Effect of Aqueous Extract of Rauvolfia vomitoria (Apocynaceae) Leaves with on Sexual Activity of Male Rats

Objective: The aim of this study is to determine the pharmacological effects of Rauvolfia vomitoria leaves on the sexual activity of animal model (male rat) Methods: Acute toxicity was performed according to OECD Guideline 423, by a dose limit of 2000 mg /kg body weight. The observations (during 14 days) focused on the number of deaths, convulsions, sleep and coma. Study of sexual activity has been realized by using 20 male rats, distributed in 4 lots of 5 animals. Group 1 treated with distilled water, group 2 treated with 5 mg/kg B.W. of sildenafil citrate and the other two batches received respectively the doses 500 and 1000 mg/kg of the aqueous extract of Rauvolfia vomitoria. Females in estrus state (in heat) were introduced for a period of 30 minutes. During this period, parameters of sexual behavior were recorded. At the end of the 8-day treatment, organs such as penis testicles, seminal vesicles, prostate, epididymis and elevator muscle were removed. These organs were studied in order to determine pharmacological effects of aqueous extract of Rauvolfia vomitoria. Results: The aqueous extract of Rauvolfia vomitoria showed no evidence of single dose toxicity (2000 mg/kg) when studying acute toxicity. Ride latency time, coitus latency time and ejaculation latency time was significantly decreased (P<0.001) with regard to negative control (distilled water). Ride frequency, coitus fraquency and ejaculation frequency was significantly increased (P<0.001) with regard to negative control (distilled water). No significant difference (P˃0.05) has been recorded on organ androgeno-dependant. Conclusion: Aqueous extract of R. vomitoria has sexual stimulating activity or an aphrodisiac potential which could justify its traditional use. The aphrodisiac potential is higher at the dose of 1000 mg/kg b.w .

Hypolipidemic Potentials of Methanolic Extract of Rauvolfia vomitoria Leaves in Rats Fed with High Cholesterol

The study was aimed to investigate the hypolipidemic potential of methanolic extract Rauvolfia vomitoria leaves in high cholesterol-fed rats. The preliminary study showed that R. vomitoria leaves were able to scavenge the 2,2-azino-bis (3-ethylbenzthiazoline-6-sufonic acid) (ABTS) and 2-Diphenyl-1- picrylhydrazyl (DPPH) radicals and these radicals scavenging abilities were found to be dose-dependent. Administration of cholesterol to rats for 45 days induced a significant increase in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and increase lipids levels in the plasma and tissues while HDL cholesterol was decreased. It also elevated the levels of malondialdehyde (MDA) and decreased superoxide dismutase (SOD) activities in the tissues. However, co-administration of high cholesterol-fed rats with R. vomitoria extract at doses of 100 and 200 mg/kg significantly reversed lipids levels to near normal with cholesterol in the plasma, liver, heart, kidney and lung reduced by (23.13% and 56.43%), (30.09% and 20.90%), (38.21% and 74.53%), (12.61% and 32.49%) and (37.11% and 29.90%) respectively while HDL cholesterol level was increased by (225.44% and 110.39%). The levels of AST, ALT and ALP in the plasma and MDA in the tissues were also decreased while SOD activities in the liver, heart, kidney and lung were elevated by (89.35% and 149.21%), (74.91% and 68.35%), (56.76% and 114.77%), and (204.91% and 274.62%) respectively. The extract of R. vomitoria was found to be rich in phenolic content and was proved to have no toxic effects on rats when administered alone to normal rats at a dose level of 200mg/kg/day. The results obtained in this study demonstrated the antioxidant and lipid-lowering effects of R. vomitoria and, suggests that the plant could serve as a new potential natural product for the treatment of hyperlipidemia.

Chronic Toxicity Study of Aqueous Roots Extract of Rauvolfia vomitoria AFZEL on Haematological Parameters in Wistar Rats

Rauvolfia vomitoria Afzel. (Apocynaceae) is a plant used in traditional medicine in Côte d'Ivoire for the treatment of several conditions. This work aims to evaluate the effects of repeated oral administration of the aqueous roots extract Rauvolfia vomitoria AFZEL (AERv) on haematological parameters in Wistar rats. Thus, 100 healthy rats were divided into four groups (T, A, B, C) of 20 rats each. The sub groups Ts and Cs from the groups T and C included 10 rats (5 males and 5 females) were formed for a reversibility study. After 6 months (180 days) of the experiment, the sub groups rats Ts and Cs were no more treated with the extract till the 210th day (7 months), day of their sacrifice to verify the reversibility and/or delayed effects of AERv. The erythrocyte, platelet and leukocyte parameters were determined. Results showed that AERv caused a significant decrease in erythrocyte and thrombocyte parameters with the high dose (1000 mg/kg bw) while an increase in leukocyte parameters was noted in a dose-dependent manner. The aqueous extract of the barkless roots is not harmful at the therapeutic dose of 700 mg/kg bw on the haematological parameters. After stoping administration the effects were reversible.

