Endangered Medicinal Plant Coscinium fenestratum ( Gaertn . ) Colebr .-A Review

Coscinium fenestratum (Gaertn.) Colebr. is commonly known as, ‘tree turmeric’. It belongs to the plant family Menispermaceae. The wood of Coscinium fenestratum has been used in traditional fabric dyeing. Yellow is the most typical color produced by this plant. Coscinium fenestratum is used in Malaysia for dyeing. Most populations of this species have been exploited on a substantial scale in its natural habitats and it has not been cultivated1. It is a woody climbing shrub with cylindrical stem, externally yellowish-brown and internally yellowish in color. Its stem has often been used as a substitute for berberis. However, it can be readily distinguished by the presence of large vessels in the wood, absence of annual rings and the crenate ring of sclerenchyma beneath the cortex. The stem yields a yellow dye, which is used either alone or in combination with turmeric and other coloring materials. The roots of Coscinium fenestratum contain alkaloids berlambine, dihydroberlambine, 12, 13-dihydro-8-oxo berberine, tetrahydroberberine, oxyberberine and noroxy hydrastinine2.


INTRODUCTION
Coscinium fenestratum (Gaertn.) Colebr. is commonly known as, 'tree turmeric' . It belongs to the plant family Menispermaceae. The wood of Coscinium fenestratum has been used in traditional fabric dyeing. Yellow is the most typical color produced by this plant. Coscinium fenestratum is used in Malaysia for dyeing. Most populations of this species have been exploited on a substantial scale in its natural habitats and it has not been cultivated 1 . It is a woody climbing shrub with cylindrical stem, externally yellowish-brown and internally yellowish in color. Its stem has often been used as a substitute for berberis. However, it can be readily distinguished by the presence of large vessels in the wood, absence of annual rings and the crenate ring of sclerenchyma beneath the cortex. The stem yields a yellow dye, which is used either alone or in combination with turmeric and other coloring materials. The roots of Coscinium fenestratum contain alkaloids berlambine, dihydroberlambine, 12, 13-dihydro-8-oxo berberine, tetrahydroberberine, oxyberberine and noroxy hydrastinine 2 .

Distribution
Coscinium fenestratum is an Indo-Malaysian species that occurs at an altitude of around 350-1200m 4 . It occurs in India, Sri Lanka, Malaysia, Cambodia, and Vietnam 45 . In India, it is restricted to the Western Ghats. It occurs sparingly in the evergreen forests in central and southern zones along the western slopes of the Western Ghats, mostly along watercourses. It is also found in crevices of rocks and trees 4

Threat status
The threat status of this species has been assessed as critically endangered for Karnataka, Kerala and Tamil Nadu in India 5,6 . It is also recorded in the red data book of Vietnam as vulnerable 7 .

Stem
Physicochemical and Organoleptic Parameters TLC finger printing profile TLC Fingerprint profile of Coscinium fenestratum stem shows one band derivatized with sulphuric acid, two bands with anisaldehyde, two bands observed under long UV radiation and no bands under short UV radiation.

Macroscopic identification of stem
15 to 30 cm. or more in length, 2 to 8 cm. in diameter, straight or occasionally slightly twisted, pale grey or greyish yellow with a fairly smooth surface, marked with longitudinal striations spaced about a mm apart, cut surface yellowish-green to yellow in colour showing wedge-shaped areas, fissured with shallow vertical slits of varying length; texture, hard; acrid in taste 46 .

Anatomy of stem
Transverse section of the stem is circular in outline. The outermost zone is cork, which is composed of 15 or more rows of thick-walled cells. Cortex is seen below this cork layer. It is composed of rectangular and polyhedral, comparatively thin-walled cells. Most of the cells contain oil droplets. The inner boundary of the cortex forms a wavy band of several arches, which is composed of yellow coloured elongated stone cells, which form the major portion of the band and few short sclerenchymatous cells. These sclerenchymatous cells are seen in definite patches opposite to phloem. Below these arches, some crushed primary phloem cells are seen. Secondary phloem forms a cup-like structure above the secondary xylem. The wood consists of large-sized vessels, very little parenchymatous elements and thick-walled fibers. Medullary rays alternate the conductive tissues, which is composed of multiseriate radially elongated thick walled cells. In addition to the broad primary medullary rays, the narrow band of secondary medullary rays is seen. Pith is very prominent; the cells towards the center of the pith are large, polyhedral and fairly thick walled. The outermost cells of the pith are smaller with more thickened walls. Starch grains are smaller with more thickened walls and are present throughout the pith and medullary rays 4 .
Macroscopic identification of root 5 to 30 cm or more in length, 2 to 5 cm. in diameter, somewhat longitudinally grooved, transversely cut surface smooth, yellow; texture rough and fibrous; acrid in taste; no particular odour 46 .

