in the breast tissue. The elevated lipid peroxidation and the suppressed antioxidant enzyme activities in DMBA-administered control were significantly prevented by the treatment with ulvan polysaccharides. The elevated levels of inflammatory cytokines tumor necrosis factor-α and nitric oxide were significantly ameliorated in DMBA-administered rats treated with ulvan polysaccharides as compared to DMBA-administered control.

CONCLUSION

In conclusion, ulvan polysaccharides at the level of initiation and promotion might have potential chemopreventive effects against breast carcinogenesis. These preventive effects may be mediated through the augmentation of apoptosis, suppression of oxidative stress and inflammation, and enhancement of antioxidant defense system.

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

The interaction of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole is an efficient synthetic approach to novel azaheterocycles. 2-Ethoxymethylidene-3-oxo esters bearing alkyl substituents react with 5-aminotetrazole to form ethyl 2-azido-4-alkylpyrimidine-5-carboxylates which are capable of subsequent nucleophilic substitution. The use of diethyl 2-ethoxymethylidenemalonate in this reaction resulted in ethyl 7-hydroxytetrazolo[1,5-a]pyrimidine-6-carboxylate, while ethyl 2-ethoxymethylidenecyanoacetate yielded 5-[2,6-diamino-3,5-bis(ethoxycarbonyl)pyridinium-1-yl]tetrazol-1-ide through an alternative pathway. Ethyl 2-benzoyl-3-ethoxyprop-2-enoate reacted with 5-aminotetrazole by two reaction routes to form ethyl 2-benzoyl-3-(1H-tetrazol-5-ylamino)prop-2-enoate and ethyl 7-(1-ethoxy-1,3-dioxo-3-phenylpropan-2-yl)-5-phenyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate.

Protective effect of Cupressus sempervirens extract against indomethacin-induced gastric ulcer in rats

Cupressus sempervirens (C. sempervirens) belongs to the family Cupressaceae. It is widspread in Northern Africa, Greece, Turkey, North America, Cyprus and Syria. Cupressuflavone is the major ingredient of the plant leave extract. The aim of the present study was to evaluate the antiulcerogenic activity of the extract of C. sempervirens leaves in gastric ulcer tissues induced by indomethacin. The results of the present study revealed that indomethacin significantly decreased glutathione S-transferase (GST), glutathione peroxidase (GPx), catalase (CAT), reduced glutathione (GSH), glutathione reductase (GR) and superoxide dismutase (SOD) levels, while it increased significantly lipid peroxidation (MDA), nitric oxide (NO) and protein carbonyl (PC) levels in gastric tissue. Furthermore, indomethacin decreased p53 expression, while it increased bcl-2 expression in gastric tissue. Pretreatment with 5%, 10% & 20% of the LD50 of C. sempervirens and cupressuflavone of indomethacin-treated rats restored all the above parameters to approach normal values. C. sempervirens at the highest dose was more effective than the two lower doses. C. sempervirens proved more potent than cupressuflavone. In conclusion, C. sempervirens exerted antiulcerogenic activity and the effect was dose-dependent and related to the cupressuflavone ingredient of the plant leave extract.

Synthesis and biological evaluation of novel 1,2-naphthoquinones possessing tetrazolo[1,5-a]pyrimidine scaffolds as potent antitumor agents

A series of novel 1,2-naphthoquinones possessing tetrazolo[1,5-a]pyrimidine scaffolds were synthesized and all the compounds exhibited excellent antitumor activities.

A review of syntheses of 1,5-disubstituted tetrazole derivatives

This report provides a brief overview of the various representative literature procedures for the synthesis of 1,5-disubstituted tetrazoles (1,5-DSTs) and fused 1,5-disubstituted tetrazoles with more than 120 references. Most of the published methods for the synthesis of 1,5-DSTs include the use of nitriles, amides, thioamides, imidoyl chlorides, heterocumulenes, isocyanates, isothiocyanates, carbodiimides, ketenimines, ketones, amines, and alkenes as the starting materials. The transformation of 1- and 5-substituted tetrazoles into 1,5-DSTs is also covered in this report.

