Bio-Prospecting of Crude Leaf Extracts from Thirteen Plants of Brazilian Cerrado Biome on Human Glioma Cell Lines.

(1) Background: Malignant gliomas are aggressive tumors characterized by fast cellular growth and highly invasive properties. Despite all biological and clinical advances in therapy, the standard treatment remains essentially palliative. Therefore, searching for alternative therapies that minimize adverse symptoms and improve glioblastoma patients' outcomes is imperative. Natural products represent an essential source in the discovery of such new drugs. Plants from the cerrado biome have been receiving increased attention due to the presence of secondary metabolites with significant therapeutic potential. (2) Aim: This study provides data on the cytotoxic potential of 13 leaf extracts obtained from plants of 5 families (Anacardiaceae, Annonaceae, Fabaceae, Melastomataceae e Siparunaceae) found in the Brazilian cerrado biome on a panel of 5 glioma cell lines and one normal astrocyte. (3) Methods: The effect of crude extracts on cell viability was evaluated by MTS assay. Mass spectrometry (ESI FT-ICR MS) was performed to identify the secondary metabolites classes presented in the crude extracts and partitions. (4) Results: Our results revealed the cytotoxic potential of Melastomataceae species Miconia cuspidata, Miconia albicans, and Miconia chamissois. Additionally, comparing the four partitions obtained from M. chamissois crude extract indicates that the chloroform partition had the greatest cytotoxic activity against the glioma cell lines. The partitions also showed a mean IC50 close to chemotherapy, temozolomide; nevertheless, lower toxicity against normal astrocytes. Analysis of secondary metabolites classes presented in these crude extracts and partitions indicates the presence of phenolic compounds. (5) Conclusions: These findings highlight M. chamissois chloroform partition as a promising component and may guide the search for the development of additional new anticancer therapies.

Natural Products for Liver Cancer Treatment: From Traditional Medicine to Modern Drug Discovery.

Primary liver cancer was the seventh most diagnosed cancer and the second leading cause of cancer death with about 906,000 cases and 830,000 deaths, respectively, in 2020. Conventional treatment for liver cancer, such as transarterial chemoembolization (TACE) or sorafenib, has limitations in that there is the recurrence of cancer, drug inefficacy, and adverse effects. Traditional medicine and natural products of several regions including Korea, China, Europe, North America, India, and the Middle East have attracted a lot of attention since they have been reported to have anticancer effects with low adverse effects. In this review, several in vivo studies on the effects of natural compounds on liver cancer and clinical trials approving their therapeutic benefits were selected and discussed. As a result of the analysis of these studies, the effects of natural compounds were classified into a few mechanisms: apoptosis, anti-metastasis, and antiangiogenesis. In addition, medications including natural products in clinical trials were observed to exhibit improvements in various liver cancer symptoms and patients' survival rates. This study presents findings suggestive of the anticancer potential of natural products and their properties in relieving related symptoms.

Inibição de metaloproteinases por extratos aquosos de Aloe vera, Annona muricata e chá preto / Inhibition of metalloproteinases by Aloe vera, Annona muricata, and black tea aqueous extracts

As Metaloproteinases de Matriz (MMPs) podem exercer importantes funções na remodelagem fisiológica e patológica da matriz extracelular. Elas são implicadas na progressão tumoral de muitas malignidades humanas interferindo em eventos angiogênicos, invasivos e metastáticos. Produtos obtidos de algumas plantas têm sido consistentemente associados a funções neoplásicas, possivelmente por reproduzir a atividade neutralizadora dos inibidores teciduais (TIMPs) das MMPs. No presente trabalho, investigou-se a inibição da atividade gelatinolítica das MMPs -2 e -9 por extratos aquosos (EA) de Aloe vera, chá preto e Annona muricata diluídos em tampão de ativação (TA, com cálcio). A atividade proteolítica das MMPs foi avaliada em ensaios zimográficos. Para avaliar o efeito inibitório dos produtos testados, géis foram seccionados e incubados em soluções contendo o TA e os EA em três diluições seriadas. Associação indireta foi observada entre o EA de A. vera e chá preto e a inibição da atividade de MMP-2. EA de A. muricata exerceu pequeno efeito inibitório na MMP-2 nas duas menores diluições. A atividade de MMP-9 foi consistentemente neutralizada por todos os EA testados, de forma dose-dependente. Estes resultados sugerem que os efeitos antitumorais verificados paraos EA de A. vera, A. muricaca, e chá preto podem ser explicados parcialmente por sua atividade inibitória sobre as MMP-2 e -9.

Matrix metalloproteinases may exert important roles in both physiologic and pathologicextracellular matrix remodeling. They have been implicated in tumoral progression of many human malignancies interfering on angiogenic, invasive, and metastatic events. Products obtained from some plants have been consistently associated to anti-neoplastic roles, possibly by reproducing the neutralizing activity of tissue inhibitors over MMPs. In the present work, we investigate the inhibition of the MMP-2 and -9 gelatinolytic activity by Aloe vera, black tea, and Annona muricata aqueous extracts (AE) diluted in activation buffer (AB, with calcium). The proteolytic activity of MMP was evaluated on zymographic assays. To evaluate the inhibitory effect of the tested products, gels were sectioned and incubated in the solutions containing the AB and AE from three serial dilutions. Indirect association was observed between the dilution of A. vera and black tea and MMP-2 activity inhibition. A. muricata exerted only small inhibition on MMP-2 effect in the two smallest dilutions. The MMP-9 activity was consistently neutralized by all of the natural solutions in a dose-dependent way. The present results suggest that the antitumoral effects verified for A. vera, A. muricaca, and black tea AE may be partially explained by their inhibitory activity on MMP.