Microscopic identification of root
In the transverse section, the root is more or less circular in outline. The outermost zone is the cork layer, which is composed of 10-13 rows of thick-walled cells. Below this cork layer is the cortex, which is composed of rectangular and comparatively thin-walled cells. In certain cells, oil drops are seen. The inner boundary of the cortex forms a wavy band of several arches, which is composed of yellow colored thick-walled cells. The tissue is composed of longer, elongated stone cells, which form the major portion of the band, and besides a few short schlerenchymatous cells. Below these arches, some crushed primary phloem cells are seen. This is followed by secondary phloem tissues. The wood consists of large-sized vessels, parenchymatous elements, and thick-walled fibers. Medullary rays consist of multiseriate radially elongated thick-walled cells. In addition to the broad primary medullary rays narrow band of secondary medullary rays are seen. Pith is not discriminable in old roots 4 .

Microscopic identification of petiole
T.S. of the petiole is somewhat circular in outline. Epidermis is singlelayered with thin cuticle and has multicellular, uniseriate trichomes. Cortical region is parenchymatous. Vascular bundles are seen in a ring and a schlerenchymatous bundle cap is seen above each bundle. In the center of the petiole parenchymatous cells are large and loosely arranged 4 .

Microscopic identification of leaf
T.S. of the leaf shows common dicotyledonous characters. In T.S. midrib portion appears in the shape of an inverted cone. Epidermis is singlelayered. Lower epidermis possesses a large number of multicellular, uniseriate trichomes. Mesophyll consists of a single-layered palisade and multilayered spongy tissue with abundant intercellular spaces. In midrib portion, collenchyma is very prominent just beneath the lower and upper epidermis. Vascular bundle is encircled by a wavy ring of schlerenchymatous tissue. Stomata are of Ranunculaceous type 4 .

Organoleptic properties
The drug has no odour, but a bitter taste 8 .
Deevanhxay et al., 14 developed a microwave-assisted extraction of berberine, jatrorrhizine, palmatine from Coscinium fenestratum at atmospheric pressure (boiling point 83 0 C) and pressurized condition (160°C ) under optimum conditions for 15 min were higher than those obtained using Soxhlet extraction for 8 h and extraction with 0.2% sulfuric acid for 24 h. jatrorrhizine(2.36 mg/g) and palmatine (0.73 mg/g) extraction yields were observed to be the highest at 170°C for 15 min. Microwave assisted extraction is more effective than conventional extraction methods concerning the extraction time and extraction yield for extracting protoberberine alkaloids from C. fenestratum.          was carried out by Deevanhxay et al., 15 . Total of 32 compounds, including 2 benzylisoquinoline alkaloids, 3 aporphine alkaloids, 12 quaternary protoberberine alkaloids, 10 8-oxoprotoberberine alkaloids, 3 tetrahydroprotoberberine alkaloids, and a steroid compound were simultaneously separated and characterized by matching the empirical molecular formulae with those published in the literature and the multi-stage mass spectrometry (MS(n)) data obtained using structural information from IT, an accurate mass measurement obtained from TOF MS, and HPLC separation. A total of 20 compounds, including 4 novel natural products were identified or tentatively identified for the first time from Coscinium fenestratum. The method can be applied for the analysis of 8-oxoberberine and other alkaloids in other herbal medicines.

Substitute/ adulterants
The stems are used in South India as a substitute for Berberis (Daaruharidraa); also as an Indian substitute for True Calumba (Jateorhiza palmate Miers) 16,43,44 .

