Chemopreventive effect of Copaifera langsdorffii leaves hydroalcoholic extract on 1,2-dimethylhydrazine-induced DNA damage and preneoplastic lesions in rat colon

Aloe vera and copaiba oleoresin-loaded chitosan films for wound dressings: microbial permeation, cytotoxicity, and in vivo proof of concept

Chitosan films are commonly used for wound dressing, provided that this polymer has healing, mucoadhesiveness and antimicrobial properties. These properties can be further reinforced by the combination of chitosan with polysaccharides and glycoproteins present in aloe vera, together with copaiba oleoresin's pharmacological activity attributed to sesquiterpenes. In this work, we developed chitosan films containing either aloe vera, copaiba oil or both, by casting technique, and evaluated their microbial permeation, antimicrobial activity, cytotoxicity, and in vivo healing potential in female adult rats. None of the developed chitosan films promoted microbial permeation, while the cytotoxicity in Balb/c 3 T3 clone A31 cell line revealed no toxicity of films produced with 2 % of chitosan and up to 1 % of aloe vera and copaiba oleoresin. Films obtained with either 0.5 % chitosan or 0.5 % copaiba oleoresin induced cell proliferation which anticipate their potential for closure of wound and for the healing process. The in vivo results confirmed that tested films (0.5 % copaiba-loaded chitosan film and 0.5 % aloe vera-loaded chitosan film) were superior to a commercial dressing film. For all tested groups, a fully formed epithelium was seen, while neoformation of vessels seemed to be greater in formulations-treated groups than those treated with the control. Our work confirms the added value of combining chitosan with aloe vera and copaiba oil in the healing process of wounds.

Red propolis exhibits chemopreventive effect associated with antiproliferative and anti-inflammatory activities

INTRODUCTION

Red propolis is synthetized from exudates of Dalbergia ecastophyllum (L) Taub. and Symphonia globulifera L.f., presents isoflavones, guttiferone E, xanthochymol, and oblongifolin B and has anti-inflammatory, antioxidant, and antiproliferative activities.

OBJECTIVES

This study aimed to evaluate the antigenotoxic and anticarcinogenic potential of red propolis hydroalcoholic extract (RPHE) in rodents.

METHODS

The influence of RPHE in doxorubicin (DXR)-induced genotoxicity was investigated through the micronucleus test in Swiss mice. Blood samples were also collected to investigate oxidative stress, hepatotoxicity, and nephrotoxicity. Was investigated the influence of RPHE in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci, as well as its influence in proliferating cell nuclear antigen (PCNA) and the cyclooxygenase-2 (COX-2) expression in colon of rats, by immunohistochemistry.

RESULTS

The results showed that RPHE (48 mg/kg) reduced DXR-induced genotoxicity. Animals treated with DXR showed significantly lower GSH serum levels in comparison to the negative control. RPHE treatments did not attenuated significantly the DXR-induced GSH depletion. No difference was observed in cytotoxicity parameters of mice hematopoietic tissues between the treatment groups, as well as the biochemical parameters of hepatotoxicity and nephrotoxicity. RPHE (12 mg/kg) reduced the DMH-induced carcinogenicity and toxicity, as well as DMH-induced PCNA and COX-2 expression in colon tissue.

CONCLUSION

Therefore, was observed that the RPHE has chemopreventive effect, associated to antiproliferative and anti-inflammatory activities.

Novel antitumor activity of the combined treatment of galloylquinic acids from Copaifera lucens and doxorubicin in solid Ehrlich carcinoma-bearing mice via the modulation of the Notch signaling pathway

AIMS

This study aims to investigate the potential synergistic effect of the combined treatment of galloylquinic acids compounds from Copaifera lucens with doxorubicin via the modulation of the Notch pathway in Ehrlich carcinoma-bearing mice model.

