A Review on Hepatoprotective and Antioxidant Activity of Boerhavia diffusa and Bauhinia variegata

The liver is a crucial organ that plays a vital role in our body’s metabolism, detoxification, and overall well-being. Unfortunately, the liver can be negatively impacted by substances such as alcohol, drugs, and toxins, leading to various liver diseases that pose a significant global health concern. Although several synthetic medications are available to promote liver health, they may cause unwanted side effects, which has sparked interest in plant-based remedies. Plant-based therapies are gaining popularity due to their safety, efficacy, and long-standing use in traditional medicine. Plants like Boerhavia diffusa (punarnava) and Bauhinia variegata (kachnar) are commonly utilized in practices like Ayurveda to address liver-related issues. Boerhavia diffusa is recognized for its antioxidant, anti-inflammatory, and phenolic properties. Similarly, Bauhinia variegata demonstrates notable antioxidant and cell-protective characteristics, indicating its potential. Recent studies, particularly those involving HepG2 cell lines and liver-toxicity models, suggest that extracts from these plants may help in restoring liver enzymes, enhancing antioxidant defenses, and safeguarding liver cells from damage caused by toxins. Therefore, Boerhavia diffusa and Bauhinia variegata hold promise as natural alternatives for developing effective treatments to support liver protection. [1]

        Most of the dangerous chemicals that harm the liver primarily damage liver cells by initiating lipid peroxidation and other oxidative injuries. The increased liver peroxidation that occurs during the breakdown of ethanol in liver cells can result in hepatitis and cirrhosis. It is estimated that approximately 90% of acute hepatitis cases are caused by viruses, including Hepatitis A, B, C, D (delta agents), E, and G. Among these, Hepatitis B infections often progress to chronic liver conditions and cirrhosis. Moreover, these viruses have been associated with the development of primary liver cancer [2]

Boerhavia diffusa           

Figure:1 Boerhavia (Punarnava)

Common names

English: Red Hogweed, Spreading Hogweed, Hogweed Weed spreading.

Hindi:  Santh, Shothagni, Rakta

Malayalam: Thazhuthama

Bengali: Punarnnava

Kannada: Kommegida

Gujarati: Vakhakhaparo, Dholia-saturdo,

Marathi: Tambadivasu, Ghetuli

Tamil: Chattarani, mukaratte

Telugu: Galijeru [3]

Taxonomical Classification

 Botanical Name: Boerhavia diffusa

  Family: Nyctaginaceae

  Division: Magnoliophyta

  Class: Magnoliopsida

  Order: Caryophyllales

  Genus: Boerhavia

 Species:  Boerhavia Diffusa

Geographical Distribution:

Boerhavia species are widespread, and their dispersal is mostly due to birds and human activity. The genus name Boerhavia was given in honour of Herman Boerhaave, a famous Dutch physician of the 18^th century. The Boerhavia Genus is made up of 40 species and is distributed in tropical, subtropical, and temperate regions around the world. One of these species, Boerhavia diffusa, originally from Brazil and India, now thrives in various countries at elevations up to 1200 meters above sea level. It is widely distributed in locations like Mexico, Asia, Africa, the Indian and Pacific Oceans, Egypt, and Sudan. In India, six species of this genus are found, including Boerhavia diffusa, Boerhavia chinensis, Boerhavia erecta, Boerhavia repanda, and Boerhavia rubicunda. B. diffusa, in particular, is native to India and grows well in wastelands and fields after the rainy season. Additionally, this plant is also cultivated in West Bengal [4]

Traditional uses:

The Punarnava plant holds a fascinating history in Ayurvedic herbal medicine, where its roots, leaves, and aerial parts have been traditionally used to treat a variety of health conditions. The roots, in particular, are renowned for their effectiveness in treating conditions such as gonorrhea, internal inflammation, dyspepsia, oedema, and jaundice. It is also valued for its diuretic, digestive aid, laxative, and emmenagogue (menstrual-promoting) properties. When combined with Mamira, it is utilized to address eye issues such as corneal ulcers and night blindness, as well as to enhance virility in men. Among tribal communities, it is highly valued for its supportive role during childbirth. The juice extracted from Boerhavia diffusa leaves is used topically for eye care and consumed for its purifying and pain-relieving benefits. [5]

