Antiinflammatory screening of the medicinal plant Gynura procumbens.

Gynura procumbens is used in Thai folk medicine to treat topical inflammation, rheumatism, and viral ailments. In the present work, attempts were made to verify the folk medicinal claim that the crude ethanolic extract of G. procumbens has antiinflammatory action and to relate the activity to particular fractions using a croton oil-induced mouse ear inflammation model. The original ethanolic extract of G. procumbens was partitioned between water and ethyl acetate. The residues were subjected to antiinflammatory evaluation. While the water extract did not show any antiinflammatory activity, the administration of the original organic extract significantly inhibited the increase in ear thickness in response to croton oil (n = 5). The activity of 0.75 mg/ear original organic extract showed similar antiinflammatory activity (inhibition 65.2%) to that of 6 mg/ear hydrocortisone 21-hemisuccinate sodium salt (inhibition 64.8%). The organic extract was then fractionated with a series of solvents in order of increasing polarity. Each fraction was dried, dissolved in acetone and monitored using the same bioassay. These experiments showed that the hexane and toluene fractions showed significant inhibitions of 44.6% and 34.8%, respectively. These two fractions had similar activities to 4 mg/ear of hydrocortisone (inhibition 35.0%). The possible chemical constituents in the extracts and fractions were investigated using thin layer chromatography and specific color reagents. These tests showed that steroids might be one class of antiinflammatory compounds in this plant.

HIV inhibitor from Thai bitter gourd.

Thai bitter gourd protein (MRK29) was isolated from Momordica charantia ripe fruit and seed. The purification was performed by ammonium sulfate fractionation and gel filtration chromatography. MRK29 possessed one isoelectric point of (pI) > or = 9, and the time of flight mass spectrum (TOFMS) indicated its molecular weight at 28.6 kD. The twenty amino acid sequence from the N-terminus was in the following order: 1Asp Val Asn Phe Arg Leu Ser Gly Ala 10Asp Pro Arg X Tyr Gly Met Phe Ile Glu 20Asp. MRK29 inhibited the HIV-1 reverse transcriptase with 50% IR at the concentration of 18 micrograms/ml. MRK29 was concentrated in the 30-60% salt precipitated fraction, at which the concentration of 0.175 microgram/ml exerted 82% reduction of viral core protein p24 expression in HIV-infected cells. MRK29 might have modulatory role on immune cells, because it increased 3-fold TNF activity.