An acetylated mannan isolated from Aloe vera induce colorectal cancer cells apoptosis via mitochondrial pathway.

The anti-cancer effects of Aloe vera barbadensis extract C (AVBEC) have been demonstrated in a previous study. However, the specific functional ingredient and mechanism remain undefined. This study aimed to evaluate the function and associated mechanisms of purified polysaccharide (ABPA1) from AVBEC on colorectal cancer. Here, we identify that ABPA1 can induce colorectal cancer apoptosis. In vivo, ABPA1 significantly suppressed tumor growth in an orthotopic colon cancer model. Mechanistically, ABPA1 alters mitochondrial membrane permeability by promoting Bax translocation while causing cytochrome-c release, which initiates the caspase cascade reaction. Additionally, we found that ABPA1 exerted distinct impacts on the mitochondrial metabolism of colorectal cancer cells. Our study elucidated the mechanism by which the polysaccharide ABPA1 induces apoptosis in colorectal cancer cells through the regulation of Bax and cytochrome-c mediated mitochondrial pathway, indicating that ABPA1 may be developed as a mitochondrial-targeting anti-cancer drug.

Aloe polymeric acemannan inhibits the cytokine storm in mouse pneumonia models by modulating macrophage metabolism.

The cytokine storm is highly associated with inflammatory-type disease severity and patients' survival. Plant polysaccharides, the main natural phytomedicine source, have a great potential to be an effective drug to treat cytokine storm. Herein we found that a polymeric acemannan (ABPA1) isolated from Aloe Vera Barbadensis extract C (AVBEC) exerted prominent inhibitory effects on inflammation-induced cytokine storm. The results displayed that ABPA1 effectively suppressed LPS-induced proinflammatory cytokines release in vitro. Moreover, ABPA1 treatment alleviated the cytokine storm and tissue damage in LPS- and IAV-induced mouse pneumonia models, and altered the phenotypic balance of macrophages in lung tissues. Functionally, ABPA1 enhanced macrophage M2 polarization and phagocytosis in RAW264.7 cells and inhibited LPS-induced M1 polarization. Mechanistically, ABPA1 enhanced mitochondrial metabolism and OXPHOS through activated PI3K/Akt/GSK-3ß signalling pathway. Overall, our findings suggest that ABPA1 may modulate macrophage activation and mitochondrial metabolism by targeting PI3K/Akt/GSK-3ß signalling pathway, thereby alleviating cytokine storm and inflammation.

Aloe vera gel extract: Safety evaluation for acute and chronic oral administration in Sprague-Dawley rats and anticancer activity in breast and lung cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Aloe vera (L.) Burm. f. is a typical traditional Chinese medicine (TCM) collected in the Pharmacopoeia of the People's Republic of China (version 2015). It has been traditionally used for the treatment of constipation, and its potential therapeutic activities have been widely evaluated, including anti-tumor, anti-inflammatory and immune regulatory effects. The wide application of Aloe vera in food and therapy has raised safety issues and there are multiple safety assessments with a diverse toxicity and adverse effects from clinics and animals. AIM OF THE STUDY: This study aimed to investigate the safety of Aloe vera barbadensis extract C (AVBEC) in rats and analyze its anticancer activity in cell lines. MATERIALS AND METHODS: We administrated AVBEC orally in an acute toxicity study and a 6-month chronic toxicity study to observe and confirm its safety in Sprague-Dawley (SD) rats. Additionally, we explored the cytotoxicity of AVBEC in cancer cells and non-cancer cells. We further investigated the anti-tumor activity of AVBEC, and in the meantime, probed the function of component from AVBEC. RESULTS: No deaths or substance-relative toxicity were observed in the acute toxicity study or the 6-month chronic toxicity study with doses of 44.8 g·kg-1 and 4.48 g·kg-1, respectively. In the chronic toxicity study, AVBEC did not cause organ toxicity, including crucial organ structure and chemical function, and peripheral and central immune system damage. Additionally, we found that AVBEC could induce cancer cell apoptosis with a relatively higher apoptotic ratio than in non-cancer cells by decreasing adenosine triphosphate (ATP) concentration and enhancing reactive oxygen species (ROS) production. We also identified components in AVBEC using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) and probed the function of malic acid. This demonstrated that under the same circumstances, malic acid induced cell necrosis in cancer cells and non-cancer cells, while AVBEC did not. CONCLUSIONS: These results reveal a novel mechanism of aloe gel extract in regulating cancer cell apoptosis via modulating the mitochondrial metabolism and imply a possible application of AVBEC for the treatment of malignant cancer with the safety evaluation from rats and anticancer investigation from cancer cells and non-cancer cells.