Pharmacological study on citrus fruits. I. Anti-allergic effect of fruit of Citrus unshiu Markovich (1)

A study was carried out to examine the effect of 50% ethanolic extract from green fruit of Citrus unshiu Markovich on type I, II and IV allergic reactions. Forty eight-hour homologous passive cutaneous anaphylaxis (PCA) in rats as a typical model of the type I reaction was significantly inhibited by the oral administration of the extract. Complement-dependent cytolysis of sheep red blood cell as a typical model of the type II reaction was significantly inhibited by incubation with it. Contact dermatitis in mice as a model of the type IV reaction caused by picryl chloride or sheep red blood cell was significantly inhibited by the oral application of it. The anti-allergic actions decreased with the growth of fruit of Citrus unshiu. These results suggested that the 50% ethanolic extract from green fruit of Citrus unshiu have anti-allergic actions against the type I, II and IV reactions.     

Anti-allergic effect of a combination of Citrus unshiu unripe fruits extract and prednisolone on picryl chloride-induced contact dermatitis in mice

Effect of 50% ethanolic extract of unripe fruits of Citrus unshiu (CU-ext) on type IV allergic reaction was examined by inhibitory activity of ear swelling of picryl chloride-induced contact dermatitis (PC-CD) in mice. Oral administration of CU-ext and subcutaneous administration of prednisolone showed inhibition of ear swelling during both induction and effector phases of PC-CD. The inhibitory activities of combinations of CU-ext (p.o.) and prednisolone (s.c.) during induction phase of PC-CD were more potent than those of CU-ext alone and prednisolone alone. Successive oral administration of hesperidin, a major flavanone glycoside of CU-ext, inhibited ear swelling during induction phase of PC-CD. The inhibitory activities of combinations of hesperidin (p.o.) and prednisolone (s.c.) were more potent than those of hesperidin alone and prednisolone alone. These results indicated that the combinations of prednisolone and CU-ext or hesperidin exerted a synergistic effect.     

Pharmacological study of mequitazine (LM-209) (II). Anti-allergic action (author's transl)

The anti-allergic effect of Mequitazine (LM-209) which was found to have an anti-histaminic activity was investigated in guinea-pigs. The inhibitory activities of LM-209 on the Schultz-Dale reaction and ileum contraction by some mediators released from the sensitized guinea-pig lung were the same as those of clemastine fumarate (CL) but with 5 times the potency. LM-209 and CL, but these activities were less potent than in the case of disodium cromoglycate. The various anaphylactic reactions mediated by IgG in guinea-pigs were inhibited by LM-209, CL and chlorpheniramine maleate (CPM). The homologous PCA mediated IgE in rats was also inhibited by LM-209, CL and CPM, but the duration of the action with LM-209 was markedly longer. In experimentally-induced asthma, the decrease of respiratory rate and volume was significantly inhibited by LM-209, but was not affected by CL. Thus, LM-209 seems to inhibit the allergic reaction mainly by an antagonistic action on allergic mediators.     

Pharmacological study of nicergoline. (II). Protective effect on ischemic brain damages in animals

Effects of nicergoline on ischemic brain damages induced by bilateral carotid arterial ligation (BCAL) in ICR-strain mice and mongolian gerbils and lipid peroxide formation (LPOF) in normal brain homogenate of rats were compared with those of dihydroergotoxine (DHE). In mice, nicergoline (16 mg/kg, i.p.) significantly reduced the cumulative mortality rate after BCAL (from 80-83% in the control to 50-55%). In gerbils, nicergoline (32 mg/kg, i.p.) significantly prolonged the mean onset time of ischemic seizure following recirculation after the 30-min BCAL (from 45.8 min in the control to 94.9 min). DHE also showed protective effects in these animals. In the ischemic brain of mice, marked decreases of creatine-P, ATP, glucose and glycogen; a remarkable increase of lactate; and elevation of L/P ratio were observed 1 to 10 min after BCAL. Nicergoline (16 mg/kg, i.p.) slightly prevented these decreases and significantly suppressed the increase of lactate and the elevation of L/P ratio 2 min after BCAL. The inhibitory action of nicergoline (20-100 microM) on LPOF is more potent than those of alpha-tocopherol and DHE. These results suggest that nicergoline may have protective effects against ischemic brain damages due to its ameliorating action on cerebral energy metabolism and partially due to its inhibitory action of LPOF.     

