Zanthoxylum nitidum (Roxb.) DC: Traditional uses, phytochemistry, pharmacological activities and toxicology.

ETHNOPHARMACOLOGICAL RELEVANCE: Zanthoxylum nitidum (Roxb.) DC. (Z. nitidum), which is known in China as Liang-Mian-Zhen, is mainly distributed in southern China and is widely used in traditional Chinese medicine. It is traditionally used for treating stomach ache, toothache, rheumatic arthralgia, traumatic injury and venomous snake bites. Additional medical applications include the treatment of inflammations, various types of cancer, bacterial and viral infections, gastric and oral ulcers and liver damage. AIM OF THIS REVIEW: This paper aims to offer up-to-date information on the botany, traditional uses, phytochemistry, pharmacology and toxicity of Z. nitidum. This review also discussed the perspectives for possible future research on Z. nitidum. MATERIALS AND METHODS: A comprehensive review was carried out on studies about Z. nitidum conducted in the past 60 years by using different resources, including Flora of China, Pharmacopoeia of the People's Republic of China and academic databases. RESULTS: At present, more than 150 chemical constituents have been separated and identified from Z. nitidum, most of which include alkaloids. Biological activities, including anti-inflammation, analgesia, haemostasis, anticancer and antibacterial, were determined via in vitro and in vivo studies. The variations in the efficacy of Z. nitidum can be attributed to the biological activities of its natural products, especially alkaloids. Toxicity studies on Z. nitidum are relatively few, thus requiring further study. CONCLUSIONS: This article generalises the current research achievements related to Z. nitidum, which is an important medicinal material in China. Some traditional uses of Z. nitidum have been assessed by pharmacological studies. Unresolved problems remain, including molecular mechanisms underlying biological activities, pharmacokinetics, toxicology and therapeutic effect, which are still being studied and explored before Z. nitidum can be integrated into clinical medicine.

Vasorelaxant activity and acute toxicity of the ethanolic extract of Zanthoxylum rhoifolium Lam leaves

The study evaluated the vasorelaxant effect induced by the ethanolic extract of the leaves of Zanthoxylum rhoifolium Lam (EEtOH-Zr/leaves). Wistar rats were treated with the leaf extract containing a single dose of 2,000 mg / kg, v.o. After 14 days, the animals were anesthetized for blood collection and subsequent analysis of the biochemical parameters; they were then euthanized (sodium pentobarbital-100 mg/kg, i.p.) for the removal and morphological analysis of the heart, lung, liver and kidney. The vasorelaxation activity the and vascular reactivity of EEtOH-Zr/leaves were evaluated on artery mesenteric rings isolated from rats. The extract showed no signs of toxicity and no significant difference in the values of the biochemical parameters between the control group and the group of treated animals. In the evaluation of pharmacological activity in the smooth muscle, the EEtOH-Zr/leaves caused vasorelaxant effect on the tonic contraction induced by phenylephrine in mesenteric artery preparations in the presence (pD2=2.17±0.05 µg/mL; Emax=99.8±5.2%) and absence (pD2=2.14±0.05 µg/mL; Emax=95.3±6.4%) of the vascular endothelium. Oral administration of EEtOH-Zr/leaves reduced the contraction induced by the cumulative addition of PHE. It is concluded that the EEtOH-Zr/leaves promote vasorelaxation and reduce vascular reactivity of adrenergic alpha-1 agonist in the mesenteric artery. The results did not show toxic effects of the extract.

Zanthoxylum alatum abrogates lipopolysaccharide-induced depression-like behaviours in mice by modulating neuroinflammation and monoamine neurotransmitters in the hippocampus.

