Preliminary phytochemical screening
The therapeutic potential of the plant extract was found to be much efficient and reliable in small therapeutic doses. The phytochemical composition was analyzed for the HAEAL and its active constituents were confirmed by confirmatory tests as alkaloid, carbohydrate, Tannin, Flavonoids, Terpenoid, Phenol and Glycosides.
Table 1
List of phytoconstituents
S.NO
|
PHYTOCHEMICAL CONSTITUENTS
|
ALKALOIDS
PRESENCE
|
OBSERVATION
|
INFERENCE
|
1
|
Alkaloids (Mayer Test)
|
Dull white precipitate
|
Dull white ppt
|
+
|
2
|
Carbohydrate (Molisch Test)
|
Violet Ring
|
Violet Ring
|
+
|
3
|
Tannin (Bromine Test)
|
Decolorization of
bromine
|
Decolorization
of bromine
|
+
|
4
|
Saponin Test (Froth)
|
Foam
|
No Foam
|
-
|
5
|
Flavonoid
(Alkaline reagent Test)
|
Concentrated Yellow
color
|
Yellow colour
|
+
|
6
|
Terpenoid (Hishon’s Test)
|
Grey color formation
|
Grey color
formation
|
+
|
7
|
Steroid (Salkowski Test)
|
Red color
|
No Red color
Formation
in Chloroform layer
|
|
8
|
Phenol (Lead acetate Test)
|
Precipitation occurs
|
Precipitation occurs
|
+
|
9
|
Glycoside Test (Fehlings Test)
|
Reddish brown color
|
Reddish brown color formed
|
+
|
+ Presence - Absence |
In-vitro studies
Nucleation Assay
The rate of nucleation of calcium oxalate crystals was determined by Aggarwal et al., [26] Nucleation assay is based on the turbidity formation and dissolution of crystal wherein absorbance increases based on the concentration and measured by spectrophotometry at 620 nm. HAEAL of 100 µg/ml showed less turbid solution and more inhibition where the rate of absorbance was found to be increased indicating that HAEAL extract had significant activity against stones formed.
Table 2
Concentration (µg/ml)
|
Standard
|
Test
|
20
|
0.512
|
0.451
|
40
|
0.534 a*
|
0.474 a#
|
60
|
0.621 a*
|
0.480 a#
|
80
|
0.629 a*
|
0.483 a#
|
100
|
0.687 a*
|
0.568 a#
|
Values are expressed as a mean of triplicate. a* Values are significantly different compared to various concentrations in standard ∗P < 0.05 a# Values are significantly different compared to various concentrations in Test ∗P < 0.05
|
Aggregation assay
The rate of aggregation of calcium oxalate crystals was determined by Chaudhary et al., [27] by estimating the absorbance at 620 nm at various concentrations in presence of the extract. The in vitro inhibitory effects of Aerva lanata on various phases of calcium oxalate crystallization was determined by measuring the turbidity and its absorbance rate. The HAEAL of 100 µg/ml concentration showed less turbid solution with more absorbance and inhibited crystal formation more when compared with Cystone at similar concentration.
Table 3
Concentration (µg/ml)
|
Test
|
Standard
|
20
|
0.009
|
0.012
|
40
|
0.005 b*
|
0.007 b#
|
60
|
0.008 b*
|
0.011 b#
|
80
|
0.009 b*
|
0.011 b#
|
100
|
0.011 b*
|
0.015 b#
|
Values are expressed as a mean of triplicate. b* Values are significantly different compared to various concentrations in Test ∗P < 0.05 b# Values are significantly different compared to various concentrations in standard ∗P < 0.05
Growth Assay
The rate of aggregation of calcium oxalate crystals was determined by Chaiyarit et al., [28] by estimating the absorbance at 214 nm at various concentrations in presence of the extract. The in vitro inhibitory effects of Aerva lanata on various phases of growth was determined by measuring the turbidity and its absorbance rate. The HAEAL of 100 µg/ml concentration showed less turbid solution with more absorbance and inhibited crystal formation. The standard Cystone was found to be much effective when compared to the test extract but was found to be similar in reducing the stone formation.
