Pharmacological screening of Hypericum androsaemum extracts for antioxidant, anti-lipid peroxidation, antiglycation and cytotoxicity activity.

Oxidative stress and glycation processes have a combined effect on diabetes related complications. Crude plant extracts and plant derived compounds possessing both antiglycation and antioxidant activities have a high therapeutic potential for treating these complications. Antioxidant, antiglycation, anti-lipid per oxidation and cytotoxic activities of crude methanol extract and solvent fractions of Hypericum androsaemum L. (Hypericaceae) were evaluated and correlated with total content of phenolics and flavonoids. Significant radical scavenging activity was observed for the methanol extract against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical used as a basis for antioxidant activity with IC50 value of 92.70±2.85 µg mL(-1) (96.20±2.34% inhibition at 500 µg mL(-1)). In case of anion scavenging activity the results were not very significant (33.20±1.22% inhibition at 500 µg mL(-1)). Anti-lipid per oxidation activity was highest for n-hexane fraction (67.83±1.33% inhibition at 500 µg mL(-1)) while the ethyl acetate fraction had the highest antiglycation activity (62.77±2.54% inhibition at 500 µg mL(-1)). Statistically significant correlation was determined for antioxidant and antiglycation activity and phenolic and flavonoid contents. In cytotoxicity assay all the extracts had IC50 values >30 µg mL(-1) as compared to the standard cycloheximide (IC50 value 0.084±0.1 µg mL(-1)). The polar extracts of H. androsaemum can be a good source of non-toxic compounds with antioxidant, anti-lipid per oxidation and antiglycation activities.

A review on biological, nutraceutical and clinical aspects of French maritime pine bark extract.

Bark extract of Pinus pinaster has a long history of ethnomedicinal use and is available commercially as herbal dietary supplement with proprietary name pycnogenol. It is used as a food supplement to overcome many degenerative disorders. Rohdewald (2002) wrote the first comprehensive review of extract highlighting its antioxidative nature and its role in different diseases. Later, Watson (2003) and Gulati (2005) in their reviews about cardiovascular health, described the extract as a best neutraceutical agent in this regard. The objective of this paper is to review the current research on this extract in terms of extraction methods, its pharmacological, toxicological and nutraceutical effects and clinical studies. Web sites of Google Scholar, Pubmed and Medline were searched for articles written in English and published in peer-reviewed journals from 2006 to 2009 and sixty-nine research articles were extracted. Of these, two are about extraction advancement and analysis while the rest relate to its clinical, biological and nutraceutical aspects.

A review of the antibacterial activity of Hypericum perforatum L.

Hypericum perforatum L. (Hypericaceae) is a perennial herb that is commonly known as St. John's Wort. The plant has been valued for its important biological and chemical perspectives and its use in the treatment of infectious diseases has been documented in ethnobotanical reports. Most recent interest in H. perforatum has focused on its antidepressant effects, and only recently has its antimicrobial activity been evaluated against a number of bacterial and fungal strains. The present review gives a comprehensive summary of the ethnobotanical uses, chemical constituents and biological effects (antibacterial and antifungal) of this species. A comprehensive account of the chemical constituents including anthraquinone derivatives (naphthodianthrones), flavonoids, prenylated phloroglucinols, tannins and volatile oils is also included. Various types of preparations, ointments, creams and extracts prepared with and compounds isolated from this species have been found to possess a broad spectrum of biological and pharmacological effects such as antidepressant effects, wound-healing, antiviral and antimicrobial activity. The antibacterial activity of crude extracts can be related to the use of the herb as a wound healer in ancient times. The sole antibacterial principle isolated to date is a tetraketone, hyperforin, also thought to be responsible for the antidepressant activity of the herb. The available literature indicates that it has a higher antibacterial activity against Gram-positive than Gram-negative bacteria, and alcoholic extracts (methanolic/ethanolic) were shown to possess more pronounced activity than aqueous extracts. Based on the chemical and pharmacological characteristics of H. perforatum, we concluded that this species has beneficial therapeutic properties and has the potential for use as an effective adaptogenic herbal remedy.