Abstract

Author:
Clement Oluwafemi Osowe, Funmilayo Temidayo Azeez, Olugbenga David Oloruntola, Olufemi Adesanya Adu, Clifford Adinma Chineke

Doi: 10.26480/mahj.01.2025.20.26

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The effect of supplementing two strains of broiler chickens under tropical settings with Ficus thonningii leaf powder (FTLP) and vitamin C on brain and meat oxidative enzymes as well as serum hormonal biomarkers is examined in this study. Three hundred thirty-six one-day-old chicks (168 Cobb 500 and 168 Arbor Acres)in total, weighing 37.40±0.45g, were split into eight groups and given seven duplicates of each experimental food (6 birds per replicate; 42 birds per treatment). Vitamin C (200 mg/kg of basal diet) was added to diets 3 and 4, whereas diets 1 and 2 functioned as controls without supplementation. Brain catalase and glutathione peroxidase levels were raised by vitamin C and FTLP treatment; the Cobb 500 strain showed greater values. Furthermore, meat glutathione peroxidase and catalase were increased, and meat lipid oxidation was decreased by vitamin C and FTLP administration. Overall, the antioxidant capacity of the brain and the quality of the meat in grill chickens were enhanced by dietary supplementation with 200 mg/kg of vitamin C and 1% FTLP. The levels of T3, insulin, and leptin were considerably (P<0.05) impacted by the combined administration of 1% FTLP and vitamin C, whereas the level of HSP 70 was dramatically (P<0.05) decreased. These results demonstrate how supplementing with both Ficus thonningii and vitamin C can strengthen antioxidant defenses and lessen oxidative stress in systems used in the production of broilers. As a result, these supplements taken together could have complementary effects.

1. INTRODUCTION

Recent years have seen a significant amount of study on dietary supplements aimed at enhancing livestock health and productivity, particularly with regard to the diets of broiler chickens (Osowe et al., 2022); African fig, or Ficus thonningii, and vitamin C are two of the many natural additions that have been the subject of much research, and when combined, they provide a thorough approach to improving broiler production systems’ physiological resilience, nutrient utilization, and antioxidant status (Osowe et al., 2023), as antioxidants are crucial for maintaining cellular integrity and minimizing damage brought on by oxidative stress, particularly in fast-growing broiler chickens maintained under high-stress circumstances (Surai et al., 2019); with a strong antioxidant profile, Ficus thonningii is a prospective food source of phytochemicals such as carotenoids, flavonoids, and polyphenols that have the ability to chelate metals and scavenge free radicals (Muhammad and Oluwaniyi, 2022), while vitamin C, a well-known water-soluble antioxidant, enhances cellular antioxidant defenses and regenerates additional antioxidants to complement these effects (Liu et al., 2020); numerous research studies have shown how supplementing with vitamin C and Ficus thonningii can improve the antioxidant status of broiler chickens, and it has been demonstrated that adding Ficus thonningii extract to the diet increases the activity of antioxidant enzymes including catalase (CAT) and glutathione (GSH) while lowering the levels of lipid peroxidation in broiler tissues (Ijoma et al., 2023); similarly, in broiler chicks exposed to heat stress and high stocking densities, vitamin C supplementation has been linked to increased plasma energy expenditure, primarily by acting as a marker of the central nervous system’s long-term energy reserves (Flier and Maratos-Flier, 2017), while in chickens, the thyroid hormone triiodothyronine (T3) is essential for controlling growth, nutritional utilization, and metabolic rate (Wasti et al., 2020), and Ficus thonningii phytochemicals have been demonstrated to have regulatory effects on T3 receptor expression and thyroid hormone metabolism, which may impact broiler chickens’ metabolic rate and energy use (Dangarembizi et al., 2014); vitamin C has also been shown to influence the synthesis and secretion of thyroid hormones, with research showing it helps lambs produce more T3 and express thyroid hormone receptors (Omidi et al., 2015); in broiler chickens, insulin is a major regulator of glucose metabolism and is essential for energy balance and food partitioning (Rahman et al., 2021), while insulin signaling pathway dysregulation might hinder the body’s ability to utilize nutrients, making birds more vulnerable to metabolic diseases like diabetes and obesity (Wen et al., 2022), and heat stress remains a major obstacle to contemporary broiler production, impairing performance by upsetting metabolic homeostasis (Nawaz et al., 2021); Ficus thonningii phytochemicals have insulin-sensitizing qualities that improve glucose absorption and insulin signaling in broilers, thereby improving metabolic efficiency and reducing the risk of metabolic disorders (Muhammad and Oluwaniyi, 2022), while vitamin C supplementation can lessen the effects of heat stress on insulin sensitivity and glucose metabolism in broiler chickens, in part because of its anti-inflammatory and antioxidant properties (Attia et al., 2022); furthermore, studies have shown that heat shock protein 70 (HSP70), a molecular chaperone, is upregulated in response to dietary supplementation with Ficus thonningii and vitamin C, and plays a critical role in cellular stress response and thermotolerance in chicken (Dangarembizi et al., 2014); in order to clarify any potential synergistic effects and provide practical implications for poultry nutrition, this paper will investigate the effects of Ficus thonningii and vitamin C supplementation on antioxidant status, leptin, triiodothyronine (T3), insulin, and heat shock protein 70 (HSP70) expression in two different strains of broiler chickens.