Table 4
Concentration (µg/ml)
|
Test
|
Standard
|
20
|
0.214
|
0.232
|
40
|
0.270 c*
|
0.384 c#
|
60
|
0.342 c*
|
0.351 c#
|
80
|
0.432 c*
|
0.441 c#
|
100
|
0.497 c*
|
0.504 c#
|
Values are expressed as a mean of triplicate. c* Values are significantly different compared to various concentrations in Test ∗P < 0.05 c# Values are significantly different compared to various concentrations in Standard ∗P < 0.05
Effect of HAEAL against Ethylene glycol using animal model
Biochemical parameters of urine and serum sample
The Urine and serum analysis of Ethylene glycol induced urolithiasis for wistar rats were observed and also HAEAL extract was also evaluated and represented in Table 5 From the analysis, the uric acid concentration was 1.12 ± 2.5 in positive control group and alternatively, the level was increased in the negative control group as 1.35 ± 1.2. But there was a reduction in the concentration as 1.15 ± 0.92 mg/dl in Cystone treated group and 1.2 ± 0.20 mg/dl in 400 mg/Kg treated group, 1.18 ± 0.42 mg/dl in 800 mg/Kg. The level of oxalate and phosphorous was found to be 1.42 ± 0.02 mg/dl and 3.6 ± 0.02 mg/dl for positive control groups while Negative control group was found to be in range of 1.93 ± 0.04 mg/dl and 7.75 ± 0.01 mg/dl which was in highest concentration in contrast to positive control. The level of minerals reduced to high dose of 800 mg/Kg for oxalate and phosphorous to 1.67 ± 0.02 mg/dl and 3.5 ± 0.02 mg/dl. Then the calcium level also decreased in the group receiving plant extract when compared to group 2 and the level was 6.3 mg/dl which reduced to 1.19 mg/dl at 30 days of feeding. From the analysis, we concluded that the level of uric acid, oxalate, phosphorous, and calcium was significantly reduced in the group feeding with the plant extract compared to negative control group.
The serum analysis was observed and Creatinine, uric acid, were calculated. The level of creatinine in group 1 and group 2 are 0.08 ± 0.2 mg/dl and 0.8 ± 0.2 mg/dl respectively which indicate that higher level of creatinine in Ethylene glycol induced group caused obstruction in kidney. But in the group 4, there was a reduction from 0.32 mg/dl for Low dose of 400 mg/Kg and 0.25 ± 0.1 mg/dl for High dose of 800 mg/Kg thereby leading to significant effect of crystal deposition inhibition. The level of uric acid in group 1 was 1.12 ± 2.5 mg/dl, but it was increased up to 1.35 ± 1.2 mg/dl respectively causing crystal sedimentation and decreased in Cystone treated group as 1.15 ± 0.92 in comparison with positive control. But in group 4, the level of uric acid was decreased to 1.2 ± 0.2 mg/dl for low dose of 400 mg/Kg and in group 5 concentration level was found to be 1.18 ± 0.42 mg/dl for high dose of 800 mg/Kg. The level of uric acid was reduced in the post-treatment and pre-treatment group due to the effect of plant extract in the induced urolithiasis rats.
Urine and serum analysis
Table 5
Analysis of Urine and serum parameters
Parameters
(mg/dl)
|
Positive
control
|
Negative
control
|
Standard
(Cystone 750mg/kg)
|
Low Dose Dose (400mg/Kg)
|
High Dose (800 (800 mg/Kg)
|
Urine parameters
Calcium
Oxalate
Phosphorous
|
0.60 ± 0.02
|
6.3 ± 0.02
a*
|
1.15 ± 0.01
a**b*
|
2.75 ± 0.03
a***b*
|
1.19 ± 0.02
a**b*
|
1.42 ± 0.02
|
1.93 ± 0.04
a***
|
1.62 ± 0.02
a***b**
|
1.75 ± 0.04
a**b***
|
1.67 ± 0.02
a***b**
|
3.60 ± 0.02
|
7.75 ± 0.01
a**
|
3.4 ± 0.02
a**b*
|
3.55 ± 0.01
a***b*
|
3.5 ± 0.02
a**b*
|
Serum parameters
Uric acid
Creatinine
|
1.12 ± 2.5
|
1.35 ± 1.2
a***
|
1.15 ± 0.92
a***b**
|
1.2 ± 0.20
a**b***
|
1.18 ± 0.42
a***b**
|
0.08 ± 0.2
|
0.8 ± 0.2 a***
|
0.14 ± 0.0 a**b**
|
0.32 ± 0.2
a**b**
|
0.25 ± 0.1
a**b***
|
The parameters are expressed as mg/24hr sample. The values are expressed as Mean ± SEM for six animals in each group a Values are significantly different compared to negative control when ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001 b Values are significantly different from negative control compared to respective experimental groups, when ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001. The results were statistically analysed by one-way ANOVA followed by Turkey’s post hoc test
