A 9-aminoacridine derivative induces growth inhibition of Ehrlich ascites carcinoma cells and antinociceptive effect in mice.

Acridine derivatives have been found with anticancer and antinociceptive activities. Herein, we aimed to evaluate the toxicological, antitumor, and antinociceptive actions of N'-(6-chloro-2-methoxyacridin-9-yl)-2-cyanoacetohydrazide (ACS-AZ), a 9-aminoacridine derivative with antimalarial activity. The toxicity was assessed by acute toxicity and micronucleus tests in mice. The in vivo antitumor effect of ACS-AZ (12.5, 25, or 50 mg/kg, intraperitoneally, i.p.) was determined using the Ehrlich tumor model, and toxicity. The antinociceptive efficacy of the compound (50 mg/kg, i.p.) was investigated using formalin and hot plate assays in mice. The role of the opioid system was also investigated. In the acute toxicity test, the LD50 (lethal dose 50%) value was 500 mg/kg (i.p.), and no detectable genotoxic effect was observed. After a 7-day treatment, ACS-AZ significantly (p < 0.05) reduced tumor cell viability and peritumoral microvessels density, suggesting antiangiogenic action. In addition, ACS-AZ reduced (p < 0.05) IL-1ß and CCL-2 levels, which may be related to the antiangiogenic effect, while increasing (p < 0.05) TNF-α and IL-4 levels, which are related to its direct cytotoxicity. ACS-AZ also decreased (p < 0.05) oxidative stress and nitric oxide (NO) levels, both of which are crucial mediators in cancer known for their angiogenic action. Moreover, weak toxicological effects were recorded after a 7-day treatment (biochemical, hematological, and histological parameters). Concerning antinociceptive activity, ACS-AZ was effective on hotplate and formalin (early and late phases) tests (p < 0.05), characteristic of analgesic agents with central action. Through pretreatment with the non-selective (naloxone) and µ1-selective (naloxonazine) opioid antagonists, we observed that the antinociceptive effect of ACS-AZ is mediated mainly by µ1-opioid receptors (p < 0.05). In conclusion, ACS-AZ has low toxicity and antitumoral activity related to cytotoxic and antiangiogenic actions that involve the modulation of reactive oxygen species, NO, and cytokine levels, in addition to antinociceptive properties involving the opioid system.

Antitumor and antiangiogenic effects of Tonantzitlolone B, an uncommon diterpene from Stillingia loranthacea.

Natural products have played a pivotal role for the discovery of anticancer drugs. Tonantzitlolones are flexibilan-type diterpenes rare in nature; therefore, few reports have shown antiviral and cytotoxic activities. This study aimed to investigate the in vivo antitumor action of Tonantzitlolone B (TNZ-B) and its toxicity. Toxicity was evaluated in mice (acute and micronucleus assays). Antitumor activity of TNZ-B (1.5 or 3 mg/kg intraperitoneally - i.p.) was assessed in Ehrlich ascites carcinoma model. Angiogenesis and reactive oxygen species (ROS) and nitric oxide (NO) production were also investigated, in addition to toxicological effects after 7-day treatment. The LD50 (lethal dose 50%) was estimated at around 25 mg/kg (i.p.), and no genotoxicity was recorded. TNZ-B reduced the Ehrlich tumor's volume and total viable cancer cell count (p < 0.001 for both). Additionally, TNZ-B reduced peritumoral microvessel density (p < 0.01), suggesting antiangiogenic action. Moreover, a decrease was observed on ROS (p < 0.05) and nitric oxide (p < 0.001) levels. No significant clinical findings were observed in the analysis of biochemical, hematological, and histological (liver and kidney) parameters. In conclusion, TNZ-B exerts antitumor and antiangiogenic effects by reducing ROS and NO levels and has weak in vivo dose-repeated toxicity. These data contribute to elucidate the antitumor action of TNZ-B and point the way for further studies with this natural compound as an anticancer drug.

Bioactivities from marine algae of the genus Gracilaria.

Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted.

Plants of the American continent with antimalarial activity: [review] / Plantas do continente Americano com atividade antimalárica: [revisão]

Malaria is a human parasitic disease caused by protozoa species of the Plasmodium genus. This disease has affected populations of the tropical and subtropical regions. About 500 million new cases occur annually on the world and therefore it is considered an emerging disease of important public health problem. In this context, the natural products as vegetables species have their bioactive molecules as targets for pharmacological, toxicological and phytochemical studies towards the development of more effective medicines for the treatment of many diseases. So this work intends to aid the researchers in the study of natural products to the treatment of malaria. In this review, 476 plants of the American continent were related for the antimalarial activity and of these vegetables species 198 were active and 278 inactive for some type of Plasmodium when they were evaluated through of in vitro or in vivo bioassays models.

