Estimation of phytochemicals and antioxidant activity of underutilized fruits of Andaman Islands (India)

The present study aimed to determine the antioxidant activity and phytochemical contents in 10 underutilized fruits of Andaman Islands (India) namely Malpighia glabra L., Mangifera andamanica L., Morinda citrifolia L., Syzygium aqueum (Burm.f) Alst., Annona squamosa L., Averrhoa carambola L., Averrhoa bilimbi L., Dillenia indica L., Annona muricata L. and Ficus racemosa L. The antioxidant activity varied from 74.27% to 98.77%, and the methanol extract of M. glabra showed the highest antioxidant activity (98.77%; inhibitory concentration, IC₅₀ = 262.46 μg/ml). Methanol was found to be a better solvent than acetone and aqueous for estimating the antioxidant activity. M. glabra was found to be rich in phytochemicals viz. polyphenol (355.74 mg/100 g), anthocyanin (91.31 mg/100 g), carotenoids (109.16 mg/100 g), tannin (24.39 mg/100 g) and ascorbic acid (394.23 mg/100 g). Carbohydrate content was estimated to be highest in M. glabra (548 mg/100 g). Phenols, tannins, anthocyanins and carotenoids contents showed positive correlation (r² = 0.846, r² = 0.864, r² = 0.915 and r² = 0.806, respectively) with antioxidant activity. The information generated in present study will be useful for bioprospecting of underutilized fruits of Andaman Islands.     

Leptospirosis in the Andaman Islands, India

Leptospirosis is an emerging zoonosis. In the Andaman Islands during the early twentieth century, it occurred in the penal settlements of the British India Administration, mostly as Weil's disease, an acute febrile illness with hepato-renal complications. It was caused by leptospires belonging to groups Akiamy A and Andamans A. After the 1930s nothing further is known regarding the disease until the late 1980s, when Andaman haemorrhagic fever (AHF), a mysterious illness with the majority of cases presenting pulmonary involvement, appeared. AHF was later identified as leptospirosis and severe pulmonary haemorrhage was shown for the first time as a complication of leptospirosis from India. Leptospirosis continues to occur in the Islands annually. It generally presents as two separate clinical syndromes: the hepato-renal form, and the pulmonary form, which is associated with high case fatality rates ranging from 10 to 15%. Infections are due to a variety of serovars, Valbuzzi being the commonest. Leptospira interrogans sensu stricto has been the predominant infecting species. Doxycycline has been shown to confer a beneficial effect in reducing the clinical illness and mortality during outbreaks. The history of leptospirosis in the Islands, its epidemiology, clinical spectrum, characteristics of the isolates and control are reviewed and discussed in this article.     

Dengue: a newly emerging viral infection in Andaman and Nicobar Islands, India

Prior to 2009 dengue fever had not been reported in the Andaman and Nicobar archipelago. In 2009, a few patients with dengue fever-like illness were reported, some of whom tested positive for dengue antibodies. In 2010, 516 suspected cases were reported, including some with dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS); 80 (15·5%) were positive for dengue antibodies. DENV RNA was detected in five patients and PCR-based typing showed that three of these belonged to serotype 1 and two to serotype 2. This was confirmed by sequence typing. Two clones of dengue virus, one belonging to serotype 1 and the other to serotype 2 appeared to be circulating in Andaman. Emergence of severe diseases such as DHF and DSS might be due to recent introduction of a more virulent strain or because of the enhancing effect of sub-neutralizing levels of antibodies developed due to prior infections. There is a need to revise the vector-borne disease surveillance system in the islands.     

Hepatitis delta virus infection among the tribes of the Andaman and Nicobar Islands, India

Hepatitis B virus infection is highly endemic among the tribes of Andaman and Nicobar Islands, India. We screened 223 hepatitis B surface antigen-positive members of these tribes for hepatitis delta virus infection (HDV). The infection was observed only among the Nicobarese. Considering the serious consequences of HDV infection, we suggest that the tribes of these islands should be monitored for HDV infection.     

