Gingko Biloba versus Neuropeptide Derivative FPF 1070 (Cerebrolysin) Effect against Cisplatin-Induced Sciatic Neuropathy

Research Article

Austin Neurosurg Open Access. 2015; 2(3): 1036.

Gingko Biloba versus Neuropeptide Derivative FPF 1070 (Cerebrolysin) Effect against Cisplatin-Induced Sciatic Neuropathy

Ereny FY Makary, Eman AI Ali*, Lamia Fargali and Somaya Hosny

Department of Histology, Suez Canal University, Egypt

*Corresponding author: Ali EAI, Department of Histology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt

Received: June 22, 2015; Accepted: September 07, 2015; Published: September 09, 2015

Abstract

Introduction: Cisplatin is one of the most widely prescribed antineoplastic agents. It has shown to be effective against various malignant neoplasms. However, its clinical use is limited due to its various side effects including peripheral neuropathy. Cerebrolysin; a neuroprotective agent, was effectively used against diabetic neuropathy and other neurodegenerative diseases. Meanwhile, Gingko biloba showed to be effective against various central nervous system disorders such as dementia, Alzheimer’s disease and cerebral insufficiency.

Aim: To study the protective effects of Gingko biloba versus cerebrolysin against cisplatin-induced sciatic neuropathy in adult male albino rat.

Materials and Methods: Animals were randomized into 6 groups, 10 rats in each group, Group 1 (control), Group 2 (received daily I.P. injection of2.5 ml/ kg of cerebrolysin for 4 weeks), Group 3 (received100 mg/kg of Gingko biloba orally daily for 4 weeks using oral gavage), Group 4 (received I.P. injection of 2 mg/kg cisplatin twice a week for 4 weeks), Group 5 (combined treatment of cerebrolysin and cisplatin for 4 weeks) and Group 6 (combined treatment of Gingko biloba and Cisplatin for 4 weeks).

Results: Cisplatin caused marked disorganization and/or shrinkage of myelinated nerve fibers with severe compression of the axoplasm. Cerebrolysin exerted more protective effect against Cisplatin induced neuropathy than that of Gingko biloba.

Conclusion: Cerebrolysin and Gingko biloba exerted a neuroprotective effect against cisplatin-induced peripheral neuropathy, but cerebrolysin showed more improvement.

Keywords: Cisplatin; Sciatic neuropathy; Cerebrolysin; Gingko biloba

Abbreviations

BW: Body weight; DRG: Dorsal Root Ganglia; EGb761: Gingko Biloba Extract 761; FPF1070: Fine Particle Fraction 1070; GSH: Glutathione; H&E: Hematoxyline and Eosin; I.P.: Intraperitoneal; LM: Light Microscope; ROS: Reactive Oxygen Species; SEM: Standard Error of the Mean; SPSS: Statistical Package of Social Sciences; TEM: Transmission Electron Microscope

Introduction

Cisplatin (Cis-diamminedichloroplatinum II) is the first member of the platinum coordination complex class of the anticancer drugs [1]. It has shown to be effective against a broad range of various solid tumors including cancers of the breast, brain, head and neck, stomach, lung, bladder, testis and ovary [2]. However; its clinical use is limited due to its severe side effects including nephrotoxicity, hepatotoxicity, ototoxicity, myelosupression, gastrointestinal and retinal toxicity in addition to peripheral neuropathy [3-5].

Cisplatin-induced peripheral neuropathy represents a major clinical problem. It is estimated that 10-40% of patients treated with cisplatin suffer from severe peripheral neuropathy [6,7]. The clinical features of this neuropathy are mainly sensory including paraesthesia, allodynia or burning pain [8,9]. Cisplatin neurotoxicity was explained by several mechanisms such as its ability to accumulate in the Dorsal Root Ganglia (DRG) leading to degeneration of their large sensory neurons, disruption of microtubule dynamics, apoptosis and vascular neurotoxicity which is triggered mainly by oxidative stress caused by increased Reactive Oxygen Species (ROS) [10-13].

Thus, it is crucial to find neuroprotective agents against cisplatininduced peripheral neuropathy, not interfering with its antineoplastic activity. A number of neuroprotective agents have shown promising results such as chelating, antioxidants & neurotrophic factors [12,14- 16]. Cerebrolysin, a neuropeptide derivative FPF 1070, is a synthetic preparation that mimics the action of endogenous neurotrophic factors. Such factors are used as a part of therapeutic strategy that can repair and protect the brain from pathological damage of acute and chronic neurological disorders including dementia, Alzheimer’s disease, stroke and traumatic brain injury. It also showed beneficial effects against peripheral diabetic neuropathy in type 2 diabetes mellitus [17-19]. Meanwhile; Gingko biloba extract EGb761, a potent natural compound extracted from Gingko biloba leaves, improved mental and cognitive functions in various central nervous system disorders such as dementia and cerebral insufficiency. It also showed a protective effect in ischemia/ reperfusion brain injuries and spinal cord injury in animal models [20-23].

