AND ITS BIOLOGICAL POTENTIALITIES – LITERATURE REVIEW

: The genus Bauhinia popularly known as “pata-de-vaca”, “unha de vaca”, “unha de boi”, “unha de anta” e “casco de vaca” is widely used in the form of teas and other herbal preparations. The aim of this literature review was to show the diversity and biological potential of Bauhinia species for health promotion. A search was carried out for articles listing some species of medical interest. The pharmacological activities of B. forficata were also highlighted in articles published in the last twenty years using the PubMed database. Research has shown that Bauhinia is used as a hypoglycemic and antidiabetic agent, diuretic, cholesterol reducer, in the treatment of cystitis, intestinal parasites, elephantiasis, tumors and other ailments, including infections and painful processes. In the last eleven years, 86% of the works carried out with B. forficata used the plant collected or acquired in Brazil, predominantly publications from the southern region of the country where almost 60% reported activity on diabetes and its complications and/or antioxidant effect. Despite the literature pointing out the great medicinal potential of Bauhinia in chronic diseases and their complications, there is still a need for more translational research.

These plants belong to the Fabaceae family, which is divided into three subfamilies They are mainly found in tropical areas of the planet and several of these species are used as a remedy in folk medicine in various regions of the world, including Africa, Asia and Central and South America (SILVA; CECHINEL FILHO, 2002;ALVES et al., 2000). Many species have adapted well to the Brazilian climate and were introduced for ornamental purposes, and today they are found in different regions of the country (SANTOS; BARRETO JUNIOR; KUSTER, 2017).
The leaves, stems and roots of Bauhinia species, especially B. manca, B. megalandra, B. racemosa, B. rufescens, B. monandra Britt. and B. ungulata L., B. forficata, B. cheitantha and B. splendens are widely used in Brazil and other countries in the form of teas and other herbal preparations for the treatment of various diseases, mainly infections, painful processes and diabetes (SILVA; CECHINEL FILHO, 2002;ALVES et al., 2000;MENEZES et al., 2007;ALMEIDA, 2015).
The flowers are zygomorphic arranged in axillary racemes that vary in color depending on the species and subspecies, usually pink or white. The inflorescence is in an axillary raceme, the flowers are showy, have five elongated petals up to 9 cm long and 10 long stamens (SILVA LÓPEZ; SANTOS, 2015).

DEVELOPMENT
For the development of this descriptive review, a bibliographic survey was carried out regarding the genus Bauhinia, listing some species of medical interest with emphasis on B. forficata.
Books were used and scientific articles published between 1989 and 2021 found on Scielo, Google Scholar and Pubmed platforms were selected. The keywords "Bauhinia", "medicinal plants", "bioactive compounds", "toxicity", "medicinal use", "property" and "effect" were used.
It is an evergreen tree native to Burma, measuring 5 to 7 meters in height, with an erect cylindrical trunk with a smooth light brown bark, with sparse branches with a globose crown. The leaves are large, simple leathery, orbicular with a "V" cut forming two lobes 10 to 18 cm long and light green. The flowers are axillary and terminal inflorescences formed from October to December; with several large pink flowers with five petals, the lower one the largest dark pink. Pod-like fruit, flat, glabrous, light brown with rounded light brown seed, flat and hard. It has a single fertile stamen, as a characteristic of the species, this is rare in southern Brazil and more frequent in the north of the country (LORENZI et al., 2003). Bauhinia monandra and Bauhinia ungulata, popularly known as pata-de-vaca and Mororó, present an active ingredient against diabetes, controlling the blood glucose level (ALVES et al., 2000).
Plant native to India and Sri Lanka, being an evergreen tree, 5 -6 meters tall with a smooth bark, light brown in color with short branches forming a rounded crown. Simple leathery, orbicular leaves with a V-shaped cut forming two lobes 12 to 17 cm long and light green. The flowers are axillary and terminal inflorescences, in short racemes with several dark purple oval-lanceolate fivepetaled flowers formed between March to August and with only three long fertile stamens. Pod-type fruits (vegetables), light brown with a leathery texture, dehiscent flat, with rounded and flattened seeds (LORENZI et al., 2003).
Bauhinia purpurea, better known as butterfly, is used in India, Sri Lanka and Pakistani folk medicine to treat conditions such as glandular swellings, skin conditions, ulcers, diarrhea, stomach tumors and wounds, in addition to being used as a hypoglycemic agent for the treatment of diabetes, in addition to other indications, it is suggested that it has laxative and astringent effects, B. purpurea flowers are used as a purgative in Pakistan, while its leaves are applied externally to the forehead to treat fever (ZAKARIA et al., 2007).