Malária é uma doença parasitária humana causada por protozoários do gênero Plasmodium. Esta doença tem acometido populações que habitam regiões tropicais e subtropicais. Anualmente, cerca de 500 milhões de casos ocorrem no mundo, o que permite ser considerada uma doença emergente de importância para a saúde pública. Neste contexto, os produtos naturais, a exemplo das espécies vegetais, têm suas moléculas bioativas como alvo para estudos farmacológicos, toxicológicos e fitoquímicos destinados à síntese de medicamentos mais eficazes para o tratamento de inúmeras doenças. Portanto, este trabalho fornece subsídio às pesquisas com produtos naturais para o tratamento da malária. Nesta revisão, 476 espécies de plantas do continente Americano foram relatadas para a atividade antimalárica, sendo destas 198 ativas e 278 inativas para algum tipo de Plasmodium, quando avaliados através de modelos in vitro e in vivo.

Natural products with antileprotic activity

Leprosy is a chronic infectious disease caused by Mycobacterium leprae bacillus. It was considered to be an incurable disease for ages. Nowadays leprosy is a vanishing disease although we can meet it principally in the tropical zone countries. Brazil has the second greatest number of leprosy cases around the world with almost 30,000 new cases diagnosed in 2005. The present work constitutes a literature review on plant extracts and chemically defined molecules of natural origin showing antileprotic activity. The review refers to 11 plants, their families, and geographical distribution, the utilized parts, the type of extract and the tested organism. It also includes 17 compounds isolated from higher plants and microorganisms, classified into appropriate chemical groups. Some aspects of recent antileprotic-activity-directed research on natural products are discussed. For this purpose 63 references were consulted.

A hanseníase é uma doença crônica infecciosa ocasionada pelo Mycobacterium leprae. Foi considerada incurável por muitos anos. Atualmente a lepra é uma doença em desaparecimento, apesar de podermos encontrá-la principalmente nos países da zona tropical. O Brasil é o país que tem o segundo maior número de casos de lepra ao redor do mundo com quase 30.000 novos casos diagnosticados em 2005. Este trabalho teve como objetivo revisar a literatura dos vegetais e substâncias de origem natural com atividade antileprótica. Foram encontradas 11 plantas e 17 substâncias isoladas de plantas e microrganismos que foram classificados em grupos químicos adequados. Alguns aspectos de pesquisa recente com produtos naturais direcionados à produção de drogas contra a lepra também são discutidos. Foram consultadas 63 referências.

Natural products inhibitors of the enzyme acetylcholinesterase / Produtos naturais inibidores da enzima acetilcolinesterase

Alzheimer's disease (AD) is a progressive, neurodegenerative pathology that primarily affects the elderly population, and is estimated to account for 50-60 percent of dementia cases in persons over 65 years of age. The main symptoms associated with AD involve cognitive dysfunction, primarily memory loss. Other features associated with the later stages of AD include language deficits, depression, behavioural problems including agitation, mood disturbances and psychosis. One of the most promising approaches for treating this disease is to enhance the acetylcholine level in the brain using acetylcholinesterase (AChE) inhibitors. The present work reviews the literature on plants and plant-derived compounds inhibitors of enzyme acetylcholinesterase. The review refers to 309 plant extracts and 260 compounds isolated from plants, which are classified in appropriate chemical groups and model tested, and cites their activity. For this purpose 175 references were consulted.

A Doença de Alzheimer (DA) é uma patologia neurodegenerativa, progressiva, que afeta principalmente a população idosa, responsável por 50-60 por cento dos casos de demência em pessoas com mais de 65 anos de idade. Os principais sintomas associado a DA envolve deficiência orgânica cognitiva, principalmente perda de memória. Outras características associadas com os estágios avançados de DA inclui déficit na linguagem, depressão, problemas de comportamento, inclusive agitação, alterações de humor e psicose.Um dos mais promissores caminhos para tratar esta doença é aumentar o nível de acetilcolina no cérebro usando inibidores da acetilcolinesterase (AChE). Este trabalho teve como objetivo revisar a literatura das plantas e substâncias encontradas nas plantas, inibidores da enzima acetilcolinesterase. Foram levantadas 309 plantas e 260 substâncias isoladas de plantas que foram classificados em grupos químicos adequados, os modelo testados, e suas atividades. Foram consultados 175 referências.

Review of the plants with anti-inflammatory activity studied in Brazil

The inflammatory reaction is a response of the organism against an injury and it involves the action of complex events and mediators through of the blood vessels. The present work is a literature survey of the extracts of plants with anti-inflammatory activity studied in Brazil. The review refers to 75 plants with their families, parts used, type of extract used, bioassay models and their activity.

Plants and their active constituents from South, Central, and North America with hypoglycemic activity

There has been marked interest in recent years in the use of plants for the treatment of diabetes. Plants have been found in many countries which have been indicated as having hypoglycemic activity. The present work is an up-to-date review with 178 references of crude plant extracts and chemically defined molecules with hypoglycemic activity from South, Central and North America. The review refers to 224 plants with their families, parts used and type of extract, organism tested and activity. It also includes 40 compounds isolated from those plants. Some aspects of recent research with natural products from plants directed to the treatment of diabetes are discussed.