Anti-inflammatory and analgesic activities of mature fresh leaves of Vitex negundo

This study confirmed the oral anti-inflammatory, analgesic and antihistamine properties of mature fresh leaves (MFL) of Vitex negundo L. (Verbenaceae) claimed in the Ayurveda medicine by orally treating a water extract of the leaves to rats. The early phase (2h) of carrageenan-induced rat paw oedema was significantly (P<0.01) suppressed in an inversely does-dependent (r(2)=1, P<0.01) manner by MFL. The EC(50) was 2g/kg of MFL. In the formaldehyde-induced rat paw oedema test, the 2.5 and 5g/kg leaves significantly (P<0.05) suppressed the inflammation on days 4-6 of the test. In the hot plate test, 2.5 and 5g/kg of MFL showed a significant (P<0.05) and directly dose-dependent analgesic activity at 1h of treatment while the activity was absent in the tail flick test in rats. The EC(50) for the analgesic activity was 4.1g/kg. In the formalin test, 1.25, 2.5 and 5g/kg of MFL significantly (P<0.05) suppressed the pain in both the phases of the test like aspirin. The leaves showed an inversely dose-dependent in vivo antihistamine and in vitro prostaglandin (PG) synthesis inhibition, membrane stabilising and antioxidant activities. Naloxone did not abolish the analgesic activity in the hot plate test. A 5g/kg of MFL did not impair muscle strength and co-ordination and did not induce sedation. The treatment of 5g/kg of MFL did not show signs of acute toxicity or stress. Fourteen-day oral treatment of 5g/kg of MFL significantly increased the serum activity of AST. Flowering of the tree did not abolish the analgesic and anti-inflammatory activities of the leaves. These observations revealed that the fresh leaves of Vitex negundo have anti-inflammatory and pain suppressing activities possibly mediated via PG synthesis inhibition, antihistamine, membrane stabilising and antioxidant activities. The antihistamine activity can produce the anti-itching effect claimed in Ayurveda medicine.     

Inhibition of chemically induced inflammation and pain by orally and topically administered leaf extract of Manihot esculenta Crantz in rodents

The aqueous leaf extract of Manihot esculenta Crantz (MELE) is being used orally and topically in traditional African medicine for the treatment of inflammation and pain, and claimed to be safe. The anti-inflammatory effects of MELE (100-400mg/kg, p.o. or 1-4%, w/w in petroleum jelly, topically) were tested against carrageenan-induced paw oedema in rats as well as against xylene-induced ear oedema in mice. The analgesic effect of MELE (100-400mg/kg, p.o. or 1-4%, w/w in petroleum jelly, topically) was tested against acetic acid-induced (20mul, 0.6%, v/v in normal saline, i.p.) and acetylcholine-induced (8.3mg/kg, i.p.) mouse writhing models. At 100-400mg/kg, p.o. and 1-4% (w/w), topically, MELE produced significant inhibitions of carrageenan-induced rat paw oedema and xylene-induced ear swelling in mice. Effects produced by MELE were significantly higher than those produced by indomethacin (10mg/kg, s.c. or 1%, w/w in petroleum jelly) in the anti-inflammatory models. For the analgesic effect, MELE (100-400mg/kg, orally) and (1-4%, w/w, topically), like aspirin (100mg/kg, i.p.) exhibited significant (P<0.05) inhibition of acetic acid- and acetylcholine-induced mouse writhing tests, compared to untreated control. Effects produced by MELE were significantly lower than those produced by aspirin (100mg/kg, i.p.) in the analgesic models, except for the topically administered extract on acetylcholine-induced pain. Acute oral administration up to 10g/kg did not cause death within 14 days, but mortalities were produced in i.p. administered extract with LD(50) of 2.5+/-0.3g/kg. Based on these, the extract may contain orally safe, topically and orally effective anti-inflammatory and analgesic principles, which justify its use in traditional African medicine.     

矮地茶药理作用研究

目的 对矮地茶水提取物和醇提取物的抗炎、镇痛作用及急性毒性进行研究.方法 采用二甲苯致小鼠耳廓肿胀法、醋酸扭体法观察矮地茶的抗炎、镇痛作用;对矮地茶水提物及醇提物的半数致死量(LD_(50))进行测定,观察其急性毒性.结果 矮地茶对二甲苯所致小鼠耳肿胀有明显的抑制作用(P<0.01,P<0.05);对0.7%醋酸所致小鼠扭体反应有明显的抑制作用(P<0.01或P<0.05).矮地茶水提物及醇提物对小鼠灌胃给药的LD50分别为(115.77±10.31)g/kg, 95%可信限为(105.92～126.54)g/kg;(94.71±10.13)g/kg ,95%可信限为(85.12～105.38 )g/kg.结论 矮地茶具有一定的抗炎、镇痛作用;矮地茶水提物及醇提取物未出现其它毒性反应.     