MAIN METHODS

The solid tumor model was induced in mice by s.c. injection of Ehrlich cancerous cells in the right hind limb. Sixty mice were allocated into five different groups which included treated groups with galloylquinic acids compounds, doxorubicin and their combination. Normal and tumor control groups were also used. Different biological samples were collected to measure the levels of Notch1, Hes1, Jagged1, TNF-α, IL-6, and VEGF. Histopathological and immunohistochemical examinations of tumor tissues using specific anti-NF-kβ and anti-cyclin D1 antibodies were also performed.

KEY FINDINGS

Our results showed that the combined treatment of galloylquinic acids compounds with doxorubicin significantly inhibited Notch1, Hes1, Jagged1, TNF-α, IL-6, VEGF, NF-kβ, and cyclin D1 activities.

SIGNIFICANCE

Galloylquinic acids compounds exhibited promising synergistic chemotherapeutic and oncostatic effects and promoted the chemosensitivity of doxorubicin, mainly by inhibiting the Notch signaling pathway and its downstream effectors. These compounds may be considered in cancer therapy exhibiting improved efficacy and reduced side effects of chemotherapeutic agents.

Preventive activity of Copaifera langsdorffii Desf. leaves extract and its major compounds, afzelin and quercitrin, on DNA damage in in vitro and in vivo models

Copaifera langsdorffii Desf. is a plant found in South America, especially in Brazil. Oleoresin and the leaves of this plant is used as a popular medicinal agent. However, few studies on the chemical composition of aerial parts and related biological activities are known. This study aimed to examine the cytotoxic, genotoxic, and antigenotoxic potential of C. langsdorffii aerial parts hydroalcoholic extract (CLE) and two of its major compounds afzelin and quercitrin. The cytotoxic and antigenotoxic potential of CLE was determined as follows: 1) against genotoxicity induced by doxorubicin (DXR) or methyl methanesulfonate (MMS) in V79 cells; 2) by direct and indirect-acting mutagens in Salmonella typhimurium strains; and 3) by MMS in male Swiss mice. The protective effects of afzelin and quercitrin against DXR or MMS were also evaluated in V79 and HepG2 cells. CLE was cytotoxic as evidenced by clonogenic efficiency assay. Further, CLE did not induce a significant change in frequencies of chromosomal aberrations and micronuclei; as well as number of revertants in the Ames test demonstrating absence of genotoxicity. In contrast, CLE was found to be antigenotoxic in mammalian cells. The results also showed that CLE exerted inhibitory effect against indirect-acting mutagens in the Ames test. Afzelin and quercitrin did not reduce genotoxicity induced by DXR or MMS in V79 cells. However, treatments using afzelin and quercitrin decreased MMS-induced genotoxicity in HepG2 cells. The antigenotoxic effect of CLE observed in this study may be partially attributed to the antioxidant activity of the combination of major components afzelin and quercitrin.

Manool, a diterpene from Salvia officinalis, exerts preventive effects on chromosomal damage and preneoplastic lesions

The present study aimed to evaluate the effect of the manool diterpene on genomic integrity. For this purpose, we evaluated the influence of manool on genotoxicity induced by mutagens with different mechanisms of action, as well as on colon carcinogenesis. The results showed that manool (0.5 and 1.0 µg/ml) significantly reduced the frequency of micronuclei induced by doxorubicin (DXR) and hydrogen peroxide in V79 cells but did not influence genotoxicity induced by etoposide. Mice receiving manool (1.25 mg/kg) exhibited a significant reduction (79.5%) in DXR-induced chromosomal damage. The higher doses of manool (5.0 and 20 mg/kg) did not influence the genotoxicity induced by DXR. The anticarcinogenic effect of manool (0.3125, 1.25 and 5.0 mg/kg) was also observed against preneoplastic lesions chemically induced in rat colon. A gradual increase in manool doses did not cause a proportional reduction of preneoplastic lesions, thus demonstrating the absence of a dose-response relationship. The analysis of serum biochemical indicators revealed the absence of hepatotoxicity and nephrotoxicity of treatments. To explore the chemopreventive mechanisms of manool via anti-inflammatory pathways, we evaluated its effect on nitric oxide (NO) production and on the expression of the NF-kB gene. At the highest concentration tested (4 μg/ml), manool significantly increased NO production when compared to the negative control. On the other hand, in the prophylactic treatment model, manool (0.5 and 1.0 μg/ml) was able to significantly reduce NO levels produced by macrophages stimulated with lipopolysaccharide. Analysis of NF-kB in hepatic and renal tissues of mice treated with manool and DXR revealed that the mutagen was unable to stimulate expression of the gene. In conclusion, manool possesses antigenotoxic and anticarcinogenic effects and its anti-inflammatory potential might be related, at least in part, to its chemopreventive activity.

