No abstract

Natural components continue to be an important source for the discovery and development of novel anticancer agents. Polymethoxyflavones are a class of flavonoids found in citrus fruits and medicinal plants used in traditional medicine. In the present study, the anticancer activity of the well-known nobiletin (5,6,7,8,3′,4′-hexamethoxyflavone) was compared against its less studied structural isomer 5,6,7,3′,4′,5′-hexamethoxyflavone. These compounds were evaluated on the Hs578T triple-negative breast cancer cell line and its more migratory subclone Hs578Ts(i)8. 5,6,7,3′,4′,5′-hexamethoxyflavone was found to be less toxic than nobiletin, while a similar growth inhibitory effect was observed after 72 h. Additionally, 5,6,7,3′,4′,5′-hexamethoxyflavone arrested the cell cycle in the G2/M phase, while no effect was observed on apoptosis or the migratory behavior of these cells. Furthermore, mechanistic studies revealed that the growth inhibition was concomitant with reduced phosphorylation levels of signaling molecules in the MAPK and Akt pathways as well as cell cycle regulators, involved in regulating cell proliferation, survival and cell cycle. In summary, the present study is the first to report on the anticancer activities of 5,6,7,3′,4′,5′-hexamethoxyflavone and to provide evidence that this flavone could have a greater potential than nobiletin for prevention or treatment of triple-negative breast cancer.

Background. The plant kingdom is rich with a numerous number of plants with various medical properties which can be used to treat various medical issues. Sri Lanka is a country full of biodiversity which is gifted with many plant resources. It has a rich history of traditional medicine systems consisting of Ayurveda, Unani, and Deshiya Chikitsa, where these plant resources are used as remedies for the diseases. In the traditional medicine system, various plant parts such as leaves, roots, fruits, flowers, and bark are used to treat disease conditions. Although less attention is paid to the medicinal importance of the flowers, some of them have been used to treat many diseases from the ancient time. Some properties of the flowers may differ from the properties of the other plant parts. For example, Sesbania grandiflora (Katuru murunga) flowers have shown anticancer properties against various cell models whereas some flowers have shown antispermatogenic properties. Flowers of Woodfordia floribunda (Militta) are added as fermenting agents in the preparation of Arishtas in Ayurveda. Also the most popular Clove oil is obtained from the flower buds of Syzygium aromaticum (Karabu-neti) which is used to treat toothaches since it has antibiotic and antiseptic properties. This article gives an overview of herbal flowers used in the traditional medicine system of Sri Lanka and their pharmacological importance. Method. A comprehensive literature survey was done on the medicinally important flowers in Sri Lanka. Data was collected from Libraries of Ayurveda in Sri Lanka and from scientific databases. Results. According to the survey many flowers are used as astringent, cardiac tonic, and febrifuge. Also some flowers are used to treat dysentery, diarrhoea, and indigestion. Some flowers are useful in the treatment of bleeding piles while some are useful in the treatment of asthma and bronchitis. Conclusion. It was revealed that there are many flowers with valuable therapeutic effects. Traditional medicine systems prevailing in Sri Lanka have made use of these flowers with therapeutic effects to cure so many diseases. The review of medicinally important herbal flowers provides knowledge and pharmacological leads which will help for the wellbeing of the human beings. Although there are phytochemical studies done to identify the chemical compounds on some flowers, chemical composition of many flowers remains unrevealed. So further studies need to be done to identify the chemical composition of these flowers.

Juneberry (Amelanchier alnifolia) is a shrub with edible berry-like fruit commonly found across the Northern Great Plains of North America and widely used by Native Americans as a medicinal plant. This study was an effort to assess the chemopreventive contents of juneberry extracts in ethanol by measuring the total phenolic content, orthophenolic content, DPPH radical scavenging activity, ABTS radical cation decolorization assay, and cytoprotective effects on HepG2 cells. The total phenolic content upon treatment with Folin-Ciocalteu's reagent ranged from 0.2261 ± 0.0031 to 19.311 ± 1.651 mg.g -1 tannic acid equivalents. Orthophenolic content quantified by monitoring the bathochromic shifts upon reacting with sodium molybdate ranged from 0.12 ± 0.03 to 2.38 ± 0.15 mg.g -1 of FW. Antioxidant activity using DPPH assay ranged from 50.08 ± 0.77 to 98.60 ± 1.12%, in contrast to quercetin dihydrate with an activity of 86.20 ± 0.05%. ABTS radical scavenging assay produced inhibition from 1.90 ± 0.11 to 60.25 ± 1.65% as opposed to 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox) with an inhibition of 94.03 ± 0.21% . HepG2 cells treated with 100 µg/µL of sample WC2B showed 56% cell-viability against tert-Butyl hydroperoxide in comparison to quercetin dihydrate which showed 90% cytoprotection. Total phenolic content and orthophenolic content in juneberries from 2012 were higher than in juneberries obtained from the 2013 and 2014. Similarly fruit grown in the wild showed significantly higher antioxidant activity and phenolic content than those grown in domestic cultivars.