The antimammary tumor effects of ethanolic extract of propolis from Adamawa region (Cameroon) are by apoptosis via reactive oxygen species-mediated mitochondrial pathway

A comparative study of the ability of recombinant oncolytic adenovirus, doxorubicin and tamoxifen to inhibit the proliferation of breast cancer cells

In this study, we compared the inhibitory effects of recombinant oncolytic adenovirus (Ad‐apoptin‐hTERTp‐E1a, Ad‐VT) with that of doxorubicin (DOX), a first‐line chemotherapy drug, and tamoxifen (TAM), an endocrine therapy drug, on the proliferation of breast cancer cells. We found that Ad‐VT could effectively inhibit the proliferation of breast cancer cells (p < 0.01); the inhibition rate of Ad‐VT on normal mammary epithelial MCF‐10A cells was less than 20%. DOX can effectively inhibit the proliferation of breast cancer cells and also has a strong inhibitory effect on MCF‐10A cells (p < 0.01). TAM also has a strong inhibitory effect on breast cancer cells, among which the oestrogen‐dependent MCF‐7 cell inhibition was stronger (p < 0.01), At higher concentrations, TAM also had a high rate of inhibition (>70%) on the proliferation of MCF‐10A cells. We also found that both recombinant adenovirus and both drugs could successfully induce tumour cell apoptosis. Further Western blot results showed that the recombinant adenovirus killed breast cancer cells through the endogenous apoptotic pathway. Analysis of the nude mouse subcutaneous breast cancer model showed that Ad‐VT significantly inhibited tumour growth (the luminescence rate of cancer cells was reduced by more than 90%) and improved the survival rate of tumour‐bearing mice (p < 0.01). Compared with DOX and TAM, Ad‐VT has a significant inhibitory effect on breast cancer cells, but almost no inhibitory effect on normal breast epithelial cells, and this inhibitory effect is mainly through the endogenous apoptotic pathway. These results indicate that Ad‐VT has significant potential as a drug for the treatment of breast cancer.

Ethanol-Extracted Cameroonian Propolis Counteracts Tamoxifen-Induced Endometrial Hyperplasia by Modulating Apoptosis and Proliferation-Regulating Proteins in the Ovaries of Intact Wistar Rats

Tamoxifen is the most common adjuvant that has been widely used in the treatment of positive estrogen receptor (ER+) breast cancer for over 20 years. However, long term exposure to tamoxifen doubles the risk of endometrial cancer. The association of tamoxifen with antiproliferative substances could abrogate its side effects on the endometrium. Recently, we demonstrated that ethanol-extracted Cameroonian propolis (EECP) has chemopreventive effects on ER+ breast cancer in rats. This study evaluated the capability of EECP to counteract tamoxifen-induced endometrial hyperplasia, without altering its effect on the breast. Thirty-six rats of ∼2 months were coadministered either EECP (16.5, 50, and 150 mg/kg BW) or fulvestrant (300 μg/kg BW) and tamoxifen (10 mg/kg BW) for 8 weeks. Afterward, the relative weights and histomorphometry of the uterus, vagina, ovaries, and mammary gland were assessed. The expression of some proteins of proliferation (PCNA), angiogenesis (VEGF), and apoptosis (Bax, Bcl-2, and caspase-3) was measured by immunohistochemistry. Rats that received only tamoxifen had endometrial hyperplasia compared to normal rats. EECP and fulvestrant protected the rats against tamoxifen-induced endometrial hyperplasia. A significant decrease in uterine wet weight (p < 0.01); endometrial height (p < 0.001); and expression of PCNA, Bcl-2, and VEGF proteins as well as a significant increase in the expression of Bax and caspase-3 proteins was observed in the EECP group compared to the Tamox group. EECP did not change the effects of tamoxifen on the breast. In summary, Cameroonian propolis which is efficacious in preventing breast cancer can also be a good complementary medicine to prevent tamoxifen-induced endometrial cancer in tamoxifen users.

