Critical review of the epidemiological literature on the potential cardiovascular effects of occupational carbon disulfide exposure.

OBJECTIVES: Occupational carbon disulfide (CS(2)) exposure has been associated with a variety of health effects since its introduction in the mid-19th century. Much of the epidemiological interest, especially since the 1960s, has focused on associations with cardiac effects. However, considerable differences in study approach, disease outcome, CS(2) exposure level, and control of confounding factors have produced mixed results and conclusions. This critical review presents a synthesis of the most relevant and best quality studies to better understand these associations. METHODS: Using specific criteria to assess methodological and scientific quality, we identified 37 studies with the potential to inform on at least one of the following questions: (1) Has a relationship between CS(2) exposure and coronary heart disease (CHD) mortality been reasonably demonstrated? If so, at what apparent exposure levels has it been observed? (2) Among studies of workers routinely exposed to CS(2) at levels greater than 20 ppm, have any health effects or indicators of CHD been observed consistently? (3) Among occupational groups exposed to CS(2) at levels less than 20 ppm, have any health effects or indicators of CHD been observed consistently? RESULTS: Several CHD-related effects have been examined relative to various levels of occupational CS(2) exposure. Overall, there was remarkably little consistency of CHD effects observed, including CHD mortality. CONCLUSIONS: Although a physiological effect of CS(2) exposure on CHD is plausible, the epidemiological evidence for an association between CS(2) exposure and various cardiac risk indicators is mixed. The only somewhat consistent finding, of CS(2) exposure on total and/or LDL cholesterol level, may be due to residual confounding by other time-dependent risk factors. If real, however, it appears to be of small magnitude and uncertain clinical importance.

Antiviral activity of Hawaiian medicinal plants against human immunodeficiency Virus Type-1 (HIV-1).

Hawaiian medicinal plants commonly used for the treatment of a variety of infections were screened for antiviral activity against human immunodeficiency virus type 1 (HIV-1). Sixty-one extracts derived from seventeen plants were tested for selective viral growth inhibition using the LAI (HTLV-IIIB) isolate. The greatest degree of antiviral activity was observed with aqueous extracts made from the bark of Eugenia malaccensis (L.) and the leaves of Pluchea indica (Less.) which had antiviral selectivity indices (50% cytotoxic concentration/50% effective antiviral concentration) of 109 and 94, respectively. These and other extracts conferred 100% cell protection against viral cytopathic effect when compared with control samples. Methanol and water extracts made from the Pipturus albidus (Gray) leaves and bark also achieved a high selective inhibition of virus replication with very low cytotoxicity. Plant extracts made from Aleurites moluccana (Willd.), Psychotria hawaiiensis (Gray), Clermontia aborescens (Mann), and Scaevola sericea (Forst.) also showed antiviral activity. These data provide a rationale for the characterization of antiviral natural products from these plants and related plant species.

Anti-microbial activity and anti-complement activity of extracts obtained from selected Hawaiian medicinal plants.

Selected plants having a history of use in Polynesian traditional medicine for the treatment of infectious disease were investigated for anti-viral, anti-fungal and anti-bacterial activity in vitro. Extracts from Scaevola sericea, Psychotria hawaiiensis, Pipturus albidus and Eugenia malaccensis showed selective anti-viral activity against Herpes Simplex Virus-1 and 2 and Vesicular Stomatitis Virus. Aleurites moluccana extracts showed anti-bacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, while Pipturus albidus and Eugenia malaccensis extracts showed growth inhibition of Staphylococcus aureus and Streptococcus pyogenes. Psychotria hawaiiensis and Solanum niger inhibited growth of the fungi Microsporum canis, Trichophyton rubrum and Epidermophyton floccosum, while Ipomoea sp., Pipturus albidus, Scaevola sericea, Eugenia malaccensis, Piper methysticum, Barringtonia asiatica and Adansonia digitata extracts showed anti-fungal activity to a lesser extent. Eugenia malaccensis was also found to inhibit the classical pathway of complement suggesting that an immunological basis for its in vivo activity was identified. This study has confirmed some of the ethnobotanical reports of Hawaiian medicinal plants having curative properties against infections using biological assays in vitro.