Epidemiology of hepatitis B virus infection among the tribes of Andaman and Nicobar Islands, India

The Andaman and Nicobar Islands, Union Territory of India, are home to six primitive tribes, namely the Great Andamanese, Onges, Jarawas and Sentinelese (Negrito race), and the Shompens and Nicobarese (Mongoloid race). These tribes account for about 8% of the island's population and the Nicobarese constitute >95% of the tribal population. Hepatitis B virus (HBV) infection is highly endemic among them with the prevalence of hepatitis B surface antigen (HBsAg) ranging from 23% among the Nicobarese to 66% among the Jarawas. The high HBsAg prevalence among pregnant mothers (20.5%), a linear increase in the age-specific rates of HBV exposure and the presence of HBsAg-positive individuals in every family suggested a combination of perinatal and horizontal transmission among the Nicobarese. Molecular studies of HBV isolates from the Onges, Nicobarese and Great Andamanese indicated a predominance of genotype D and there was a close similarity between these isolates and isolates from mainland India, suggesting that HBV may have been introduced from mainland India. In contrast, genotype C predominated among the Jarawas, with isolates similar to strains from Southeast Asian countries. Due to its high prevalence, hepatitis B vaccine is included in the childhood vaccination programme in these islands. It might be worth considering a pilot screening programme for chronic HBV patients to detect hepatocellular carcinoma.     

Estimation of proximate composition, micronutrients and phytochemical compounds in traditional vegetables from Andaman and Nicobar Islands

In present study, 10 preferred traditional vegetables from Andaman and Nicobar Islands, India, were analysed for nutritional profiles. Moisture content in their edible parts ranged from 83.43 to 94.78%. Maximum ash content was recorded in Portulaca oleracea, crude protein in Colocasia esculenta, crude fibre in Eryngium foetidum and fat in E. foetidum. Phosphorus was maximum in Ipomea aquatica, potassium in C. esculenta, zinc, calcium and manganese in Centella asiatica, copper in Sauropus androgynous, sodium and iron in P. oleracea, magnesium in Amaranthus viridi and cobalt in C. esculenta. Maximum polyphenol was recorded in Hibiscus sabdariffa, carotenoids in A. viridi, ascorbic acid in Saursops androgynus, anthocyanin in C. esculenta and chlorophyll in S. androgynus. Antioxidant activity was maximum in P. oleracea. Positive correlation was observed between polyphenol and tannin content and also between antioxidant activity and photochemicals. The developed nutritional profiles is being used in health and nutrition related schemes in Islands.     

Estimation of proximate composition,micronutrients and phytochemical compounds in traditional vegetables from Andaman and Nicobar Islands

In present study, 10 preferred traditional vegetables from Andaman and Nicobar Islands, India, were analysed for nutritional profiles. Moisture content in their edible parts ranged from 83.43 to 94.78%. Maximum ash content was recorded in Portulaca oleracea, crude protein in Colocasia esculenta, crude fibre in Eryngium foetidum and fat in E. foetidum. Phosphorus was maximum in Ipomea aquatica, potassium in C. esculenta, zinc, calcium and manganese in Centella asiatica, copper in Sauropus androgynous, sodium and iron in P. oleracea, magnesium in Amaranthus viridi and cobalt in C. esculenta. Maximum polyphenol was recorded in Hibiscus sabdariffa, carotenoids in A. viridi, ascorbic acid in Saursops androgynus, anthocyanin in C. esculenta and chlorophyll in S. androgynus. Antioxidant activity was maximum in P. oleracea. Positive correlation was observed between polyphenol and tannin content and also between antioxidant activity and photochemicals. The developed nutritional profiles is being used in health and nutrition related schemes in Islands.     

Antioxidant capacity and total phenolic content of Malaysian underutilized fruits

The purpose of this study was to evaluate the antioxidant capacity (AC) and total phenolic content (TPC) of selected Malaysian underutilized fruits. The 58 underutilized fruits of 32 different species from 21 genera were analyzed for AC and TPC. AC was measured using β-carotene bleaching, ferric reducing antioxidant potential (FRAP) and 2,2-diphenyl-1-picryl hydrazyl (DPPH) assays, and TPC was determined using the Folin–Ciocalteu reagent assay. Our findings showed that the fruits from genera of Pometia, Averrhoa, Syzygium, Sallacca, Phyllanthus, Garcinia, Sandoricum and Maipighia had higher AC compared to other studied genera. Among the underutilized fruits, Sandoricum and Phyllanthus fruits contained the highest TPC (>2000 mg/100 g edible portion). The correlation between AC and TPC varied. The study indicated that some of these underutilized fruits have the potential to be sources of antioxidant components.     