Pharmacological studies on sufoxazine (Y-8894). (II). Anti-anoxic effect

The anti-anoxic effect of sufoxazine was investigated in various cerebral anoxia models with mice, in comparison with those of various cerebroactive drugs. Sufoxazine reduced dose-dependently the duration of coma induced by a sublethal dose of KCN (1.8 mg/kg, i.v.), significantly stimulating recovery from the coma at 5 mg/kg, i.p. and 30 mg/kg, p.o. It also protected against a lethal dose of KCN (2.5 mg/kg, i.v.). Sufoxazine prolonged the survival time of mice subjected to hypobaric and normobaric hypoxia. Dihydroergotoxin and ifenprodil gave similar protection in the KCN-induced anoxia models, but produced adverse effects in the hypoxia models. Calcium hopantenate exerted similar but weak protection only at a dose as high as 300 mg/kg, i.p. These findings suggest that sufoxazine has an anti-anoxic action superior to those of the other cerebroactive drugs used.     

Anti-allergic constituents in the culture medium of Ganoderma lucidum. (II). The inhibitory effect of cyclooctasulfur on histamine release

For centuries, Ganoderma lucidum has been used in Oriental medicine for the treatment of chronic bronchitis. Sequential fractions of the culture medium of this plant revealed that one of the active constituents was cyclooctasulfur. The latter effectively inhibited histamine release from rat peritoneal mast cells and impeded 45Ca uptake into these cells without affecting the cyclic AMP content. SDS-PAGE analysis indicated that cyclooctasulfur induced some changes in protein bands obtained from the membrane fraction of mast cells, suggesting that this compound interacts with membrane proteins so as to inhibit 45Ca uptake, and that this may be the main cause of histamine release inhibition.     

Studies on the preparation and evaluation of Kijitsu, the immature citrus fruits. II. Analysis of factors which affect the flavonoid contents

Factors which affect the content of flavonoids in Kijitsu were studied. Flavonoids in immature citrus fruit decomposed gradually by standing after divided horizontally in two parts. About 90% of flavonoids were retained by use of hot air drying of fresh samples. The content of flavonoids in Kijitsu decreased to about 60% by standing one year. Flavonoid contents decreased corresponding with an increase in diameter of Kijitsu. There is no wide difference between Hassaku and other Citrus fruits in their essential oils determined by gas chromatography-mass spectrometry. It was concluded that C. hassaku might be used for the material for Kijitsu.     

Effects of chronic administration of fruit extract (Citrus unshiu Marc) on endothelial dysfunction in streptozotocin-induced diabetic rats

We investigated the effects of chronic administration of fruit extract (Citrus unshiu MARC) on the endothelial dysfunction seen in aortae from streptozotocin (STZ)-induced diabetic rats. A ten-week administration of this fruit extract preserved acetylcholine (ACh)-induced endothelium-dependent relaxation, but not sodium nitroprusside (SNP)-induced endothelium-independent relaxation, in the diabetic aorta. In age-matched control rats, chronic administration of the fruit extract had no influence on the ACh- or SNP-induced aortic relaxation. The increased total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels seen in STZ-induced diabetic rats were not normalized by fruit-extract treatment. These results suggest that Citrus unshiu MARC extract preserves endothelial function in the aorta in STZ-induced diabetic rats without lowering plasma cholesterol. This beneficial effect may be due to this extract protecting of nitric oxide against inactivation by oxygen free radicals.     

Studies on the preparation and evaluation of Kijitsu, the immature citrus fruits. IV. Biological activities of immature fruits of different citrus species]

Biological activities of the 50% ethanolic extract of Kijitsu, dried immature Citrus fruits prepared from C. hassaku Hort. ex Tanaka (H), C. natsudaidai Hayata (N) or allied plants (T, A) were observed. Weak toxicities, weak intestine or uterine relaxant activities, beta-adrenergic activities were shown by in vitro experiments and antiasthmatic activity by intraperitoneal administration. These activities among each extract did not differ. The content of flavonoids (narirutin, naringin hesperidin, neohesperidin) or synephrine did not show much difference among the four dried immature Citrus fruits. These results suggest that H can be used for medicine as the substitute for N, T or A which has been commonly used as Kijitsu. This method is generally applicable to the proof of the biological equivalency of the crude drug and its substitutes.     

