Introduction

Plants have been an age-old friend of man. To date, they never fail to provide humans with all the necessities required for them to survive, like oxygen. Additionally, they provide phytochemicals which support human health.² Since the ancient period, plants have been used traditionally as medicine and are quite effective as allopathic drugs, with fewer side effects and their potential to overcome drug resistance.³ 

In recent years, the use of medicinal plants has increased as the phytochemical components have proven to be safe, therapeutically effective, and cost-effective.

Swietenia macrophylla king, also known as large-leafed mahogany, is one of the species of the genus Swietenia which belongs to the family Meliaceae. They are mostly found in tropical rainforests and tropical deciduous forests in North America, Africa and the southern part of Asia.⁴ 

Overview of the mahogany leaf and its traditional uses

Mahogany trees are usually medium-sized, yet they can grow to greater heights depending on the conditions. These trees grow in areas of high precipitation where the soil is moist, deep and has a lower pH.³

The morphology of the leaf:

• Leaves: dark coloured, alternate and are pinnately compound ⁵
• Leaflets: ovate

There are many other medicinal uses of the S.mahogany leaf which were discovered in different parts of the world, such as for tumours, inflammation, pain, worm infestation and to improve blood circulation etc.⁶

Due to its anti-inflammatory, antimicrobial, hepatoprotective, antioxidant, anticonvulsant , antimicrobial and antifungal and many more properties, it holds a prominent role as a natural curative phytochemical agent.⁷

Significance of natural remedies in the digestive health 

Gut health plays a vital role in the survival of a human being. It performs various crucial functions such as digestion, absorption of nutrients and water, and production of energy. Additionally, it also facilitates the maintenance of the immune system, as a major part of the immune system lies in the gut. It also serves the important function of detoxification, which in turn plays a major role in disease prevention. Furthermore central nervous system (CNS) function has been associated with gut health, as the neurotransmitters, hormones, etc. released from the gut are believed to transmit signals to the brain.⁸ 

Examples of illnesses and their natural remedies:

• Heartburn and acidity: chamomile and slippery elm 
• Diarrhea: raspberry leaf: Yarrow & cinnamon
• Constipation: Liquorice, dandelion, & burdock

Nutritional and bioactive components

Preparation of the Swietenia mahagoni leaf extract

Swietenia leaves are collected and are dried for almost 2 weeks at 25 °C. Later the dried leaves are ground into fine powder using a grinding mill. 100 grams of the prepared powder are mixed with 400 milliliters of 96% acetone, and the mixture is filtered after a week. The resulted extract is known as Swietenia Mahagoni Extract (SMAL).⁹ Then this extract is concentrated using a rotary vacuum evaporator.

Now the prepared extract is subjected to 10 hours of refluxing in the soxhlet apparatus using suitable solvents for sequential extraction of various bioactive components.

Various phytochemicals are found in the Swietenia mahagoni leaf extract, including:

• Alkaloids
• Flavonoids
• Tannins
• Saponins
• Terpenoids
• Limonoids
• Terpenoids
• Phenolic compounds
• Essential oils

Antioxidant properties

Oxidative stress in the digestive system

Oxidative stress is a condition caused due to the accumulation of reactive oxygen species (ROS) in the cells and the body loses the ability to detoxify them.Some of the common examples of these are superoxide ion (O^2•−), hydrogen peroxide (H₂O₂),hydroxyl radicals and singlet oxygen.¹⁰ The major causes for oxidative stress and ROS formation includes inflammation and environmental stressors like exposure to UV ionizing rays, pollutants, heavy metals and xenobiotics.¹¹ 

Excess ROS accumulation leads to damage in cellular structures such as membranes, lipids, protiens, lipoprotiens and DNA.¹¹ ROSis beneficial and to perform various important functions like cell signaling, cell division and differentiation, regulation of gene expression and apoptosis regulation under normal circumstances. Additionally it protects the body from external pathogens and also from inflammation. But under abnormal conditions, when there is excess ROS production, all functions mentioned above are hampered leading to negative effects.

ROS are an important players in the pathogenesis in many of the chronic inflammatory gastrointestinal tract disorder, such as gastroentestinal reflux disease (GERD), Barrett's Esophagus, gastritis (caused by helicobacter pylori) and inflammatory bowels disease like Crohn's disease and ulcerative colitis.¹¹

Oxidative stress caused by the chronic inflammation brought by the chemical irritation, infection or any immunological imbalance raises the ROS production and weakens the antioxidant defenses. Overtime, oxidative stress might cause dysphagia and organ cancer in the affected area. Numerous studies on the use of antioxidants in the management of the different GI disorders have shown that antioxidant have enough potential to ameliorate the inflammation.¹¹

Role of antioxidants in mahogany leaf extract in reduction of oxidative stressTEAC and Folin-Ciocalteau techniques were used to assess the antioxidant capacity of the mahogany leaf extract and the results showed considerable level of antioxidant nature.