Folk uses
Root-stomachic, diuretic, hypotensive, anti-dysenteric, antibacterial, antifungal, bitter tonic in dyspepsia and debility. The plant is also used against fractures; for dressing wounds and ulcers and in cutaneous leishmaniasis 16 . the plant is used in the treatment of skeletal fractures in Sri Lanka 43 .
It is widely used as a traditional medicine in the Northeastern part of Thailand, particularly along the border of the Lao People's Democratic Republic for many purposes including the treatment of high blood cholesterol, hyperglycemia as well as hypertension 17 .
The product of this plant in Sri Lanka is used as a therapeutic agent for various conditions including ophthalmopathy, inflammation, ulcers, skin disease, abdominal disorders, jaundice, fever, and general debility 18 .
The rural people of Kanyakumari District, Tamil Nadu, India use the decoction of the stem for the treatment of diabetes 2 . a paste of the root is applied to the head as a cooling application and also to bruises and contusions 44 .
The root is used in Sri Lanka as an efficient bitter tonic. It has antiseptic properties due to which it can be used for dressing wounds and ulcers. It is used as a cure for tetanus. The decoction of the bark is used against malarial fever 3 .
Crude alcoholic extracts of the stem are prescribed in Vietnam for colic and stomachache. A formulation along with other anti-inflammatory agents makes a good topical application for arthritis, rheumatism, gout, and fibromyalgia 6 .
The plant is mainly used for treating diabetes mellitus in traditional Ayurvedic and Siddha systems of medicine 20 . The infusion and tincture preparation of stem is widely used in the traditional Ayurvedic system for the treatment of diabetes mellitus 2 .

Siddha uses
In the Siddha system of medicine, the powdered stems are dissolved in milk and given to the diabetic patients 2 .

Medicinal uses
Coscinium fenestratum has been reported to possess various pharmacological actions such as antioxidant, laxative, antiproliferative, antidiabetic, anti-hypotensive, anti-plasmodial and antibacterial activities. Various parts of the plant is used for fever, muscle pain, stomach pain, malaria, diarrhea, ulcers and infection of the eyes 17,18 . The stem is anti-inflammatory and antiseptic. Used to treat tastelessness, bleeding piles, cough, wounds, ulcers, skin diseases, abdominal disorders, jaundice, liver disorders, intrinsic hemorrhage, diabetes, fever, and general debility 5 . It also has antifungal and anti-yeast, activities 13 .
The stem is useful in ophthalmopathy, wounds, ulcers, skin diseases, abdominal disorders, jaundice, diabetes, tetanus, fever and general debility 21 . It is used for dyspepsia, and as a febrifuge 20 . It is known to treat influenza and eye diseases. It is used to treat bleeding piles and excessive bleeding during menstruation. The bark is also used in the treatment of leucorrhea and other gynecological problems 6 . It could protect against hepatotoxicity induced by carbon tetrachloride and also exhibited strong anti-feeding 18 .

General uses
The dye obtained from the wood has been used in traditional fabric dyeing either alone or in combination with turmeric or other coloring matters 19,43 . It is used as hair shampoo and soap in Sri Lanka to enhance the skin complexion; it is also used in ayurvedic bath soap and bath oil. It is used as a tea extract with other herbals as an immunity booster. The dried root is insect resistant. Berberine has a fluorescent property, which is used to conserve the old documents like Dunhuang Diamond Sutra in China 6 . Birds and animals consume edible fruits 43 .