Bauhinia variegata

Figure:2 Bauhinia variegata (Kachnar)                 Figure:3 Bauhinia variegata Plant

Common names:

Sanskrit:  Raktakanchan, Phalgu

 Kannada: Bilimandar, Kanchavala

Telugu: Adavimandaramu, Devakankanchamu

Hindi: Kachnar, Bogakatra, Koliar, Mandari

English: Mountain Ebony, Orchid tree,

Spanish: Flamboyanorquidea,

Urdu: Kachnal

Gujarati: Kovindara

 Punjabi: Kanchan [6]

Plant profile:

Kingdom: Plantae

Subkingdom: Tracheobionta - Vascular plants

Super division: Spermatophyte – Seed plants

Division       : Magnoliopsida-Dicotyledons

Subclass       : Rosidae

Order           : Fabales

Family         : Fabaceae-Pea family

Genus          : Bauhinia L

Species        : Bauhinia variegata L.

Geographical distribution

Bauhinia species can be found in various tropical and subtropical regions around the world. They are commonly found at elevations up to 1300 meters and around 900 meters in dry mixed forests. They are most commonly seen in Asia, including countries such as India, China, Nepal, Bhutan, Sri Lanka, and Myanmar. These species are also present in Africa, South and Central America, and certain parts of Australia. In India, you’ll often come across Bauhinia species in forests, plains, and hilly areas, especially in the northern, southern, and northeastern regions. They grow as trees, shrubs, or climbers, contributing to the diverse flora of these areas. [7]

Traditional uses:

In medicine, the leaves of the tree contain a good amount of reducing sugar and are highly nutritious for the healthy growth of tasar silk worms. They are commonly used to make bidis. The roots are known for their carminative properties and are used to alleviate dyspepsia, flatulence, and even act as an antidote to snake poison. The bark of the tree is recognized for its astringent and tonic qualities, and is used in treating various conditions such as scrofula and skin diseases. The flowers and flower buds are consumed as vegetables and are also known for their laxative effects. The flower juice is used to address issues like diarrhea, dysentery, and other stomach ailments. Additionally, dried flower buds are utilized in treating diarrhea, dysentery, worms, piles, and tumors. According to ayurvedic literature, this plant is said to have a bitter taste, dry properties, cooling potency, and pungent post digestive effect. The stem bark of Bauhinia variegata is traditionally used to treat conditions such as worm infections, scrofula, cervical lymphadenitis, and wounds [8]

Phytochemical profile of the biherbal extract:

Phyto-chemical components of Boerhavia diffusa:

This herb contains a wide range of natural compounds, including flavonoids such as (C-methylflavone,5,7-dihydro-3`,4`-dimethoxy-6,8-dimethylflavone, and more), alkaloids: punarnavine, and glycosides like punarnovoside. Researchers have also found rotenoids:(boeravinone B) steroids, triterpenoids, lipids, lignans, carbohydrates, proteins, and glycoproteins in this plant. Numerous studies have highlighted the herb’s various biological, pharmacological, and clinical properties along with those of its natural   components [9]

Punarnavine                                                                    Punarnavoside

Phytochemical Component of Bauhinia Variegata:

Bauhinia variegata is rich in a variety of compounds, including flavonoids, glycosides, saponins, triterpenoids, phenolic compounds, oxepins, fatty acids, and phytosterols. The stem specifically contains β-sitosterol, lupeol, kaempferol-3-glucoside, and 5,7 dihydroxy and 5,7-demethoxy flavanone-4-O-α-L-rhamnopyranosyl-β-D-glucopyranosides. The pale violet flowers are known to contain cyanidin -3-diglucoside and peonidin-3-diglucoside, while the white flowers contain kaempferol-3-galactoside and kaempferol. Various flavonoids, such as quercetin, rutin, and apigenin-7-O-glucoside, have been identified in different parts of Bauhinia variegata. Additionally, phytochemical analysis of the root bark has revealed the presence of compounds like 3’,4’-methylenedioxyflavonoid

And a new dihydrobenzoxepine compound [10]                                                                                     

β-sitosterol                                                            Lupeol

Antioxidant Activity and Its Role in Hepatoprotective:

 Oxidative stress is a key player in the progression of liver diseases, as the liver is highly susceptible to oxidative harm due to its crucial roles in metabolism and detoxification. This susceptibility leads to an excess production of reactive oxygen species (ROS). Antioxidants play a vital role in protecting liver cells by neutralizing free radicals and maintaining redox balance.

