Sahel Medical Journal

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 21  |  Issue : 1  |  Page : 13--17

Immunomodulatory and hepatoprotective properties of Solanum torvum (Turkey berry)


Silvanus Olu Innih1, Kingsley Chukwunonso Agu2, Gerald Ikechi Eze1,  
1 Department of Anatomy, School of Basic Medical Sciences, College of Medical Sciences, University of Benin, Benin City 300001, Edo State, Nigeria
2 Department of Medical Biochemistry, School of Basic Medical Sciences, College of Medical Sciences, University of Benin, Benin City 300001, Edo State, Nigeria

Correspondence Address:
Dr. Kingsley Chukwunonso Agu
Department of Medical Biochemistry, School of Basic Medical Sciences, College of Medical Sciences, University of Benin, Benin City 300001, Edo State
Nigeria

Abstract

Background: Solanum torvum, commonly known as turkey berry, is used majorly as a medicinal plant, especially in Africa. Thus, this research investigated the effects of aqueous leaf extract of S. torvum on the status of liver (alkaline phosphatase [ALP], alanine transaminase, aspartate transaminase, plasma total protein, plasma albumin, plasma globulin, plasma total bilirubin, plasma conjugated bilirubin), hematological profile, as well as on the histology of the liver, spleen, lungs, and bone marrow of treated rats. Methods: Assays were done using ready to use Randox® kits and photomicrographs of various tissues were prepared after histological staining. Results: The results indicated that at the highest dose, there was an activation of the hepatic Kupffer cells and a significant increase in white blood cells (WBCs) and lymphocytes depicting potent immunomodulation in the various tissues. Alanine transaminase and aspartate transaminase increased but decreased at the highest administered dose, while ALP followed an opposite trend. WBCs and platelets level increased significantly. Conclusion: S. torvum aqueous leaf extract possesses potent immunomodulatory and Hepato-protective properties.



How to cite this article:
Innih SO, Agu KC, Eze GI. Immunomodulatory and hepatoprotective properties of Solanum torvum (Turkey berry).Sahel Med J 2018;21:13-17


How to cite this URL:
Innih SO, Agu KC, Eze GI. Immunomodulatory and hepatoprotective properties of Solanum torvum (Turkey berry). Sahel Med J [serial online] 2018 [cited 2024 Mar 29 ];21:13-17
Available from: https://www.smjonline.org/text.asp?2018/21/1/13/232777


Full Text



 Introduction



Solanum torvum, commonly known as turkey berry, is found in tropical Africa, Asia, and South America,[1],[2] where it is used majorly as a medicinal plant. Its antioxidant properties have been reported due to phytochemical content, including, alkaloids such as jurubine, paniculogenin,[3] and steroids such as sisalogenin, torvogenin, and sisalogenone,[4] and also flavonoids such as torvanol A and a torvosíde H.[5] Various biological activities have also been published, viz., bactericidal,[6],[7] antimicrobial [8] fungicidal,[6] antiviral,[5] immuno-secretory,[9] anti-inflammatory,[10] immunomodulatory, erythropoietic,[9] anti-ulcerogenic,[11] and antihypertensive,[12] etc., Thus, it is based on this available information that this research was designed to investigate the influence of aqueous leaf extract of S. torvum on hepatic function, hematological profile, as well as, on the histology of the liver, spleen, lungs and bone marrow, as there are limited scientific information about these aspects.

 Materials and Methods



Preparation of plant extract

The leaves of S. torvum were obtained from bush farms around Benin City. It was identified and authenticated at the herbarium by the Department of Botany, Faculty of Life Sciences, University of Benin. The properly washed leaves (760.32 g) were dissolved in 5 L of distilled water and left for 72 h after which filtration was carried out using sintered filter and then Whatman #1 filter paper giving a dark green filtrate then extract was concentrated in vacuo using a rotary evaporator to remove the ethanol at a temperature of 99°C. The syrup that was obtained was dried to powder form using a freeze-dryer and the weight of the dry leaf extract was weighed to be 16.3 g; the evaporated extract was then reconstituted in distilled-deionized water at 5 g% (w/v). The reconstituted extract was then stored in capped plastic container in a refrigerator at about +4°C until usage period.

Experimental animals

A total of 20 Wistar rats weighing between 150 and 300 g were used for this study. The animals were housed in the animal house of the Department of Anatomy, University of Benin, and handled according to the stipulated guidelines for handling animals [13],[14] and were acclimatized for 1 week. The research ethics committee guideline principles and consent on the handling of animals of the College of Medicine, University of Benin (CMR/REC/2014/57), was obtained, adopted and strictly adhered to.

Experimental protocol

The animals were weighed before, during, and at the end of the experiment. The rats were divided into four groups: A, B, C, and D of five rats each. Group A was the control (fed normal rat chow). Group B was administered 500 mg/kg of body weight of S. torvum extract, Group C rats were given 1000 mg/kg of body weight of S. torvum extract, and Group D was administered 2000 mg/kg of body weight of S. torvum extract. The extract was administered orally using an orogastric gavage,[15] daily for a period of 28 days.