Screening of antioxidant activity and phenolic compounds of various date palm (Phoenix dactylifera) fruits from Algeria

The phenolic contents of methanolic extracts from five varieties of date palm (Phoenix dactylifera) fruits from Algeria, Deglet Nour (DN), Degla Baidha (DB), Ghars (Gh), Tamjhourt (Tam), and Tafezauine (Taf) were measured in this work. The antioxidant activities of these extracts were also evaluated. Total phenolic content ranged from 41.80 to 84.73 mg gallic acid equivalents (GAE)/100 g and the total flavonoid content varied from 7.52 to 14.10 mg rutin equivalents (RE)/100 g. The antioxidant activities of methanolic extracts were evaluated in vitro using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical ion (ABTS⁺) and potassium ferricyanide complex as reducing power assay. Effective scavenging concentration (IC₅₀) on DPPH radical ranged from 10.83 to 21.27 mg/l, the IC₅₀ values decreased in the order DN > Gh > Tam > DB > Taf. ABTS radical cation scavenging activity (trolox equivalent 1.66–3.35 mM), the trolox equivalent antioxidant capacity values decreased in the order of DN > Gh > DB > Tam > Taf. In the potassium ferricyanide complex assay, the antioxidant capacity of the extracts ranged between 2.06 and 4.21 mM ascorbic acid equivalents and the ascorbic acid equivalents antioxidant capacity values of the extracts decreased in the order Gh > Tam > DB > DN > Taf. These results suggest that all date varieties constitute a good source of natural antioxidants and could potentially be considered as a functional food.     

Epidemiology of hepatitis B infection among the Nicobarese--a mongoloid tribe of the Andaman and Nicobar Islands,India

Andaman and Nicobar Islands, Union Territory of India, is home to six primitive tribes. Preliminary serological studies carried out earlier among the four accessible tribes revealed that hepatitis B virus (HBV) infection is hyper-endemic among them. The present study was carried out to understand important modes of transmission and to identify possible risk factors associated with HBV infection among the Nicobarese tribe. The epidemiology of HBV infection in these islands appears to be distinct with a high prevalence of the chronic carrier state (22.2%) associated with a comparable proportion of the population being anti-HBs positive (26.3%). More than half of the HBsAg and anti-HBs negative individuals have anti-HBc antibodies. Age, past history of hospital admission, intramuscular injections and number of carriers in the tuhet were found to be significantly associated with exposure to hepatitis B virus. Horizontal transmission through close contact with carriers and perinatal route appears to be an important mode of transmission of HBV in this community. Besides this, use of unsafe injections represents an independent risk factor for acquiring HBV infection in this population. Introducing HBV vaccine in the infant immunization programme and improving injection safety would help to control the infection in the tribal community of these islands.     

Phenolic compounds,carotenoids and antioxidant activity of three tropical fruits

Major compounds (i.e. phenolic compounds and carotenoids) were analysed in the extracts of the edible part of three tropical fruits: the Andean blackberry, the naranjilla and the tree tomato. Ellagitannins and anthocyanins were predominant in blackberries and phenolic composition can be used to differentiate the two species studied. Similar phenolic composition occurred in red and yellow tree tomato except for anthocyanins which were absent in the yellow tree tomato. Phenolic acids were detected in the naranjilla pulp. Carotenoids were analysed in the fruits. The composition in carotenoids was similar in the two varieties of tree tomato and their vitamin A activity was calculated. Carotenol fatty acid esters were predominant. β-Cryptoxanthin esters and β-carotene were the major carotenoids. The carotenoid content was high compared to literature data, providing an important high vitamin A activity. In blackberries and naranjilla, this class of compounds was found only at trace level. Finally, ORAC values were estimated in different solvent extracts and results were compared with published data in common fruits.     