2. MATERIALS AND METHODS

2.1 Ethical Approval: Collection, Processing, and Analysis of Phytogens

The Research and Ethics Committee of the Department of Animal Production and Health, Federal University of Technology, Akure, Nigeria, approved the animal and animal protocol requirements (FUTA/APH/2023/12), and the techniques for collecting Ficus thonningii leaves, processing them into Ficus thonningii Leaf Powder (FTLP), and analyzing FTLP for phytochemical content, proximate components, antioxidants, and mineral composition were described and published by Osowe et al. (2021).

2.2 Management and Arrangement of Experimental Birds

The feeding trial took place in February and March 2021 at the Federal University of Technology’s Teaching and Research Farm in Akure, Nigeria. Based on the description provided by Jimoh et al. (2017), the temperature-humidity index (THI) was constructed using a thermo-hygrometer. The formula applied was: **THI = Ta − [(0.31 − 0.31 × RH) (Ta − 14.4)]**, where **Ta** represents ambient temperature and **RH** represents relative humidity divided by 100. THI categorizes heat stress into four levels: mild (<27.8 °C), moderate (27.8–28.9 °C), severe (28.9–30 °C), and very severe (>30 °C). The THI during the study was determined to be 28.57, with an average temperature of 29.79 °C and relative humidity of 74.5%.

A 2 × 2 × 2 factorial arrangement was employed in a completely randomized experimental design, involving two strains of broiler chickens: Cobb 500 (CO) and Arbor Acres (AB), two doses of vitamin C (0 and 200 mg/kg), and two levels of Ficus thonningii Leaf Powder (FTLP, 0 and 1%). For the starter and finisher phases of broiler chicken rearing, a baseline diet was developed and divided into eight equal portions (Table 1), with appropriate supplements added to each portion. Vitamin C (200 mg/kg of the basal diet) was included in diets 3 and 4, but not in diets 1 or 2. Diets 7 and 8 combined 1g FTLP/kg of the basal diet with 200 mg of vitamin C, while diets 5 and 6 were supplemented with 1g FTLP/kg each.

A total of 336 day-old chicks (168 CO and 168 AB breeds) weighing **37.40 ± 0.45g** were divided into eight experimental feeding groups, each consisting of seven replicates (42 birds per treatment; six birds per replicate).

Means with different superscripts in the same column are significantly (P<0.05) different; BRD: Breeds; VC: Vitamin C; FTLP: Ficus thonningii leaf powder; BTP: Brain Total Protein; BCAT: Brain Catalase; BGSH: Brain Glutathione; AB: Arbor Acres; CO: Cobb 500; SEM: Standard Error of the Means.