Testicular antioxidants and testosterone enhancing effects of the hydro-ethanolic extract of Rauvolfia vomitoria (Apocynacaea) in male Wistar rats

Background: Natural products such as extracts of plants have been seen as a possible alternative to conventional therapies in the treatment and management of male infertility. This study aimed at investigating the testicular antioxidant and testosterone enhancing ability of the hydro-alcoholic extract of Rauvolfia vomitoria in male rats. Methods: Twenty-four male rats were divided into four groups of 6 rats each, treated daily with either vehicle (distilled water; 5 mL/kg) or hydro-ethanolic extract of R. vomitoria (20 mg/kg, 40 mg/kg, and 100mg/kg) for 60 days, and body weights recorded once every three days. At the end of the treatment, each animal was sacrificed, and reproductive organs were dissected out and weighed. Serum from capillary blood was used for testosterone quantification, while testicular homogenates were used for the estimation of antioxidant biomarkers. Results: Treatment with R. vomitoria extract did not alter the animal’s body weight. Instead, the extract at the dose of 40 mg/kg significantly increased (P< 0.05) the weights of all reproductive organs investigated. The plant extract also increased serum testosterone concentrations significantly (P< 0.05), with the highest effect observed in the animals treated with a dose of 40 mg/kg. Testicular antioxidant markers, thiobarbituric acid substances, glutathione, and catalase were equally improved (P< 0.05) by treatment with the plant extract at the dose of 40 mg/kg. Conclusion: Hydro-ethanolic extract of R. vomitoria portrayed beneficial pharmacological properties on reproductive organs, testicular antioxidants, and testosterone concentrations in male rats. These pharmacological activities support the traditional use of the plant in the management of male fertility disorders.

Ethno - Medicinal Studies of Finima Nature Park - A Protected Tropical Rain Forest

Objective: This study was aimed at conducting a pilot survey of the ethno-medicinal plants in Finima Nature Park (FNP), Bonny, Nigeria, to elicit common medicinal plants and their uses. Method: A set of structured questionnaire was used to obtain information from three key informants (Traditional Medicine Practitioners-TMPs) and 62 household heads on the local medicinal utilization of plants in FNP. Plant utilization and preferences, perceived conservation status and use values were documented. Results: Eighty-three (83) plant species belonging to 45 Botanical families were frequently collected from FNP for local medicinal purposes. Rubiaceae was the most abundant (8%) plant family while the plant forms showed trees (46%), herbs (23%), shrubs (21%) and ferns (3%). Plant parts used for local medicine included leaves (44%), stem/barks (21%), roots (16%), whole plant (5%), fruits (5%), seeds (6%), tubers (2%) and flowers (1%). Infectious diseases were the most treated (30%), urogenital and endocrine diseases - such as thyroid (15%) and abdominal diseases (11%). Oral (62%) and dermal (30%) constitutes the main modes of administration. Rauvolfia vomitoria Afzel. had the highest use value (3.5 - 4) while Ocimum gratissimum Linn., Vernonia amygdalina Delile and Alchornea cordifolia Schumach. & Thonn had the least (1). Perceived conservation status of medicinal plants by respondents revealed scarce (9%), threatened (31%) and abundance (60%). Conclusion: Finima Nature Park (FNP) is a repository of medicinal genetic resource and as such, its conservation should be upheld.

Cytogenotoxicity Assessment of Aqueous Extracts of Rauvolfia vomitoria (Apocynaceae) on the Male Germ Line Cells of the Pest Grasshopper Zonocerus variegatus (Orthoptera: Pyrgomorphidae)

