C. citratus essential oil and carvacrol have shown an antitumor effect on breast tumor cell lines; the main objective of this research was to evaluate the antitumor effect of the essential oil of Cymbopogon citratus (EOCc) and carvacrol on 7,12-dimethylbenz [a] anthracene (DMBA)-induced breast cancer in female rats. Cancer was induced by a single administration of DMBA at dose of 80 mg/kg body weight (BW). A total of 54 female Holtzman rats were randomly assigned into 9 groups (n = 6). Group I: PS (Physiological saline); Group II: DMBA; Groups III, IV, and V: DMBA + EOCc at doses of 50, 100 and 200 mg/kg/day BW, respectively; Groups VI, VII, and VIII: DMBA + carvacrol at doses of 50, 100 and 200 mg/kg/day BW, respectively; and group IX: DMBA + EOCc + carvacrol at doses of 100 mg/kg/day BW. The treatment lasted 14 weeks. As results, EOCc showed a reduction in tumors as well as necrosis and mitosis. Animals treated with carvacrol did not show necrosis, mitosis, or infiltration. Carvacrol at dose of 100 mg/kg/day BW revealed a significant decrease in the cumulative tumor volume down to 0.11 ± 0.05 cm³ compared to 0.38 ± 0.04 cm³ of the DMBA group (p < 0.01). It is concluded that EOCc and carvacrol had an antitumor effect on DMBA-induced breast cancer in female rats.

Thymus vulgaris L. is widely used as an ingredient in cooking and in herbal medicine. However, there is little information about its toxicity. The present study was performed to evaluate the acute and repeated 28-day oral dose toxicity of thyme essential oil in rats. For the acute toxicity test, two groups of three rats were used. The rats received a single dose of essential oil: 300 or 2,000 mg/kg of body weight (bw). The rats were observed individually during the first four hours, and then daily until day 14. For the toxicity test with repeated doses, four groups of 10 rats were used. Doses of 100, 250, and 500 mg/kg/day were tested for 28 days. At the end of the experiment, blood was collected and the animals were sacrificed. Histopathological examination showed that in the lungs of rats given the 2,000 mg/kg bw dose, polymorph nuclear infiltrates, hemosiderin macrophages, and interstitial space thickening were present. In the repeated dose study, all rats survived the 28-day treatment period and apparently showed no signs of toxicity. The hematological and biochemical parameters were not altered. The histopathological study of the organs showed severe changes in the lung, with the dose of 500 mg/kg/day; in the other organs, no alterations were observed or the changes were slight. The body weight was only altered in male rats given the 500 mg/kg dose. The relative weight of the organs did not show any significant changes. Our studies revealed that the essential oil of Thymus vulgaris has moderate oral toxicity according to the results of the acute test, whereas the results of the 28-day oral toxicity test suggest that the no-observed-adverse effect level (NOAEL) is greater than 250 mg/kg/day.

Carvacrol is a phenol monoterpene found in aromatic plants specially in Lamiaceae family, which has been evaluated in an experimental model of breast cancer. However, any proposed mechanism based on its antitumor effect has not been reported. In our previous study, carvacrol showed a protective effect on 7,12‐dimethylbenz[α]anthracene‐ (DMBA‐) induced breast cancer in female rats. The main objective in this research was to evaluate by using in silico study the carvacrol on HER2, PI3Kα, mTOR, hER‐α, PR, and EGFR receptors involved in breast cancer progression by docking analysis, molecular dynamic, and drug‐likeness evaluation. A multilevel computational study to evaluate the antitumor potential of carvacrol focusing on the main targets involved in the breast cancer was carried out. The in silico study starts with protein‐ligand docking of carvacrol followed by ligand pathway calculations, molecular dynamic simulations, and molecular mechanics energies combined with the Poisson–Boltzmann (MM/PBSA) calculation of the free energy of binding for carvacrol. As result, the in silico study led to the identification of carvacrol with strong binding affinity on mTOR receptor. Additionally, in silico drug‐likeness index for carvacrol showed a good predicted therapeutic profile of druggability. Our findings suggest that mTOR signaling pathway could be responsible for its preventive effect in the breast cancer.