Probing the chemoprevention potential of the antidepressant fluoxetine combined with epigallocatechin gallate or kaempferol in rats with induced early stage colon carcinogenesis

The enhanced chemopreventive action against 1,2 Dimethylhydrazine (DMH)-induced preneoplastic lesion in rats could be achieved via simultaneous administration of the antidepressant fluoxetine (FLX) with two natural polyphenolic compounds viz., kaempferol (KMP) and/or epigallocatechin-gallate (EGCG). The obtained results revealed that single FLX pre-treatment possess a significant apoptotic effect by increasing the activity of serum and colon tissue caspase 3. It also attenuated the DMH driven increase in, colon tissue MDA, NO, PCNA and COX-2 expression as well as serum and colon tissue β-catenin, with a decrease in the multiplicity of ACF and number of MPLs. The combination of FLX with either KMP or EGCG improved the antioxidant, anti-inflammatory and antiproliferating activities but with higher apoptotic activity in case of KMP. Eventually, histopathological assessment of colon tissues exposed that while sole pre-treatment can improve DMH-induced hyperplasia with only moderate inflammatory infiltration, tissues from the combined pre-treatment regimens groups exhibited almost a normal colonic architecture with slight submucosal edema. The study proved that single FLX administration prior to DMH exerts a chemopreventive effect and that the investigated combined pre-treatment regimens demonstrated more potent chemopreventive and antiproliferative actions.

Licochalcone A, a licorice flavonoid: antioxidant, cytotoxic, genotoxic, and chemopreventive potential

Licochalcone A (LicoA) is a flavonoid derived from Glycyrrhiza spp. plants. The present study aimed to investigate the antioxidant, cytotoxic, genotoxic, and chemopreventive effects of LicoA in in vitro and in vivo systems. The results showed that LicoA (197.1 μM) scavenged 77.92% of free radicals. Concentrations of 147.75 µM or higher LicoA produced cytotoxicity in Chinese hamster ovary (CHO) fibroblasts. LicoA treatments of 4.43 to 10.34 µM did not exert genotoxic activity, but at 11.8 µM significantly lowered nuclear division indexes, compared to negative control, revealing cytotoxicity. Lower concentrations (1.85 to 7.39 µM) exhibited protective activity against chromosomal damage induced by doxorubicin (DXR) or methyl methanesulfonate (MMS) in CHO cells. LicoA exerted no marked influence on DXR-induced genotoxicity in mouse erythrocytes, but reduced pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in rat colon at 3.12 to 50 mg/kg b.w. Biochemical markers and body weight indicated no apparent toxicity. These findings contribute to better understanding the mechanisms underlying LicoA-initiated activity as a promising chemopreventive compound.

ABBREVIATIONS

AC, aberrant crypts; ACF, aberrant crypt foci; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BOD, biochemical oxygen demand; CHO, Chinese hamster ovary fibroblast; DMH, 1,2-dimethylhydrazine; DMSO, dimethyl sulfoxide; DPPH, 2,2-diphenyl-1-picrylhydrazyl; DXR, doxorubicin hydrochloride; EDTA, ethylenediaminetetraacetic acid; GA, gallic acid; LicoA, licochalcone A; MMS, methyl methanesulfonate; MNBC, micronucleated binucleated cells; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; XTT, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide.