The Potential Use of Propolis as an Adjunctive Therapy in Breast Cancers

Propolis is a resinous beehive product that has a wide range of biological activities, namely antimicrobial, antioxidant, and anti-inflammatory properties. Propolis is collected by the bees from plant resin and exudates to protect hives and maintain hive homeostasis. The aim of the present systematic scoping review is to explore the potential and suitability of propolis as an adjunctive treatment in breast cancers, based on the latest available experimental evidence (2012-2021). After applying the exclusion criteria, a total of 83 research publications were identified and retrieved from Scopus, Web of Science, and Pubmed. Several relevant key themes identified from the included studies were cytotoxicity, synergistic/combination treatment, improvement in bioavailability, human clinical trials, and others. A majority of the studies identified were still in the in vitro and in vivo stages. Nonetheless, we managed to identify 4 human clinical trials that demonstrated the successful use of propolis in alleviating side effects of chemotherapy and radiotherapy while increasing the quality of life of breast cancer patients, with minimal adverse effects. In conclusion, propolis, as an adjunctive treatment, may have therapeutic benefits in alleviating symptoms related to breast cancers. However, further clinical trials, preferably with higher number of participants/subjects/patients, are urgently needed.

Anti-breast cancer potential of Anonidium mannii (Oliv.) Engl. & Diels barks ethanolic extract: UPLC-ESI-QTOF-MS detection of anticancer alkaloids

ETHNOPHARMACOLOGICAL RELEVANCE

Breast cancer is a serious threat in low-income as well as developed countries. To face this, many herbal preparations are prescribed by traditional healers in Cameroon, among which is Anonidium mannii commonly called "wild soursop".

AIM

This study was undertaken to assess the anti-tumor effect of A. mannii ethanolic extract on cancer cell growth and against DMBA-induced mammary tumors in rats.

MATERIALS AND METHODS

The well characterized MTT bioassay was used to assess the cytotoxic potential of A. mannii ethanolic extract in liver (HepG2), prostate (DU145 & PC3) and breast (MCF-7) cancer cell lines. Considering the fact that breast cells were the most sensitive to the extract, a 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast tumor rat model was used to assess the possible anticancer effect of A. mannii extract. Indeed, rats were treated with either tamoxifen (3.3 mg/kg BW) or A. mannii extract (16.5, 50 and 150 mg/kg BW) or vehicle (2% ethanol) for 20 weeks. Tumor incidence, tumor mass and volume, oxidative stress status in tumor as well as tumor histoarchitecture were evaluated.

RESULTS

A 24 h incubation of tested cells with the A. mannii extract significantly slowed cell growth in a concentration-dependent manner with an interesting effect in breast cells (IC50 ~61.5 μg/mL). As compared to the DMBA rats, those treated with A. mannii extract (50 and 150 mg/kg) showed reduced breast tumor incidence (28%), tumor burden (95.34% at 50 mg/kg and 99.14% at 150 mg/kg) and tumor volume (~92%). A. mannii extract counteracted the high proliferation of terminal mammary ducts induced by DMBA, mainly at 50 mg/kg. Furthermore, the extract decreased MDA and nitrite levels but increased SOD activity in the mammary gland. High Performance Liquid Chromatography coupled with Mass Spectrometry (HPLC-MS) analysis detected potential anticancer and antioxidant alkaloids in A. manni extract, which are close to those found in Annona muricata.

CONCLUSION

These results provide evidence on the in vitro and in vivo anticancer effects of A. mannii, and therefore support its use in traditional medicine system to fight against cancer.

LCT-3d Induces Oxidative Stress-Mediated Apoptosis by Upregulating Death Receptor 5 in Gastric Cancer Cells

Gastric cancer is a global health problem. In this study, we investigate the role of a novel Indole derivative, named LCT-3d, in inhibiting the growth of gastric cancer cells by MTT assay. The Western blotting results showed that LCT-3d modulated the mitochondrial-related proteins and Cleaved-Caspases 3/9, to induce cell apoptosis. The up-regulation of Death receptor 5 (DR5) in MGC803 cells was observed with LCT-3d treatment. Knockdown of DR5 on MGC803 cells partially reversed the LCT-3d-induced mitochondrial apoptosis. The level of Reactive Oxygen Species (ROS) in MGC803 cells was increased with LCT-3d treatment and could be blocked with the pretreatment of the ROS inhibitor N-Acetylcysteine (NAC). The results demonstrate that the elevating ROS can up-regulate the expression of DR5, resulting in apoptosis via mitochondrial pathway. Although the nuclear factor erythroid-2 related factor 2 (Nrf2) pathway served an important role in protecting gastric cancer cells against the injury of ROS, it can’t reverse LCT-3d-induced cell apoptosis. Taken together, our study showed that LCT-3d induced apoptosis via DR5-mediated mitochondrial apoptotic pathway in gastric cancer cells. LCT-3d could be a novel lead compound for development of anti-cancer activity in gastric cancer.