Cytogenotoxic effects of aqueous extracts of Rauvolfia vomitoria Afzel (Apocynaceae) stem bark were assessed on male germ line cells of the grasshopper Zonocerus variegatus. Concentrations of 0, 10, 15 and 20 µg/ml of infused and macerated aqueous extracts of R. vomitoria were prepared and administered through injection to the grasshoppers. Grasshoppers were dissected after 72 hours of incubation and the different parameters were then evaluated. Results revealed significant (p < 0.05) reduction of the length and the width of testis follicles with increasing concentrations of the two aqueous plant extracts. Meiosis analysis revealed a significant (p < 0.05) increase in meiotic abnormalities with increasing concentrations of the two aqueous plant extracts. Infused and macerated aqueous extracts of R. vomitoria at different concentrations did not modify the karyotype of Z. variegatus. Cyclophosphamide (CP) induced chromosomes aberrations and significantly (p < 0.05) reduced the mean chromosomes complement number which ranged from 2n= 19.00 ± 0.00 (controlled individuals) to 2n= 17.60 ± 1.82 (CP treated individuals). These observations indicate that infused and macerated aqueous extracts of R. vomitoria stem bark could induced cytogenotoxicity on the germ line cells of the grasshopper Z. variegatus. These results also confirm the utilization of CP as positive control in chromosomes aberration assays on grasshoppers.

Attenuation of potassium dichromate and sodium arsenite toxicities by methanol extract of Rauvolfia vomitoria in mice

Objectives Exposure to arsenic and hexavalent chromium is a major public health concern especially in the developing part of the world and there is paucity of information on reliable treatment modalilities. It is in this regard that this study evaluates the efficacy of methanol leaf extract of Rauvolfia vomitoria (MRV) when used as pretreatment agent against potassium dichromate (K2Cr2O7) and sodium arsenite (NaAsO2) exposure. Methods Swiss albino mice between 7 and 10 weeks old were divided into eight cohorts of five animals each. Treatment groups consisted of a distilled water control, MRV alone (275 mg/kg po daily), K2Cr2O7 (12.0 mg/kg, single ip injection) +/− MRV pretreatment, NaAsO2 (2.5 mg/kg, single ip injection) +/− MRV pretreatment, Na2AsO2 + K2Cr2O7 +/− MRV pretreatment. MRV was given for seven consecutive days, while K2Cr2O7 and NaAsO2 were injected on day seven of the experiment. The frequency of micronucleated polychromatic erythrocytes (mPCEs) was determined in bone marrow cells, while aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were assessed in the plasma. Hepatic glutathione (GSH), malondialdehyde (MDA), catalase (CAT) and glutathione-S-transferase (GST) levels were also determined. Results The NaAsO2 and K2Cr2O7 significantly (p<0.05) increased mPCE formation, AST, ALT, and CAT when compared with the control. Simultaneous exposure to NaAsO2 and K2Cr2O7 further increased the levels of the markers. Furthermore, GSH and GST were significantly reduced by NaAsO2 or K2Cr2O7 or their combination. Pretreatment with MRV reversed the markers towards that of control. Conclusions Methanol extract of Rauvolfia vomitoria may therefore ameliorate NaAsO2 and K2Cr2O7-induced toxicities via reduction of oxidative stress and fortification of anti-oxidant system.

Phenolic constituents and inhibitory effects of the leaf of Rauvolfia vomitoria Afzel on free radicals, cholinergic and monoaminergic enzymes in rat’s brain in vitro

ObjectivesRauvolfia vomitoria is a medicinal plant used traditionally in Africa in the management of several human diseases including psychosis. However, there is inadequate scientific information on the potency of the phenolic constituents of R. vomitoria leaf in the management of neurodegeneration. Therefore, this study characterized the phenolic constituents and investigated the effects of aqueous and methanolic extracts of R. vomitoria leaf on free radicals, Fe2+-induced lipid peroxidation, and critical enzymes linked to neurodegeneration in rat’s brain in vitro.MethodsThe polyphenols were evaluated by characterizing phenolic constituents using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). The antioxidant properties were assessed through the extracts ability to reduce Fe3+ to Fe2+; inhibit ABTS, DPPH, and OH radicals and Fe2+-induced lipid peroxidation. The effects of the extracts on AChE and MAO were also evaluated.ResultsThe phenolic characterization of R. vomitoria leaf revealed that there were more flavonoids present. Both aqueous and methanolic extracts of R. vomitoria leaf had inhibitory effects with the methanolic extract having higher significant (p≤0.05) free radicals scavenging ability coupled with inhibition of monoamine oxidases. However, there was no significant (p≤0.05) difference obtained in the inhibition of lipid peroxidation and cholinesterases.ConclusionThis study suggests that the rich phenolic constituents of R. vomitoria leaf might contribute to the observed antioxidative and neuroprotective effects. The methanolic extract was more potent than the aqueous extract; therefore, extraction of R. vomitoria leaf with methanol could offer better health-promoting effects in neurodegenerative condition.