Protective effect of Matricaria chamomilla extract against 1,2-dimethylhydrazine-induced colorectal cancer in mice

Background Colorectal cancer (CRC) is a major public health problem, with almost 1.8 million newly diagnosed cases and about 881,000 deaths annually. Chamomile (Matricaria chamomilla) is a well-documented medicinal herb that possesses anti-inflammatory and anti-carcinogenic properties. This study aimed to unravel the effect of aqueous chamomile extract against 1,2-dimethylhydrazine(DMH)-induced CRC in mice. Methods Male Balb/c mice received a weekly intraperitoneal injection of DMH (20 mg/kg body weight) for 12 weeks. Chamomile extract (150 mg/kg body weight/5 days/week p.o.) was administered at the initiation and post-initiation stages of carcinogenesis. Polyps count, histopathological analysis, real-time polymerase chain reaction (RT-PCR) analysis of Wnt signaling genes, ELISA of cyclooxygenase-2 (COX-2), and enzyme assay for inducible nitric oxide synthase (iNOS) were performed. Results Chamomile extract modulated the Wnt pathway in colonic tissues, where it significantly downregulated Wnt5a, β-catenin, T cell factor (Tcf4), lymphoid enhancer factor 1 (Lef1), c-Myc and Cyclin D1 expression levels, while it upregulated adenomatous polyposis coli (APC) and glycogen synthase kinase (GSK3β) expression levels. This extract significantly reduced COX-2 levels and iNOS activities. Polyps count and histopathological analysis provided supportive evidence for the biochemical and molecular analyses. Conclusions Chamomile can act as a potent dietary chemopreventive agent against DMH-induced CRC.

Phyto-derived Products as Matrix Metalloproteinases Inhibitors in Cardiovascular Diseases

Matrix metalloproteinases (MMPs) are enzymes that present a metallic element in their structure. These enzymes are ubiquitously distributed and function as extracellular matrix (ECM) remodelers. MMPs play a broad role in cardiovascular biology regulating processes such as cell adhesion and function, cellular communication and differentiation, integration of mechanical force and force transmission, tissue remodeling, modulation of damaged-tissue structural integrity, cellular survival or apoptosis and regulation of inflammation-related cytokines and growth factors. MMPs inhibition and downregulation are correlated with minimization of cardiac damage, i.e., Chinese herbal medicine has shown to stabilize abdominal aorta aneurysm due to its antiinflammatory, antioxidant and MMP-2 and 9 inhibitory properties. Thus phyto-derived products rise as promising sources for novel therapies focusing on MMPs inhibition and downregulation to treat or prevent cardiovascular disorders.

Biochemical and molecular aspects of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis: a review

1,2-dimethylhydrazine (DMH) is a member in the class of hydrazines, strong DNA alkylating agent, naturally present in cycads. DMH is widely used as a carcinogen to induce colon cancer in animal models. Exploration of DMH-induced colon carcinogenesis in rodent models provides the knowledge to perceive the biochemical, molecular, and histological mechanisms of different stages of colon carcinogenesis. The procarcinogen DMH, after a series of metabolic reactions, finally reaches the colon, there produces the ultimate carcinogen and reactive oxygen species (ROS), which further alkylate the DNA and initiate the development of colon carcinogenesis. The preneolpastic lesions and histopathological observations of DMH-induced colon tumors may provide typical understanding about the disease in rodents and humans. In addition, this review discusses about the action of biotransformation and antioxidant enzymes involved in DMH intoxication. This understanding is essential to accurately identify and interpret alterations that occur in the colonic mucosa when evaluating natural or pharmacological compounds in DMH-induced animal colon carcinogenesis.