Effect of extract on urine volume and pH
Table 6
Effect of extract on urine volume and PH
Days
|
Positive control
|
Negative control
|
Standard (Cystone750 mg/kg)
|
Low Dose (400 mg/Kg)
|
High Dose (800 mg/Kg)
|
Volume
(mL/24h)
|
pH
|
Volume
(mL/24h)
|
pH
|
Volume
(mL/24h)
|
pH
|
Volume
(mL/24h)
|
pH
|
Volume
(mL/24h)
|
pH
|
0
|
7.1
|
6
|
7.2
|
6
|
7.4
|
6
|
6.5
|
7
|
7
|
6
|
7
|
7.3
|
7
|
6.5
|
5
|
2
|
6
|
6.2
|
7
|
6.4
|
7
|
14
|
7.5
|
6
|
5.2
|
5
|
5.4
|
7
|
5.7
|
6
|
6.2
|
6
|
21
|
7.2
|
6
|
4.5
|
4
|
5.6
|
7
|
5.8
|
6
|
7.3
|
8
|
28
|
7.4
|
6
|
3.2
|
5
|
6.8
|
6
|
6.5
|
7
|
7.2
|
8
|
Microscopic analysis of urine sample
The microscopic view of urine sample was performed by taking sufficient quantity of urine sample in a centrifuge tube and Operating the Centrifuge at 1500-2000 rpm for 5 – 10 min. The supernatant solution was discarded after centrifugation and the sediment layer was examined under microscope. The microscopic examination of the urine of control group did not reveal any crystal formation while ethylene glycol induced group i.e., negative control alone revealed abundant and large calcium oxalate crystals formed. Treatment with HAEAL (400 mg/Kg and 800 mg/Kg) showed less formation of crystals in small sizes in contrast to negative control treated group. The standard treated group showed less turbidity in urine sample and less stinking smell when compared with negative group which had stinking smell due to bacterial infection. The treated group with LD and HD showed significant results when compared with positive group and negative control group which indicates that there was less formation of crystals and low odour of urine.
EFFECT ON BODYWEIGHT
Table 7
Effect of extract on changes in body weight
Days
|
Positive control
|
Negative control
|
Standard (Cystone750 mg/kg)
|
Low Dose
(400 mg/Kg)
|
High Dose
(800 mg/Kg)
|
0
|
225 ± 3.5
|
239 ± 3.2
|
247 ± 2.5
|
200 ± 4.2
|
217 ± 2.8
|
7
|
229 ± 4.3
|
230 ± 3.5 a*
|
238 ± 2.7 a**b***
|
215 ± 3.6
a*b**
|
225 ± 4.7
a**b**
|
14
|
237 ± 5.6
|
220 ± 4.2 a***
|
242 ± 2.7 a*b***
|
232 ± 5.1
a**b**
|
237 ± 5.4
b**
|
21
|
240 ± 5.6
|
224 ± 4.9 a**
|
244 ± 3.2 a*b**
|
245 ± 6.2
a*b***
|
243 ± 3.8
a*b***
|
28
|
245 ± 6.8
|
232 ± 3.6 a*
|
246 ± 3.7 b**
|
243 ± 2.8
b***
|
247 ± 2.9
b**
|
The body weight of the rat is expressed in grams. The values are expressed as Mean ± SEM (n=6) a Values are significantly different compared to negative control when ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001 b Values are significantly different from negative control compared to respective experimental groups, when ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001
Histological analysis of kidney sample
The photomicrograph of the section of kidney was illustrated in Fig. 2. The positive control group showed no significant pathological findings in kidney parenchyma. No evidence of tubule interstitial inflammation/acute tubular injury was also noticed at the end of 28th day but Kidney parenchyma with chronic interstitial inflammatory infiltrate was observed in Negative control group i.e., Ethylene glycol fed besides Glomerulus, tubules and blood vessels appeared unremarkable. Mild chronic interstitial inflammation was observed in Standard group i.e., Cystone treated and both low dose and high dose showed significant changes with no evidence of acute tubular injury. Low dose of 400 mg/Kg showed slight evidence of interstitial inflammation with lymphocytic infiltrate. High Dose of 800 mg/Kg showed Kidney parenchyma with no significant pathological findings indicating that plant extract of 800 mg/Kg plays a major role in reduction of injury to kidney and thereby controlling/ preventing the disease.