Antiproliferative effects of Plumbago rosea and its purified constituent plumbagin on SK-MEL 28 melanoma cell lines

Prostate cancer: Therapeutic prospect with herbal medicine

Prostate cancer (PCa) is a major cause of morbidity and mortality in men worldwide. A geographic variation on the burden of the disease suggested that the environment, genetic makeup, lifestyle, and food habits modulate one's susceptibility to the disease. Although it has been generally thought to be an older age disease, and awareness and timely execution of screening programs have managed to contain the disease in the older population over the last decades, the incidence is still increasing in the population younger than 50. Existing treatment is efficient for PCa that is localized and responsive to androgen. However, the androgen resistant and metastatic PCa are challenging to treat. Conventional radiation and chemotherapies are associated with severe side effects in addition to being exorbitantly expensive. Many isolated phytochemicals and extracts of plants used in traditional medicine are known for their safety and diverse healing properties, including many with varying levels of anti-PCa activities. Many of the phytochemicals discussed here, as shown by many laboratories, inhibit tumor cell growth and proliferation by interfering with the components in the pathways responsible for the enhanced proliferation, metabolism, angiogenesis, invasion, and metastasis in the prostate cells while upregulating the mechanisms of cell death and cell cycle arrest. Notably, many of these agents simultaneously target multiple cellular pathways. We analyzed the available literature and provided an update on this issue in this review article.

•

Prostate cancer in a major cause of death in older population worldwide.

•

Efficacies of current treatment options are limited in many cases.

•

Phytochemicals and extracts isolated from plants show anti-prostate cancer activity with unique mechanisms.

•

Certain phytochemicals alone or in combination with current chemotherapy show therapeutic promise.

Quinonoids: Therapeutic Potential for Lung Cancer Treatment

Lung cancer is the leading cause of cancer-related deaths worldwide. Owing to its high incidence and mortality, the development and discovery of novel anticancer drugs is of great importance. In recent years, many breakthroughs have been achieved in the search for effective anticancer substances from natural products. Many anticancer drugs used clinically and proven to be effective are derived from natural products. Quinonoids, including naphthoquinones, phenanthrenequinones, benzoquinones, and anthraquinones, constitute a large group of natural bioactive compounds that widely exist in higher and lower plant species. Given that most of these compounds possess anticancer effects, they are applied in many cancer studies, especially in lung cancer research. They can promote apoptosis, induce autophagy, and inhibit proliferation, angiogenesis, and cell invasion and migration. Some drugs can enhance anticancer effects when combined with other drugs. Thus, quinonoids have broad application prospects in the treatment of lung cancer. Here, we summarize the previous studies on the antilung cancer activities of quinonoids together with their underlying mechanisms and analyze the common research targets with different effects so as to provide references for the discovery of quinonoids against lung cancer.

Evaluation of anticancer, antioxidant and antibacterial properties of methanol extract of three Acantholimon Boiss. species

OBJECTIVE

Acantholimon is a genus of perennial plant within the Plumbaginaceae family. Here, we aimed to investigate anticancer, antioxidant, and antibacterial potential of methanol extract of three Iranian endemic species of Acantholimon including A. austro-iranicum, A. serotinum and A. chlorostegium.

MATERIALS AND METHODS

MTT assay was used to evaluate the in vitro cytotoxicity and apoptosis induction was examined by annexin V-PE apoptosis detection kit. Antioxidant activity was reported based on the DPPH-scavenging and DCF-DA assay. Antibacterial activity was measured by disc diffusion and micro-well dilution assay.

RESULTS

MTT assay showed less cytotoxicity of methanol extracts against the HUVEC normal cell line (IC₅₀ values: 817-900 µg/ml) compared to cancer cell lines MCF-7, HT29, SH-SY5Y, NCCIT and A549 (IC₅₀ values: 213 to 600 µg/ml) that show the specificity of extracts toward cancer cells. Plant extract showed apoptosis induction and cell cycle arrest at the G0/G1 phases documented by annexin V staining and flow cytometry. According to antioxidant tests, extracts exhibited significant DPPH scavenging potential (IC₅₀ values: 30-37 µg/ml) and could protect against H₂O₂-induced oxidative stress. Antibacterial activities showed a stronger inhibitory effect on Escherichia coli and Pseudomonas aeruginosa as Gram- negative bacteria (diameter of inhibition zone: 11-13 mm and minimal inhibition concentration (MIC): 3.175 to 12.5 mg/ml) compared to Gram-positive bacteria including Enterococcus faecalis and Staphylococcus aureus (diameter of inhibition zone: 3-7 mm and MIC: 25 to 50 mg/ml).

CONCLUSION

Our results suggested moderate cytotoxic and antibacterial potential and noteworthy antioxidant activity for the examined Acantholimon species.

Calcium alginate encapsulated synthetic seed production in Plumbago rosea L. for germplasm exchange and distribution

Plumbago rosea L. (Plumbaginaceae), is a medicinal shrub commercially exploited for its naphthoquinone principle, plumbagin, extracted from the roots especially for treating skin disorders. As the plant is exploited from the wild without being replenished, conservation of the species becomes inevitable. Synthetic seeds would provide for effective conservation, germplasm exchange and distribution of this species. A reliable protocol for synthetic seed production in Plumbago rosea has been developed encapsulating the axillary buds. The axillary buds from P. rosea cultures established and multiplied using the nodal explants in Murashige and Skoog (MS) medium supplemented with Benzyl Adenine (BA) 1.5 mg/L and Indole 3-Acetic acid 1.0 mg/L, were used for synseed production. The plantlet conversion efficiency was the highest in synthetic seeds developed with sodium alginate 2.5% in modified MS with 0.4 M sucrose and CaCl₂ 100 mM. This combination gave the earliest bud initiation (9.19 ± 0.39 days) and maximum number of shoots per explant (2.31 ± 0.16 shoots). Microshoots from the culture, when inoculated on to MS medium supplemented with Naphthalene Acetic Acid 1.0 mg/L gave the best rooting response with 10.67 ± 0.94 roots per plant and 5.42 ± 0.29 cm root length. This is the first report of synthetic seed production in P. rosea using axillary buds as explant.

Plumbagin Suppresses α-MSH-Induced Melanogenesis in B16F10 Mouse Melanoma Cells by Inhibiting Tyrosinase Activity

Recent studies have shown that plumbagin has anti-inflammatory, anti-allergic, antibacterial, and anti-cancer activities; however, it has not yet been shown whether plumbagin suppresses alpha-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis to prevent hyperpigmentation. In this study, we demonstrated that plumbagin significantly suppresses α-MSH-stimulated melanin synthesis in B16F10 mouse melanoma cells. To understand the inhibitory mechanism of plumbagin on melanin synthesis, we performed cellular or cell-free tyrosinase activity assays and analyzed melanogenesis-related gene expression. We demonstrated that plumbagin directly suppresses tyrosinase activity independent of the transcriptional machinery associated with melanogenesis, which includes micropthalmia-associated transcription factor (MITF), tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP1). We also investigated whether plumbagin was toxic to normal human keratinocytes (HaCaT) and lens epithelial cells (B3) that may be injured by using skin-care cosmetics. Surprisingly, lower plumbagin concentrations (0.5–1 μM) effectively inhibited melanin synthesis and tyrosinase activity but do not cause toxicity in keratinocytes, lens epithelial cells, and B16F10 mouse melanoma cells, suggesting that plumbagin is safe for dermal application. Taken together, these results suggest that the inhibitory effect of plumbagin to pigmentation may make it an acceptable and safe component for use in skin-care cosmetic formulations used for skin whitening.