Research Article |
Corresponding author: Nidal Qinna ( nqinna@uop.edu.jo ) Academic editor: Danka Obreshkova
© 2024 Reem Issa, Mahmoud Abu Samak, Manal M. Abbas, Talal Al-Qaisi, Razan Obeidat, Bayan Ghanim, Nidal Qinna.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Issa R, Abu Samak M, Abbas MM, Al-Qaisi T, Obeidat R, Ghanim B, Qinna N (2024) Effect of Equisetum ramosissimum Desf. on body weight and Leptin/Ghrelin in standard and high-fat diet. Pharmacia 71: 1-7. https://doi.org/10.3897/pharmacia.71.e117823
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The necessity of maintaining healthy habits, diet and minimal medical complications is challenging. The current study investigates Equisetum ramosissimum on levels of leptin, ghrelin, and their ratio in association with body weight changes in animals receiving standard and high-fat diet. Ethanolic extract was prepared by maceration and total phenols and flavonoids contents were determined using Folin-cicalto and AlCl3 methods. Study animals were fed with either standard or high-fat diets prior treatment with E. ramosissimum extract (500mg/kg). Body weights were monitored and serum concentrations of leptin, ghrelin and their ratios were determined. The plant extract comprised total phenols and flavonoids of 0.03 ± 0.01 mg/mg as Gallic acid, and 0.04 ± 0.03 mg/mg as quercetin, respectively. Findings revealed significant decrease in body weights of standard-diet animals and restoration of weight to normal after treatment with extract along with significant increase in serum ghrelin concentrations with strong correlation R and R2 values in respect to body weight. As well, significant reduction in serum leptin/ghrelin ratio was positively correlated with body weight and serum leptin levels. E. ramosissimum extract possessed promising characteristics on being introduced in dietary supplements and weight control regimens. The current study presented the influence of extract in decreasing body weight in animals fed with standard diet. Moreover, it restored the weights of obese animals which received the extract after gaining weight and being on high-fat diet. Further preclinical studies are warranted to reveal the translational potentials of E. ramosissimum extract and its vital effect on adipokines.
Branched horsetail, leptin, ghrelin, diet, metabolic syndromes
In terms of known global pandemics, metabolic syndromes and cardiovascular diseases score highly in records of clinically distressed patients. The principal and most well-known metabolic diseases include, but are not limited to, insulin resistance and glucose intolerance, abdominal obesity, hypertension, low high-density cholesterol, and hypertriglyceridemia (
Leptin is a hormone released by the adipose tissue and indirectly functions as a suppressor of appetite through signalling feedback concerning food intake and energy disbursement. In addition, leptin is reported to influence glucose homeostasis, immune response, pathogenesis of hypertension, atherosclerosis, and cancer (
The interest in identifying natural products or chemicals that enhance the body to modulate the levels of either leptin, ghrelin or both is increasing. Chemical compounds which have been obtained from natural sources, including saponins, tannins, alkaloids, alkenyl phenols, glycol-alkaloids, flavonoids, sesquiterpenes lactones, terpenoids and phorbol esters, are plant constituents that have diverse medicinal properties (
Equisetum ramosissimum Desf. is a native and rare plant known as “branched horse-tail”. A recent study reported high prevalence of phenolic and flavonoid contents in its airborne parts (
The E. ramosissimum plant has been used in folk medicine for treatment of various conditions, including reducing body weight and controlled some metabolomics diseases. The use of the extract is widely communicated between local herbalists for the treatment of different conditions and as an ingredient in herbal mixtures used for diabetes, lipidaemia and obesity. Therefore, the current study was conducted to answer whether E. ramosissimum plant extract would affect serum levels of leptin and ghrelin hormones and their ratios in an in vivo high-fat diet (HD) rat model. To our knowledge, it is a first to investigate the effect of this extract on metabolic hormones concerning body weight.