Bauhinia blakeana Dunn
Popular names: Hong Kong Orchid Tree, Hong Kong Bauhinia.
This species was found in Hong Kong by the friars in the Roman cathedral and preserved by them, never being found in a native state. Of unknown origin; suspect that it is hybrid because it does not bear fruit. It is an evergreen tree, 6-8 meters tall with a trunk with irregular bark, reddish-brown in color with dense branches forming a rounded crown. Simple orbicular leaves with short petioles and a V-shaped cut forming two lobes, its surface on both sides and dark green. The flowers are axillary and terminal inflorescences, long reddish-purple flowers are fragrant and large that form and open throughout the year with greater intensity from April to August the flowers are sterile and fruiting does not occur (LORENZI et al., 2003).
Bauhinia blakeana, in Brazil it has adapted well to local climatic and edaphic conditions. Today it is cultivated mainly in the southeastern region of Brazil, where it is known by the name of "pata-de-vaca". The Brazilian population usually uses it for the treatment of diabetes as a therapeutic alternative in the treatment of this disease (FERREIRA et al., 2003).
It is a plant native to India being a semideciduous tree that measures between 7 and 10 meters in height, with a cylindrical trunk with a dark brown rough bark, slightly fissured. It has dense branches with a more or less globose crown. The leaves are simple, leathery, orbicular with a Vshaped cut forming two gray-green lobes, 12 to 18 cm long. The flowers are axillary and terminal inflorescences in short racemes with several corolla flowers with five oval-elongated pink petals, striated with purple spot, formed from June to September. Pod-like fruit, flat, dehiscent, light brown with rounded flat seed somewhat fleshy light green. The Candida strain Roxb. (Bauhinia alba-Ham.), producer of white flowers is widely cultivated in Brazil (LORENZI et al., 2003).
The Bauhinia variegata plant, commonly known as Mountain Ebony, is widely used in Indian folk medicine: the bark, root, leaves, seeds and flowers are used for dyspepsia, bronchitis, leprosy, ulcer, to prevent obesity, as an astringent, tonic and anthelmintic (DHALE, 2011).

Bauhinia longifolia (Bong.) Steud.
Synonymy: Pauletia longifolia Bong. Popular names: pata- de-vaca, unha-de-vaca, unha-devaca -do-campo, unha-de-boi (LORENZI, 1998). It is a plant without thorns, measuring between 4 and 7 meters in height, with a thin, slightly rounded crown and its new, rusty, stormy branches, the trunk is slightly crooked and with fine helical flutes and the bark is thin and rough. Leaves alternate, simple bipartite up to the middle of the leaf, with acute or obtuse apices, slightly discolored with a subcoriaceous texture measuring from 6 to 14 cm, glabrous upper and lower surface with 5 to 8 cm long, the flowers are axillary inflorescences and terminals confertiflorous, puberulous, 6 to 8 cm long, with reddish white flowers, pod-like fruit, flattened, dehiscent, woody, ferruginous-tomentose when young (LORENZI, 1998).
This plant occurs in the State of São Paulo and Minas Gerais, in the cerrados and in the highaltitude semideciduous broadleaf forest (LORENZI, 1998). Bauhinia ungulata is a legume native to Brazil known as pata-de-vaca or mororó found mainly in the north, northeast, midwest and southeastern regions of Brazil. (PAULA et al., 2015). B. ungulata is a poorly studied plant, Morais et al. (2005) cite its use by the Tapebas Indians and by the inhabitants of Ceará as a hypoglycemic agent in the treatment of diabetes. The petals of fresh flowers of B. forficata are edible in natura, being fleshy and sweet, or can be added to jams, jams and jellies, and also, they are honey and provide pollen. Its leaves are used in animal feed as fodder, as they are rich in proteins and carbohydrates (SILVA LÓPEZ; SANTOS, 2015).

Popular and Medicinal Use
The South American natives used the infusion of the leaves as a healing agent, to wash wounds, and also as a diuretic, digestive and expectorant, before they were known as hypoglycemic agents. In Brazil, it is popularly used as an antidiabetic, diuretic, cholesterol reducer and also against cystitis, intestinal parasites and elephantiasis (SAAD et al., 2016).
They are used in homemade medicine as syrup, the zest of the stem for cough and cold, also for kidney problems, diabetes and, for treatment and urinary infections, leaves, bark, wood and roots are used both in bathing and drinking. The leaves and flowers have a great calming effect, acting directly on the sympathetic system (SILVA et al., 2003).
It is indicated as an adjuvant in the treatment of skin diseases, ulcers and hypertension, to increase the elimination of uric acid, in back pain, in bladder disorders, constipation and elephantiasis.
It has mucilaginous and astringent properties. In the past, its medicinal use was as a diuretic, tonic, stimulant, and also against diabetes, gonorrhea, tuberculosis and anemia (SILVA LÓPEZ; SANTOS, 2015).

