BIOACTIVITY, ELEMENTOLOGY AND ECONO-MEDICINAL IMPORTANCE OF CERTAIN SEA WEEDS FROM KARACHI COAST

Forty-two commonly occurring species of marine benthic algae namely Ulva intestinalis Linnaeus, Ulva fasciata Delile, Ulva lacluca Linnaeus, Chaetomorpha antennina (Bory de Saint-Vincent) Bryopsis pennata, lamouroux, Codium iyengarii Borgesen, Codium shameelii Nizamuddin, Caulerpa racemosa (Forsskal) J Agardh, Caulerpa scalpelliformis (R Brown ex Turner) C Agardh, Caulerpa taxifolia (Vahl) C Agardh, Dictyota dichotoma var intricata (C Agardh) GreviIIe, Dictyota hauckiana Nizamuddin, Padina pavonica (Linnaeus) Thivy, Padina antillarum (Piceone, Spatoglossum variabile Figari et De Notaris, Stoechospermum polypodiodes (N Lamour) J Agardh, Stypopodium shameelii Nizamuddin et Aisha, Colpomenia sinuosa (Mertens ex Roth) Derbes et Soiler, Iyengaria stellata (Borgesen) Borgesen, Jolyna laminarioides GuhnarAes, Cysioseira indica (Thivy et Doshi) Mairh, Sargassum boveanum J Agardh, Sargassum ilicifolium (Turner) C Agardh, Sargassum swartzii C Agardh, Sargassum tenerrimum J Agardh, Sargassum vulgare C Agardh, Dermonema abbolliae Afaq-Husain, Nizamuddin et Shameel, Gelidium usmanghanii Afaq-Husain et Shameel, Gracilaria corticata (J Agardh) J Agardh, Gracilaria foliifrra (ForssIclI) Borgesen, Gracilaria gracilis (Stacy.house) Steentoft et al, Asparagopsis taxiformis (Delile) Trevisan, Scinaia saifullahii Afaq Hussain et Shameel, Sarconema filiforme (Sonder) Kylin, Solieria robusta (Greville) Kylin, Cystoclonium purpureum(Hudson) Batters, Hypnea musciformis (Wulfen) Lamouroux, Hypnea valentiae (Turner) Montagne, Botryocladia leptopoda (J Agaroh) Kylin, Champia compressa Harney, Melanotham.~1IS afaqhuainii Shameel and Osmundea pinnatifida (Hudson) Stackhoue were collected during December 1997 and April 2003 from different coastal areas of Karachi (Pakistan) such as Manora, Sandspit, Buleji and Paradise Point. They were taxonomka1ly determined and found to belong to 3 phyla (Cholorophyta, Phaeophyta and Rhodophyta), 7 classes, 15 orders, 20 families and 29 genera. All the investigated seaweeds were found to be taxonomica1ly known species. Their crude, gummy, methanol extracts were tested for bioactivities, like antibacterial, antifungal, phytotoxic, insecticidal and uematicidal activities. From ashes of the dried algae, elemental compositions were determined qualitatively as we1l as quantitatively. Extracts of 26 species were tested for antibacterial activity against 4 (ram positive and 7 Gram negative bacteria. Colpomemia sinuosa and Iyengaria stellato were found to be most active, Codium shameelii, Cystoseira indica and Botryocladia leptepoda were the next active species while Ulva intertinalis, Stoechospermum polypodioides and Osmundea prinnatifida the least active species. On the average, brown seaweeds were found to be most active and green seaweeds the least active, while species of red seaweeds were in between. Among Chlorophyta members, of the classes Ulvophyceae and Siphonocladophycese did not show conclusive differences. Within Phaeophyta seaweeds of the class Laminariophyceae were most active, those of the Dictyophyceae least active and of the F ucophyceae were in between. In Rhodophtyta, seaweeds of the class Ceramiophyceae were more active than those of the Nemaliophyceae. Among tested bacteria, Streptococcus pyogenes was found to be most sensitive and Staphylococcus aureus the most resistant species. Methanol extracts of 27 seaweeds were tested for antifungal activity against 7 human, 3 animal and 3 plant pathogenic fungi. Caulerpa racemosa, Padina antillarum and Champia compressa appeared to be most active, Chaetomorpha anlennina and Dermonema abbottiae were the next active, while Dictyota. hauckiana was the least Dermonema abbottiae were the next active, while Dictyota hauckialla was the least active alga. Collectively considered, green seaweeds were found most active while brown and red seaweeds less and equally active. Within Chlorophyta, no differences ere observed between species of the classes Ulvophyceae and Siphonocladophycea In Phaeophyta, seaweeds if the class Laminariophyceae were least active while those of the classes Dictyophyceae and Fucophyceae more and equally active, while among Rhodophyta no class-wise distinction could be made. Among tested fungi, Microsporum canis was found to be most sensitive, Fusarium solani the next sensitive, and Candida albicans the most resistant pathogen. Crude methanol extracts of 26 marine benthic algae were tested for phytotoxic activity against the plant Lemna aequinoctislis. Botryocladia leptopoda exhibited highest activity. Ulva intestinalis, Caulerpa taxifolia, Dictyota dichotoma var intricata, Spatoglassum variable, Stoechospermum polypodioides, Cystoseira indica, Dermonema abbottiae, Asparagopsis taxiformis. Cystoclomium purpureum and Melanothammus afaqhusainii were other highly active seaweeds, while Gracilaria