The species of E. ramosissimum was collected from Mujib Biosphere Reserve (84 Km from Amman –FH4V+6PQ, Dead sea road, Sweimeh, Jordan) after authentication by a professional taxonomist at the Nature Conservation Monitoring Centre (Amman, Jordan) (RCSN herbarium no. E.r-5/7/2017). The shoot (ariel) part of the plant was dried under shade and stored thereafter at room temperature. On demand, the dried plant was crushed using a commercial blender (Philips HL7756/00 Mixer Grinder, 750W, USA) to obtain an acceptable particle size for further processing. A maceration method using an ethanolic medium (100% EtOH) was used for phytochemical extraction based on an in-house validated method. Briefly, 0.3% (w/v) of plant powder was soaked in ethanol for 24 h with constant agitation at room temperature. The mixture was then paper-filtered and evaporated at 60 °C using a rotary evaporator (R-300, Buchi, USA) at 90 rpm producing an extraction yield of 40.3% (w/w dry weight) for ethanolic extract. Extracts were stored dry conditions at room temperature 22 °C.
In order to determine the total phenol content within the extract, the Folin-Ciocalteu method was used as described earlier (
For the determination of total flavonoid content, a colorimetric method, based on the formation of a complex flavonoid–aluminium was employed, as described previously (
Eight-week old male Wistar rats were housed and acclimated at the animal house of Applied Science University, Amman Jordan. Handling and treatment procedures were conducted after acquisition of ethical approval from the Institutional Review Board approval no. 2021-PHA-40 (Date: 5/12/2021), and in accordance with the guidelines of its Institutional Animal Ethical Committee. Animals were maintained under conditions of 12 h light/ dark cycle, ambient room temperature (25 ± 2 °C), and with ad libitum access to water.
In our previous published work, an in vivo study on healthy standard diet-fed animals and an induced hyperlipidaemia model, it was concluded that the extract alone and in combination with Atorvastatin had a significant (P<0.05) reducing effect on serum lipid profile (
In order to determine the concentrations of leptin and ghrelin in treated animals, serum samples were collected from all rats at the termination of the study. On the 28th day of the study, animals were fasted overnight and prepared for sampling under 2% isoflurane anaesthesia. Blood samples were collected from the orbital plexus using heparinized capillary tubes into plain mini-collect tubes. Animals were sacrificed by cervical dislocation after completion of sampling. Serum was separated after centrifuging the blood tubes at 8,000×g for 10 mins at ambient temperature. Serum samples were quantified for leptin and ghrelin concentrations using colorimetric assays and in accordance with the manufacturer’s instructions for each kit, Abcam (ab100773, UK) and MyBiosource (MBS731169, US), respectively.
The statistical analysis of data was done using SPSS, version 27.0 (Chicago, IL, USA). One-way ANOVA test using Tukey’s post hoc was used to obtain statistical significance between all study groups, and student t-test was made to compare data of treated and non-treated groups of the same diet. Data are presented as mean values with standard deviation (SD). All experiments were run in triplicates unless stated otherwise.
Methanol extract of E. ramosissimum was examined for phenol and flavonoid content. The extract presented a yield of 0.032 ± 0.01 mg/mg phenolic content in dry extract, calculated as gallic acid equivalence. As for the flavonoid content, a yield of 0.44 ± 0.03 mg was calculated in the dry extract as quercetin equivalence, as shown in Fig.
After confirming the weight-gain animal model, animals were treated with E. ramosissimum extract and weights were recorded after 14 days of treatment. As shown in Fig.
Percent Body Weight change in healthy and obese animals treated with E. ramosissimum extract. Comparison of weight change was made between: Standard Diet (SD); SD receiving Plant extract (SDP); High-fat Diet (HD); and HD receiving Plant extract (HDP). ***: p<0.001 in comparison to SD, as calculated through t-test.
As shown in Fig.
Serum concentrations of leptin and ghrelin and their corresponding ratios. Serum concentrations of leptin and ghrelin and their corresponding ratios were quantified for animals receiving Standard Diet (SD); SD receiving Plant extract (SDP); High-fat Diet (HD); and HD receiving Plant extract (HDP). Ratios of leptin/ghrelin were calculated and presented in normalized values to the standard body levels (right y-axis), specifically per animals receiving SD. **: p<0.01; *p<0.05 in comparison to SD.