Usnic acid attenuates genomic instability in Chinese hamster ovary (CHO) cells as well as chemical-induced preneoplastic lesions in rat colon

Usnic acid (UA) is one of the pharmacologically most important compounds produced by several lichen species. To better understand the mechanism of action (MOA) of this important substance, this study examined the genotoxicity attributed to UA and its influence on mutagens with varying MOA using the micronucleus (MN) test in Chinese hamster ovary cells (CHO). Additional experiments were conducted to investigate the effect of UA on colon carcinogenesis in Wistar rats employing the aberrant crypt focus (ACF) assay. In vitro studies showed a significant increase in the frequency of MN in cultures treated with the highest UA concentration tested (87.13 µM). In contrast, UA concentrations of 10.89, 21.78, or 43.56 µM produced an approximate 60% reduction in chromosomal damage induced by doxorubicin, hydrogen peroxide, and etoposide, indicating an antigenotoxic effect. In the ACF assay, male Wistar rats treated with different UA doses (3.125, 12.5, or 50 mg/kg b.w.) and with the carcinogen 1,2-dimethylhydrazine exhibited a significantly lower incidence of neoplastic lesions in the colon than animals treated only with the carcinogen. Data suggest that the MOA responsible for the chemopreventive effect of UA may be related to interaction with DNA topoisomerase II and/or the antioxidant potential of the compound.

Investigation of Safety Profile of Four Copaifera Species and of Kaurenoic Acid by Salmonella/Microsome Test

Trees of the Copaifera genus are native to the tropical regions of Latin America and Western Africa. Copaifera sp is widely used as a popular medicine and it has various ethnopharmacological indications, including gonorrhea, bronchitis, asthma, skin ulcers, ulcers, sore throat, uterine infections, general inflammations, cancer, and leishmanioses. Kaurenoic acid is a naturally occurring diterpene found in Copaifera and has been used as an anti-inflammatory, treatment of ulcer, leishmaniasis, and cancer. Bearing in mind the fact that the Ames test is an excellent tool to assess the safety of extracts, oils, and phytochemicals isolated from medicinal plants, from it, we evaluate the mutagenic potential of four species, between oleoresins (C. oblongifolia; C. langsdorffii) and leaves extracts (C. lucens; C. multijuga), of the Copaifera genus and also of kaurenoic acid, which is one of its major compounds. The results showed that the Copaifera spp. and kaurenoic acid did not induce an increase in the number of revertant colonies, without mutagenic effect in experiments, in the all concentrations evaluated by Ames test. The results obtained in our study support the safe use of the Copaifera genus medicinal plants selected and of kaurenoic acid.

Occurrence, chemical composition, biological activities and analytical methods on Copaifera genus-A review

Copaifera is a genus of large trees found in Brazil, mainly in Amazon forest, but also in Atlantic forest and cerrado biomes. It has also been found in other countries in South America. In Africa, it is found mainly in Congo, Cameroon, Guinea and Angola. Its oleoresin has been used in folk medicine in the treatment of numerous healthy disorders, such as urinary, respiratory, skin and inflammatory diseases, for which there are several studies corroborating its ethnopharmacological uses. It is also extensively employed in the pharmaceutical and cosmetic industries in the development of ointments, pills, soaps, perfumes, among others. Copaifera oleoresin contains mainly diterpenes, such as: kaurenoic acid, kaurenol, copalic acid, agathic acid, hardwiickic acid, polyalthic acid, and sesquiterpenes, comprising β-caryophyllene, caryophyllene oxide, α-copaene, α-humulene, γ-muurolene and β-bisabolol, among other compounds. On the other hand, Copaifera leaves contain mainly phenolic compounds, such as flavonoids and methylated galloylquinic acid derivatives. Therefore, considering the economic importance of Copaifera oleoresin, its ethnopharmacological uses, the need to develop new pharmaceuticals for the treatment of many diseases, as well as the pharmacological potential of the compounds found in Copaifera spp., it was undertaken a review covering mostly the last two decades on the distribution, chemistry, pharmacology, quality control and safety of Copaifera species.