Analgesic, anti-inflammatory and hypoglycaemic effects of Rhus chirindensis (Baker F.) [Anacardiaceae] stem-bark aqueous extract in mice and rats

In an attempt to scientifically evaluate some of the anecdotal, folkloric, ethnomedical uses of Rhus chirindensis Baker F. ('red currant'), the present study was undertaken to investigate the analgesic, anti-inflammatory and hypoglycaemic effects of the plant's stem-bark aqueous extract (RCE) in mice and rats. The analgesic effect of RCE was evaluated by 'hot-plate' and 'acetic acid' analgesic test methods in mice; while its anti-inflammatory and hypoglycaemic effects were investigated in rats, using fresh egg albumin-induced pedal oedema, and streptozotocin (STZ)-induced diabetes mellitus animal models. Morphine (MPN, 10 mg/kg), diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used as reference drugs for comparison. RCE (50-800 mg/kg i.p.) produced dose-dependent, significant (P<0.05-0.001) analgesic effects against thermally- and chemically-induced nociceptive pain in mice. The plant's extract (RCE, 50-800 mg/kg p.o.) also significantly (P<0.05-0.001) inhibited fresh egg albumin-induced acute inflammation, and caused dose-related, significant (P<0.05-0.001) hypoglycaemia in normal (normoglycaemic) and diabetic (hyperglycaemic) rats. The flavonoids, triterpenoids and other chemical compounds present in RCE are speculated to account for the observed pharmacological effects of the plant's extract in the experimental animal paradigms used. The findings of this experimental animal study indicate that Rhus chirindensis stem-bark aqueous extract possesses analgesic, anti-inflammatory and hypoglycaemic properties; and thus lend pharmacological credence to the anecdotal, folkloric, ethnomedical uses of the plant in the treatment and/or management of painful, arthritic, inflammatory conditions, as well as in the management and/or control of type 2 diabetes mellitus in some rural communities of South Africa.     

Spinal serotonergic system is partially involved in antinociception induced by Trigonella foenum-graecum (TFG) leaf extract

It has been reported that Trigonella foenum-graecum (TFG) extract exerts analgesic, anti-inflammatory and anti-pyretic effects in different experimental models. The major objective of this paper was to investigate the site and mechanism of the analgesia induced by Trigonella foenum-graecum extract. We studied the analgesic effects of different doses of Trigonella foenum-graecum extract after i.p., i.t. and i.c.v. administration in formalin test, using male NMRI rats (200-250 g). Trigonella foenum-graecum extract showed analgesic effects in i.p. (1 g/kg) and i.t. (0.5, 1, and 2 mg/rat) (P < 0.05 in all groups) but not in i.c.v. (1 and 3 mg/rat) administrations. Based on the similarities between the effects of Trigonella foenum-graecum extract with those of nonsteroidal anti-inflammatory drugs (NSAIDs) and the role of 5-HT system in analgesic effects of NSAIDs, we tried to investigate the role of spinal 5-HT system in analgesic effects of Trigonella foenum-graecum extract. After lesioning of spinal 5-HT system by 5,7-dihydroxytryptamine (5,7-DHT), it was shown that the analgesic effect of Trigonella foenum-graecum extract (0.5 and 3 mg/rat) in the second phase of formalin test, was abolished completely and reduced relatively after using a low-dose (0.5 mg/rat) and a high-dose (3 mg/rat), respectively (P < 0.05). So, the antinociception partially remained (P < 0.05) after using the latter dose. Meanwhile, administration of naloxone (2mg/kg, i.p.) had no effect on the Trigonella foenum-graecum extract (1 g/kg, i.p.) analgesia. In conclusion, this study confirms the central action of Trigonella foenum-graecum extract and that spinal 5-HT system is partially involved in the analgesia induced by it in the second phase of formalin test and also indicates for co-existence of other analgesic mechanism(s).     

