Phytochemicals: Key to Effective Anticancer Drugs

Research on Anthocyanins from Rubus “Shuofeng” as Potential Antiproliferative and Apoptosis-Inducing Agents

Blackberries have high nutritional value and strong biological activities, such as antiproliferative activity. Anthocyanins are important functional components in blackberries. We collected 25 kinds (lines) of blackberries from our nursery to investigate antiproliferative agents in natural foods. Among them, the Shuofeng variety had the highest anthocyanin content, with 2.54 mg/g of fresh fruit, which increased to 357.75 mg/g of dried powder through ultrasound-assisted solvent extraction and macroporous resin adsorption. Additional experiments showed that Shuofeng’s anthocyanin content had high anti-HepG2 activity in vitro and in vivo, as well as activity against Hela (68.62 μg/mL), HepG2 (55.85 μg/mL), MCF-7 (181.21 μg/mL), and A549 cells (82.01 μg/mL), as determined by MTT assay. It also had no apparent toxic effects. The combination of DDP and DOX significantly enhanced the antiproliferative activity of the four cell lines. The IC50 value of Shuofeng’s anthocyanin content combined with DOX in HepG2 cells was the lowest at only 0.08 μg/mL, indicating that the combination of drugs had additive and synergistic effects. Shuofeng’s anthocyanin content might intercalate into DNA and alter or destroy DNA, causing apoptosis and inhibiting cell proliferation. Our results show that blackberry anthocyanins can inhibit the proliferation of cancer cells and their possible mechanisms. However, we must study the deeper mechanism and explore its targeting effects in the future.

A Review of Medicinal Plants of the Himalayas with Anti-Proliferative Activity for the Treatment of Various Cancers

Simple Summary

Drugs are used to treat cancer. Most drugs available in the market are chemosynthetic drugs and have side effects on the patient during and after the treatment, in addition to cancer itself. For instance, hair loss, loss of skin color and texture, loss of energy, nausea, infertility, etc. To overcome these side effects, naturally obtained drugs from medicinal plants are preferred. Our review paper aims to encourage the study of anticancer medicinal plants by giving detailed information on thirty-three medicinal plants and parts that constitute the phytochemicals responsible for the treatment of cancer. The development of plant-based drugs could be a game changer in treating cancer as well as boosting the immune system.

Abstract

Cancer is a serious and significantly progressive disease. Next to cardiovascular disease, cancer has become the most common cause of mortality in the entire world. Several factors, such as environmental factors, habitual activities, genetic factors, etc., are responsible for cancer. Many cancer patients seek alternative and/or complementary treatments because of the high death rate linked with cancer and the adverse side effects of chemotherapy and radiation therapy. Traditional medicine has a long history that begins with the hunt for botanicals to heal various diseases, including cancer. In the traditional medicinal system, several plants used to treat diseases have many bioactive compounds with curative capability, thereby also helping in disease prevention. Plants also significantly contributed to the modern pharmaceutical industry throughout the world. In the present review, we have listed 33 medicinal plants with active and significant anticancer activity, as well as their anticancer compounds. This article will provide a basic set of information for researchers interested in developing a safe and nontoxic active medicinal plant-based treatment for cancer. The research will give a scientific foundation for the traditional usage of these medicinal herbs to treat cancer.

Phytochemical Discrimination, Biological Activity and Molecular Docking of Water-Soluble Inhibitors from Saussurea costus Herb against Main Protease of SARS-CoV-2