Assessment of the antibacterial, cytotoxic and mutagenic potential of the phenolic-rich hydroalcoholic extract from Copaifera trapezifolia Hayne leaves

Copaifera trapezifolia Hayne occurs in the Atlantic Rainforest, which is considered one of the most important and endangered tropical forests on the planet. Although literature works have described many Copaifera spp., their biological activities remain little known. In the present study, we aimed to evaluate (1) the potential of the hydroalcoholic extract from C. trapezifolia leaves (CTE) to act against the causative agents of tooth decay and apical periodontitis and (2) the cytotoxicity and mutagenicity of CTE to ensure that it is safe for subsequent application. Concerning the tested bacteria, the MIC and the minimum bactericidal concentration of CTE varied between 100 and 400 µg ml-1. The time-kill assay conducted at a CTE concentration of 100 µg ml-1 evidenced bactericidal activity against Porphyromonas gingivalis (ATCC 33277) and Peptostreptococcus micros (clinical isolate) within 72 h. CTE at 200 µg ml-1 inhibited Porphyromonas gingivalis and Peptostreptococcus micros biofilm formation by at least 50 %. A combination of CTE with chlorhexidine dichlorohydrate did not prompt any synergistic effects. The colony-forming assay conducted on V79 cells showed that CTE was cytotoxic at concentrations above 156 µg ml-1. CTE exerted mutagenic effect on V79 cells, but the micronucleus test conducted on Swiss mice and the Ames test did not reveal any mutagenicity. Therefore, the use of standardized and safe extracts could be an important strategy to develop novel oral care products with antibacterial action. These extracts could also serve as a source of compounds for the discovery of new promising biomolecules.

Chemopreventive effect of myrtenal on bacterial enzyme activity and the development of 1,2-dimethyl hydrazine-induced aberrant crypt foci in Wistar Rats

Colon cancer remains as a serious health problem around the world despite advances in diagnosis and treatment. Dietary fibers are considered to reduce the risk of colon cancer as they are converted to short chain fatty acids by the presence of anaerobic bacteria in the intestine, but imbalanced diet and high fat consumption may promote tumor formation at different sites, including the large bowel via increased bacterial enzymes activity. The present study was conducted to characterize the inhibitory action of myrtenal on bacterial enzymes and aberrant crypt foci (ACF). Experimental colon carcinogenesis induced by 1,2-dimethylhydrazine is histologically, morphologically, and anatomically similar to human colonic epithelial neoplasm. Discrete microscopic mucosal lesions such as ACF and malignant tumors function as important biomarkers in the diagnosis of colon cancer. Methylene blue staining was carried out to visualize the impact of 1,2-dimethylhydrazine and myrtenal. Myrtenal-treated animals showed decreased levels of bacterial enzymes such as β-glucuronidase, β-glucosidase, and mucinase. Characteristic changes in the colon were noticed by inhibiting ACF formation in the colon. In conclusion, treatment with myrtenal provided altered pathophysiological condition in colon cancer-bearing animals with evidence of decreased crypt multiplicity and tumor progression.

Antiedematogenic Evaluation of Copaifera langsdorffii Leaves Hydroethanolic Extract and Its Major Compounds

Inflammatory disorders affect many people worldwide, and medicinal plants are used to ameliorate these health problems. This paper reports the antiedematogenic and analgesic evaluation of Copaifera langsdorffii Desf. leaves hydroethanolic extract (Cop) and two of its isolated compounds: quercetin-3-O-α-l-rhamnopyranosyl (quercitrin) and kaempferol-3-O-α-l-rhamnopyranosyl (afzelin). For that, the following experimental protocols were undertaken locomotor performance, writhing induced by acetic acid, antinociceptivity induced by formalin, hot plate latency, paw oedema induced by carrageenan and dextran, and cell migration induced by lipopolysaccharide (LPS), as well as the measurement of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 10 (IL-10) in macrophages. Neither the extract nor the isolated compounds displayed analgesic activity. The obtained results showed that C. langsdorffii extract possesses antiedematogenic properties acting on peripheral sites, whereas quercitrin and afzelin are not involved. Moreover, these properties are not associated with cell migration inhibition, TNF-α, IL-6, or IL-10 regulation.

