Dose-dependent therapeutic antiinfectives from ethnomedicines of bay islands.

BACKGROUND: The methanol extract of Ophirrhiza nicobarica, Alstonia macrophylla and Mallotus peltatus, ethnomedicines of Little Andaman, were investigated for antiinfective, antiinflammatory and antioxidant activities. METHODS: Toxicity was determined in cells and in an animal model. Antiviral, antibacterial and antifungal activity was determined by plaque reduction, disc diffusion and agar dilution methods. The antiinflammatory and antioxidant activities were also studied. RESULTS: O. nicobarica at 300 microg ml(-1) showed anti-HSV activity while M. peltatus and A. macrophylla showed antibacterial activity at 64-1,000 microg ml(-1). Both extracts showed significant dose-dependent antiinflammatory and antioxidant activity at nontoxic concentrations. CONCLUSION: The alkaloid, flavonoid and beta-sitosterol isolated from bioactive parts had a dose-dependent therapeutic efficacy, justifying their use. Further study is required to know the mechanism of action.

CNS activity of Alstonia macrophylla leaf extracts: an ethnomedicine of Onge of Bay Islands.

Methanol extract at 100-200 mg/kg p.o. and major nonpolar fraction B at 50 mg/kg of Alstonia macrophylla leaves caused a significant reduction in spontaneous activity, remarkable decrease in exploratory behavioural pattern, a reduction in muscle relaxant activity and also significantly potentiated phenobarbitone sodium-induced sleeping time. The phytochemical study of crude leaf extract revealed the presence of tannin, triterpenoid, flavonoid, sterol, alkaloid and reducing sugars. Further fractionation and purification of the n-butanol part of methanol extract yielded fraction A, fraction B and fraction C along with some minor fatty acids as the major compounds.

Anti-diabetic potential of Barleria lupulina extract in rats.

We have undertaken a study to evaluate the anti-hyperglycemic effect of a methanol extract of aerial parts of Barleria lupulina Lindl. (Acanthaceae) in streptozotocin-diabetic rats, based on folkloric reports its use as an anti-diabetic agent. The extract exerted significant (p < 0.05) anti-hyperglycemic efficacy at all levels tested from 4 h after its administration, as compared with the control group, and the effect was also prolonged up to 12 h. The extract at doses of 200 mg kg(-1) body wt. and above exhibited a maximum activity (p < 0.001) at 12 h after administration. The most significant activity (15.35% blood glucose reduction) was observed for the group administered 300 mg kg(-1) body wt. at 12 h after administration, while the standard drug glibenclamide (10 mg/kg(-1) body wt.) showed an 18.80% reduction of blood glucose at the same time interval. Based on our current results, it appears that the methanol extract of aerial parts of Barleria lupulina Lindl. shows a pronounced blood-glucose-lowering potential in streptozotocin hyperglycemic rats, and is thus provided with a pharmacological support of the folklore claims of anti-diabetic activity.

CNS activity of the methanol extract of Mallotus peltatus (Geist) Muell Arg. leaf: an ethnomedicine of Onge.

The aim of the present study was to investigate several neuropharmacological effects of the methanol extract and different fractions of Mallotus peltatus (Geist) Muell Arg. var acuminatus (Euphorbiaceae) leaves in Wistar albino rats and Swiss albino mice. General behavior, exploratory behavior, muscle relaxant activity and phenobarbitone sodium-induced sleeping time were studied. The results revealed that the crude extract at 200-300 mg kg(-1) p.o. and its fractions A and B at 50 mg kg(-1) caused a significant reduction in spontaneous activity (general behavioral profile), remarkable decrease in exploratory behavioral pattern (Y-maze and head dip tests), a reduction in muscle relaxant activity (rotarod, 30 degrees inclined screen and traction tests), and also significantly potentiated phenobarbitone sodium-induced sleeping time. The phytochemical study of crude leaf extract revealed the presence of tannin, triterpenoid, flavonoid, sterol, alkaloid and reducing sugar. Further fractionation and purification yielded two major fractions A (ursolic acid) and B (beta-sitosterol) with some fatty acids as the major compounds. The psychopharmacological activity of the crude leaf extracts appeared to be either due to fraction A (50 mg kg(-1)) or a combination of fractions A and B (50 mg kg(-1)) along with some fatty acids present in the n-butanol part of methanol extract of M. peltatus leaf (MEMPL).

Evaluation of anti-inflammatory activity of Alstonia macrophylla Wall ex A. DC. leaf extract.