foliifera was the only species that caused growth promotion of the frond proliferations. On the average, red seaweeds were most active and green ones least active, while brown algae were intermediate. Within Chlorophyta, members of the class Ulvophyceae were slightly most active than those 0f the Siphonocladophyceae. In Phaeophyta, species of the class Dictyophyceae were most active, those of Laminariophyceae least active, and Fucophyceae intermediate. Among Rhodophyta no class-wise distinction could be made. Extracts of 2 I species were tested for insecticidal activity against 5 common grain pests. Osmundea pinnatifida appeared to be most active. Species of brown seaweeds were more active than green and red ones, which were equally active. Siphonoladophyceae. In Phaeophyta, species of the class Laminariophyceae were less active than those of other two classes, which were equally active. Within Rhodophyta, members of the class Ceramiophyceae were more active than Nemaliophyceae. Among tested insects, Trogoderma granarium was most sensitive, Callosobruchus analis next sensitive and Sitophilus oryzae most resistant pest. Methanol extracts of 22 seaweeds were tested for nematicidal activity against larvae of Meloidogyne javanica. Sioechospemum polypodioides was the most active alga, and Jolyna laminarioides the least active. Collectively considered, brown seaweeds were found to be most active and green ones least active while red algae were intermediate. Within Chlorophyta, members of the class Ulvophyceae were more active than those of the Siphonocladophyceae. Among Phaeophyta, species of the class Laminariophyceae showed smaller activity than those of other two classes, which were equally active, In Rhodophyta, algae of the class Nemaliophyceae were less active than Ceramiophyceae. When different species of Caulerpa, Codium, Ulva, Dictyola, Padina, Sargassum, Gracilaria and Hypnea were investigated for various bioactivities, they revealed specific differences among themselves due to variations in their genetic constitutions, T1e ashes of 26 seaweeds were analyzed for their elemental composition (Ca, Cd, Cr,Cu, Fe, K, Mg, Na, Pb, Zn), Sodium (Na) was found in highest quantity followed by K and then Ca. Cadmium (Cd) was present in smallest amount, Co and Cr were slightly more, and Cu and Pb were still much more in average proportions, Codium iyengarii possessed the highest quantity of the detected 11 elements; Sarconema filiforme was the next and Iyengazia stellata still next, while Scinaia saifullahii showed the lowest amount. Dictyola dichotoma var intricata was the next saifullahii showed the lowest amount, Dictyota dichotoma var intricatc; was the next lowest and Bryopsis pennata and Padina pavonica still next. Average quantity of the elements was highest in red seaweeds and lowest in brown ones, while in green algae it was intermediate. Among Chlorophyta, seaweeds of the class Ulvophyceae resented lower quantities than Siphonocladophyceae. Within Phaeophyta, the highest proportion of elements was found in Laminariophyceae and lowest in Dictyophyceae while Fucophyceae was intermediate. In Rhodophyta no class-wise distinction could be made. The different investigated species of Codium, Caulerpa, Padina, Sargassum and Hypnea exhibited specific differences in their elemental composition, when compared among themselves. Nine seaweeds (3 from each) of green, brown and red categories were investigated for elemental compositions in basal, middle and terminal parts of their thalli. Total average quantity of the detected elements increased in the middle part to more than 11/2 time of basal portion and decreased in the terminal part to a lesser amount than the basal portion. In Chlorophyta, the average amount decreased in the middle portion to less than 11/2 times of the basal part and slightly increased in the terminal portion. In Phaeophyta, average quantity tremendously increased more than 4 times in the middle part but suddenly decreased in the terminal part being lesser than basal portion. In Rhodophyta, no major change was observed in the three thallus regioll3. The three groups of seaweeds behaved differently in this regard, but in all of them the average quantity of elements in the terminal part was always lesser than the basal portion of thallus. The class-wise conclusion. drawn about the three groups are not quite appropriate.A very detailed and well-documented literature survey was made about the econo-medicinal importance of Karachi seaweeds and presented after "Introduction". Informations have been gathered about their uses as food, fodder, fertilizer, their utility in the preparation of medicine, pharmaceuticals, chemicals and industrial products. References have been collected about their cultivation and farming in advanced countries, and potential of their utilization in Pakistan has also been discussed and valuable suggestions given under different heads.