Anti-inflammatory and analgesic properties of the stem bark extract of Mitragyna ciliata (Rubiaceae) Aubrév. & Pellegr

Mitragyna ciliata is widely used in traditional medicine for the treatment of inflammation, hypertension, headache, rheumatism, gonorrhoea and broncho-pulmonary diseases. In the present study, the anti-inflammatory and analgesic properties of the stem bark extract of M. ciliata were investigated. The stem bark of this plant was extracted over Soxhlet with hexane followed by another extraction with methanol. The resulting methanol extract was used for the pharmacological test. Anti-inflammatory activity was evaluated on the basis of the inhibitory effect of the extract on 5-lipoxygenase, and carrageenin-induced hind paw oedema in the rat. The methanol extract, at a dose of 19.2 microg/ml, exhibited no inhibition on 5-lipoxygenase. However, this extract administered per os (50 mg/kg) produced about 70% inhibition of carrageenin-induced paw oedema 1 h after administration. This inhibition was maintained to about 50% 2 h after administration. The dose of 50 mg/kg of MeOH extract significantly decreased sensitivity to pain from 78.75 to 107.5 g These findings suggest that extracts of the bark of M. ciliata, possess potent anti-inflammatory and analgesic effects. Chemical analysis of the extract showed the presence of alkaloids and kaempferol derivative which may be responsible for the anti-inflammatory properties.     

Anti-inflammatory and analgesic effects of the ethanol extract of Rosa multiflora Thunb. hips

This study aimed to assess the anti-inflammatory and analgesic effects of Fructus Rosae Multiflorae (FRM, hips of Rosa multiflora Thunb.). FRM was extracted with 75% ethanol and the dried extract (FRME) was administered intragastrically (i.g.) at 100, 200 and 400mg/kg. The anti-inflammatory effect was evaluated in four experimental animal models and analgesic effect in two animal models. Pretreatment with a single dose of FRME produced significant dose-dependent anti-inflammatory effects on carrageenin-induced rat hind paw edema, xylene-induced mouse ear edema and acetic acid-induced mouse vascular permeation. In a 7-day study, daily administration of FRME suppressed cotton pellet-induced rat granuloma formation. Pretreatment with a single dose of FRME also produced dose-dependent anti-nociceptive effects in thermally- and chemically induced mouse pain models. In addition, a single dose of FRME at 2.4g/kg body weight (equivalent to 87.6g of dried hips per kg body weight) produced no observable acute toxicity in mice within seven days. These results demonstrate that FRME possesses anti-inflammatory and analgesic effects and has no obvious acute toxicity, which advanced our understanding of the folk use of FRM in treating various inflammatory disorders.     

Evaluation of the analgesic, anti-inflammatory and anti-diabetic properties of Sclerocarya birrea (A. Rich.) Hochst. stem-bark aqueous extract in mice and rats

In order to appraise some of the ethnomedical uses of Sclerocarya birrea (A. Rich.) Hochst., subspecies caffra (Sond.) Kokwaro [family: Anacardiaceae], the present study was undertaken to investigate the analgesic, anti-inflammatory and anti-diabetic properties of the plant's stem-bark aqueous extract in experimental models of pain, inflammation and diabetes mellitus. The analgesic effect of Sclerocarya birrea stem-bark aqueous extract was evaluated in mice, while its anti-inflammatory and anti-diabetic effects were investigated in rats. Diclofenac (DIC, 100 mg/kg p. o.) and chlorpropamide (250 mg/kg p. o.) were used respectively as reference analgesic, anti-inflammatory and anti-diabetic agents for comparison. Like diclofenac (DIC, 100 mg/kg p. o.), Sclerocarya birrea stem-bark aqueous extract (SBE, 100-800 mg/kg p. o.) produced dose-dependent, significant protection (p < 0.05-0.001) against electrical heat-induced pain. The plant extract (SBE, 25-800 mg/kg p. o.) also produced dose- and time-related, sustained and significant reductions (p < 0.05-0.001) in the fresh egg albumin-induced acute inflammation of the rat hind paw oedema. However, the analgesic and anti-inflammatory effects of the plant's extract were found to be approximately 10-15 times less than that of diclofenac. In one set of experiments involving hypoglycaemic/antidiabetic evaluation of the plant's extract, graded doses of Sclerocarya birrea stem-bark aqueous extract (SBE, 25-800 mg/kg p. o.) were separately administered to groups of fasted normal and fasted diabetic rats. In another set of experiments, a single dose of the plant's aqueous extract (SBE, 800 mg/kg p. o.) was used. The hypoglycaemic effect of this single dose of Sclerocarya birrea stem-bark aqueous extract (SBE, 800 mg/kg p. o.) was compared with that of chlorpropamide (250 mg/kg p. o.) in both fasted normal and fasted streptozotocin (STZ)-treated diabetic rats. Following acute treatment, relatively moderate to high doses of Sclerocarya birrea stem-bark aqueous extract (SBE, 25-800 mg/kg p. o.) produced dose-dependent, significant reductions (p < 0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. Chlorpropamide (250 mg/kg p. o.) also produced significant reductions (p < 0.05-0.001) in the blood glucose concentrations of the fasted normal and fasted diabetic rats. Administration of the single dose of Sclerocarya birrea stem-bark aqueous extract (SBE, 800 mg/kg p. o.) significantly reduced (p < 0.01-0.001) the blood glucose levels of both fasted normal (normoglycaemic) and fasted STZ-treated, diabetic rats. The results of this experimental animal study indicate that Sclerocarya birrea stem-bark aqueous extract possesses analgesic, anti-inflammatory and hypoglycaemic properties. These experimental findings lend pharmacological support to the suggested folkloric uses of the plant's stem-bark in the management and/or control of pain, inflammatory conditions, and adult-onset, type-2 diabetes mellitus in some communities of South Africa.     

