PubMed Health⌕ Search

Biomedical subjects

M H Malone

Publications and source records attributed to M H Malone.

At least 37 records · Page 2Linked to original sources

The pharmacological evaluation of natural products--general and specific approaches to screening ethnopharmaceuticals.

Natural product research is most efficiently conducted in a systematic fashion concentrating on ten critical questions which must be answered in sequential fashion by thoroughly trained professionals experienced in such research. The minimum ethnopharmacology research team should consist of a botanist, a chemist and a pharmacologist with each carrying the responsibility for answering certain of the critical questions. The screening procedures used for the evaluation of synthetic medicinals generally are not appropriate for guiding the extraction of active principles from crude drugs and establishing extraction efficiency; therefore, specialized techniques unique to ethnopharmacology must be used.

Chemical Phenomena↗

Neurogram recording during acute inflammation in the rat hind paw.

Electrophysiological recording was conducted using the intact tibiotarsal nerve of the left hind leg of adult male rats before and after subplantar injections of three different phlogistic agents or saline vehicle in the left hind paw. In three-hour recordings, peak neural activity as activated by 5 g of pressure to the injected paw was reached in 90 min (dextran), 120 min (brewer's yeast) and 150 min (carrageenan). The least neural hyperactivity was seen with dextran, while yeast and carrageenan produced comparably high degrees of hyperactivity. Neurograms were also studied in rats receiving orally administered prototype anti-inflammatory agents or chlorpromazine 1 hr before carrageenan was injected pedally. Chlorpromazine HCl pretreatment (100 mg/kg) exerted the greatest protective effect with the nadir of neural activity seen at 90-120 min. The nadir for phenylbutazone (100 mg/kg) was at 60-120 min, indomethacin (10 mg/kg) at 60-90 min and aspirin (300 mg/kg) at 45-90 min. Despite these temporal differences, the protective effects of these three anti-inflammatory agents were statistically equivalent at the doses tested. Hydrocortisone alcohol (20 mg/kg) provided a significant reduction in hyperactivity at 30-60 min but the duration was much shorter than the other agents which showed protective effects through to the end of the 180-min observation period.

Animals↗

Evaluation of immunosuppressive potential of cryogenine using developing and established adjuvant arthritis in rats.

Both developing (Days --1-+12 relative to inoculation) and established (Days +18-+29) stages of Mycobacterium butyricum adjuvant-induced polyarthritis in rats were treated orally with cryogenine (100 mg/kg/day), a prototype anti-inflammatory (phenylbutazone, 100 mg/kg/day), or a prototype immunosuppressive (cyclophosphamide, 6 mg/kg/day). During developing adjuvant arthritis, cryogenine and phenylbutazone significantly reduced the nonimmune-mediated inflammation in the inoculated hindpaw. Neither cryogenine nor phenylbutazone provided protection against the development of the delayed-onset, immune-mediated inflammation and the reduction in growth rate seen after Day +12 in unmedicated rats. Cyclophosphamide failed to reduce the nonimmune-mediated inflammation, but it provided significant protection against both the delayed-onset, immune-mediated inflammation and the reduced growth rate. During established adjuvant arthritis, cryogenine and phenylbutazone were effective against the established inflammation, while cyclophosphamide was ineffective. These results confirm the known anti-inflammatory and immunosuppressive activities of phenylbutazone and cyclophosphamide, respectively, and indicate that cryogenine lacks immunosuppressive capability at the effective anti-inflammatory dosage level used.

Alkaloids↗

Evaluation of cryogenine on rat paw thermal oedema and rat isolated uterus.

1. Significant inhibition of oedema formation caused by thermal injury was observed for calcium carbaspirin, phenylbutazone, hydrocortisone, cryogenine and indomethacin when given daily beginning 2 days prior to thermal exposure and afterwards. Several anti-inflammatory drugs, including cryogenine, failed to reduce thermal oedema significantly when given as single doses 1 h prior to the thermal injury.2. Kinetic experiments on the rat isolated uterus demonstrated that cryogenine, chlorpromazine, and flufenamic acid were, in part, competitive inhibitors of synthetic bradykinin, while indomethacin and tetrabenazine showed only non-competitive antagonism.

Alkaloids↗