Scientific Studies of the Bauhinia Genus with Health-Related Effects
The In another study, the hydroalcoholic extract of B. forficata leaves inhibited the growth of eight bacteria, being more active for Gram-positive and inefficient for fungi. The results also showed that at the concentrations administered, there was no increase in micronuclei, there was no action on the growth and differentiation of Herpetomonas samuelpessoai and the extract did not show toxicity (PEREIRA et al., 2014).
In the evaluation of the leaf extract of B. cheilandra with diabetic rats induced by alloxan and treated with extracts (doses of 300, 600 and 900 mg kg -1 ), the results showed significant hypoglycemic activity (ALMEIDA et al., 2006). In another study with rabbits with alloxan-induced diabetes, treatment with different fractions of B. candicans extract showed hypoglycemic activity, along with a decrease in urinary glucose excretion. Among the fractions, the highest activity was with the butanolic fraction which reduced the plasma glucose level in normal rabbits as well as in diabetic rabbits. These results suggest hypoglycemic activity (FUENTES et al., 2004).
When using streptozotocin to induce diabetes mellitus, a decoction of B. forficata leaf (150 g/L) was administered orally for one month, with a hypoglycemic effect (PEPATO et al., 2002). In an evaluation with extract of B. forficata with pregnant rats induced to diabetes with streptozotocin, the results suggest that pregnant diabetic rats not submitted to treatment with the plant extract had gestational problems, while diabetic rats treated indicated that the extract of pata-de-vaca may have favored the implantation of the fetus, as it showed a greater number of live fetuses. It was also observed that the extract may have contributed to the maintenance of the integrity of the fetus, however, it had no hypoglycemic effect in the diabetic and non-diabetic rats (VOLPATO et al., 1999). Not found Curcio et al. (2012). Antimutagen Maringá, Paraná, Brasil Düsman et al. (2013).

Antioxidant and prevention of involuntary movements induced by antipsychotics
China Peroza et al. (2013).
Reduction of oxidative damage to the liver in diabetic mice South of Brazil Salgueiro et al. (2013).

Toxicity
B. forficata is a medicinal plant that can be used as an adjuvant in the treatment of diabetes and is included among the 71 plants in RENISUS, due to its hypoglycemic action (BRASIL, 2009).
It has already been reported that its use as a decoction does not cause detectable tissue damage or toxicity (CECILIO et al., 2008). Pepato et al. (2004) evaluated the toxicity of B. forficata and its effects on markers of amylase toxicity (pancreatic toxicity), creatine kinase (muscle toxicity), lactate dehydrogenase (muscle and liver toxicity), bilirubin (liver and bile toxicity) and enzyme converting angiotensin (renal microcirculation toxicity and renal toxicity). With the results, the authors concluded that the plant demonstrates potential for treatment for diabetes and does not produce measurable toxic effects.
The genotoxicity of the aqueous infusion of B. monandra leaves was evaluated by means of a phytochemical screening of the plant. The tests were performed in an in vitro model with plasmid DNA. The concentrations of B. monandra infusion tested were: 0.8 μg/μL, 4 μg/μL, 20 μg/μL and 100 μg/μL, and at these concentrations the infusion did not cause mutagenicity or cytotoxicity. At higher concentrations, they were able to induce breakage in DNA phosphodiester bonds and form abasic sites, an effect suggested by the presence of phenolic hydroxyl groups. The results revealed the risks and benefits of this plant extract for therapeutic use and its effects on the integrity of the genetic material, especially when used as a hyperglycemic agent (MACÊDO et al., 2008).
A study where they were tested for mutagenicity by the Ames test using Salmonella Typhimurium strains with and without metabolic activation, the genotoxicity of aqueous extracts of two Bauhinia species was evaluated. The species B. variegata did not produce a mutagenic effect while the species B. forficata was mutagenic (RIVERA et al., 1994).
Another study of B. forficata demonstrated a possible inhibition of thyroid peroxidase with B.
forficata extract, where a 50% inhibition of the activity of iodide oxidation catalyzed by TPO (thyroperoxidase) was observed in vitro in the presence of 0.011% of plant extract, suggesting that chronic use could lead to hypothyroidism and lead to the formation of endemic goiter (NOGUEIRA; SABINO, 2012).
In B. variegata seeds, there are possible toxic or anti-nutritional factors that should be studied in more detail, therefore, care must be taken when using the seed as these components can be harmful to humans and animals (NOGUEIRA: SALBINO, 2012).
It is important to emphasize when there is a mixture of medicines and plants; the active ingredients are complex, and the effects resulting from the mixture can be additive, synergistic or antagonistic. It is urgent to establish rules for the evaluation of medicinal herbs for pharmacological, toxicological, and hemotoxic effects because, currently, instead of being used as a simple tea, they are being marketed in mixtures and capsules with higher concentrations of these herbs (RIVERA et al. al., 1994).

FINAL CONSIDERATIONS
In the present literature review of the Bauhinia genus, popularly known as pata-de-vaca due to the shape of its leaves, it was exposed that the different species have similar leaves, flowers with different colors such as purple, white and pink, however, B. forficata differs from others for presenting thorns and white flowers, being known as true cow's paw. It has been shown that Bauhinia has several therapeutic activities (hypoglycemic, antibacterial, diuretic, cholesterol lowering and antioxidant); having potential for use in the production of herbal medicines, as it has low toxicity.
Despite this, there are still few clinical studies that would qualify it to be used in the treatment of diseases of great population impact. Thus, there is still much for future research with this genus, mainly correlating the biological effects with its chemical composition.