CONTEXT: Depression is an inflammatory, commonly occurring and lethal psychiatric disorder having high lifetime prevalence. Zanthoxylum alatum Roxb. (Rutaceae), commonly called Timur, has high medicinal value and is used ethnomedicinally for the treatment of various diseases. OBJECTIVE: To evaluate the effect of hexane extract of Z. alatum seeds (ZAHE) on lipopolysaccharide (LPS)-induced depression-like behaviour in Swiss albino mice. MATERIALS AND METHODS: Mice were treated with ZAHE (100 and 200 mg/kg, p.o.) and imipramine (10 mg/kg injected i.p.) for 14 days. On 14th day of the treatment, depression-like behaviour was induced by LPS (0.83 mg/kg injected i.p.) and after 24 h of LPS administration, it was assessed by measuring behavioural parameters and biochemical estimations. RESULTS: Behavioural tests, including the open field test, forced swimming test, tail suspension test and sucrose preference test revealed that ZAHE (100 and 200 mg/kg, p.o.) and imipramine (10 mg/kg injected i.p.) alleviated the depression symptoms of LPS-induced mice. Moreover, ZAHE treatments reversed the LPS-induced alterations in the concentrations of norepinephrine and serotonin (5-HT) and inhibited the expression of brain-derived neurotrophic factor, pro-inflammatory cytokines and oxido-nitrosative stress in the mice. Acute toxicity was calculated to be LD50 > 2500 mg/kg. DISCUSSION AND CONCLUSIONS: This study showed that LPS-induced depression in mice was significantly prevented by ZAHE at both the dosages. In conclusion, ZAHE exhibited an antidepressant activity by altering monoaminergic neurotransmitters in the brain combined with its anti-inflammatory potential. Thus, it could be an effective therapeutic against inflammation-induced depression and other brain disorders.

Pharmacological basis for the medicinal use of Zanthoxylum armatum in gut, airways and cardiovascular disorders.

This study describes the gut, airways and cardiovascular modulatory activities of Zanthoxylum armatum DC. (Rutaceae) to rationalize some of its medicinal uses. The crude extract of Zanthoxylum armatum (Za.Cr) caused concentration-dependent relaxation of spontaneous and high K(+) (80 mM)-induced contractions in isolated rabbit jejunum, being more effective against K(+) and suggestive of Ca(++) antagonist effect, which was confirmed when pretreatment of the tissues with Za.Cr shifted Ca(++) concentration-response curves to the right, like that caused by verapamil. Za.Cr inhibited the castor-oil-induced diarrhea in mice at 300-1000 mg/kg. In rabbit tracheal preparations, Za.Cr relaxed the carbachol (1 microM) and high K(+)-induced contractions, in a pattern similar to that of verapamil. In isolated rabbit aortic rings, Za.Cr exhibited vasodilator effect against phenylephrine (1 microM) and K(+)-induced contractions. When tested in guinea pig atria, Za.Cr caused inhibition of both atrial force and rate of spontaneous contractions, like that caused by verapamil. These results indicate that Zanthoxylum armatum exhibits spasmolytic effects, mediated possibly through Ca(++) antagonist mechanism, which provides pharmacological base for its medicinal use in the gastrointestinal, respiratory and cardiovascular disorders.

Acute toxicity effects of the methanolic extract of Fagara zanthoxyloides (Lam.) root-bark.

BACKGROUND: Fagara zanthoxyloides is a well known medicinal plant in Uganda. It is used extensively in malaria and other infections. However nothing is known about its toxicity. OBJECTIVE: The objective of the study was to evaluate the acute toxicity of the methanolic extract of the root-bark of F. zanthoxyloides, in mice. METHODS: Methanolic extract of the root-bark of the plant was administered orally to mice at various dose levels to determine the acute toxic effects and the median lethal dose (LD50) in mice. RESULTS: The LD50 of the methanolic extract was found to be 5.0 g/Kg body weight within 95% confidence limits. The mice showed signs of cerebral irritation before dying. Histopathological examinations of the viscera showed congestion and focal necrosis of the liver and renal tubules. CONCLUSION: It was concluded that the extract of F. zanthoxyloides is safe, however the cerebral mechanism that lead to the death of the mice need to be investigated further.