Ismat Naeem

A review of the antibacterial activity of Hypericum perforatum L.

Hypericum perforatum L. (Hypericaceae) is a perennial herb that is commonly known as St. Johns 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.

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.

New pregnane-type steroidal alkaloids from Sarcococca saligna and their cholinesterase inhibitory activity

Five new steroidal alkaloids, 5,14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-pregn-5,14-diene] (1), 14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-5alpha-pregn-14-ene] (2), 16-dehydrosarcorine [(20S)-20-(N,N-dimethylamino)-3beta-(N(a)-acetylamido)-5alpha-pregn-16-ene] (3), 2,3-dehydrosarsalignone [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-pregn-2,5-diene-4-one] (4), and 14,15-dehydrosarcovagine-D [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-5alpha-pregn-2,14-diene-4-one] (5), were isolated from the ethanolic extract of Sarcococca saligna, along with two known bases, sarcovagenine-C (6) and salignarine-C (7). Their structures were elucidated on the basis of spectroscopic methods. All seven compounds were found to possess cholinesterase inhibitory potential in a concentration-dependent manner with the IC50 values ranging from 12.5 to 200 microM against acetylcholinesterase and from 1.25 to 32.2 microM against butyrylcholinesterase.

Sources of Bisphenol A Contamination in Drinking Water in Pakistan and Determination of Migration Rates

This is a first study of BPA contamination in stored drinking water in Pakistan. Commercial filters, installed at ten different locations at Lahore College for Women University, were selected for analyses of BPA in triplicate by reversed phase High Performance Liquid Chromatography (HPLC). Migration of BPA in 10% ethanol at different exposure timings (24, 48, 72, 96 and 120 hours) was also determined (5.78-31.2 ppb, M=11, SD=9.7). The BPA contents detected in commercial filter samples were 1.38-11.30 ppb (M=5.99, SD=2.96). BPA amounts detected in samples plastic bottled samples ranged from 11.89 ppb to 12.42 ppb (M=12.15, SD=0.2). In plastic material of bottle BPA contents ranged from 5.78 ppb to 6.34 ppb (M=6.0, SD=0.2) after accounting for free BPA present in plastic-ware. The daily intake of BPA calculated (60 kg body wt.) was 12.42 μg/L/ body weight. Which far exceeded the provisional TDI of BPA set by Health Canada (25 μg/kg/body weight).