Beatriz del Carmen Couder-García’s research while affiliated with National Autonomous University of Mexico and other places

Currently, there are various physical and mechanical agents that can cause skin wounds, which are still traditionally treated with plant extracts. It has been reported that the genus Tagetes has a wide range of biological properties, including antibacterial and wound healing activity. Likewise, Agave americana extract and Aloe vera gel have shown potential in the treatment of burn wounds and other skin conditions both in vitro and in vivo. In this study, the antibacterial and wound healing activities of each of these plants were investigated, as well as the possibility of enhancing these activities by combining them. First, the secondary metabolites of the extracts were quantified, the antibacterial activity was evaluated using the Kirby-Bauer method, and their cytotoxicity was measured in 3T3 and HaCaT cells using the sulforhodamine B assay. The results revealed that Tagetes nelsonii extract had a higher amount of secondary metabolites, which is why it exhibited antibacterial activity. Finally, the scratch assay showed that the individual extracts of T. nelsonii and A. americana demonstrated greater cell migration and proliferation starting from 12 h, as well as when using the combination of A. americana extract and A. vera gel, which almost completely closed the wound compared to the control.

Parthenium argentatum (Gray), commonly known as guayule, has been used to obtain natural rubber since the beginning of the 20th century. Additionally, the so called “resin” is a waste product derived from the industrial process. The cycloartane-type triterpene Argentatin A (AA) is one of the main constituents of the industrial waste resin. In this study we evaluated the AA anticancer activity both in vitro and in vivo in the HCT116 colon cancer cells. The apoptosis promotion of AA was assessed by the annexin V/propidium iodide (PI) assay. The senescence was evaluated for SA-β-galactosidase, and PCNA was used as a marker of proliferation. Its antitumor activity was evaluated using a xenograft mouse model. The results indicated that AA-induced apoptosis in HCT-116 cells and was positively stained for SA-β-galactosidase. In the xenografted mice test, the administration of AA at the dose of 250 mg/kg three times a week for 21 days reduced tumor growth by 78.1%. A comparable tumor reduction was achieved with cisplatin at the dose of 2 mg/kg administered three times a week for 21 days. However, nude mice treated with AA did not lose weight, as they did remarkably when treated with cisplatin. Furthermore, the animals treated with AA showed similar blood profiles as the healthy control group. These data indicate the low toxicity of AA compared to that shown by cisplatin.

Objective: This study aimed to evaluate the cytotoxic activity of peniocerol against human colon cancer cell lines and its antitumor effect in vivo in a xenograft model using nu/nu mice. Materials and Methods: SW-620, HCT-15, and HCT-116 colon cancer cell lines were treated with peniocerol for cytotoxicity by crystal violet technique. Cell apoptosis induction was detected by flow cytometry, and the antitumor activity of peniocerol was evaluated in a xenograft model of HCT-116 in nu/nu mice. After treatment, the effect of peniocerol was analyzed in histological sections of tumors by immunohistochemistry using DAPI, anti-PCNA, and PARP-1 antibodies. Results: Peniocerol inhibited cell growth and induced apoptosis in vitro in a time and dose-dependent manner. Besides, peniocerol administration (30 or 15 mg/kg) inhibited tumor growth and induced apoptosis in the xenograft mice. The lack of peniocerol toxicity was proved by a biochemical blood analysis of healthy nu/nu mice administrated with this sterol. Conclusions: Our results proved that peniocerol induces apoptosis in vitro and in vivo assays.