Anti-diabetic activity
The antidiabetic potential of the alcoholic stem extract of Coscinium fenestratum Colebr. (Menispermaceae), was evaluated in the STZnicotinamide induced type 2 diabetic model. Graded doses of the alcoholic stem extract were administered to normal and experimental diabetic rats for 12 days. Significant reduction in fasting blood glucose along with serum triglyceride, and cholesterol levels were observed in the normal as well as in the treated diabetic animals. Significant results were observed, thereby justifying the use of the plant in the indigenous system of medicine 2,22 .
Coscinium fenestratum (Gaertn.) Colebr. Or "Hamm" has been widely used as traditional medicine. The anti-hyperglycemic effects of Coscinium fenestratum on plasma glucose levels were studied in both normal and. streptozotocin-induced diabetic rats by performing OGTT with several kinds of sugar, glucose, maltose, and sucrose. In normal rats, Coscinium fenestratum inhibited the increase of plasma glucose levels in all three kinds of sugar-loaded rats in a dose-dependent manner. In diabetic rats, Coscinium fenestratum significantly decreased plasma glucose levels in glucose and maltose loaded rats. ,The further stimulatory effect on insulin secretion from perfused rat pancreas and its inhibitory activity on rat intestinal alpha-glucosidase, maltase and sucrase was investigated. The result showed that the plant significantly increased insulin secretion in a biphasic pattern and gradually stimulated insulin secretion in a monophasic pattern, indicating that the in vivo hypoglycemic effect was due to stimulation of insulin secretion from pancreatic beta-cells. Also, it inhibited in vitro activities of maltase better than sucrase, which was similar to acarbose. Taken together, it is concluded that the crude ethanol extract of C. fenestratum had anti-hyperglycemic action in both normal and STZ-induced diabetic rats. The mechanisms underlying hypoglycemic activity were at least partly due to stimulation of insulin secretion and inhibition of intestinal alpha-glucosidase, maltase, and sucrase 41 .
Oral administration of alcoholic extract of the stems of Coscinium fenestratum caused a significant increase in enzymatic antioxidants such as catalase, superoxide dismutase, glutathione synthetase, peroxidase, and glutathione peroxidase and the nonenzymatic antioxidants ascorbic acid, ceruloplasmin, and tocopherol. The significant increase was seen in glycolytic enzymes such as glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and hexokinase, whereas a significant decrease was observed in the levels of gluconeogenic enzyme, glucose-6phosphatase and alanine aminotransferase in treated diabetic rats along with serum creatinine and urea. Thus demonstrating the significance of C. fenestratum as antidiabetic 20 .
The effect of Coscinium fenestratum ethanolic extract on plasma glucose concentrations in normal and streptozotocin (STZ)-induced diabetic rats, the stimulatory effect on insulin secretion from perfused rat pancreas and the inhibitory effects on rat intestinal α-glucosidase enzymes, maltase and sucrase was carried out by Yibchok-anun et al., 23 . In oral glucose, maltose and sucrose loading tests, the extract significantly decreased plasma glucose concentrations in a dosedependent manner. The extract was most effective in decreasing plasma glucose concentrations and was closed to those of glibenclamide and acarbose. In perfused rat pancreas, the extract stimulated insulin secretion in a biphasic pattern. However, the berberine at the same dose as the extract slightly increased insulin secretion by 1.33-fold over the basal control group. In addition, the extract inhibited the activities of both maltase and sucrase with the IC 50 value of 3.89 and 11.22 mg/ ml, respectively. Suggesting that the C. fenestratum ethanolic extract exerted anti-hyperglycemic activity by stimulating insulin secretion and α-glucosidase inhibition.

Formulation anti-diabetic activity
Evaluation of the anti-hyperglycemic effect of 'Ilogen-Excel' in streptozotocin-induced diabetic rats was carried out which contains Cosnium fenestratum as one of the 8 plants present in the drug. Oral administration for 60 days resulted in significantly lowered levels of blood glucose and significantly increased levels of plasma insulin, hepatic glycogen, and total hemoglobin. The drug also decreased the levels of glycosylated hemoglobin, plasma thiobarbituric acid reactive substances, hydroperoxides, ceruloplasmin and vitamin E in diabetic rats. Plasma reduced glutathione and vitamin C were significantly elevated. Administration of insulin normalized all the biochemical parameters studied in diabetic rats. A dose of 100 mg/kg was more effective than 50 mg/kg and brought back all the parameters to near normal levels 24 .

Anti-hypertensive activity
A 50% ethanol extract of Coscinium fenestratum stem material (AECF) has been found to possess hypotensive action in anaesthetised dogs, rats and guinea pigs in a dose-related pattern. The effect was more pronounced in spinal-transected animals. It non-specifically inhibited the pressor responses to epinephrine, norepinephrine, DMPP and depressor responses to acetylcholine and histamine. It failed to exhibit any hypotension when administered via a cannula into the lateral cerebral ventricle. When treated orally it did not exhibit grossly observable central nervous effects up to doses of 800 mg/kg 25 .
Hypotensive and vasorelaxant effect of Coscinium fenestratum water extract was tested on rats. The extract showed an endotheliumdependent and independent vasorelaxant activity in isolated aortic rings precontracted with phenylephrine and KCl. The capacity of L-NAME, an inhibitor of nitric oxide synthase, to reduce the vasorelaxant action of the extract indicates the involvement of nitric oxide 17 .