Animal sacrifice

After 28 days, the animals were fasted over-night, sacrificed using a decapitator, and the liver, lungs, spleen, and bone tissues were removed immediately, and blotted dry on a filter paper. They were weighed and organ-weight ratio were calculated using the following formula: Organ-weight (%) = (organ-weight [g]/body weight [g]) ×100. The tissues were fixed in 10% buffered formal saline for routine hematoxylin and eosin histological processing using the method of Drury et al.[16] Blood samples were collected into ethylenediaminetetraacetic acid (EDTA) and heparinized sample bottles from the abdominal aorta. The heparinized blood were centrifuged, and plasma was transferred into plain sample bottles for onward assay of alanine amino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP) and plasma total protein (TP), plasma albumin, plasma globulin, plasma total bilirubin, plasma conjugated bilirubin using ready to use Randox ® kits (Randox Laboratory, Northern Ireland). The bloods in the EDTA bottles were used for hematological analysis using automated procedure.[17] The slides were viewed under light microscope and analyzed to obtain photomicrographs.

Histological procedure

The liver, lungs, spleen, and bone were excised and promptly transferred into 10% formalin for fixation. Dehydration was carried out by passing the tissues through ascending grades of alcohol (70%, 90%, and 100%), respectively. The tissues stayed in 70% alcohol for 2 h, 90% alcohol for 18 h (overnight). Clearing was carried out using xylene. The tissues were immersed in xylene for 5 h, so that the alcohol will be completely removed. Infiltration of the tissues was carried out in an oven using molten paraffin wax at a temperature range of 56–60°C. The molten paraffin wax was poured into the embedding mold and the infiltrated tissues were placed in it. The orientation of the tissues was such that both longitudinal and transverse sections were cut. The molten paraffin wax was allowed to cool and form the tissue block. Prior to sectioning the tissue, blocks were trimmed and mounted on a wooden block holder. Sectioning was carried out on a rotatory microtome. The tissues were clipped to the microtome and sectioned at the thickness of five microns. Sections came out as ribbon and were placed in 20% alcohol for spreading of the tissue. The ribbons were cut and floated in water bath at a temperature of 30°c. The sectioned tissues were placed in xylene for 5 min to remove paraffin wax from the tissues. Hydration was carried out by passing the tissues through descending grades of [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6] and [Figure 1], [Figure 2], [Figure 3], [Figure 4].{Table 1}{Table 2}{Table 3}{Table 4}{Table 5}{Table 6}{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Statistical analysis

Values were represented as mean ± standard error of the mean for five determinations and entered into Microsoft 7 Excel spread sheet. The values were subsequently analyzed with the SPSS software version 17.0 (IBM corporations, NY, USA) using the paired sample Student's t-test at P = 0.05.

Ethical Consideration

The research ethics committee guideline principles and consent on the handling of animals of the College of Medicine, University of Benin (CMR/REC/2014/57), was obtained, adopted and strictly adhered to.

 Results



Haematological profile of the rats after treatments

As observed from [Table 1], there were progressive increases for the parameters compared to the control group as dose of administration increase (P>0.05), but lymphocyte and platelet counts did not follow this trend as there were undulating changes (P>0.05) with the 500mg/kg giving the peak value and a decrease at 500mg/kg compared to control followed by a subsequent progressive increase with higher doses, respectively. Platelets increased significantly at the highest dose. The percentage lymphocyte count increased with the 500mg/kg dose compared to the control (P<0.05), but decreased with 1000 and 2000mg/kg (P=0.001). Percentage monocytes increased progressively (P=0.000).

As demonstrated by [Table 2], RBC count decreased with the 500mg/kg dose compared to the control group. Haemoglobin concentration, MCHC and MPV followed similar pattern of change with the RBC.

 Discussion



From the research, it was observed that with progressive increase in dose of extract administered, there was an activation of the hepatic Kupffer cells (as observed in the histology of the liver tissue) and a significant increase in the lymphocytes fraction, especially at a dose of 2000 kg/mg (55.6%) compared to control (50.2%). At the same dose, white blood cell (WBC) (11.6 × 10−3 /uL) and and granulocytes (19.3%) increased significantly compared to control WBC (9.98 × 10−3/UL) and granulocytes (14.9%). This is in agreement with the report of Israf et al.[9] who posited that the aqueous extract of S. torvum has an immunomodulatory effects through an increase in WBCs count. Observation of the photomicrographs of other tissues showed that the extract immunomodulatory effects on the lungs as progressive increase in administration of the extract per kilogram body weight also caused progressive activation or increase of the bronchioloalveolar lymphoid aggregates (alveolar macrophages and lymphocytes); spleen and bone marrow (mildly increased the cellular constituents) as well. Red blood cell and the differentials followed similar trend of increase. With regards to the hepatic profile, ALP activity (29.0 U/L) of the highest dose decreased compared to the control (30.8 U/L; P > 0.05), whereas, ALT (23.0 U/L) increased compared to the control (16.6 U/L) and AST (83.8 U/L) decreased compared to the control (91.6 U/L). These changes were not statistically significant. The plasma TP showed a marked increase (P< 0.05) with the 1000 mg/kg dose compared to the control group, attributable to the significant increase in plasma globulin. With an increase in dose, plasma TP decreased (P< 0.05), but remained higher compared to the control group (P > 0.05). However, plasma total bilirubin showed a progressive decrease with increasing administered doses compared to the control group, though this was not significant. Plasma conjugated bilirubin showed similar pattern. Conclusively, S. torvum aqueous leaf extract possesses potent immunomodulatory and hepatoprotective properties.

 Conclusion



Solanum torvum has potent modulatory abilities that could influence increases in lymphocytes, WBC and granulocytes. The plant also possesses hepato-protective properties.

Acknowledgment

We acknowledge the in-depth and expertise contribution of Dr. Gerald Ikechi Eze (A Consultant Histopathologist) of the Department of Anatomy, University of Benin, in the area of slides interpretation.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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