stilbenes and lupeol

Covering: 2010 to 2020This review article describes how cationic rearrangement reactions have been used in natural product total synthesis over the last decade as a case study for the many productive ways by which isomerization reactions are enabling for synthesis. This review argues that isomerization reactions in particular are well suited for computational evaluation, as relatively simple calculations can provide significant insight.

Topics: Benzofurans; Benzophenones; Benzoquinones; Biological Products; Cations; Cyclization; Diterpenes, Kaurane; Indole Alkaloids; Isomerism; Pentacyclic Triterpenes; Sesquiterpenes; Stilbenes; Terpenes

Accumulating data clearly indicate that induction of apoptosis is an important event for chemoprevention of cancer by naturally occurring dietary agents. In mammalian cells, apoptosis has been divided into two major pathways: the extrinsic pathway, activated by pro-apoptotic receptor signals at the cellular surface; and the intrinsic pathway, which involves the disruption of mitochondrial membrane integrity. This process is strictly controlled in response to integrity of pro-death signaling and plays critical roles in development, maintenance of homeostasis, and host defense in multicellular organisms. For chemoprevention studies, prostate cancer (PCa) represents an ideal disease due to its long latency, its high incidence, tumor marker availability, and identifiable preneoplastic lesions and risk groups. In this article, we highlight the studies of various apoptosis-inducing dietary compounds for prevention of PCa in vitro in cell culture, in preclinical studies in animals, and in human clinical trials.

Topics: Adenocarcinoma; Aged; Animals; Apoptosis; Carotenoids; Catechin; Clinical Trials as Topic; Curcumin; Drug Screening Assays, Antitumor; Flavonoids; Flavonols; Genistein; Humans; Lycopene; Lythraceae; Male; Mice; Mice, Nude; Mice, Transgenic; Middle Aged; Neoplasm Proteins; Pentacyclic Triterpenes; Phytotherapy; Plant Extracts; Prostatic Neoplasms; Resveratrol; Stilbenes; Tumor Cells, Cultured

It is estimated that nearly one-third of all cancer deaths in the United States could be prevented through appropriate dietary modification. Various dietary antioxidants have shown considerable promise as effective agents for cancer prevention by reducing oxidative stress which has been implicated in the development of many diseases, including cancer. Therefore, for reducing the incidence of cancer, modifications in dietary habits, especially by increasing consumption of fruits and vegetables rich in antioxidants, are increasingly advocated. Accumulating research evidence suggests that many dietary factors may be used alone or in combination with traditional chemotherapeutic agents to prevent the occurrence of cancer, their metastatic spread, or even to treat cancer. The reduced cancer risk and lack of toxicity associated with high intake of fruits and vegetables suggest that specific concentrations of antioxidant agents from these dietary sources may produce cancer chemopreventive effects without causing significant levels of toxicity. This review presents an extensive analysis of the key findings from studies on the effects of dietary antioxidants such as tea polyphenols, curcumin, genistein, resveratrol, lycopene, pomegranate, and lupeol against cancers of the skin, prostate, breast, lung, and liver. This research is also leading to the identification of novel cancer drug targets.

Topics: Animals; Anticarcinogenic Agents; Antioxidants; Carotenoids; Curcumin; Dietary Supplements; Fruit; Genistein; Humans; Lycopene; Neoplasms; Oxidative Stress; Pentacyclic Triterpenes; Resveratrol; Stilbenes; Triterpenes

The present study is aimed to evaluate the inhibitory effect of the combination of two phytochemicals; pterostilbeneand lupeol (generally obtained from blue berries, grapes, white cabbage, green pepper, olive and mangoes) on mouse skin tumorigenesis. We hypothesized that the concomitant topical treatment of selected phytochemicals would lead to improved impediment of skin cancer. Swiss albino mice (n = 25) received a topical dose of Benzo[a]pyrene (B[a]P, 5 μg/animal) with pre/post application of pterostilbene (16 μM/0.2 ml acetone/animal) and/or lupeol (500 μM/0.2 ml acetone/animal) for 32 weeks. Results showed that pterostilbene and/or lupeol treatment resulted in a significant delay in onset of tumorigenesis. However, a more promising effect on tumor suppression was noted with the combination of both the phytochemicals. A significant reduction in average tumor volume, cumulative number of tumors and tumor multiplicity was recorded in combination treated group. The histopathological analysis illustrated the marked suppression in epidermal hyperplasia and necrotic cells in combination treated groups. Our study suggests that the combination of pterostilbene and lupeol was more effective in prevention of skin cancer as compared to either of the phytochemical alone. Therefore, the combined treatment of phytochemicals has better potential to prevent skin carcinogenesis.

Topics: Administration, Topical; Animals; Anti-Inflammatory Agents; Benzo(a)pyrene; Cell Cycle; Cell Transformation, Neoplastic; DNA Damage; Flow Cytometry; Immunoenzyme Techniques; Male; Mice; Pentacyclic Triterpenes; Pterocarpus; Skin Neoplasms; Stilbenes