3.2 Meat Antioxidative Status

Table 3 shows the meat antioxidant status of the two breeds of grill chickens fed diets supplemented with vitamin C and FTLP; meat glutathione, meat catalase, and lipid oxidation were significant (P<0.05); the control diet 1 had considerably higher (P<0.05) levels of lipid oxidation than the other diets; meat glutathione levels indicated that diets 5 and 6 had significantly greater amounts (P<0.05) compared to the other diets; the levels of meat catalase in diets 3, 4, 5, 6, 7, and 8 were considerably greater (P<0.05) than in diets 1 and 2, but not significantly different from each other (P>0.05); the interaction between vitamin C and FTLP was significant (P<0.05) for lipid oxidation and glutathione, while the interactive effect of strain, vitamin C, and FTLP was significant for lipid oxidation.

Means with different superscripts in the same column are significantly (P<0.05) different; BRD: Breeds; VC: Vitamin C; FTLP: Ficus thonningii leaf powder; LPDOX: Lipid oxidation; CHOL: Cholesterol; GSH: Glutathione; CATLS: Catalase; AB: Arbor Acres; CO: Cobb 500; SEM: Standard Error of the Means.

3.3 Serum Hormonal Marker Levels

Table 4 shows the impact of vitamin C-supplemented meals and Ficus thonningii leaf powder (FTLP) on hormonal indicators in two strains of broiler chickens; T3 levels in diets 6 and 8 were significantly (P<0.05) higher than the other diets but not significantly different from one another; T3 levels in Cobb 500 were notably higher than those in Arbor Acres (P<0.05); vitamin C and FTLP supplementation were significant (P<0.05), as were the interactions between FTLP and strain, FTLP and vitamin C, and the combined effect of FTLP, vitamin C, and strain.

Means with different superscripts in the same column are significantly (P<0.05) different; BRD: Breeds; VC: Vitamin C; FTLP: Ficus thonningii leaf powder; T3: Triiodothyronine; INSULIN; LEPTIN; HSP70: Heat Shock Protein 70; AB: Arbor Acres; CO: Cobb 500; SEM: Standard Error of the Means. Diets 7 and 8 did not differ significantly from one another but did significantly (P<0.05) raise insulin levels compared to the other diets; Cobb 500 strain displayed much higher (P<0.05) insulin levels compared to Arbor Acres; significant impacts (P<0.05) were observed with the addition of vitamin C and FTLP supplementation, as well as interactions between vitamin C and FTLP and the combined effect of strain, vitamin C, and FTLP. Diet 8 had considerably (P<0.05) greater levels of leptin compared to the other diets; Cobb 500 strain exhibited significantly (P<0.05) greater leptin levels compared to Arbor Acres; vitamin C inclusion had no significant (P>0.05) effect, while FTLP supplementation had a significant (P<0.05) effect; significant (P<0.05) interactions were seen between strain and vitamin C, strain and FTLP, vitamin C and FTLP, and the combined effect of strain, vitamin C, and FTLP. Diets 6, 7, and 8 had the least significant (P<0.05) HSP 70 levels, while diet 1 had significantly (P<0.05) greater levels; Arbor Acres strain exhibited significantly (P<0.05) greater HSP 70 levels compared to Cobb 500; FTLP supplementation was the least significant (P>0.05), while vitamin C inclusion was significant (P<0.05); significant (P<0.05) interactions were seen between strain and FTLP, as well as between vitamin C and FTLP and the combined effect of the three factors.

