The antianaphylactic activity of 35% EtOH extract (IB) from the white petals of Impatiens balsamina L. was investigated using murine immediate hypersensitivity reaction system induced by hen egg-white lysozyme (HEL). IB has a significant antianaphylactic activity.Keywords: Impatiens balsamina L; hen egg-white lysozyme; anaphylaxis in mice.The aerial parts of lmpatiens balsamia L. serve as a Chinese herbal medicine for the treatment of articular rheumatism, bruises and beriberi (Dictionary of Chinese Crude Drugs, 1977). The coloured flowers of lmpatiens balsamina have been reported to contain flavonols (Clevenger, 1958), flavonoid pigments (Charles and Hargen, 1966), phenolic compounds (Bohm and Towers, 1962) and quinones (Glennie and Bohm, 1965).In some areas of Japan, juice squeezed from the white petals of Impatiens balsamia L. is painted topically on the skin to alleviate lesions of several types of dermatites including urticaria (personal observation). We tried to determine whether this folklore use of the plant could be supported by pharmacological evidence, and in this communication we have examined the petal extract for antiallergic substances.
MATERIALS AND METHODSPlant materials and extraction. Impatiens balsamia L. was planted in our university medicinal plant garden and the white flowers were collected in August 1989. Fresh flowers (2.5 kg) were freeze-dried (200 g), extracted with cold 35% EtOH for 24h and concentrated in uacuo, giving a residue (designated IB) of 8.47g. IB was dissolved in saline before use in biological experiments.HEL sensitization and challenge. Immunization with HEL (hen egg-white lysozyme, Sigma, 6 times recrystallized) was performed by methods reported previously (Semma et a f . , 1981). Male ddY mice (Japan SLC Co) of 6 weeks of age were sensitized subcutaneously at the base of the tail on day 0 with 50 pg of HEL emulsified in Freund's incomplete adjuvant (FIA) (DIFCO). On day 9, each mouse was challenged intravenously (i.v.) with 50 pg of HEL in 50 pL saline. In some experiments, Author to whom correspondence should be addressed. serum was prepared from each mouse before challenge for use in the experiments under passive cutaneous anaphylaxis (PCA) rections. As a control group, HEL-sensitized mice were challenged with 10 pg of bovine serum albumin (BSA) (Sigma) instead of HEL. To investigate the antiallergic activities of IB, at different times before or after challenge with HEL, 0.001 -256 mg/kg of IB dissolved in saline was administered i.v. to each mouse. Heterologous PCA reactions were conducted by slightly modifying the method of Mota and Wong (1969). Briefly, 50 pL of undiluted serum prepared from each HEL-sensitized mouse was intradermally injected into the' shaved back of normal male Std Wistar/ST rats (Japan SLC Co.). Forty-eight hours later, the rats were challenged by intravenous injection into the tail veins of 1 mg of HEL mixed with 0.5%Evans blue in 500 pL of saline. After 30 min the rats were killed and the skin was removed and the extent of extravasation of th...
Individual protein domains and two domains in combination were prepared by enzymatic and chemical cleavage of turkey ovomucoid followed by isolation and purification by size-exclusion and ion-exchange chromatography. Silica bonded-phase HPLC columns were made from either whole or isolated domains of turkey ovomucoid. The protein columns were tested for chiral recognition by their abilities to resolve enantiomers among a wide range of racemates. The columns made from whole turkey ovomucoid displayed chiral activity toward many racemates, where as a combination of the first and second domain resolved only a selected number of aromatic weak bases. The first and second domains independently gave no appreciable chiral activity. The turkey ovomucoid third domain exhibited enantioselective protein binding for fused-ring aromatic weak acids. Glycosylation of the third domain did not affect chiral recognition. Titration of the third domain with model compounds in conjunction with NMR measurements enabled the identification of the amino acids responsible for binding. Molecular modeling of the ligand-protein complexation provided insights into the ability of a protein surface to discriminate enantiomers on the basis of multiple intermolecular interactions.
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