Pharmacological analysis of the mode of action of mandelamidine with sustained antihypertensive effect. (II). Mechanism of transient hypotensive action of mandelamidine]

The mode of a transient hypotensive action of dl-Mandelamidine (MA) was studied in both anesthetized and unanesthetized animals. In the blood pressure of unanesthetized rats, a transient hypotensive action of MA (1 approximately 30 mg/kg i.v.) like papaverine (1 approximately 10 mg/kg i.v.) was much less predominant than in rats anesthetized with urethane (1.5 g/kg s.c.). The transient hypotensive action of MA (10 mg/kg i.v.) in rats anesthetized with urethane (1.5 g/kg s.c.) was not reduced when MA was injected continuously. Moreover C6 (5 mg/kg i.v.), propranolol (1 mg/kg i.v.), diphenhydramine (10 mg/kg i.v.) and atropine (2 mg/kg i.v.) did not block this transient hypotensive action. MA blocked the pressor action of epinephrine (3 mug/kg i.v.) in three minutes, but then potentiated it. MA (10 mug/kg i.a. approximately 1 mg/kg i.a.) caused a temporary vasodilation on the perfused leg artery and vertebral artery in dogs anesthetized with sodium pentobarbital (30 mg/kg i.v.). In the perfused leg artery, atropine (2 mg/kg i.v.) and propranolol (1 mg/kg i.v.) did not block the vasodilation of MA, and MA showed no marked blocking effect of the vasoconstriction of norepinephrine (0.2 mug/kg i.a.). In the dog heart-lung preparation and the guinea-pig heart, MA showed inhibiting effects. On the contraction of the cat nictitating membrane elicited by the stimulation of the postganglionic cervical sympathetic nerve, the blocking action of MA (1 mug/kg i.a. approximately 1 mg/kg i.a.) was much less predominant than that of phentolamine (10 mug/kg i.a.). In the rabbit descending aorta, MA (3 X 10(-4) g/ml) antagonized non-competitively the contraction elicited by norepinephrine. These findings suggest that a transient hypotensive action of MA depends upon the inhibiting effects on the cardiovascular system, and the adrenergic alpha-blocking effect of MA may be very weak.     

Immunomodulatory effect of Consupren Sol. Spofa (cyclosporin A). Preclinical study]

Consupren Spofa was demonstrated in our tests to be a distinguished immunomudulating agent. The preparation did not show any direct lymphotoxicity or myelotoxicity but it markedly influenced maturation of T lymphocytes in the thymus. When testing the functional activity of the immunity system in vivo, the inhibitory effect of Consupren Spofa was manifested only when administering a relatively larger dose of the drug with an antigenic stimulus or shortly after it, i.e., in the period of early activating processes. The use of a suitable time and dosage regimen is therefore decisive to induce an inhibitory effect. On the basis of comparative experiments it can be stated that Consupren Spofa is minimally as much effective as, or in some experiments even more effective than Sandimmun Sandoz.     

Pharmacological action of cattle prostate extracts (PE). V. Effect on the bladder]

As the extract of cattle prostate (PE) is clinically effective in treating prostatic hypertrophy, a study was carried out on urinary bladders of rat, guinea pig, rabbit and dog as well as on guinea pig ileum. Muscle strip of rat and/or dog bladder contracted with PE with increasing spontaneous movement, and was unaffected by atropine. The isolated ileum of guinea pig also contracted with PE, and the contraction was inhibited by papaverine, but not by atropine. A rise in intravesical pressure was observed with increasing spontaneous movement in guinea pig bladder treated with PE, as well as in rabbit bladder in vitro or in situ. The sphincter vesica of guinea pig was dilated by PE as well as by ACh and methacholine.     

Anti-allergic constituents in the culture medium of Ganoderma lucidum. (I). Inhibitory effect of oleic acid on histamine release

The chloroform extract from Ganoderma lucidum broth markedly inhibited histamine release from rat peritoneal mast cells. From the active fractions, palmitic acid, stearic acid, oleic acid and linoleic acid were isolated. Oleic acid dose-dependently inhibited the histamine release and 45Ca uptake into mast cells induced by compound 48/80 and A-23187 at concentrations of 5 to 50 microM and 0.5 to 5 microM, respectively. Saturated fatty acids, however, had only a weak inhibitory effect on histamine release. Although linoleic acid and linolenic acid effectively prevented this release, these two compounds caused marked release at concentrations higher than 10 microM and 20 microM, respectively. Oleic acid induces membrane-stabilization in model membrane systems. It was concluded that one of the effective constituents obtainable from the chloroform extract of G. lucidum-cultured broth is oleic acid.