The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

Plant Products as Antimicrobial Agents

http://www.dietcan.net/docs/Polifenoles%20en%20alimentos%20y%20biodisponibilidad.pdf

Polyphenols: food sources and bioavailability

The therapeutic properties of light have been known for thousands of years, but it was only in the last century that photodynamic therapy (PDT) was developed. At present, PDT is being tested in the clinic for use in oncology--to treat cancers of the head and neck, brain, lung, pancreas, intraperitoneal cavity, breast, prostate and skin. How does PDT work, and how can it be used to treat cancer and other diseases?

Photodynamic therapy for cancer

Resveratrol, a phytoalexin found in grapes and other food products, was purified and shown to have cancer chemopreventive activity in assays representing three major stages of carcinogenesis. Resveratrol was found to act as an antioxidant and antimutagen and to induce phase II drug-metabolizing enzymes (anti-initiation activity); it mediated anti-inflammatory effects and inhibited cyclooxygenase and hydroperoxidase functions (antipromotion activity); and it induced human promyelocytic leukemia cell differentiation (antiprogression activity). In addition, it inhibited the development of preneoplastic lesions in carcinogen-treated mouse mammary glands in culture and inhibited tumorigenesis in a mouse skin cancer model. These data suggest that resveratrol, a common constituent of the human diet, merits investigation as a potential cancer chemopreventive agent in humans.

https://science.sciencemag.org/content/sci/275/5297/218.full.pdf

Cancer Chemopreventive Activity of Resveratrol, a Natural Product Derived from Grapes

Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer

Improved methods of manufacturing betulinic acid from betulin are disclosed. The methods provide the β-isomer of betulinic acid in high purity and high yield.

Methods of manufacturing betulinic acid

Chemoprevention of Esophageal Squamous Cell Carcinoma with Berries, by Gary D. Stoner and Li-Shu WangChemoprevention of Esophageal Squamous Cell Carcinoma with Berries, by Gary D. Stoner and Li-Shu Wang.- Cancer Prevention by Different Forms of Tocopherols, by Chung S. Yang and Nanjoo Suh.- Cancer Chemopreventive and Therapeutic Potential of Guggulsterone, by Inas Almazari and Young-Joon Surh.- Inhibition of UVB-Induced Nonmelanoma Skin Cancer: A Path from Tea to Caffeine to Exercise to Decreased Tissue Fat, by Allan H. Conney, You-Rong Lou, Paul Nghiem, Jamie J. Bernard, George C. Wagner and Yao-Ping Lu.- Cancer Chemoprevention and Nutri-Epigenetics: State of the Art and Future Challenges, by Clarissa Gerhauser.- A Perspective on Dietary Phytochemicals and Cancer Chemoprevention: Oxidative Stress, Nrf2, and Epigenomics, by Zheng-Yuan Su, Limin Shu, Tin Oo Khor, Jong Hun Lee, Francisco Fuentes and Ah-Ng Tony Kong.- Keap1-Nrf2 Signaling: A Target for Cancer Prevention by Sulforaphane, by Thomas W. Kensler, Patricia A. Egner, Abena S. Agyeman, Kala Visvanathan, John D. Groopman, Jian-Guo Chen, Tao-Yang Chen, Jed W. Fahey and Paul Talalay.- Chemoprotection Against Cancer by Isothiocyanates: A Focus on the Animal Models and the Protective Mechanisms, by Albena T. Dinkova-Kostova.- Human Cancer Chemoprevention: Hurdles and Challenges, by Vaqar Mustafa Adhami and Hasan Mukhtar.- Personalizing Lung Cancer Prevention Through a Reverse Migration Strategy, by Kathryn A. Gold, Edward S. Kim, Ignacio I. Wistuba and Waun K. Hong.- Natural-Agent Mechanisms and Early-Phase Clinical Development, by Janet L. Wang, Kathryn A. Gold and Scott M. Lippman.

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John M. Pezzuto

Papers

Methods of manufacturing betulinic acid

Natural products in cancer prevention and therapy

Structure-activity relationships and docking studies of synthetic 2-arylindole derivatives determined with aromatase and quinone reductase 1.

Autoxidation and Antioxidants

Paralinones A and B, novel diterpene esters from Euphorbia paralias