Role of Oxidative stress in liver injury: 

Certain hepatotoxic substances such as carbon tetrachloride, paracetamol, alcohol, and environmental toxins, induce oxidative stress leading to liver damage. This results in: -

• Damage to cell membranes
• Release of liver enzymes (ALT, AST, ALP)
• Disturbances of mitochondrial function
• Triggering of inflammatory reactions
• Liver cell death via apoptosis and necrosis

Hence the oxidative stress is a key factor in the development of liver damage. [11, 12]

Antioxidant activity of Boerhavia diffusa:

Boerhavia diffusa’s significant phytochemical composition which includes flavonoids, phenolic compounds, and rotenoids like boeravinones, is responsible for its potent antioxidant effect. In hepatotoxicity models, B. diffusa extracts dramatically lower lipid peroxidation while raising antioxidant enzyme levels, according to experimental research. Its hepatoprotective potential is largely dependent on this antioxidant characteristic. [13]

Antioxidant Activity of Bauhinia variegata:

Bauhinia variegata’s hepatoprotective efficacy is mainly due to its antioxidant compounds, which include quercetin, rutin, and kaempferol. These chemicals have free radical scavenging activity and boost endogenous antioxidant levels in liver tissues. B. variegata extracts have been shown to normalize oxidative stress indicators and liver enzymes levels in experimental models. [14]

Mechanism of Hepatoprotection:

Hepatoprotective agents are substances that help shield liver cells (hepatocytes) from harm caused by toxins, medications, alcohol, and oxidative stress. Numerous medicinal plants display hepatoprotective benefits through various mechanisms including antioxidant properties, anti-inflammatory actions, stabilization of hepatocyte membranes, and boosting detoxification systems. The protective effects are primarily attributed to bioactive compounds like flavonoids, phenolics, alkaloids, terpenoids, and glycosides. [15]

1. Antioxidant Mechanism

Oxidative stress plays a crucial role in the development of liver diseases. During liver injury, excessive production of reactive oxygen species (ROS) such as superoxide radicals, hydroxyl radicals and hydrogen peroxide leads to lipid peroxidation and cellular damage. Hepatoprotective phytochemicals act as antioxidants that neutralize these free radicals and reduce oxidative stress. They also enhance endogenous antioxidant defence systems by increasing the activity of enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). These enzymes help maintain redox balance and prevent damage to hepatocyte membranes. [16]

2. Anti-inflammatory Activity

Inflammation plays a significant role in the progression of liver injury and various liver diseases. During hepatic damage, inflammatory cells release several pro-inflammatory cytokines, including tumor necrosis factor –α (TNF), interleukin-1β (IL-1β), and interleukin-6(IL-6), which contribute to further tissue damage and impaired liver function. Many hepatoprotective compounds derived from medicinal plants have been reported to exhibit strong anti-inflammatory properties. These phytochemicals can suppress the production and release of pro-inflammatory cytokines and modulate important inflammatory signalling pathways such as nuclear factor-kappa B (NF-kB) and mitogen-activated protein kinase (MAPK). By regulating these pathways, plant-based compounds help reduce hepatic inflammation and protect liver tissues from further damage. [17]

3. Mitochondrial Protection

Mitochondria play an essential role in cellular energy production and metabolism. Toxic substances can damage mitochondrial membranes, resulting, in reduced ATP production and increased oxidative stress. Hepatoprotective compounds help maintain mitochondrial integrity by preserving membrane potential, reducing oxidative stress, and preventing apoptosis. This helps maintain normal hepatocyte function and promotes liver cell survival. [18]

4. Stabilization of Hepatocyte Membranes

Many hepatotoxic substances cause lipid peroxidation in hepatocyte membranes, leading to leakage of liver enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) into the bloodstream. Hepatoprotective plant compounds stabilize liver cell membranes and prevent enzyme leakage, thereby maintaining normal liver function and reducing tissue damage.[19]

Other plants used in Hepatoprotective Activity