As shown in Table
The difference in correlation factor, coefficient determination, and significance p-values between change in body weight and its relation to serum levels of leptin, ghrelin and their ratio in study groups (n = 6).
Correlation factor (R) | Coefficient determination (R2) | p-value | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
SD | SDP | HD | HDP | SD | SDP | HD | HDP | SD | SDP | HD | HDP | |
Leptin | 0.13 | 0.7 | -0.63 | -0.2 | 0.02 | 0.5 | 0.39 | 0.04 | 0.8 | 0.12 | 0.18 | 0.7 |
Ghrelin | 0.07 | -0.58 | -0.63 | -0.89 | 0.01 | 0.34 | 0.39 | 0.79 | 0.89 | 0.23 | 0.18 | 0.18 |
L/G ratio | -0.24 | -0.14 | 0.44 | 0.74 | 0.06 | 0.02 | 0.19 | 0.54 | 0.66 | 0.79 | 0.38 | 0.1 |
The natural collaboration between leptin and ghrelin in maintaining appetite, weight control and energy homeostasis remains an important topic that needs further understanding. Adiposity and appetite regulating hormones, including leptin, ghrelin, insulin and others, are key biotargets in the fields of nutraceutics, herbal medicines and general physical health. The investigation of nutraceuticals has great potential value for limiting or preventing excess weight gain and its accompanying metabolic syndrome.
Extracts collected from different species of Equisetum have been reported to be rich sources of phenolic compounds and flavonoids that have pharmacological properties (
Introducing the use of E. ramosissimum extract as a potential candidate in regulating targets involved in metabolic diseases has not previously been studied. Therefore, the current study focused on observing the potential of the extract on animals of high weight, and its capacity in stimulating body weight loss. Identifying the suspected underlying mechanism, we focused on evaluating the correlation of serum levels of leptin, ghlerin and their calculated ratios. Despite the levels were considerably lower than treated animals fed on SD, the direct effect of the E. ramosissimum extract on leptin levels in animals fed on HD was statistically insignificant, which is in accordance with previously published results (
Conclusions on leptin levels and its correlation with body weight loss could be completed through calculating and understanding its ratio in comparison to levels of ghrelin. Findings of the study revealed a direct effect of E. ramosissimum extract on body weight, regardless of whether exposed to a standard or high-fat diet. Nevertheless, its potential for reducing the body weight of high weight animals was also observed. These data highlighted the differences in the correlations between body weight and the measured biomarkers within the two sets of groups: standard and high-fat diet fed animals. Treatment with the plant extract showed that leptin levels are strongly correlated to body weight in animals on a standard diet. On the other hand, the correlation was considered statistically weak when levels of leptin were compared in animals fed with a high-fat diet. Several studies have investigated the role of leptin on the changes in energy metabolism that occur during weight loss. In obesity, the existence of an endogenous leptin-resistance mechanism limits its impact on weight, interpreted as an energy-sparing mechanism operating in obese animals (
E. ramosissimum extract shows promising characteristics of being introduced in dietary supplements, weight control regimens and some medical interventions. The current study presents the influence of E. ramosissimum extract in decreasing body weight in animals receiving standard diet and limiting weight gain in animals on high-fat diet. Further preclinical studies are warranted to reveal the clincial outcomes of E. ramosissimum extract and its vital influence on adipokines, specifically leptin and ghrelin.
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
The authors declare no potential conflicts of interests with respect to the research, authorship, and/or publication of this article.
The authors confirm that the data supporting the findings of this study are available within the article.
The authors appreciate the Pharmacological and Diagnostic Research Centre at Al-Ahliyya Amman University, Jordan, as well as the efforts of botanist and taxonomist Anas Sabarini at the Nature Conservation Monitoring Centre for authenticating the species and facilitating its collection within Mujib Biosphere Reserve of the Royal Society for the Conservation of Nature (RSCN), Jordan.