Assessment of the cytotoxic, genotoxic, and antigenotoxic activities of Celtis iguanaea (Jacq.) in mice

Bioactivity and modulatory functions of Napoleona vogelii on oxidative stress-induced micronuclei and apoptotic biomarkers in mice

Napoleona vogelii is used in traditional medicine for the management of pain, inflammatory conditions and cancer. This study was conducted to investigate the modulatory mechanisms of methanol stem bark extract of N. vogelii on induction of micronuclei, apoptotic biomarkers and in vivo antioxidant enzymes in mice. Forty male albino mice were randomly divided into eight groups (n = 5) and were administered distilled water (DW, 5 mL/kg) as negative control, 100, 200 or 400 mg/kg of the extract respectively for 28 days before the injection of cyclophosphamide (CP, 40 mg/kg) i.p. on the 28th day. The remaining groups were administered 100, 200 or 400 mg/kg of the extract only for 28 days. Twenty four hours after injection of CP or administration of the last dose of extract, animals were euthanized by cervical dislocation and blood samples collected for determination of in vivo antioxidants, the spleen harvested for immunohistochemical expression of NFκB, Bcl-2, Bax and p53. Bone marrow smears were also made for the micronucleus assay. Treatment with the extract resulted in a significant (p < 0.0001) reduction in frequency of micronucleated polychromatic erythrocytes (MNPCEs) compared to CP exposed control conferring protection of 75.09, 94.74 and 96.84% at 100, 200 or 400 mg/kg respectively. In extract and CP exposed animals, there were significant (p < 0.05) increases in GSH, GST and SOD with a corresponding significant (p < 0.05) reduction in MDA. In addition, the extract significantly downregulated cytoplasmic levels of NFκB and Bcl-2 and upregulated Bax and p53. These findings demonstrate that N. vogelli may serve as an interesting lead for chemo-preventive drug development.

Chemical characterization, pharmacological effects, and toxicity of an ethanol extract of Celtis pallida Torr. (Cannabaceae) aerial parts

ETHNOPHARMACOLOGICAL RELEVANCE

Celtis pallida Torr (Cannabaceae) is employed as a folk medicine for the treatment of inflammation, pain, skin infections, and diarrhea, among other diseases.

AIM OF THE STUDY

The purpose of this work was to assess the chemical composition, the in vitro and in vivo toxicity, the antimicrobial, anti-inflammatory, antidiarrheal, antinociceptive, locomotor, and sedative effects of an ethanolic extract obtained from Celtis pallida aerial parts (CPE).

MATERIALS AND METHODS

The composition of CPE was carried out by GC-MS. The in vitro and in vivo toxic activity of CPE was estimated with the comet assay (10-1000 µg/ml) for 5 h in peripheral blood mononuclear cells, and the acute toxicity test (500-5000 mg/kg p.o.), for 14 days, respectively. The antimicrobial effect of CPE was evaluated using the minimum inhibitory concentration (MIC) assay, whereas the antidiarrheal activity (10-200 mg/kg p.o.) was calculated using the castor oil test. The antinociceptive effects of CPE (50-200 mg/kg p.o.) were estimated with the acetic acid and formalin tests, as well as the hot plate test. The sedative and locomotor activities of CPE (50-200 mg/kg p.o.) were assessed with the pentobarbital-induced sleeping time test and the rotarod test, respectively.

RESULTS

The main compound found in CPE was the triterpene ursolic acid (22% of the extract). CPE at concentrations of 100 µg/ml or higher induced genotoxicity in vitro and showed low in vivo toxicity (LD₅₀ > 5000 mg/kg p.o.). Additionally, CPE lacked (MIC > 400 µg/ml) antimicrobial activity but exerts antinociceptive (ED₅₀ = 12.5 ± 1.5 mg/kg) and antidiarrheal effects (ED₅₀ = 2.8 mg/kg), without inducing sedative effects or altering the locomotor activity. The antinociceptive activity of CPE suggests the participation of adrenoceptors, as well as the nitric oxide/cyclic guanosine monophosphate (cGMP) pathway.

CONCLUSION

C. pallida exerts its antinociceptive effects probably mediated by the nitric oxide/cyclic guanosine monophosphate (cGMP) pathway.

Antigenotoxicity protection of Carapa guianensis oil against mitomycin C and cyclophosphamide in mouse bone marrow

The aim of this study was to evaluate the possible protective of C. guianensis oil against MMC and CP, which are direct- and indirect-acting chemical mutagens, using the micronucleus test. Three experiments were performed. First the C. guianensis oil was co-administered to mice at doses of 250, 500 and 1000 mg/kg bw with 4 mg/kg bw MMC or 50 mg/kg bw CP. Second, the mutagenic drug (CP) was administered ip 50 mg/kg bw and after 6 and 12 hours 250 and 500 mg/kg bw of C. guianensis oil were administered. In the last, C. guianensis oil was administrated (250 and 500 mg/kg bw) during five days and after it was administered ip 50 mg/kg bw CP. The results obtained showed that the C. guianensis oil is not cytotoxic neither genotoxic to mouse bone marrow. Regarding the antimutagenic effect, all doses of C. guianensis oil were significantly (p < 0.05) effective in reducing the frequency of micronucleated polychromatic erythrocytes, when compared with MMC or CP alone. Based on these results, our results suggest that the C. guianensis oil shows medicinal potential as an antimutagenic agent, modulating the mutagenicity caused by both direct- and indirect-acting chemical mutagens, in a mammalian model.

