**3.7 Hematological analysis**

180 Toxicity and Drug Testing

Weeks

**Spl**

**Kidneys**

Fig. 6. Plots of the mean SE. Of the harvested organ weights during the sub-chronic toxicity

**Liver**

**een**

**Testes**

 Control 750mg/kg 1500mg/kg 3000mg/kg

**Heart**

Fig. 5. Evolution of the mean ±SE of rat body weight during the subchronic toxicity of

 Control 750mg/kg 1500mg/kg 3000mg/kg

Weight (g)

*Vernonia amygdalina* extract.

0

study of *V.amygdalina* extract.

**Lungs**

2

4

6

**grams**

8

10

12

The mean values of the nine haematological parameters are reported in (Table 6)


Table 6. Mean hematology values of rats after repeated (6 weeks) oral dosing with extract leave of *V.amygdalina.* 

The WBC count presented a significant increase in the two high doses (8.47 ± 0.3 in 3000 mg/kg/d) and (8.02 ± 0.7 in 1500 mg/kg/d) versus control (4.80 ± 0.8).

There was a significant increase in the lymphocyte values in high doses (7.33 0.2 in 3000 mg/kg/d) and (6.94 0.6 in 1500 mg/kg/d) as compared to control (4.13 0.7)

Herbal Medicine in the Treatment of Malaria:

**4. Discussion** 

by long distances.

effects are central or peripheral.

response test model of mice (Deraedt, et al, 1980).

induced activation (Puig and Sorkin, 1980).

side effect of nausea that result from the herb's bitter taste (15).

*Vernonia amygdalina*: An Overview of Evidence and Pharmacology 183

As herbal medicine become more popular especially in rural areas, pharmacological evidences to understand the action of these medicine and the underlying mechanisms, to

Our ethnopharmacology survey showed that medicinal plants are still widely used by the population in the area where the study was conducted. Several types of preparations of plants were used. The plants grow over an extended area and are used by healers separated

In the current study, the analgesic effect of the leave extract of *Vernonia amygdalina* was assessed using three nociceptive animal models. In the writhing response model, acetic acid is injected into the peritoneal cavity of mice. The acid causes nociception in the abdomen due to the release of various substances that excite pain nerve ending (Raj, 1996). According to previous reports this assay is commonly used in mice to detect both central and peripheral analgesic efficacy of agents (Dewey, 1970; Fukawa et al 1980), *V amygdalina* showed an ability to diminish the numbers of the writhing episode in a dose-dependent manner. The results of the writhing test alone did not ascertain whether antinociceptive

The formalin test is considered a model for chronic pain (Duduisson and Dennis, 1977). In this test, animals present two distinct nociceptive behavior phases, which probably involve different stimuli. The first phase initiates immediately after formalin injection and lasts 3 to 5 mins, resulting from chemical stimulations of nociceptor. The second phase initiates 15 to 20 mins after formalin injection, lasts 20 to 40 mins and seems to depend on a peripheral mechanism as well as a central one. While substance P and bradykinins are involved in the first phase, histamine, 5HT, prostaglandins and bradykinin are involved in the second phase. The effect of extract was significant in both phases. Since the mechanism of the analgesic effect of *V. amygdalina* is apparent in these two models, it can however be speculated that this effect may be linked to processes in the prevention of sensitization of the nociceptor, down-regulation of the sensitized nociceptor and/or blockade of the nociceptor at peripheral and/or central levels.(Ferreira, 1990). Another possible mechanism may be that the extract blocks effect or the release of endogenous substances, including prostaglandin E2 (PGE2) and PGF2 that excites pain nerve ending which is found in writhing

The extract fails to exhibit antinociceptive effect in the tail-flick test, as values obtain were not significantly different from control animals. Pethidine (50mg/kg p.o.) the reference drug used exhibited significant antinociceptive effect in rats. It is known that the tail-flick (thermal nociceptive) response appears to be a spinal reflex sensitive to opioid -agonists and non-thermal tests to opioid -agonists (Abbott, 1988; Furst et al, 1988), furthermore thermally-induced pain is also mediated by A and C fibers. The data in the present study suggest the involvement of opioid receptors in the analgesic activity and a decrease activity of A and C fibers against inflammatory-induced activation but not thermally-

Aqueous extracts of *V. amygdalina* were found to have *in vivo* activities against *P. berghei* in mice. At 200 mg/kg the antiplasmodial activity were comparable to CQ treated mice. Empirically, this plant is used in decoction alone, other plants may be added to reduce the

The acute oral toxicity results from the *V. amygdalina* extract (3.32 0.15 g/kg p.o) indicate that the extract may be safe based on the chemical labeling and classification of acute

support the proper and safe use of these medicine are indispensable

There was also a significant increase in the values of Neutrophil count (1.08 0.7 in 750 mg/kg/d) versus control (0.53 0.02). However, no major difference was noted between the control and assayed groups.

#### **3.8 Biochemical analysis**

Clinical chemistry analysis of the rats indicate increased ASAT and ALAT ratios in the 1500 mg/kg/d dose, compared to control values (Table 7). In addition, significant increased in HDL levels were noted in the same dose level when compared to controls.


Table 7. Mean clinical chemistru values of rats after repeated (6 weeks) orad dosing with aqueous extract leave of *V.amygdalina.*
