Chemotaxonomic studies on Schwenckia americana LINN.

This study investigated the chemotaxonomic studies on Schwenckia americana Linn., a member of the family Solanaceae predominantly found mostly in low grass fields, Nigeria. The habit is annual herbaceous weed with slender stem characterized with free branching and growing up to 45cm in height.They are used mainly as medicine. The leaves are simple, entire, elliptic to ovate in shape, smooth, variable, petiolate and larger at the lower region of stem and narrowing to smaller almost sessile and oblanceolate towards the apical regions which are alternately arranged and acrescently structured from the top to the base upto 3.7 ± 1.5cm long and 2.4±0.6cm wide. The inflorescence is a panicle of 15 or more flowers occurring at stem terminal.The flowers are whitish tubular structures measuring up to 1.0±0.2cm in length and 0.1cm in diameter. The petals are whitish up to 0.9 ±0.2cm in length and sepals are greenish up to 0.1cm in length. The berry fruit is greenish when unripe and pale yellowish when ripe up to 0.3±0.1cm in diameter. The seeds are blackish and spherical or triangular shaped with rough edges measuring up to 0.1cm in diameter. The epidermal studies reveal anomocytic stomata whereas the trichomes are simple uniseriate forms wth bulge heads. The anatomy of mid-ribs and petioles showed bicollateral vascular systems. There are three vascular traces and the node is unilacunar. The petioles have 2 rib traces at primary growth phase. At secondary growth phase, the mid-rib and petiole revealed vascular arcs and the stem has a ring of open vascular system. The cytological studies showed a diploid chromosome number of 2n = 24 and n = 12 for the haploids. Alkaloids, saponins, tannins, phlobatannins, flavonoids, combined anthraquinones, free anthraquinones and cardiac glycosides are present.

Antileishmanial activity of the essential oil from Tetradenia riparia obtained in different seasons

The herbaceous shrub Tetradenia riparia has been traditionally used to treat inflammatory and infectious diseases. Recently, a study showed that T. riparia essential oil (TrEO) obtained in summer has antileishmanial effects, although these results could be influenced by seasonal variation. This study evaluated the activity of the TrEO obtained in different seasons against Leishmania (Leishmania) amazonensis , in vitro and in vivo. The compounds in the TrEO were analysed by gas chromatography-mass spectrometry; terpenoids were present and oxygenated sesquiterpenes were the majority compounds (55.28%). The cytotoxicity and nitric oxide (NO) production were also tested after TrEO treatment. The TrEO from all seasons showed a 50% growth inhibitory concentration for promastigotes of about 15 ng/mL; at 30 ng/mL and 3 ng/mL, the TrEO reduced intracellular amastigote infection, independently of season. The TrEO from plants harvested in summer had the highest 50% cytotoxic concentration, 1,476 ng/mL for J774.A1 macrophages, and in spring (90.94 ng/mL) for murine macrophages. NO production did not change in samples of the TrEO from different seasons. The antileishmanial effect in vivo consisted of a reduction of the parasite load in the spleen. These results suggest that the TrEO has potential effects on L. (L.) amazonensis, consonant with its traditional use to treat parasitic diseases.