Effects of an extract of Celtis aetnensis (Tornab.) Strobl twigs on human colon cancer cell cultures

Cancers of the digestive tract, in particular colorectal cancer (CRC), are among those most responsive to dietary modification. Research has shown that approximately 75% of all sporadic cases of CRC are directly influenced by diet. Many natural compounds have been investigated for their potential usefulness as cancer chemopreventive agents as they have been thought to suppress carcinogenesis mainly during the initiation phase due to their radical scavenger activity. Since there is an increasing interest in the in vivo protective effects of natural compounds contained in plants against oxidative damage involved in several human diseases such as cancer, the aim of the present research was to test the effects of a Celtis aetnensis (Tornab.) Strobl twig extract on a human colon carcinoma cell line (Caco2). In order to elucidate the mechanisms of action of this extract, LDH release, GSH content, ROS levels, caspase-3 and γ-GCS expression were also evaluated. The results revealed that the Celtis aetnensis extract reduced the cell viability of the Caco2 cells inducing apoptosis at the lowest concentration and necrosis at higher dosages. In addition, this extract caused an increase in the levels of ROS, a decrease in RSH levels and in the expression of HO-1. The expression of γ-GCS was not modified in the Celtis aetnensis-treated Caco-2 cells. These results suggest an interference of this extract on the oxidant/antioxidant cell balance with consequent cell damage. The present study supports the growing body of data suggesting the bioactivities of Celtis aetnensis (Tornab.) Strobl and its potential impact on cancer therapy and on human health.

Mitigating effect of Indian propolis against mitomycin C induced bone marrow toxicity

A major drawback with cancer chemotherapy is its severe toxic effects on non-target tissues. Assessment of natural products for their protective effect against anticancer drugs-induced toxicity is gaining importance in cancer biology. The present study was aimed at assessing the protective effect of hydroethanolic extract of Indian propolis (HEIP) against mitomycin C (MMC)-induced genotoxicity and cytotoxicity. Swiss albino mice were injected with various doses of HEIP (100, 200, 300, 400, 600 and 800 mg/kg b. wt., i.p) 1 h prior to MMC (8 mg/kg, i.p.) injection. The geno- and cyto-toxicities were evaluated in mice by performing bone marrow micronucleus and TUNEL assays. In vitro antioxidant and lipid peroxidation inhibitory assays were carried out to understand the mechanism of the protective effects. The significant increase in the frequency of micronculeated cells (12.51 ± 0.48), apoptotic cells (23.43 ± 1.86) and reduction in P/N ratio (0.69 ± 0.04) compared with control indicated the potential geno- and cytotoxic effects of MMC in bone marrow. Pretreatment with HEIP resulted in the significant recovery of the toxic effects induced by MMC. HEIP at 400 mg/kg b. wt. was found to be the optimum dose imparting the maximum protective effects. The in vitro antioxidant and lipid peroxidation inhibitory assays suggest that the extract possesses substantial free radical scavenging activities. In conclusion, HEIP possesses substantial geno- and cyto-protective properties against MMC, which could be mediated through efficient free radical scavenging and inhibitory effect on lipid peroxidation.

Mechanisms involved in the gastroprotective activity of Celtis iguanaea (Jacq.) Sargent on gastric lesions in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Celtis iguanaea (Canabaceae) is popularly known as esporão-de-galo, stands out among the medicinal plants used for treatment of gastric ulcers. In Brazil, the leaves they are used traditionally in infusion forms as an analgesic, antiasthmatic, digestive and diuretic.

AIM OF THE STUDY

The present study was aimed to investigate the antiulcer mechanisms of hexane extract Celtis iguanaea leaves (HE) in several induced-gastric ulcer and characterize its chemical composition.

MATERIALS AND METHODS

The HE was obtained by exhaustive extraction in Soxhlet apparatus. The chemical characterization of HE was performed by Electrospray Fourier transform ion cyclotron mass spectrometry (ESI FT-ICR MS) analysis. Mice were used for the evaluation of the gastroprotective activity. HE was analyzed in the HCl/ethanol, hypothermic restraint stress ulcer and acetic acid. In the investigation of the gastroprotective mechanisms of HE, were performed the amount of adhered gastric mucus, participation of the α2-adrenoceptor, nitric oxide (NO) and prostaglandins (PGs) using the HCl/ethanol-induced gastric mucosa lesion model.

RESULTS

ESI FT-ICR MS analysis of HE suggest the presence of compounds as lipids, sterol lipids, steroids glycosides and polyphenol glycosides. The oral administration of HE at doses of 100 mg/kg or 200 mg/kg was able to protect the gastric mucosa against HCl/ethanol (10 mL/kg p.o.), and HE at dose of 100mg/kg protected against hypothermic-restraint stress and acetic -induced gastric lesions. The pretreatment with Yoimbine (2mg/kg, s.c.), an antagonist α2-adrenergic, L-NAME (20mg/kg, s.c.), an inhibitor of nitric oxide synthesis or indomethacin (10mg/kg, s.c.), an inhibitor of prostaglandin production, reversed the gastroprotective activity of HE (100mg/kg, p.o.).

CONCLUSIONS

Our results suggest that the Celtis iguanaea HE exhibits gastroprotective activity in different gastric ulcer models. The mechanism of gastroprotective effect of Celtis iguanaea HE suggests the participation of mucus as well as the involvement of α2-adrenergic receptors, NO and prostaglandins. The hydroxyl-linolenic acid, linoleic acids and conjugated oxo-linoleic acids are among the phytoconstituents that were identified in the Celtis iguanaea HE.