Hibiscus sabdariffa or roselle tea is popular around the globe for its antioxidant capability along with various other health benefits. Besides, it has uses in Ayurvedic and Chinese herbal medicines for the treatment of several diseases. However, the investigation for the anticancer potential of the plant began roughly in the last decade that emerged with encouraging results. Both crude extracts and pure compounds of the plant were reported to induce chemoprevention, selective cytotoxicity, cell cycle arrest, apoptosis, autophagy and anti-metastasis effects in varied types of human cancer cells. The plant contains a high quantity of polyphenolic compounds and at least two of them were proven to induce potent anticancer effects. Although, the molecular mechanism underlying the anticancer activity was roughly estimated in several studies. The present review aimed to assemble all ambiguous information to report the molecular evidence establishing the potent anticancer activity of Hibiscus sabdariffa and its implication for cancer therapy. This study suggests that Hibiscus sabdariffa is an ideal candidate to investigate its role as a herbal supplement for cancer prevention and treatment. With excellent safety and tolerability record, polyphenolic compounds from the plant need better designed clinical trials.

The estrogen hormone receptor (ER) mediated gene expression mainly regulate the development and physiology of the primary and secondary reproductive system alongside bone-forming, metabolism and behaviour. Over-expressed ER is associated with several pathological conditions and play a crucial role in breast cancer occurrence, progression and metastasis. Hibiscus sabdariffa L. or roselle is a rich source of naturally occurring polyphenolic compounds that reportedly have robust estrogenic activity. However, the estrogen-like ingredient of the plant remains ambiguous. This study has screened a library of already recorded and less-explored compounds of Hibiscus sabdariffa for their estrogen receptor binding affinity and safety using a suite of computational methods that include protein-ligand docking, ADME and Toxicity prediction, and 2D/3D QSAR. The study revealed that the estrogen-receptor binding potential of Pelargonidin, Delphinidin, Cyanidin, and Hibiscetin are more efficient than popular breast cancer drugs, Tamoxifen and Raloxifene. Besides, the compounds exhibited favourable toxicological parameters with potent bioactivity towards binding ER-α subunit. Thus, these compounds can serve as prototypes for designing novel Selective Estrogen Receptor Modulator molecules with a few structural modifications. This is the first report exploring the phytochemical basis of estrogenic activity of Hibiscus sabdariffa L. Communicated by Ramaswamy H. Sarma

Breast cancer is among the most common type of cancer in women around the globe. Prevention of breast cancer is better than its treatment. Because of the molecular variation and complexity underlying breast cancer occurrence, its treatment by using chemotherapy and/or radiotherapy is very complicated and often leads to undesirable side effects. Plants and their extracts have been used for centuries for the treatment of almost every disease and breast cancer is not an exception. Herbal products can be trusted for cancer treatment because of their low toxicity. Besides, herbal remedies are easily accepted by the majority of woman suffering from breast cancer because of their easy availability and affordability. In the last decade, a large number of plants and their compounds were reported to show promising anticancerous effects against breast cancer cells in both in vivo and in vitro models. However, their beneficial effects on breast cancer treatment are still doubtful due to the lack of randomized clinical trials. This chapter is dedicated to reporting the potential of some herbal products for the prevention and/or treatment of breast cancer. Besides, it focused on the anticarcinogenic mechanism of those phytocompounds to report their potential chemotherapeutic role.

Among luminal types of breast cancers, ER + breast cancer is the most frequently diagnosed cancer globally. ER + breast cancer is commonly treated with SERM drugs that block ER to prevent ER-mediated cancerous growth. Our previous computational screening found pelargonidin (PG) can inhibit ER-signaling with potent bioactivity and satisfactory toxicological features. The present study explored the anti-tumoral prospect of PG against DMBA-induced ER + murine mammary carcinogenesis. The female BALB/c mice were divided into control (A) and DMBA-exposed groups. Following tumor appearance, the DMBA-exposed group was divided into five groups: tumor control, PG-treated (Groups P25, P50, and P100), and tamoxifen-treated (TAM). The results indicated that PG-treatment dose-dependently reduced the mean tumor volume, reinstated body weight loss, and enhanced the percentage survival of tumor-bearing mice. In addition, we recorded a significant reduction in LPO, total cholesterol, and triglycerides and a surge in the activity of antioxidases and phase II detoxifying enzymes in PG-treated animals. PG also dose-dependently increased the serum level of unbound estradiol, an indicator of competitive ER binding by an ER agonist/antagonist. These data suggest that pelargonidin has potent anticancer potential against the animal model of ER + breast cancer that matches the efficiency of tamoxifen with conceivably fewer side effects.

The estrogen hormone receptor (ER) mediated gene expression mainly regulate the development and physiology of primary and secondary reproductive system alongside bone-forming, metabolism and behaviour. Over-expressed ER is associated with several pathological conditions and play a key role in breast cancer occurrence, progression and metastasis. Hibiscus sabdariffa L. or roselle is a rich source of naturally occurring polyphenolic compounds including anthocyanins and reportedly have strong estrogenic activity. To validate these findings, we have investigated the estrogen receptor binding affinity and safety of some previously recorded polyphenols using a suite of computational methods. Our investigation showed the estrogen-receptor binding potential of Pelargonidin, Delphinidin, Cyanidin, and Hibiscetin are more efficient than popular breast cancer drugs, Tamoxifen and Raloxifene, with favourable toxicological parameters and low half maximal inhibitory concentration. This is the first report to investigate the phytochemical basis of estrogenic activity of Hibiscus sabdariffa L.