Toxicity
In the acute toxicity test, an oral dose of 5000 mg/kg of water extract of Coscinium fenestratum did not produce mortality or significant changes in the general behavior of animals and the gross appearance of internal organs of rats. Further, in the sub-chronic toxicity test, an oral dose of 2500 mg/kg/day of the Coscinium fenestratum extract given to rats for 90 days did not cause any significant change of any of the parameters observed when compared with those of the control animals. Moreover, the extract did not produce any effect on the central nervous system when spontaneous motor activity in rats was assessed. However, some hematological and blood chemistry values were found to be statistically different, further studies, including chronic toxicity test, should be done to confirm the safety when it is used over a long period of time 17 .

Antioxidant activity
Antioxidant effect of methanol extract of Coscinium fenestratum stem powder was examined using carbon tetrachloride-intoxicated rat liver as the experimental model. Rats were treated with the methanol extract for 90 days orally at the dose of 60-mg/kg body weight. Rats co-administered with the methanol extract retained an almost normal level of thiobarbituric acid reactive substances and diene conjugates, and also a profound diminution in glutathione content in the liver. The decreased activities of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase in rats were retrieved towards normalcy in the extract co-administered animals. Thus confirming the effectiveness of Coscinium fenestratum in combating oxidative stress due to hepatic damage 26 .
Antioxidant status in STZ-nicotinamide induced type 2 diabetic rats at two dosage levels (250 mg/kg and 500 mg/kg) of aqueous extract of Coscinium fenestratum was carried out by Punitha et al., 28 , diabetic rats showed a significant increase in the levels of enzymatic antioxidants such as glutathione peroxidase, glutathione synthetase, peroxidase, superoxide dismutase and catalase as compared to the untreated control. A significant increase was also observed in levels of the nonenzymatic antioxidants ceruloplasmin, ascorbic acid, and tocopherol. Thus suggesting that the aqueous stem extract prevents type 2 diabetesinduced oxidative stress.
In vitro scavenging activity of methanolic extract of Coscinium fenestratum in DPPH scavenging, nitric oxide scavenging, iron chelation activity, superoxide scavenging, ABTS radical scavenging and lipid peroxidation was carried out by Shirwaikar et al., 27 . In all the methods, the extract showed its ability to scavenge free radicals in a concentration-dependent manner. The results indicate that C. fenestratum has potent antioxidant activity.

CNS depressant activity
A study was conducted by Prashith Kekuda et al.,29 , to investigate the analgesic and CNS depressant property of methanol extracts of Coscinium fenestratum Colebr. in an animal model. In analgesic activity, the reaction time increased significantly for the extract and standard groups when compared to the pre-drug treatment. The locomotor activity count in the extract and standard drug-treated group was significantly reduced when compared to the control group. The analgesic and CNS depressant activity of extracts was found to be more than that of the standard drug.

Antiproliferative activity
Methanol and methanol-water extracts of Coscinium fenestratum exhibited antiproliferative activities in a concentration-dependent manner against human HT-1080 fibrosarcoma cells among the seventy-seven Vietnamese medicinal plants. It also showed selective activity against lung carcinoma and/or lung metastatic cell lines, A549, LLC and B16-BL6. Characteristic morphological change and DNA fragmentation indicated the antiproliferative activity to be due to the induction of apoptosis 30 .
In a trial to determine the molecular mechanism of beneficial effects of Coscinium fenestratum 80% ethanolic extract, aqueous extract and dichloromethane fraction was investigated. 80% ethanolic extract, aqueous extract and dichloromethane fraction showed antiproliferative activity as assessed by cell growth assay. Further, the proapoptotic proteins NAG-1 and ATF3 were increased and the cell cycle protein cyclin D1 was decreased. The results indicate that the extract from the plant has anti-proliferative activity through the activation of pro-apoptotic proteins and PPARγ, and have potential as a preventive regimen in the treatment of cancer 31 .

