Although pure α-mangostin has shown a variety of pharmacological activities in in vitro assays at present it is uncertain if the same magnitude of effects will be achieved in vivo when its low bioavailability is considered.

No abstract

Summary From 12 bitches of various breeds with fertile oestrus cycles faecal samples were collected daily from the onset of pro‐oestrus till 20 days after the start of vulval bleeding, then once per week till about 1 week before term. Immunoreactive progesterone metabolites were extracted from the samples using methanol and measured using immunoassays. In a first experiment four different assays were compared in regard to the amounts of immunoreactive substances measured: the enzyme immunoassay against 20‐oxo‐3‐hydroxypregnanes showed twice to four times higher values of immunoreactive material than another using an antibody against 6β‐hydroxyprogesterone. An enzyme immunoassay for pregnanediol measured only low concentrations of immunoreactive material. Also a radio immunoassay using an antibody against 11β‐hyroxyprogesterone detected only small amounts of reacting material. High performance liquid chromatography showed that in faeces of bitches the immunoreactive progesterone metabolites were present in unconjugated form, mainly as 3α/β hydroxylated progestagens with a 20‐oxo group. In the second experiment the samples were measured with the assay system using the 20‐oxo‐3‐hydroxypregnane antibody. A few days before mating the concentration of progesterone metabolites increased, reaching 5.77 μmol/kg faeces (median) at the day of mating. High levels (10.45 μmol/kg faeces) were measured till the end of the first month after mating. Thereafter, the concentrations decreased, reaching 2.68 μmol/kg (median) at the end of the second month.

The effect of the angiotensin-converting enzyme (ACE) inhibitor quinapril on myocardial ischaemia was tested in a randomized double-blind cross-over study of 16 men (mean age 62 [44-75] years) with angiographically demonstrated coronary heart disease, exercise-induced ST-segment depression and stable angina. Exercise ECGs were recorded before and 4 hours after a single dose of 10 mg quinapril and after a 14-day course of 10 mg quinapril twice daily. The single dose decreased the average ST-segment depression from 1.12 mV (placebo) to 0.74 mV (P less than 0.05); after 14 days on quinapril the ST-segment depression decreased from 0.91 mV (placebo) to 0.72 mV (P less than 0.05). While heart rate remained unchanged the average resting arterial blood pressure fell from 136/80 to 120/74 mmHg (P less than 0.05) after a single dose and from 141/83 to 127/78 mmHg (P less than 0.05) after 14 days on the drug. These data indicate that ACE inhibitors should be considered as a means of treating coronary heart disease and angina.