Anti-inflammatory, analgesic and antipyretic effects of methanol extract from Bauhinia racemosa stem bark in animal models

In this study, the anti-inflammatory, analgesic, and antipyretic effects of 50, 100 and 200 mg/kg body weight of methanol extract obtained from Bauhinia racemosa stem bark, the so-called MEBR, were investigated. The effects of MEBR on the acute and chronic phases of inflammation were studied in carrageenan, dextran and mediators (histamine and serotonin)-induced paw oedema and cotton pellet-induced granuloma, respectively. Analgesic effect of MEBR was evaluated in acetic acid-induced writhing and hotplate tests. Antipyretic activity of MEBR was evaluated by yeast-induced hyperpyrexia in rats. The anti-oedema effect of MEBR was compared with 10 mg/kg of indomethacin orally. In acute phase of inflammation, a maximum inhibition of 44.9, 43.2, 44.8 and 45.9% (P<0.001) was noted at the dose of 200 mg/kg b.w. after 3h of treatment with MEBR in carrageenan, dextran, histamine and serotonin-induced paw oedema, respectively. Administration of MEBR (200 mg/kg b.w.) and indomethacin (10 mg/kg b.w.) significantly (P<0.05) decreased the formation of granuloma tissue induced by cotton pellet method at a rate of 50.4 and 56.2%, respectively. The extract also inhibited peritoneal leukocyte migration in mice. The MEBR also produced significant (P<0.01) analgesic activity in both models. Further, the MEBR potentiated the morphine- and aspirin-induced analgesic in mice. Treatment with MEBR showed a significant (P<0.01) dose-dependent reduction in pyrexia in rats. The results suggest that MEBR possess potent anti-inflammatory, analgesic and antipyretic activity.     

Antinociceptive and anti-inflammatory effects of Elaeagnus angustifolia fruit extract

In this study, probable antinociceptive and anti-inflammatory effects of Elaeagnus angustifolia fruit components, were evaluated. For evaluation of antinociceptive effects, the chronic (formalin test) and acute (tail-flick) pain models of rats were used. For the anti-inflammatory effects, the paw inflammation model was used through subcutaneous injection of 5% formalin to the paw of male rats. Water extracts of the fruit and its components in the single dose were assessed through comparison with the antinociceptive and anti-inflammatory effects of sodium salicylate (SS) as a positive control. Administration of 300 mg/kg of SS (i.p.) had no effect on tail flick latency, while 1000 mg/kg of total (i.p. and p.o.) and endocarp (i.p.) extract, increased this latency (P<0.01, P<0.001, respectively), which was not reversed by naloxone (2 mg/kg). In the formalin test, SS (300 mg/kg, i.p.) and the extract (1000 mg/kg, p.o. ) alleviated the animals nociception in the second phase, while in the first phase they were not effective. The total and endocarp extracts (1000 mg/kg, i.p.) showed a significant effect on both phases (P<0.01, P<0.001, respectively) which was also not reversed by naloxone (2 mg/kg, i.p.). In the acute anti-inflammatory test, the total extract and the aqueous extract of individual fruit components showed a significant effect (P<0.001). This anti-inflammatory effect was not significant compared with the anti-inflammatory effect of SS. Because of the extract effect on the tail-flick latency and both phases of the formalin test, the site of its analgesic action is probably central, and the mechanism of antinociceptive action of the extract are not related to the opioid system. Our phytochemical studies indicated that aqueous extract of E. angustifolia fruit contains flavonoids, terpenoids and cardiac glycosides.