Thus; the present study was designed to investigate the possible neuroprotective effect of ginko biloba versus cerebrolysin against cisplatin-induced sciatic neuropathy.

Materials and Methods

Chemicals

Cerebrolysin used in this study was produced by Ebewe Pharmaceuticals in the form of ampoules containing 1ml or 5ml cerebrolysin. Gingko biloba was produced by Ema Pharm Company in the form of capsules, each containing 260 mg. The capsule was dissolved in 52 ml distilled water. Accordingly, the dose of a rat (150 g) is 15 mg dissolved in 3 ml distilled water. Cisplatin (Cisplatyl 50) was produced by Laboratoire Roger Bellon, France.

Experimental animals

Sixty adult male albino rats of the same age & weight (130- 150 g) were used in this study. The animals were acclimatized in suitable cages for 1 week before the experiment, housed under standardized conditions; with free access to standard pellet animal diet and tap water. Animals were anaesthetized before scarification. The experiment was performed in the Histology department, Faculty of Medicine, Suez Canal University. Approval of the research committee of the school was taken for ethical consideration of dealing with animals.

Experimental design

The animals were randomized into 6 groups (n=10 rats) (i) Control group (G1): received daily Intraperitoneal (I.P) injection of 1 ml 0.9 % saline for 4weeks; (ii) Cerebrolysin group (G2): received daily I.P. injection of 2.5 ml/ kg Body Weight (BW) of Cerebrolysin for 4 weeks; (iii) Gingko biloba group (G3): received 100 mg/kg BW Gingko biloba orally by oral gavage, daily for 4 weeks; (iv) Cisplatin group (G4):received I.P injection of 2 mg/kg BW Cisplatin, twice a week for 4 weeks; (v) Cerebrolysin + Cisplatin group (G5): received daily I.P. injection of 2.5 ml/ kg BW Cerebrolysin combined with I.P injection of 2 mg/kg BW Cisplatin twice a week, for 4 weeks; (vi) Gingko biloba + Cisplatin group (G6): received 100 mg/kg BW Gingko biloba orally combined with I.P injection of 2 mg/kg BW Cisplatin twice a week, for 4 weeks. At the end of the experiment; all animals were anesthetized using I.P. injection of 90 mg/kg BW ketamine and then sacrificed. The sciatic nerve was exposed through an incision along the veins which run between the semi-tendinosus and the biceps muscle. Then, it was excised and processed for light and transmission electron microscopic examination.

Processing for Light Microscopic (LM) examination

The sciatic nerve was dissected and cut into small segments and H&E stained paraffin sections, 5 μm thick, were prepared. Qualitative assessment was performed by the examination of 5 high power fields (X400) in 10 serial sections from each animal of all the studied groups, to assess the integrity of axons (preserved/lost) and the space of myelin (Well-organized/Disorganized/obliterated).

Processing for Transmission Electron Microscopic (TEM) examination

A very small piece (1-2 mm in length) of the sciatic nerve was cut and processed as described by Bozzola & Russell [24]. Nerve samples were fixed in a mixture of 2.5% glutaraldehyde and 2.5% paraformaldehyde in 0.1 M Cacodylate buffer for 24 hours at 4 CO, post fixed for 2 hours in 1% buffered OSO4 and dehydrated by ascending grades of alcohol and cleared in propylene oxide. Then, nerve samples were embedded in absolute resin, sectioned transversely into Semithin (0.5 μm) sections which were stained with toluidine blue and examined by light microscope. Ultrathin (40- 50nm) sections, cut with ultra microtome and stained with 4% uranyl acetate and 2% lead citrate, were examined using Transmission Electron microscope (in Transmission Electron Microscope Unit, Ain Shams Specialized Hospital & Alazhar University) to detect histopathological changes in the axon, myelin sheath, Schwann cells and unmyelinated nerve fibers.

Statistical Analysis

The frequency distribution of each change was calculated, Data were analyzed using the Statistical Package of Social Sciences (SPSS) program version 17, (Chicago, IL, USA). Comparisons among groups were carried out using one-way ANOVA. Histopathological scoring, statistical analysis was performed using nonparametric tests. All p values reported are two-tailed and p < 0.05 was considered significant.

Results

Clinical observations

No mortality was recorded among animals of different groups. However, Five to six days after cisplatin treatment, marked weight loss was observed in animals of Cisplatin group compared to other groups.

Microscopic examination

(i) Control group (G1)

In the H&E stained sections, all animals showed normal appearance of sciatic nerve. Each nerve bundle was surrounded by connective tissue perineurium. It contained large and small myelinated nerve fibers separated by connective tissue endoneurium. Each nerve fiber has a central axon, surrounded by space of dissolved myelin. Crescent- shaped nuclei of Schwann cells, some nuclei of endoneurial cells and blood vessel were also seen (Table 1) (Figure 1).