Siddha medicine is one of the oldest medical systems in the world and is believed to have originated more than 10,000 years ago and is prevalent across ancient Tamil land. It is undeniable that inhibitor preferences rise with increasing solubility in water due to the considerations pertaining to the bioavailability and the ease of which unabsorbed residues can be disposed of. In this study, we showed the phytochemical discrimination of Saussurea costus extracted with water at room temperature as a green extraction procedure. A total of 48 compounds were identified using gas chromatography-mass spectrometry (GC-MS). The fatty acids had a high phytochemical abundance at 73.8%, followed by tannins at 8.2%, carbohydrates at 6.9%, terpenoids at 4.3%, carboxylic acids at 2.5%, hydrocarbons at 2.4%, phenolic compounds at 0.2%, and sterols at 1.5%. Of these compounds, 22 were docked on the active side and on the catalytic dyad of His41 and Cys145 of the main protease of SARS-CoV-2 (M^pro). Eight active inhibitors were carbohydrates, five were fatty acids, three were terpenoids, two were carboxylic acids, one was a tannin, one was a phenolic compound, and one was a sterol. The best inhibitors were 4,8,13-Cyclotetradecatriene-1,3-diol, 1,5,9-trimethyl-12-(1-methylethyl), Andrographolide, and delta.4-Androstene-3.beta.,17.beta.-diol, with a binding affinity that ranged from −6.1 kcal/mol to −6.5 kcal/mol. The inhibitory effect of Saussurea costus of SARS-CoV-2 entry into the cell was studied using a pseudovirus with Spike proteins from the D614G variant and the VOC variants Gamma and Delta. Based on the viral cycle of SARS-CoV-2, our results suggest that the Saussurea costus aqueous extract has no virucidal effect and inhibits the virus in the events after cell entry. Furthermore, the biological activity of the aqueous extract was investigated against HSV-1 virus and two bacterial strains, namely Staphylococcus aureus ATCC BAA 1026 and Escherichia coli ATCC 9637. According to this study, an enormous number of water-soluble inhibitors were identified from Saussurea costus against the M^pro, and this is unprecedented as far as we know.

Anti-Proliferative and Anti-Telomerase Effects of Blackberry Juice and Berry-Derived Polyphenols on HepG2 Liver Cancer Cells and Normal Human Blood Mononuclear Cells

BACKGROUND

Previous studies have provided strong evidence for anticancer activity of berry fruits.

OBJECTIVE

In this study, we investigated the effects of blackberry juice and three berry- polyphenolic compounds on cell proliferation and telomerase activity in human hepatoma HepG2 and normal peripheral blood mononuclear cells (PBMCs).

METHODS

The cell viability and telomerase activity were measured by MTT and TRAP assay, respectively. Berry effects on the expression of genes were determined by quantitative RT-PCR assay.

RESULTS

Blackberry, gallic acid, and resveratrol inhibited proliferation of both HepG2 and PBMC cells in a dose-dependent manner. Resveratrol was more effective than gallic acid for reducing the viability of HepG2 cells, but both showed the same level of growth inhibition in PBMC cells. Berry, resveratrol, and gallic acid significantly inhibited telomerase activity in HepG2 cells. The antiproliferative effect of berry was associated with apoptotic DNA fragmentation. Gallic acid was more effective for reducing telomerase activity than resveratrol, but anthocyanin moderately increased telomerase activity in cancer cells. Telomerase activity was induced by all three polyphenols in PBMCs. Overall, Krumanin chloride was more effective to induce telomerase than gallic acid and resveratrol in PBMC cells. There was no significant difference in hTERT, hTR, and Dnmts expressions between berry treated and the control untreated HepG2 cells. But, a significant downregulation of HDAC1 and HDAC2 and upregulation of SIRT1 were observed in berry-treated cells.

CONCLUSION

These data indicate that the berry anticancer effect is associated with antitelomerase activity and changes in HDACs expression. The data also suggest that berry antitelomerase activity is mainly related to its gallic acid and resveratrol, but not anthocyanin content.

Cytotoxic Effects of Diterpenoid Alkaloids Against Human Cancer Cells

Diterpenoid alkaloids are isolated from plants of the genera Aconitum, Delphinium, and Garrya (Ranunculaceae) and classified according to their chemical structures as C18-, C19- or C20-diterpenoid alkaloids. The extreme toxicity of certain compounds, e.g., aconitine, has prompted a thorough investigation of how structural features affect their bioactivities. Therefore, natural diterpenoid alkaloids and semi-synthetic alkaloid derivatives were evaluated for cytotoxic effects against human tumor cells [A549 (lung carcinoma), DU145 (prostate carcinoma), MDA-MB-231 (triple-negative breast cancer), MCF-7 (estrogen receptor-positive, HER2-negative breast cancer), KB (identical to cervical carcinoma HeLa derived AV-3 cell line), and multidrug-resistant (MDR) subline KB-VIN]. Among the tested alkaloids, C19-diterpenoid (e.g., lipojesaconitine, delcosine and delpheline derivatives) and C20-diterpenoid (e.g., kobusine and pseudokobusine derivatives) alkaloids exhibited significant cytotoxic activity and, thus, provide promising new leads for further development as antitumor agents. Notably, several diterpenoid alkaloids were more potent against MDR subline KB-VIN cells than the parental drug-sensitive KB cells.