Immunomodulatory action of Copaifera spp oleoresins on cytokine production by human monocytes

Copaifera spp oleoresins have been used in folk medicine for centuries; nevertheless, its immunomodulatory action has not been investigated. Thus, the goal of this study was to characterize different oleoresins and to verify their action on human monocytes regarding pro- and anti-inflammatory cytokine production (TNF-α and IL-10, respectively). The chemical composition of Brazilian Copaifera reticulata, Copaifera duckey and Copaifera multijuga oleoresins was analyzed by HPLC-MS. Cell viability was assessed by MTT method after incubation of cells with Copaifera spp. Noncytotoxic concentrations of oleoresins were incubated with human monocytes from healthy donors, and cytokine production was determined by ELISA. HPLC-MS analysis for terpenes allowed the identification of six diterpene acids and one sesquiterpene acid. Oleoresins exerted no cytotoxic effects on human monocytes. All oleoresins had a similar profile: LPS-induced TNF-α production was maintained by oleoresins, while a significant inhibitory action on IL-10 production was seen. Copaifera oleoresins seemed to exert an activator profile on human monocytes without affecting cell viability. Such effect may be due to the presence of either diterpene or sesquiterpene acids; however, further studies are necessary to determine the involvement of such compounds in Copaifera immunomodulatory effects.

Chemopreventive effects of (-)-hinokinin against 1,2-dimethylhydrazine-induced genotoxicity and preneoplastic lesions in rat colon

(-)-Hinokinin (1) is a dibenzylbutyrolactone lignan obtained by the partial synthesis of (-)-cubebin. This study reports the antigenotoxic and anticarcinogenic potential of 1 by the comet and aberrant crypt focus assays in the peripheral blood and colon of 4-5-week-old Wistar rats, respectively. The rats were exposed to 1,2-dimethylhydrazine (40 mg/kg) and were treated by gavage with doses of 10, 20, and 40 mg/kg of 1. The results showed that the dose of 40 mg/kg was neither genotoxic nor carcinogenic. In the comet assay, all 1 doses displayed antigenotoxic effects. In addition, this compound (20 and 40 mg/kg) exhibited an anticarcinogenic effect in the aberrant crypt focus assay.

Promising medicinal plants for bioprospection in a Cerrado area of Chapada do Araripe, Northeastern Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medical systems represent an important source of knowledge about the use of biodiversity. Ethnobotanical and ethnopharmacological studies can encourage bioprospecting in the pursuit and selection of promising medicinal plants. This study investigated the diversity of medicinal plants in a disjunct area of cerrado in Chapada do Araripe, Ceará, Brazil, and assessed the species of interest for bioprospecting.

MATERIALS AND METHODS

Structured and semi-structured interviews were conducted through free listing, and the informants were recruited using the "snowball" technique. The relative importance and informant consensus factor were analyzed for the selection of plant species with therapeutic potential.

RESULTS

A total of 68 species were recorded and cited for 91 therapeutic purposes. Of these, 10 species showed great versatility of use, including Copaifera langsdorffii Desf., Caryocar coriaceum Wittn., Himatanthus drasticus (Mart.) Plumel, Stryphnodendron rotundifolium Mart., and Dimorphandra garderiana Tull. The therapeutic citations were grouped into 16 categories of body systems, of which Injuries, Poisonings and Other Consequences of External Causes, and Neoplasias showed the highest agreement of use.

CONCLUSIONS

Regarding the diversity of the species, some including Tocoyena Formosa (Cham. & Schlecht.) Schum., Himatanthus drasticus, Caryocar coriaceum, Roupala montana Aubl. and Stryphnodendron rotundifolium showed both high relative importance and strong consensus among informants, and although many have already been investigated scientifically, others are almost unknown with respect to their medicinal properties and can be targets for bioprospecting.