Therapeutic effect of pectin on octylphenol induced kidney dysfunction, oxidative stress and apoptosis in rats

Octylphenol (OP) is one of ubiquitous pollutants in the environment. It belongs to endocrine-disrupting chemicals (EDC). It is used in many industrial and agricultural products. Pectin is a family of complex polysaccharides that function as a hydrating agent and cementing material for the cellulose network. The aim of this study was to evaluate the therapeutic effect of pectin in kidney dysfunction, oxidative stress and apoptosis induced by OP exposure. Thirty-two male albino rats were divided into four equal groups; group 1 control was injected intraperitoneally (i.p) with saline [1 ml/kg body weight (bwt)], groups 2, 3 & 4 were injected i.p with OP (50 mg/kg bwt) three days/week over two weeks period where groups 3 & 4 were injected i.p with pectin (25 or 50 mg/kg bwt) three days/week over three weeks period. The results of the present study revealed that OP significantly decreased glutathione-S-transferase (GST), glutathione peroxidase (GPx), catalase (CAT), reduced glutathione (GSH), glutathione reductase (GR) and superoxide dismutase (SOD) levels while increased significantly lipid peroxidation (MDA), nitric oxide (NO) and protein carbonyls (PC) levels in the kidney tissues. On the other hand, OP increased serum urea and creatinine. Furthermore, OP increased significantly serum uric acid but decreased significantly the kidney weight. Moreover, OP decreased p53 expression while increased bcl-2 expression in the kidney tissue. The treatment with either dose of pectin to OP-exposed rats restores all the above parameters to approach the normal values where pectin at higher dose was more effective than lower one. These results were supported by histopathological investigations. In conclusion, pectin has antioxidant and anti-apoptotic activities in kidney toxicity induced by OP and the effect was dose-dependent.

DNA binding, molecular docking and apoptotic inducing activity of nickel(ii), copper(ii) and zinc(ii) complexes of pyridine-based tetrazolo[1,5-a]pyrimidine ligands

The biological activity of metal(ii) complexes of tetrazolo[1,5-a]pyrimidine ligands show that the copper(ii) complexes may act as promising anticancer agents.

Synthesis and antimicrobial activity of some novel 5-alkyl-6-substituted uracils and related derivatives

6-chloro-5-ethyl-, n-propyl- and isopropyluracils 5a-c were efficiently prepared from the corresponding 5-alkybarbituric acids 3a-c via treatment with phosphorus oxychloride and N,N-dimethylaniline to yield the corresponding 5-alkyl-2,4,6-trichloro-pyrimidines 4a-c, which were selectively hydrolyzed by heating in 10% aqueous sodium hydroxide for 30 minutes. The reaction of compounds 5a-c with 1-substituted piperazines yielded the corresponding 5-alkyl-6-(4-substituted-1-piperazinyl)uracils 6a-j. The target 8-alkyltetrazolo[1,5-f]pyrimidine-5,7(3H,6H)-diones 7a-c were prepared via the reaction of 5a-c with sodium azide. Compounds 6a-j and 7a-c were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Compound 6h displayed potent broad-spectrum antibacterial activity, while compound 6b showed moderate activity against the Gram-positive bacteria. All the tested compounds were practically inactive against Candida albicans.

Prazosin induces p53-mediated autophagic cell death in H9C2 cells

Prazosin, a quinazoline-based α(1)-adrenoceptor antagonist, is known to induce cell death, and this effect is independent of its α-blockade activity. However, the detailed molecular mechanisms involved are still not fully understood. In this study, we found that prazosin, but not doxazosin, could induce patterns of autophagy in H9C2 cells, including intracellular vacuole formation, microtubule-associated protein 1 light chain 3 (LC3) conversion, and acidic vesicular organelle (AVO) augmentation. Western blot analysis of phosphorylated proteins showed that exposure to prazosin increased the levels of phospho-p53 and phospho-adenosine monophosphate-activated protein kinase (AMPK) but dramatically decreased the levels of phospho-mammalian target of rapamycin (mTOR), phospho-protein kinase B (Akt), and phospho-ribosomal protein S6 kinase (p70S6K). Furthermore, although pretreatments with the pharmacological autophagy inhibitor 3-methyladenine and the p53 inhibitor pifithrin-α suppressed prazosin-induced AVO formation, they did not reverse prazosin-induced decline in cell viability but enhanced prazosin-induced caspase-3 activation. From these results we suggest that prazosin induces autophagic cell death via a p53-mediated mechanism. When the autophagy pathway was inhibited, prazosin still induced programmed cell death, at least in part through apoptotic caspase-3 cascade enhancement. Thus, our results indicate a potential new target in prazosin-induced cell death.