4.DISCUSSION

All organisms exposed to oxygen include the antioxidant enzyme catalase, which helps in breaking down hydrogen peroxide (H2O2) into water, getting rid of organic hydroperoxides, and using H2O2 to oxidize poisons like alcohols, formic acid, phenols, and formaldehyde (Singh and Kumar, 2019). Studies show that the brain’s microglial cells have high concentrations of glutathione and catalase, providing them with powerful antioxidant capacity to shield them from oxidative damage, which is important for their defensive and reparative roles (Dringen, 2005). Research also shows that birds given FTLP and vitamin C-enriched diets exhibit high antioxidant levels, demonstrating the potent antioxidative qualities of FTLP (Osowe et al., 2021). Herbal antioxidants, such as those found in FTLP, improve the oxidative stability of poultry meat by preventing oxidation of cholesterol and unsaturated fatty acids (UFA), thus increasing the animal’s total antioxidant capacity (Jachimowicz et al., 2022). Changes in animal diets can alter fatty acid content in meat, better aligning it with dietary recommendations (Jachimowicz et al., 2022). Supplemented diets have shown significantly lower lipid peroxidation levels, indicating that FTLP’s antioxidant properties may enhance the quality of broiler meat (Osowe et al., 2021). Muscle oxidation after death depends on an animal’s ability to combat oxidative stress, with endogenous enzymes like Glutathione Peroxidase (GPx), Catalase, and Superoxide Dismutase (SOD) helping delay muscle component oxidation (Chen et al., 2012). Broiler diets containing FTLP, rich in these antioxidants, could improve broilers’ antioxidative state, enhancing muscle quality and shelf life (Osowe et al., 2021). Thyroid hormones (T3 and T4) control homeostasis and nutrition digestion in response to internal and external stimuli (Garasto et al., 2017), and are essential for energy metabolism in chickens, particularly in regulating body temperature and homeostasis during growth and egg production (Jiang et al., 2020; Melesse et al., 2011). High ambient temperatures disrupt the neuroendocrine system, decreasing T3 and T4 levels, leading to reduced weight gain and metabolic function (Kumari et al., 2018). Diets supplemented with FTLP and vitamin C significantly increased T3 levels, helping reduce heat stress effects, as confirmed by studies showing lower T3 levels in broilers exposed to heat stress (Ahmad et al., 2022). Insulin helps in the storage of lipids, proteins, and carbs and minimizes their breakdown (Cefalu, 2001). Heat stress raises insulin levels to preserve glucose tolerance (Wang et al., 2021), and FTLP supplementation in this study aligns with this response, maintaining normal metabolic processes (Lu et al., 2007). Leptin, a 16-kDa protein produced by adipose tissue, regulates feed consumption and energy balance, influencing body temperature and immune responses (Zhang et al., 1994; Chan et al., 2003). FTLP supplementation in this study showed higher leptin levels, indicating maintained homeostasis and optimal metabolic activity, enhancing broiler performance (Wardah et al., 2012). Heat shock proteins (HSPs) are activated under environmental stresses like heat to protect cells and promote cellular repair (Frier and Locke, 2007; Shankar and Mehendale, 2014). FTLP supplementation reduced HSP70 levels in broiler serum, indicating its antioxidative benefits during heat stress (Osowe et al., 2021).

5. CONCLUSION

These findings demonstrate the potential advantages of supplementing with both vitamin C and Ficus thonningii to enhance antioxidant defenses and reduce oxidative stress in broiler production systems. The combined use of Ficus thonningii and vitamin C may have synergistic effects on thyroid and leptin function, leading to improved feed efficiency and growth performance in broiler chickens.

CREDIT AUTHORSHIP CONTRIBUTION STATEMENT
Clement O. Osowe: Experimental design, original draft preparation, validation, supervision, project administration, methodology, investigation, formal analysis, data curation.
Olugbenga D. Oloruntola: Review and editing of writing; validation; supervision; formal analysis; resources; methodology; conceptualization.
Funmilayo T. Azeez: Validation, supervision, methodology, data curation.
Olufemi A. Adu: Review and editing of writing; validation; resources; visualization; data curation.
Clifford A. Chineke: Review and editing of writing, validation, resources.

DECLARATION OF GENERATIVE AI AND AI-ASSISTED TECHNOLOGIES IN THE WRITING PROCESS
During the preparation of this work, the authors utilized GPT-3.5 and Quillbot for paraphrasing and to reduce the similarity index of the initial draft. The authors subsequently reviewed and edited the content as necessary and took full responsibility for the content of the publication.

DATA AVAILABILITY
The datasets used and/or analyzed during the current study are available from the corresponding author upon request.

ETHICAL APPROVAL
The study was conducted with the approval of the institutional ethics committee for the care and use of animals for research at the host institution. Ethics Reference No.: FUTA/APH/2023/12.

CONFLICT OF INTEREST
The authors declare no competing interests.

ACKNOWLEDGEMENTS
The authors express their gratitude to Oguntimehin Paul, Dorcas Diekola, Oyedepo Tosin, and Ogunmokun Tolulope for their assistance with animal handling. Appreciation is also extended to the farm officers at FUTA Teaching and Research Farm and the staff at the Central Laboratory of the University.

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