Mahogany leaf extract has a high concentration of polyphenols which are proven to show antioxidant properties. A study shows that the extract contained 27 phenolic chemicals which have high potential to combat oxidative stress.¹³ Additionally limonoid compounds present in the mahogany leaf extract have shown antioxidant property by inhibiting the production and accumulation of ROS which in turn reduces the oxidative stress and inflammation.¹⁴ 

In vitro studies have demonstrated that mahogany has cytoprotective properties. For instance, in the presence of mahogany leaf extract the cells of cerebellar cultures, when exposed to methyl mercury, significantly enhanced the cell viability indicating its protective effect towards neural damage due to its antioxidative nature.¹⁵ 

Anti-inflammatory effects

Importance of controlling inflammation for the digestive health

Inflammation is a part of the body’s defense mechanisms. It is how the body identifies a foreign substance and gets rid of it and starts the healing process. There are 2 different types of inflammation: acute and chronic.¹⁶ Controlling inflammation is essential for preserving gut health. Chronic inflammation might result in wide range of issues such as:

• Issues related to digestive health like flatulence, constipation and diarrhea etc¹⁷
• Higher chances of developing chronic inflammatory conditions like ulcerative colitis and Crohn's disease¹⁷
• Headaches, skin rashes, brain fog and joint pain may result due to the gut-brain connection¹⁷
• Immune system may be affected¹⁷

Anti-inflammatory properties of mahogany leaf extract

Neutrophils are the primary source that release potent ROS such as superoxide, hydrogen peroxide etc. Oxygen free radicals produced from neutrophils that have penetrated ulcerated stomach tissues have an inhibiting influence on healing of gastric ulcers in rat.⁶ 6 limonoid compounds have shown anti-inflammatory properties in an experiment of 17 compounds by suppressing free radical ions produced by human neutrophil.⁶ 

Despite the fact that numerous studies have demonstrated S.mahogany's potent anti-inflammatory effects in animal models, the exact mechanism is unknown.

Antimicrobial and antiparasitic activities

Common digestive disorders which are caused by microorganisms and the parasites

Typical digestive conditions caused by microorganisms and parasites:

• Giardiasis
• Cryptosporidiosis
• Amoebic Dysentery
• Helminth Infections
• Pinworm Infection
• Peptic ulcer disease
• GERD
• Gastritis
• Ascariasis etc

Efficacy of mahogany leaf extract in combating harmful bacteria and parasites

According to one study, S.Mahogany extract have modest antibacterial activity against certain gram-negative and gram-positive bacteria, in addition to good cytotoxic and antioxidant activity.¹⁹ Studies have also highlighted that Mahogany leaf extract has inhibitory effect on Escherichia coli (E.Coli). Furthermore, the flavonoid components in the extract has been linked with the antibacterial action against Bacillus cereus and E.coli.^19,20 

The basic mechanism of antibacterial action is by lysis (breaking down the cell wall) and reducting in the surface tension of the bacterial cell membrane by the saponins present in the extract. They are most effective towards gram-positive organisms because of their simpler cell wall structure compared to gram-negative organisms.¹⁹ 

There is little research done on the parasitic nature of mahogany leaf extract but certain reports show that there are possibilities of the extract having effectiveness against specific parasitic infection.The phytochemicals present may prevent the formation of certain protozoan parasites.²⁰

Gut health and microbiota balance

Importance of a healthy gut microbiome

The gut microbiota is a community of microorganisms that live in a symbiotic relationship with their host (ie.humans) offering a wide range of benefits like maintaining homeostasis in the intestine, protection against foreign bodies, digestion of starch, lipid storage and production of vitamins.²¹

Specific digestive health benefits

Relief from common digestive issues (indigestion, bloating,)

Mahogany has reported to contain flavonoids which are known to provide antiulcer effect by protecting the mucosal layer without formation of lesions. These findings are from the animal studies which were conducted on rats. Based on this, we can say that flavonoids stimulate the secretion of stomach mucous and strengthen the mucosal defense system and prevent inflammation which protects digestive system.¹⁸

Based on the above findings we can say that mahogany leaf extract gives relief against indigestion and bloating.

Support for chronic digestive conditions (IBS, IBD)

IBS (Irritable bowel syndrome) is believed to occur due to gastrointestinal motor abnormalities, visceral hypersensitivity and alterations in the intestinal transit.²³In IBD (inflammatory bowel disease) the tight junctions present on the primary barrier of gastrointestinal tract (GIT) is disrupted leading to severe inflammation. Additionally, the protective mechanism like goblet cell’s mucous production and paneth cells secretion of a-defensins are affected. As a result excessive deterioration of epithelium occurs due to exacerbation of inflammation.²²

As we are aware, the mahogany leaf extract has anti-ulcerative and anti-inflammatory properties. Neutrophils release strong ROS which causes inflammation and this in turn causes tissue damage and is extremely cytotoxic. Based on the studies conducted on rats, mahogany leaf extract possesses an anti-inflammatory effect which causesthe gastro-protective effect.¹⁸ Therefore they might prove useful for IBD.

Flavonoids which are present in the extract are known to protect mucosal layer by preventing the formation of lesions and ulcers. These flavanoids have cytoprotective and anti-secretory properties and they stimulate the mucus secretion and strengthen the defense system and also improves GI motility.¹⁸ Therefore these can be used to treat IBS.

Overview of existing research on mahogany leaf extract and digestive health

• The impact of mahogany leaf extract on promoting beneficial gut bacteria and inhibiting harmful ones further research has to be conducted on this topic
• Efficacy of mahogany leaf extract against particular parasites and the mechanism involved needs to be investigated further

Summary

Mahogany leaf extract offers a wide variety of benefits to the digestive system in the human body. It has antioxidant, anti-inflammatory ,anti-ulcerative, anti-diabetic, gastroprotective effects which are proven essential for healthy functioning of digestive system. It is well known that mahogany leaf extract is useful to increase bile production and helps in digestion. Due to its anti-inflammatory effect, it alleviates many inflammatory conditions like IBD and IBS. It is the rich source of antioxidants therefore it is useful to amiloride oxidation stress. Tincture of the mahogany leaf extract has anti-aging properties and maintain healthy skin. Additionally it stimulates the modulation of immune system. Overall it has all the positive benefits towards the digestive health and with a little research it will prove to be one of the best alternate for various digestive complications in the future.