Cytotoxicity
Thai edible plant Coscinium fenestratum was extracted with 95% ethanol and tested with cytotoxic effects using Hep2 cells. The results showed that C. fenestratum, exhibited high cytotoxic activity against the Hep2 cell lines at a minimum concentration of 0.05% in ethanol extract. In addition, it demonstrated the most potent cytotoxic extract based on its lowest IC 50 (5 mg/mL) 32 .

Anti-nociceptive activity
In a study by Chitra et al., 33 the effect of Coscinium fenestratum on inflammatory pain induced by formalin in mice was conducted. The extract and its polar and non-polar fractions were administered intraperitoneally 30 minutes before formalin injection. The extract induced a significant reduction in response as compared to control. Fraction I (water phase) in doses (mg/kg) of 40, 80 and 160 in an early phase and 40, 80, 160 in the late phase induced antinociception when compared to controls. It is concluded that the polar ingredients of the extracts are responsible for the analgesic and anti-inflammatory properties of Coscinium fenestratum (Gaertn).

Hepatoprotective activity
Hepatotoxic rats were treated with methanol extract of Coscinium fenestratum stem for 90 days. Serum marker enzymes like aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, lactate dehydrogenase, etc. and glucose-6-phosphate dehydrogenase in liver registered a significant elevation in carbon tetrachloride-treated rats, which were significantly recovered towards an almost normal level in animals co-administered with methanol extract of Coscinium fenestratum stem. Other biochemical changes induced by carbon tetrachloride too showed reliable signs of retrieving towards the normalcy. Histopathological analysis confirmed the biochemical investigations. This study unravels the anti-hepatotoxic activity of methanol extract of Coscinium fenestratum stem 34 .

Antibacterial activity
The antibacterial activity of Coscinium fenestratum is mainly due to the presence of berberine 21 .
Aqueous extracts of Coscinium fenestratum and its major alkaloid, berberine, inhibited the in vitro growth of Clostridium tetani. Thus, the traditional use of C. fenestratum as a prophylactic against tetanus must be based on its antibacterial activity rather than any inhibitory effect on the production or activity of toxin 36 .
Ethanolic extract of Coscinium fenestratum stem had strong inhibitory effects against Propionibacterium acnes and Staphylococcus epidermidis. Based on a broth dilution method, the Coscinium fenestratum extract had the greatest antimicrobial effect. In the bioautography assay, the Coscinium fenestratum extract produced strong inhibition zones against Propionibacterium acnes. Phytochemical screening revealed the presence of alkaloids, which could be responsible for the activity. Taken together, the data indicate that Coscinium fenestratum had a strong inhibitory effect on Propionibacterium acnes and Staphylococcus epidermidis 37 .
According to Kumar et al., 38 , berberine alkaloidal fraction of Coscinium fenestratum stem showed potent antiacne activity. It showed maximum anti-acne activity and the Minimum Bactericidal Concentration against both Propionibacterium acnes, and Staphylococcus epidermidis. The mechanism of action of highly aromatic planar quaternary alkaloids such as berberine is attributed to their ability to intercalate with DNA. Thus berberine could be of interest for further development as an alternative treatment for acne.

Antiplasmodial activity
The methanol extract of Coscinium fenestratum had the strongest antiplasmodial activity with EC (50) value of 0.5-µg/ml of the 42 extracts from 14 medicinal plants used in Vietnamese traditional medicine to treat malaria. the activity guided fractionation led to identification of berberine as the major active constituent 40 .

Negative study (Neurotoxicity)
Oral administration of Coscinium fenestratum alcoholic extract at dosages of 5, 10 and 20 mg/kg body weight for 14 days increased the rats body weight and decreased the neuron density in the cerebral cortex, hippocampus and striatum. The plant extract significantly increased stereotyped behavior in licking but did not cause anxiolytic activity, anti-depression, sensory motor co-ordination impairment and ataxia.
Thus it is concluded that Coscinium fenestratum possesses neurotoxicity and can induce neurobehavioral changes in rats 18 .