Methanolic extract of dried leaves of Alstonia macrophylla Wall ex A. DC. and its fractions were investigated for its anti-inflammatory activity. The extract at a concentration of 200 mg kg(-1) and 400 mg kg(-1), p.o. and its fractions at 25 mg kg(-1) and 50 mg kg(-1), p.o. showed the significant dose dependent antiinflammatory activity in carrageenan and dextran-induced rats hind paw edema (acute models) as well as in cotton pellet-induced granuloma (chronic model) in rats. Anti-inflammatory activity of the tested extract and its fractions was comparable with that of the standard drug Indomethacin (10 mg kg(-1)).

Antimicrobial and anti-inflammatory activity of folklore: Mallotus peltatus leaf extract.

Since ages Mallotus peltatus (Geist) Muell. Arg. var acuminatus (Euphorbiaceae) leaf and stem bark is used in folk medicine to cure intestinal ailments and skin infections. In several intestinal ailments, localized inflammation is of common occurrence and hence we have evaluated the antimicrobial as well as anti-inflammatory activity of M. peltatus leaf extract. The crude methanol extract of M. peltatus leaves was found to be active against Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus faecalis, Bacillus subtilis, Escherichia coli and Proteus mirabilis and the dermatophytic fungi Microsporum gypseum. The minimum inhibitory concentration (MIC) ranges from 128 to 2000 microg ml(-1) for bacteria and 128 mg ml(-1) for fungi, while the minimum bactericidal concentration (MBC) was 2-4-fold higher than MIC. The methanol-water fraction of the extract showed similar activity against Staphylococcus, Streptococcus, Bacillus and Proteus isolates. The anti-inflammatory activity of the extract against carrageenan (acute model) and dextran-induced (subacute model) rat paw oedema and cotton pellet-induced granuloma (chronic model) in rats were studied using indomethacin (10 mg kg(-1)), a nonsteroid anti-inflammatory drug, as standard. The methanol extract at 200 and 400 mg kg(-1), and the n-butanol fractions A and B at 25 mg kg(-1), exhibited significant anti-inflammatory activity in Albino rats, compared with indomethacin. Phytochemical study revealed the presence of tannins, saponins, terpenoids, steroids and reducing sugars in the crude extract while the n-butanol fractions showed the presence of ursolic acid, beta-sitosterol and some fatty acids as major compounds. Further study with fractions showed that the antibacterial and anti-inflammatory activity is due to either fraction A (ursolic acid) alone or the combination of fractions A and B (beta-sitosterol and fatty acids) of the extract.

Studies on the psychopharmacological activities of Rumex nepalensis Spreng. root extract in rats and mice.

The methanol extract of Rumex nepalensis Spreng. (Family - Polygonaceae) was assessed for different psychopharmacological activities in rats and mice by evaluation of general behaviour, exploratory behaviour, muscle relaxant activity and phenobarbitone sodium-induced sleeping time. The extract at doses 200 mg/kg and above exhibited a reduction in spontaneous activity (general behavioural profile), a decrease in exploratory behavioural pattern in the Y-maze and Head-dip tests, a reduction in muscle relaxant activity in rotarod, 30 degrees inclined screen and traction tests, and also potentiated phenobarbitone sodium-induced sleeping time.

Effect of Trichodesma indicum extract on cough reflex induced by sulphur dioxide in mice.

The effect of methanol extract of whole plants of Trichodesma indicum R. Br. has been investigated on sulphur dioxide (SO2) induced cough reflex in Swiss albino mice. The extract has demonstrated significant (p < 0.001) inhibition in frequency of cough in all the tested doses when compared with untreated control group. The effect persisted up to 90 min of its oral administration and also comparable to that of the effect exhibited by the standard drug (Codeine phosphate). This study confirmed the traditional use of this plant in the treatment of cough. Determination of underlying mechanism of beneficial effect is major topic requiring further comprehensive investigation.

Evaluation of antipyretic activity of leaf extracts of Mallotus peltatus (Geist) Muell. arg. var acuminatus: a folk medicine.

A study was carried out to evaluate the anti-pyretic potential of the methanol extract of Mallotus peltatus (Geist) Muell. Arg. var acuminatus leaf, a folk medicine of Onge tribes of Bay Islands, on normal body temperature and yeast-induced pyrexia in Wister albino rats. The leaf extract at oral doses of 100, 200 and 300 mg kg(-1), p.o., showed significant reduction in normal body temperature and yeast-provoked elevated temperature in a dose-dependent manner and the anti-pyretic effect was comparable to that of standard anti-pyretic agent paracetamol (150 mg kg(-1), p.o.). The effect also extended up to 5 hours after the drug administration.