Annona muricata leaves are traditionally used as an anticancer plant in the world. The aim of this study was to evaluate the ameliorative effect of the essential oil from Annona muricata leaves (EOAm) in an experimental model of breast cancer and to determine the volatile constituents with gas chromatography-mass spectrometry (GC-MS). Thirty female rats were assigned to five groups: the control group; the DMBA (7,12-dimethylbenz[α]anthracene) group; and three groups received daily EOAm doses of 50, 100, and 200 mg/kg/day, plus DMBA, respectively. After 13 weeks of treatment, tumors were analyzed pathologically and biochemical markers in serum were noted. As a result, in GC-MS analysis, 40 compounds were identified and 4 of them were abundant: Z-caryophyllene (40.22%), followed by α-selinene (9.94%), β-pinene (8.92%), and β-elemene (7.48%). Furthermore, EOAm in a dose-dependent form produced a reduction in tumor frequency and the accumulated tumor volume was reduced by 50% and 71% with doses of 100 and 200 mg/kg, respectively. Serum levels of reduced glutathione (GSH) increased and malondialdehyde (MDA) decreased significantly compared to the DMBA group. Serum levels of vascular endothelial growth factor (VEGF) decreased significantly from 70.75 ± 7.15 pg/mL in the DMBA group to 46.50 ± 9.00 and 34.13 ± 11.50 pg/mL in groups treated with doses of 100 and 200 mg/kg, respectively. This study concludes that the EOAm leaves showed an ameliorative effect in a murine model of breast cancer.

Piper aduncum, commonly known as matico, is a plant that grows in the mountainous and coastal regions of Peru, and is studied for its antimicrobial properties and various ethnopharmacological uses. The main objective of this study was to determine the cytoprotective and antioxidant effects of the methanolic extract of Piper aduncum leaves in Mus musculus previously administered with sodium fluoride (NaF) using the Micronucleus test and the Comet assay. The extract was administrated orally in four different concentrations: 150, 300, 600, and 1200 mg/Kg for ten days. At the 11th day, a single dose of NaF was administrated via intraperitoneal at 20 mg/Kg. The genotoxicity study was performed with mice from the strain BALB/c, using the Micronucleus test on bone marrow and the Comet assay on peripheral blood according to OECD guidelines 474 and 489, respectively. The statistical analysis was performed by median analysis with ANOVA. Significant differences were found in Micronucleus frequency between the highest concentrations of Piper aduncum and NaF. The Comet assay showed significant reduction of NaF-induced damage on erythrocytes depending on the different concentrations of the extract which were evaluated in this study. It is concluded that the methanolic extract of P. aduncum leaves has cytoprotective and antioxidant activity against sodium fluoride.

Background: Cancer is considered a serious public health problem in the world; searching alternative treatments of medicinal plants constitute a promissory field to find new anticancer drugs. Objective: The aim of this study is to evaluate the phytochemical screening, total phenolic content (TPC), antioxidant, and cytotoxic activity of ethanol extracts of Waltheria ovata (WO), Piper aduncum (PA), Myrciaria dubia (MD), Physalis peruviana (PP), and Geranium dielsianum (GD) on human tumor cell lines. Materials and Methods: Phytochemical screening was assessed using chemical reactives. TPC was developed using Folin Ciocalteu reactive, and the antioxidant activity was determined against 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals by spectrophotometry. The cytotoxic activity was determined on human tumor cell lines followed as: MCF-7, H-460, HT-29, M-14, K-562, and DU-145. Results: Phytochemical study confirmed flavonoids and phenolic compounds in all extracts. TPC was found to be the highest in WO extract (1250 mg of gallic acid equivalent/g of dried extract) rather than other extracts. The highest antioxidant activity was stablished in WO extract for DPPH and ABTS radical scavenging tests (inhibitory concentration [IC₅₀] = 0.89 ± 0.01 μg/mL, IC₅₀ =4.20 ± 1.50 μg/mL). Ethanolic extracts (μg/mL) showed low cytotoxicity on human tumor cell lines (CI₅₀>20 μg/mL) for PA, PP, GD, MD. Meanwhile, WO presented cytotoxicity on H460, MCF-7, and K562 tumor cell lines. Conclusion: In our findings, WO and MD extracts revealed a high antioxidant and TPC. WO exhibited better cytotoxic effect compared with 5-FU. Hence, these medicinal plants could be effective to prevent cancer disease and oxidative stress. Abbreviations Used: IC50: Half inhibitory concentration. TPC: Total phenolic content. DPPH: ,2-Diphenyl-1-picrylhydrazyl. ABTS: 2,2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid). AA: Ascorbic acid.