Antioxidant compounds and antioxidant activity in acerola (Malpighia emarginata DC.) fruits and derivatives

Acerola (Malpighia emarginata DC.) is a wild plant from Central America. This fruit is well known as an excellent food source of vitamin C, and it also contains phytochemicals such as carotenoids and polyphenols. The present work evaluates the antioxidant capacity of hydrophilic extracts of acerola pulps and juices by 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ORAC and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods. Antioxidant activity values obtained for acerola juice were higher than those reported for other fruit juices particularly rich in polyphenols such as strawberry, grape and apple juices, among others. Vitamin C, total phenol index (TPI), total anthocyanins and polyphenolic compounds by high performance liquid chromatography (HPLC), as main factors responsible for antioxidant activity, were determined. Contents in total ascorbic acid ranged from 6.32 to 9.20 g kg⁻¹ of pulp and 9.44 to 17.97 g L⁻¹ of juice. Five different polyphenolic compounds were identified in the samples by means of HPLC and diode-array detection: chlorogenic acid, (−)-epigallocatechin gallate, (−)-epicatechin, procyanidin B1 and rutin, being the two last predominant. By means of solid phase extraction (SPE) three soluble polyphenolic fractions (phenolic acids, anthocyanins and flavonoids) were separated from the different sample extracts, and their respective antioxidant activities calculated. Among them, phenolic acids are the main contributors to the antioxidant activity.     

Cold storage of blueberry (Vaccinium spp.) fruits and juice: Anthocyanin stability and antioxidant activity

Blueberries (Vaccinium spp.) may be considered one of the best potential sources of antioxidants in the diet. This characteristic results from the presence of flavonoids (especially anthocyanins), tannins and phenolic acids in the fruits. The objective of this work was to analyze the anthocyanin stability and antioxidant activity of refrigerated whole blueberry juice stored at 4 °C for 10 d, and of fruits stored frozen (−18 °C) for 6 months, in order to determine the changes occurring during storage. The frozen fruits showed a significant increase (p < 0.05) in antioxidant activity during the 3rd month of frozen storage, followed by a decrease up to the end of the 6-month period. The juice was analyzed every other day, and the antioxidant activity changed on the 8th d of refrigerated storage, remaining stable up to the 10th d. There were significant losses of anthocyanins both in the frozen fruits (59%) and refrigerated juice (83%). The antioxidant capacity was shown to be stable during cold storage both in the case of the fruits and whole juice, whereas the anthocyanins were degraded, possibly due to oxidations and/or condensation reactions with other phenolic compounds. More studies are required to optimize the storage time and temperature of these products with respect to nutrient stability.     

Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits

The present study sought to determine the nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits from different districts in Malaysia, namely Kanowit, Sarikei, Kapit and Song in Sarawak. Two varieties of the fruits were investigated. Lipid (21.16 ± 4.71 to 25.76 ± 3.03 g/100 g FW) was the major macronutrient in dabai fruits, while the predominant minerals were calcium, sodium and potassium. The fruit protein was rich in aspartic and glutamic acids which accounted for 45–49% of total amino acids. Purple dabai fruits from Kapit were found to contain the highest total phenolic levels, flavonoids and anthocyanin contents (p < 0.01) and to exhibit the most significant antioxidant activities (p < 0.01), using trolox equivalent antioxidant capacity (TEAC) and ferric reducing ability (FRAP) assays. Antioxidant activities were highly correlated with total phenolic and flavonoid contents of dabai fruits.     

Leptospiral infection among primitive tribes of Andaman and Nicobar Islands.

The Andaman islands were known to be endemic for leptospirosis during the early part of the century. Later, for about six decades no information about the status of the disease in these islands was available. In the late 1980s leptospirosis reappeared among the settler population and several outbreaks have been reported with high case fatality rates. Besides settlers, these islands are the home of six primitive tribes of which two are still hostile. These tribes have ample exposure to environment conducive for transmission of leptospirosis. Since no information about the level of endemicity of the disease among the tribes is available, a seroprevalence study was carried out among all the accessible tribes of the islands. A total of 1557 serum samples from four of the tribes were collected and examined for presence of antileptospiral antibodies using Microscopic Agglutination Test (MAT) employing 10 serogroups as antigens. An overall seropositivity rate of 191% was observed with the highest rate of 53.5% among the Shompens. The seropositivity rates in the other tribes were 16.4% among Nicobarese, 222% among the Onges and 14.8% among the Great Andamanese. All of the tribes except the Onges showed a similar pattern of change in the seroprevalence rates with age. The prevalence rates were rising from low values among children to reach a peak in those aged 2140 years and then declined. Among Onges the seroprevalence rates continued to rise beyond 40 years. In all the tribes, seroprevalence rates were found to be significantly higher among the males. The commonest serogroups encountered were Australis followed by Grippotyphosa, Icterohaemorrhagiae, Pomona and Canicola.